Association between QRS duration and obstructive sleep apnea.

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Gupta, Shuchita; Cepeda-Valery, Beatriz; Romero-Corral, Abel; Shamsuzzaman, Abu; Somers, Virend K; Pressman, Gregg S

2012-12-15

Both obstructive sleep apnea (OSA) and prolonged QRS duration are associated with hypertension, heart failure, and sudden cardiac death. However, possible links between QRS duration and OSA have not been explored. Cross-sectional study of 221 patients who underwent polysomnography at our center. Demographics, cardiovascular risk factors and ECG were collected to explore a relationship between OSA and QRS duration. The apnea-hypopnea index (AHI) was positively correlated with QRS duration (r = 0.141, p = 0.03). Patients were divided into 3 groups: AHI 30 (55). The mean QRS duration prolonged significantly as OSA worsened (AHI 30, 95 ± 19.9 ms, p = 0.001). QRS ≥ 100 ms was present in 12.7% of patients with severe OSA compared with 0% in the rest of the sample (p < 0.0001). After adjustment for age, race, and cardiovascular risk factors, this association remained significant in women but not in men. QRS duration and OSA were significantly associated. Severity of OSA independently predicted prolonged QRS in women but not men. Nevertheless, prolongation of QRS duration in either sex may potentiate arrhythmic risks associated with OSA.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

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Bortolo Martini

2015-01-01

Full Text Available A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT. ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

Tachycardia

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... rate to rise during exercise or as a physiological response to stress, trauma or illness (sinus tachycardia). ... increase the risk of tachycardia include: Older age. Aging-related wear on the heart makes you more ...

Myocardial ischemia analysis based on electrocardiogram QRS complex

International Nuclear Information System (INIS)

Song, J.; Yan, H.; Xu, Z.; Yu, X.; Zhu, R.

2011-01-01

Full text: Electrocardiogram (ECG) is an economic, convenient, and non-invasive detecting tool in myocardial ischemia (MI), and its clinical appearance is mainly exhibited by the changes in ST-T complex. Recently, QRS complex characters were proposed to analyze MI by more and more researchers. In this paper, various QRS complex characters were extracted in ECG signals, and their relationship was analyzed systematically. As a result, these characters were divided into two groups, and there existed good relationship among them for each group, while the poor relationship between the groups. Then these QRS complex characters were applied for statistical analysis on MI, and five characters had significant differences after ECG recording verification, which were: QRS upward and downward slopes, transient heart rate, angle R and angle Q. On the other hand, these QRS complex characters were analyzed in frequency domain. Experimental results showed that the frequency features of RR interval series (Heart Rate Variability, HRV), and QRS barycenter sequence had signjficant differences between MI states and normal states. Moreover, QRS barycenter sequence performed better. (author)

Mobile/android application for QRS detection using zero cross method

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Rizqyawan, M. I.; Simbolon, A. I.; Suhendra, M. A.; Amri, M. F.; Kusumandari, D. E.

2018-03-01

In automatic ECG signal processing, one of the main topics of research is QRS complex detection. Detecting correct QRS complex or R peak is important since it is used to measure several other ECG metrics. One of the robust methods for QRS detection is Zero Cross method. This method uses an addition of high-frequency signal and zero crossing count to detect QRS complex which has a low-frequency oscillation. This paper presents an application of QRS detection using Zero Cross algorithm in the Android-based system. The performance of the algorithm in the mobile environment is measured. The result shows that this method is suitable for real-time QRS detection in a mobile application.

Reentry Tachycardia in Children: Adenosine Can Make It Worse.

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Hien, Maximilian D; Benito Castro, Fernando; Fournier, Philippe; Filleron, Anne; Tran, Tu-Anh

2016-10-08

We report on a rare but severe complication of adenosine use in a child with reentry tachycardia. Treatment with adenosine, which is the standard medical therapy of atrioventricular reentry tachycardia, led to the development of an irregular wide complex tachycardia, caused by rapid ventricular response to atrial fibrillation. The girl was finally stabilized with electrical cardioversion. We analyze the pathomechanism and discuss possible treatment options. Atrial fibrillation, as well as its conduction to the ventricles, can be caused by adenosine. Rapid ventricular response in children with Wolff-Parkinson-White syndrome is more frequent than previously believed. A patient history of atrial fibrillation is a contraindication for cardioversion with adenosine and needs to be assessed in children with reentry tachycardia. High-risk patients may potentially profit from prophylactic comedication with antiarrhythmic agents, such as flecainide, ibutilide, or vernakalant, before adenosine administration.

Postexertional Supraventricular Tachycardia in Children with Catecholaminergic Polymorphic Ventricular Tachycardia

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Scott D. N. Else

2012-01-01

Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a severe arrhythmia associated with sudden death in the young. It is caused by defective calcium handling in ventricular myocytes. The association of supraventricular tachycardia (SVT with CPVT is described in the literature, occurring in the lead-up to ventricular tachycardia during exercise testing. We describe three cases of SVT that were initiated in the recovery period of exercise testing in children with CPVT.

Diphenhydramine Overdose with Intraventricular Conduction Delay Treated with Hypertonic Sodium Bicarbonate and IV Lipid Emulsion

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Amin Abdi

2014-11-01

Full Text Available Diphenhydramine toxicity commonly manifests with antimuscarinic features, including dry mucous membranes, tachycardia, urinary retention, mydriasis, tachycardia, and encephalopathy. Severe toxicity can include seizures and intraventricular conduction delay. We present here a case of a 23-year-old male presenting with recurrent seizures, hypotension and wide complex tachycardia who had worsening toxicity despite treatment with sodium bicarbonate. The patient was ultimately treated with intravenous lipid emulsion therapy that was temporally associated with improvement in the QRS duration. We also review the current literature that supports lipid use in refractory diphenhydramine toxicity. [West J Emerg Med. 2014;15(7:–0.

Sodium channel blockade with QRS widening after an escitalopram overdose.

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Schreffler, Susan M; Marraffa, Jeanna M; Stork, Christine M; Mackey, Jennifer

2013-09-01

Escitalopram is rarely associated with prolongation of the QTc interval; however, there are no reported cases of QRS complex widening associated with escitalopram overdose. We report a case of a patient who presented with both QRS complex widening and QTc interval prolongation after an escitalopram overdose. A 16-year-old girl presented to the emergency department after ingestion of escitalopram, tramadol/acetaminophen, and hydrocodone/acetaminophen. Laboratory results were significant for 4-hour acetaminophen 21.1 μg/mL. Serum electrolytes including potassium, magnesium, and calcium were all normal. Initial electrocardiogram (ECG) revealed a widened QRS with an incomplete right bundle branch pattern. After administration of 100-mEq sodium bicarbonate, a repeat ECG revealed narrowing of the QRS complex and a prolonged QTc interval. Magnesium sulfate 2 g intravenous and sodium bicarbonate drip were initiated. A repeat ECG, 1 hour after the second, revealed normalization of the QRS complex and QTc interval. Prolongation of the QTc interval is an expected effect of escitalopram. Both escitalopram and citalopram are metabolized to the cardiotoxic metabolite S-didesmethylcitalopram and didesmethylcitalopram, respectively, which have been implicated in numerous cardiac abnormalities including widening of the QRS complex. Although never previously described with escitalopram, this mechanism provides a reasonable explanation for the QRS complex widening and incomplete right bundle branch block that occurred in our patient. Both QRS complex widening and QTc interval prolongation should be monitored in cases of escitalopram and citalopram overdoses.

QRS Detection Based on Improved Adaptive Threshold

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Xuanyu Lu

2018-01-01

Full Text Available Cardiovascular disease is the first cause of death around the world. In accomplishing quick and accurate diagnosis, automatic electrocardiogram (ECG analysis algorithm plays an important role, whose first step is QRS detection. The threshold algorithm of QRS complex detection is known for its high-speed computation and minimized memory storage. In this mobile era, threshold algorithm can be easily transported into portable, wearable, and wireless ECG systems. However, the detection rate of the threshold algorithm still calls for improvement. An improved adaptive threshold algorithm for QRS detection is reported in this paper. The main steps of this algorithm are preprocessing, peak finding, and adaptive threshold QRS detecting. The detection rate is 99.41%, the sensitivity (Se is 99.72%, and the specificity (Sp is 99.69% on the MIT-BIH Arrhythmia database. A comparison is also made with two other algorithms, to prove our superiority. The suspicious abnormal area is shown at the end of the algorithm and RR-Lorenz plot drawn for doctors and cardiologists to use as aid for diagnosis.

The Selvester QRS Score is more accurate than Q waves and fragmented QRS complexes using the Mason-Likar configuration in estimating infarct volume in patients with ischemic cardiomyopathy.

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Carey, Mary G; Luisi, Andrew J; Baldwa, Sunil; Al-Zaiti, Salah; Veneziano, Marc J; deKemp, Robert A; Canty, John M; Fallavollita, James A

2010-01-01

Infarct volume independently predicts cardiovascular events. Fragmented QRS complexes (fQRS) may complement Q waves for identifying infarction; however, their utility in advanced coronary disease is unknown. We tested whether fQRS could improve the electrocardiographic prediction of infarct volume by positron emission tomography in 138 patients with ischemic cardiomyopathy (ejection fraction, 0.27 +/- 0.09). Indices of infarction (pathologic Q waves, fQRS, and Selvester QRS Score) were analyzed by blinded observers. In patients with QRS duration less than 120 milliseconds, number of leads with pathologic Q waves (mean, 1.6 +/- 1.7) correlated weakly with infarct volume (r = 0.30, P wave prediction of infarct volume; but Selvester Score was more accurate. Published by Elsevier Inc.

Clinical and electrophysiological characteristics of patients with paroxysmal intra-His block with narrow QRS complexes.

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Ragupathi, Loheetha; Johnson, Drew; Greenspon, Arnold; Frisch, Daniel; Ho, Reginald T; Pavri, Behzad B

2018-04-18

Atrioventricular (AV) block is usually due to infranodal disease and associated with a wide QRS complex; such patients often progress to complete AV block and pacemaker dependency. Uncommonly, infranodal AV block can occur within the His bundle with a narrow QRS complex. The aims of this study were to define clinical/echocardiographic characteristics of patients with AV block within the His bundle and report progression to pacemaker dependency. We retrospectively identified patients with narrow QRS complexes and documented intra-His delay or block at electrophysiology study (group A) or with electrocardiogram-documented Mobitz II AV block/paroxysmal AV block (group B). Clinical, electrophysiological, and echocardiographic variables at presentation and pacemaker parameters at the last follow-up visit were evaluated. Twenty-seven patients (19 women) were identified (mean age 64 ± 13 years; range, 38-85 years). Four patients who had block with narrow QRS complexes rarely progress to pacemaker dependency and require infrequent pacing. This entity is more common in women, with a higher prevalence of aortic and/or mitral annular calcification. If confirmed by additional studies, single-chamber pacemaker may be sufficient. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Real time QRS complex detection using DFA and regular grammar.

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Hamdi, Salah; Ben Abdallah, Asma; Bedoui, Mohamed Hedi

2017-02-28

The sequence of Q, R, and S peaks (QRS) complex detection is a crucial procedure in electrocardiogram (ECG) processing and analysis. We propose a novel approach for QRS complex detection based on the deterministic finite automata with the addition of some constraints. This paper confirms that regular grammar is useful for extracting QRS complexes and interpreting normalized ECG signals. A QRS is assimilated to a pair of adjacent peaks which meet certain criteria of standard deviation and duration. The proposed method was applied on several kinds of ECG signals issued from the standard MIT-BIH arrhythmia database. A total of 48 signals were used. For an input signal, several parameters were determined, such as QRS durations, RR distances, and the peaks' amplitudes. σRR and σQRS parameters were added to quantify the regularity of RR distances and QRS durations, respectively. The sensitivity rate of the suggested method was 99.74% and the specificity rate was 99.86%. Moreover, the sensitivity and the specificity rates variations according to the Signal-to-Noise Ratio were performed. Regular grammar with the addition of some constraints and deterministic automata proved functional for ECG signals diagnosis. Compared to statistical methods, the use of grammar provides satisfactory and competitive results and indices that are comparable to or even better than those cited in the literature.

Microcontroller-based real-time QRS detection.

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Sun, Y; Suppappola, S; Wrublewski, T A

1992-01-01

The authors describe the design of a system for real-time detection of QRS complexes in the electrocardiogram based on a single-chip microcontroller (Motorola 68HC811). A systematic analysis of the instrumentation requirements for QRS detection and of the various design techniques is also given. Detection algorithms using different nonlinear transforms for the enhancement of QRS complexes are evaluated by using the ECG database of the American Heart Association. The results show that the nonlinear transform involving multiplication of three adjacent, sign-consistent differences in the time domain gives a good performance and a quick response. When implemented with an appropriate sampling rate, this algorithm is also capable of rejecting pacemaker spikes. The eight-bit single-chip microcontroller provides sufficient throughput and shows a satisfactory performance. Implementation of multiple detection algorithms in the same system improves flexibility and reliability. The low chip count in the design also favors maintainability and cost-effectiveness.

Automatic QRS complex detection using two-level convolutional neural network.

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Xiang, Yande; Lin, Zhitao; Meng, Jianyi

2018-01-29

The QRS complex is the most noticeable feature in the electrocardiogram (ECG) signal, therefore, its detection is critical for ECG signal analysis. The existing detection methods largely depend on hand-crafted manual features and parameters, which may introduce significant computational complexity, especially in the transform domains. In addition, fixed features and parameters are not suitable for detecting various kinds of QRS complexes under different circumstances. In this study, based on 1-D convolutional neural network (CNN), an accurate method for QRS complex detection is proposed. The CNN consists of object-level and part-level CNNs for extracting different grained ECG morphological features automatically. All the extracted morphological features are used by multi-layer perceptron (MLP) for QRS complex detection. Additionally, a simple ECG signal preprocessing technique which only contains difference operation in temporal domain is adopted. Based on the MIT-BIH arrhythmia (MIT-BIH-AR) database, the proposed detection method achieves overall sensitivity Sen = 99.77%, positive predictivity rate PPR = 99.91%, and detection error rate DER = 0.32%. In addition, the performance variation is performed according to different signal-to-noise ratio (SNR) values. An automatic QRS detection method using two-level 1-D CNN and simple signal preprocessing technique is proposed for QRS complex detection. Compared with the state-of-the-art QRS complex detection approaches, experimental results show that the proposed method acquires comparable accuracy.

[Surgical treatment of supraventricular tachycardia].

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Vigano, A N; Minzioni, G; Graffigna, A; Paganini, F; Salerno, J A

1991-10-01

The article deals with the modern approaches to the treatment of supraventricular tachycardia . The authors analyse the results of operations in ectopic atrial tachycardias, the Wolff-Parkinson-White syndrome, modal re-entry tachycardias, and atrial fibrillation . The last-named is of most interest because the authors possess experience in a new operation for isolation of the internodal tracts. In all conditions the authors obtained convincing evidence on the efficacy of modern surgical treatment in supraventricular tachycardias.

Phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia or Wolff-Parkinson-White syndrome

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Le Guludec, D.; Bourguignon, M.; Sebag, C.; Valette, H.; Sirinelli, A.; Davy, J.M.; Syrota, A.; Motte, G.

1987-01-01

Accuracy of Fourier phase mapping of radionuclide gated biventriculograms in detecting the origin of abnormal ventricular activation was studied during ventricular tachycardia or preexcitation. Group I included six patients suffering from clinical recurrent VT; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right ventricular pacing, and induced sustained VT-Group II included seven patients with Wolff-Parkinson-White syndrome and recurrent paroxysmal tachycardia; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right atrial pacing and orthodromic reciprocating tachycardia. Each acquisition lasted 5 min, in 30 degrees-40 degrees left anterior oblique projection. In Group I, the Fourier phase mapping was consistent with QRS morphology and axis during VT (5/6), except in one patient with LV aneurysm and LBBB electrical pattern during VT. Origin of VT on phase mapping was located in the right ventricle (n = 2) or in left ventricle (n = 4), at the border of wall motion abnormalities each time they existed (5/6). In Group II, the phase advance correlated with the location of the accessory pathway determined by ECG and endocardial mapping (n = 6) and per-operative epicardial mapping (n = 1). Discrimination between anterior and posterior localization of paraseptal pathways and location of intermittent preexcitation was not possible. We conclude that Fourier phase mapping is an accurate method for locating the origin of VT and determining its etiology. It can help locate the site of ventricular preexcitation in patients with only one accessory pathway; its accuracy in locating multiple accessory pathways remains unknown.

Phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia or Wolff-Parkinson-White syndrome

International Nuclear Information System (INIS)

Le Guludec, D.; Bourguignon, M.; Sebag, C.; Valette, H.; Sirinelli, A.; Davy, J.M.; Syrota, A.; Motte, G.

1987-01-01

Accuracy of Fourier phase mapping of radionuclide gated biventriculograms in detecting the origin of abnormal ventricular activation was studied during ventricular tachycardia or preexcitation. Group I included six patients suffering from clinical recurrent VT; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right ventricular pacing, and induced sustained VT-Group II included seven patients with Wolff-Parkinson-White syndrome and recurrent paroxysmal tachycardia; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right atrial pacing and orthodromic reciprocating tachycardia. Each acquisition lasted 5 min, in 30 degrees-40 degrees left anterior oblique projection. In Group I, the Fourier phase mapping was consistent with QRS morphology and axis during VT (5/6), except in one patient with LV aneurysm and LBBB electrical pattern during VT. Origin of VT on phase mapping was located in the right ventricle (n = 2) or in left ventricle (n = 4), at the border of wall motion abnormalities each time they existed (5/6). In Group II, the phase advance correlated with the location of the accessory pathway determined by ECG and endocardial mapping (n = 6) and per-operative epicardial mapping (n = 1). Discrimination between anterior and posterior localization of paraseptal pathways and location of intermittent preexcitation was not possible. We conclude that Fourier phase mapping is an accurate method for locating the origin of VT and determining its etiology. It can help locate the site of ventricular preexcitation in patients with only one accessory pathway; its accuracy in locating multiple accessory pathways remains unknown

Predicting QRS and PR interval prolongations in humans using nonclinical data.

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Bergenholm, L; Parkinson, J; Mettetal, J; Evans, N D; Chappell, M J; Collins, T

2017-10-01

Risk of cardiac conduction slowing (QRS/PR prolongations) is assessed prior to clinical trials using in vitro and in vivo studies. Understanding the quantitative translation of these studies to the clinical situation enables improved risk assessment in the nonclinical phase. Four compounds that prolong QRS and/or PR (AZD1305, flecainide, quinidine and verapamil) were characterized using in vitro (sodium/calcium channels), in vivo (guinea pigs/dogs) and clinical data. Concentration-matched translational relationships were developed based on in vitro and in vivo modelling, and the in vitro to clinical translation of AZD1305 was quantified using an in vitro model. Meaningful (10%) human QRS/PR effects correlated with low levels of in vitro Na v 1.5 block (3-7%) and Ca v 1.2 binding (13-21%) for all compounds. The in vitro model developed using AZD1305 successfully predicted QRS/PR effects for the remaining drugs. Meaningful QRS/PR changes in humans correlated with small effects in guinea pigs and dogs (QRS 2.3-4.6% and PR 2.3-10%), suggesting that worst-case human effects can be predicted by assuming four times greater effects at the same concentration from dog/guinea pig data. Small changes in vitro and in vivo consistently translated to meaningful PR/QRS changes in humans across compounds. Assuming broad applicability of these approaches to assess cardiovascular safety risk for non-arrhythmic drugs, this study provides a means of predicting human QRS/PR effects of new drugs from effects observed in nonclinical studies. © 2017 The British Pharmacological Society.

QRS peak detection for heart rate monitoring on Android smartphone

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Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

2017-11-01

In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

An Analysis Of QRS Interval Of The Electrocardiogram In ...

African Journals Online (AJOL)

Objectives: This cross-sectional study of the 12-lead electrocardiogram (ECG) was undertaken to establish the normal QRS interval of the adult Nigerian from Jos; to find significant correlation coefficients for QRS interval and the various anthropometric measurements and also to establish prediction equations for the QRS ...

Determinants of developing widened spatial QRS-T angle in HIV-infected individuals

DEFF Research Database (Denmark)

Dawood, Farah Z; Roediger, Mollie P; Grandits, Greg

2014-01-01

BACKGROUND: A widened electrocardiographic spatial QRS-T angle has been shown to be predictive of cardiovascular disease in HIV-infected individuals. However, determinants and risk factors of developing widened QRS-T angle over time in this population remain unknown. METHODS AND RESULTS: Spatial...... QRS-T angle was automatically measured from standard electrocardiogram of 1444 HIV-infected individuals without baseline widened spatial QRS-T angle from the Strategies for Management of Antiretroviral Therapy [SMART], a clinical trial comparing two antiretroviral treatment strategies [Drug...... Conservation (DC) vs. Viral Suppression (VS)]. Conditional logistic regression analysis was used to examine the association between baseline characteristics and incident widened spatial QRS-T angle (a new angle>93° in males and>74° in females). During 2544 person-years of follow-up, 199 participants developed...

Presence of Fragmented QRS Complexes in Patients with Obstructive Sleep Apnea Syndrome

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Muhammet Rasit Sayin

2015-01-01

Conclusions: In our study fragmented QRS frequency and QRS duration were found to increase in OSAS patients. Both parameters are related with increased cardiovascular mortality. Considering the prognostic importance of ECG parameters, it may be reasonable to recommend more detailed evaluation of OSAS patients with fragmented or prolonged QRS complexes with respect to presence of cardiovascular diseases.

A deep learning approach for fetal QRS complex detection.

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Zhong, Wei; Liao, Lijuan; Guo, Xuemei; Wang, Guoli

2018-04-20

Non-invasive foetal electrocardiography (NI-FECG) has the potential to provide more additional clinical information for detecting and diagnosing fetal diseases. We propose and demonstrate a deep learning approach for fetal QRS complex detection from raw NI-FECG signals by using a convolutional neural network (CNN) model. The main objective is to investigate whether reliable fetal QRS complex detection performance can still be obtained from features of single-channel NI-FECG signals, without canceling maternal ECG (MECG) signals. A deep learning method is proposed for recognizing fetal QRS complexes. Firstly, we collect data from set-a of the PhysioNet/computing in Cardiology Challenge database. The sample entropy method is used for signal quality assessment. Part of the bad quality signals is excluded in the further analysis. Secondly, in the proposed method, the features of raw NI-FECG signals are normalized before they are fed to a CNN classifier to perform fetal QRS complex detection. We use precision, recall, F-measure and accuracy as the evaluation metrics to assess the performance of fetal QRS complex detection. The proposed deep learning method can achieve relatively high precision (75.33%), recall (80.54%), and F-measure scores (77.85%) compared with three other well-known pattern classification methods, namely KNN, naive Bayes and SVM. the proposed deep learning method can attain reliable fetal QRS complex detection performance from the raw NI-FECG signals without canceling MECG signals. In addition, the influence of different activation functions and signal quality assessment on classification performance are evaluated, and results show that Relu outperforms the Sigmoid and Tanh on this particular task, and better classification performance is obtained with the signal quality assessment step in this study.

Rapid recovery from congestive heart failure following successful radiofrequency catheter ablation in a patient with late onset of Wolff-Parkinson-White syndrome.

Science.gov (United States)

Yodogawa, Kenji; Ono, Norihiko; Seino, Yoshihiko

2012-01-01

A 56-year-old man was admitted because of palpitations and dyspnea. A 12-lead electrocardiogram showed irregular wide QRS complex tachycardia with a slur at the initial portion of the QRS complex. He had preexisting long-standing persistent atrial fibrillation, but early excitation syndrome had never been noted. Chest X-ray showed heart enlargement and pulmonary congestion. He was diagnosed with late onset of Wolff-Parkinson-White syndrome, and congestive heart failure was probably caused by rapid ventricular response of atrial fibrillation through the accessory pathway. Emergency catheter ablation for the accessory pathway was undertaken, and heart failure was dramatically improved.

Paroxysmal supraventricular tachycardia in an octogenarian.

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Lutwak, Nancy; Dill, Curt

2012-09-01

Paroxysmal supraventricular tachycardia is a common dysrhythmia that occurs at all ages. Its management is determined by presenting symptoms and previous history of the patient. Patients present with a continuum of symptoms ranging from palpitations to syncope. The incidence of supraventricular tachycardia increases with age. To discuss the etiology, precipitating factors, and acute management of supraventricular tachycardia; and to discuss nodal reentry circuits and representative electrocardiographic findings. We present the case of an 84-year-old man with gallstone pancreatitis, choledolcholithiasis, and cholecystitis complicated by paroxysmal supraventricular tachycardia. We review this dysrhythmia, emphasizing its significance in elderly patients. Supraventricular tachycardia is a common dysrhythmia that can result in syncope or myocardial infarction. We present a case of an elderly man with new-onset atrioventricular (AV) nodal reentry tachycardia, possibly precipitated by overdrive of his autonomic nervous system due to pain and infection. As the percentage of the elderly in our population is growing rapidly and the incidence of AV nodal reentry tachycardia increases with age, emergency physicians should be familiar with this dysrhythmia-its etiology, precipitating factors, presentations, and treatment. It will present more frequently in the future. Published by Elsevier Inc.

Association between QRS duration on prehospital ECG and mortality in patients with suspected STEMI

DEFF Research Database (Denmark)

Hansen, Rikke; Frydland, Martin; Møller-Helgestad, Ole Kristian

2017-01-01

BACKGROUND: QRS duration has previously shown association with mortality in patients with acute myocardial infarction treated with thrombolytics, less is known in patients with suspected ST segment elevation myocardial infarction (STEMI) when assessing QRS duration on prehospital ECG. Thus......, the objective was to investigate the prognostic effect of QRS duration on prehospital ECG and presence of classic left and right bundle branch block (LBBB/RBBB) for all-cause mortality in patients with suspected STEMI. METHOD: In total 2105 consecutive patients (mean age 64±13years, 72% men) with suspected...... STEMI were prospectively included. QRS duration was registered from automated QRS measurement on prehospital ECG and patients were divided according to quartiles of QRS duration (111ms). Primary endpoint was all-cause 30-day mortality. Predictors of all-cause mortality were...

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

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Cros, C., E-mail: caroline.cros@hotmail.co.uk [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Skinner, M., E-mail: Matthew.Skinner@astrazeneca.com [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Moors, J. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Lainee, P. [Sanofi-Aventis R and D, 371, rue du Pr Joseph Blayac, 34184 Montpellier Cedex 04 (France); Valentin, J.P. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)

2012-12-01

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I{sub Na}) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I{sub Na}, this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E{sub max} 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

International Nuclear Information System (INIS)

Cros, C.; Skinner, M.; Moors, J.; Lainee, P.; Valentin, J.P.

2012-01-01

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I Na ) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I Na , this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E max 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two out of three

Descriptive evaluation of holter recordings at a teaching hospital in ...

African Journals Online (AJOL)

Wide QRS complex tachycardia was detected in 20.4%, ST segment depression in 47.8% and atrial fibrillation in 28.7%. Asystole was seen in 18% of subjects with a mean duration of 2.17secs, arrest was recorded in 26.7% of those with asystole. The longest duration was 7.58secs. Premature atrial ectopics were seen in ...

Clinical significance of fragmented QRS complexes or J waves in patients with idiopathic ventricular arrhythmias.

Science.gov (United States)

Seong, Choong Sil; Gwag, Hye Bin; Hwang, Jin Kyung; Park, Seung Jung; Park, Kyoung-Min; Kim, June Soo; On, Young Keun

2018-01-01

Idiopathic ventricular fibrillation (IVF) can cause sudden cardiac death. Previous studies have reported that J waves and fragmented QRS complexes (f-QRS) are arrhythmogenic markers and predictors of cardiac events. We evaluated the prevalence and clinical significance of J waves and f-QRS in patients with IVF. We studied 81 patients who received an implantable cardioverter defibrillator (ICD) due to IVF between October 1999 and June 2015. We assessed the prevalence of J waves and f-QRS using electrocardiograms (ECGs). Patients were classified into three groups: J wave group (n = 35), f-QRS group (n = 20), or normal ECG group (n = 26). The control group included 81 subjects without heart disease who were matched for age, sex, and race. We compared syncope, sudden cardiac arrest, and appropriate ICD shock between the three groups. The follow-up duration was 4.1 years. J waves and f-QRS were more frequent in patients with IVF than in control subjects (43.2%, 21% vs. 24.7%, 19.7%, P J wave and f-QRS versus the normal ECG group revealed that the combined group had a higher frequency of clinical cardiac events than the normal ECG group (47.3% vs. 11.5%, respectively, P = 0.009). Patients with IVF had higher prevalence of f-QRS or J waves. And patients with f-QRS or J waves were at higher risk of recurrent ventricular fibrillation.

[Parahisian atrial tachycardia or atrioventricular nodal reentrant tachycardia with tendon of Todaro breakthrough?].

Science.gov (United States)

Orczykowski, Michał; Jaworska-Wilczyńska, Maria; Urbanek, Piotr; Bodalski, Robert; Derejko, Paweł; Gajek, Jacek; Hryniewiecki, Tomasz; Szumowski, Lukasz; Walczak, Franciszek

2010-08-01

We present a case of a 61 year-old woman with tachycardia originating close to the His bundle where radiofrequency (RF) ablation may bear potential risk of atrioventricular (AV) block. In this case report we discuss the possibility of a AV nodal reciprocating tachycardia with tendon of Todaro breakthrough. Patient was safely and effectively treated with RF catheter ablation.

Fetal tachycardia : diagnosis and treatment

NARCIS (Netherlands)

Oudijk, Martijn Alexander

2003-01-01

Part I: Fetal tachyarrhythmias Diagnosis Fetal tachycardia is a serious condition warranting specialized evaluation. In chapter 2, methods of diagnosis of fetal tachycardia are described, including doppler and M-mode echocardiography and fetal magnetocardiography. The study presented in chapter 3

Oxygen therapy reduces postoperative tachycardia

DEFF Research Database (Denmark)

Stausholm, K; Kehlet, H; Rosenberg, J

1995-01-01

Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

Envelopment filter and K-means for the detection of QRS waveforms in electrocardiogram.

Science.gov (United States)

Merino, Manuel; Gómez, Isabel María; Molina, Alberto J

2015-06-01

The electrocardiogram (ECG) is a well-established technique for determining the electrical activity of the heart and studying its diseases. One of the most common pieces of information that can be read from the ECG is the heart rate (HR) through the detection of its most prominent feature: the QRS complex. This paper describes an offline version and a real-time implementation of a new algorithm to determine QRS localization in the ECG signal based on its envelopment and K-means clustering algorithm. The envelopment is used to obtain a signal with only QRS complexes, deleting P, T, and U waves and baseline wander. Two moving average filters are applied to smooth data. The K-means algorithm classifies data into QRS and non-QRS. The technique is validated using 22 h of ECG data from five Physionet databases. These databases were arbitrarily selected to analyze different morphologies of QRS complexes: three stored data with cardiac pathologies, and two had data with normal heartbeats. The algorithm has a low computational load, with no decision thresholds. Furthermore, it does not require any additional parameter. Sensitivity, positive prediction and accuracy from results are over 99.7%. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Members of the emergency medical team may have difficulty diagnosing rapid atrial fibrillation in Wolff-Parkinson-White syndrome.

Science.gov (United States)

Koźluk, Edward; Timler, Dariusz; Zyśko, Dorota; Piątkowska, Agnieszka; Grzebieniak, Tomasz; Gajek, Jacek; Gałązkowski, Robert; Fedorowski, Artur

2015-01-01

Atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome is potentially life-threatening as it may deteriorate into ventricular fibrillation. The aim of this study was to assess whether the emergency medical team members are able to diagnose AF with a rapid ventricular response due to the presence of atrioventricular bypass tract in WPW syndrome. The study group consisted of 316 participants attending a national congress of emergency medicine. A total of 196 questionnaires regarding recognition and management of cardiac arrhythmias were distributed. The assessed part presented a clinical scenario with a young hemodynamically stable man who had a 12-lead electrocardiogram performed in the past with signs of pre-excitation, and who presented to the emergency team with an irregular broad QRS-complex tachycardia. A total of 71 questionnaires were filled in. Only one responder recognized AF due to WPW syndrome, while 5 other responders recognized WPW syndrome and paroxysmal supraventricular tachycardia or broad QRS-complex tachycardia. About 20% of participants did not select any diagnosis, pointing out a method of treatment only. The most common diagnosis found in the survey was ventricular tachycardia/broad QRS-complex tachycardia marked by approximately a half of the participants. Nearly 18% of participants recognized WPW syndrome, whereas AF was recognized by less than 10% of participants. Members of emergency medical teams have limited skills for recognizing WPW syndrome with rapid AF, and ventricular tachycardia is the most frequent incorrect diagnosis.

Fragmented QRS may predict new onset atrial fibrillation in patients with ST-segment elevation myocardial infarction.

Science.gov (United States)

Yesin, Mahmut; Kalçık, Macit; Çağdaş, Metin; Karabağ, Yavuz; Rencüzoğulları, İbrahim; Gürsoy, Mustafa Ozan; Efe, Süleyman Çağan; Karakoyun, Süleyman

Fragmented QRS (fQRS) has been shown to be a marker of local myocardial conduction abnormalities, cardiac fibrosis in previous studies. It was also reported to be a predictor of sudden cardiac death and increased morbidity and mortality in selected populations. However, there is no study investigating the role of fQRS in the development of atrial fibrillation in patients with ST segment elevation myocardial infarction (STEMI). In this study we aimed to investigate the relationship between the presence of fQRS after primary percutaneous coronary intervention (pPCI) and in-hospital development of new-onset atrial fibrilation (AF) in patients with STEMI. This study enrolled 171 patients undergoing pPCI for STEMI. Among these patients 24 patients developed AF and the remaining 147 patients were designated as the controls. All clinical, demographical and laboratory parameters were entered into a dataset and compared between AF group and the controls. The presence of fQRS was higher in the AF group than in the controls (P=0.001). Diabetes mellitus and fQRS was significantly more common in the AF group (P=0.003 and P=0.001 respectively) Logistic regression analysis demonstrated that the presence of fQRS was the independent determinant of AF (OR: 3.243, 95% CI 1.016-10.251, P=0.042). Increased atrial fibrillation was observed more frequently in STEMI patients with fQRS than in patients without fQRS. fQRS is an important determinant of AF in STEMI after pPCI. Copyright © 2017 Elsevier Inc. All rights reserved.

Aiding the Detection of QRS Complex in ECG Signals by Detecting S Peaks Independently.

Science.gov (United States)

Sabherwal, Pooja; Singh, Latika; Agrawal, Monika

2018-03-30

In this paper, a novel algorithm for the accurate detection of QRS complex by combining the independent detection of R and S peaks, using fusion algorithm is proposed. R peak detection has been extensively studied and is being used to detect the QRS complex. Whereas, S peaks, which is also part of QRS complex can be independently detected to aid the detection of QRS complex. In this paper, we suggest a method to first estimate S peak from raw ECG signal and then use them to aid the detection of QRS complex. The amplitude of S peak in ECG signal is relatively weak than corresponding R peak, which is traditionally used for the detection of QRS complex, therefore, an appropriate digital filter is designed to enhance the S peaks. These enhanced S peaks are then detected by adaptive thresholding. The algorithm is validated on all the signals of MIT-BIH arrhythmia database and noise stress database taken from physionet.org. The algorithm performs reasonably well even for the signals highly corrupted by noise. The algorithm performance is confirmed by sensitivity and positive predictivity of 99.99% and the detection accuracy of 99.98% for QRS complex detection. The number of false positives and false negatives resulted while analysis has been drastically reduced to 80 and 42 against the 98 and 84 the best results reported so far.

Paroxysmal supraventricular tachycardia: physiopathology and management

Directory of Open Access Journals (Sweden)

Paola Neroni

2014-06-01

Full Text Available Paroxysmal supraventricular tachycardia (PSVT is the most frequent arrhythmia in newborns and infants. Most supraventricular tachycardias affect structurally healthy hearts. Apart from occasional detection by parents, most tachycardias in this age group are revealed by heart failure signs, such as poor feeding, sweating and shortness of breath. The main symptom reported by school-age children is palpitations. The chronic tachycardia causes a secondary form of dilative cardiomyopathy. Treatment of acute episode usually has an excellent outcome. Vagal manoeuvres are effective in patients with atrioventricular reentrant tachycardia. Adenosine is the drug of choice at all ages for tachycardias involving the atrioventricular node. Its key advantage is its short half life and minimum or no negative inotropic effects. Verapamil is not indicated in newborns and children as it poses a high risk of electromechanical dissociation. Antiarrhythmic prophylaxis of PSVT recurrence is usually recommended in the first year of life, because the diagnosis of tachycardia may be delayed up to the appearance of symptoms. Digoxin can be administered in all forms of PSVT involving the atrioventricular node, except for patients with Wolff-Parkinson-White syndrome below one year of age. Patients with atrioventricular reentrant PSVT can be treated effectively by class Ic drugs, such as propaphenone and flecainide. Amiodarone has the greatest antiarrhythmic effect, but should be used with caution owing to the high incidence of side effects. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in Neonatology Guest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Supraventricular tachycardia associated with phentermine use

Directory of Open Access Journals (Sweden)

Pakpoom Tantrachoti

2016-07-01

Full Text Available Phentermine, a very popular diet pill, is reportedly associated with tachycardia but rarely with other cardiac arrhythmias. We report a 36-year-old woman with no significant past medical history who developed supraventricular tachycardia after taking phentermine for four months. The supraventricular tachycardia has not recurred after the patient stopped taking the medication. With growing prevalence of obesity, clinicians should be aware of the potential serious side effects of phentermine and people with high cardiovascular risk should avoid using this medication.

The Shortest QRS Duration of an Electrocardiogram Might Be an Optimal Electrocardiographic Predictor for Response to Cardiac Resynchronization Therapy.

Science.gov (United States)

Chen, Jan-Yow; Lin, Kuo-Hung; Chang, Kuan-Cheng; Chou, Che-Yi

2017-08-03

QRS duration has been associated with the response to cardiac resynchronization therapy (CRT). However, the methods for defining QRS duration to predict the outcome of CRT have discrepancies in previous reports. The aim of this study was to determine an optimal measurement of QRS duration to predict the response to CRT.Sixty-one patients who received CRT were analyzed. All patients had class III-IV heart failure, left ventricular ejection fraction not more than 35%, and complete left bundle branch block. The shortest, longest, and average QRS durations from the 12 leads of each electrocardiogram (ECG) were measured. The responses to CRT were determined using the changes in echocardiography after 6 months. Thirty-five (57.4%) patients were responders and 26 (42.6%) patients were non-responders. The pre-procedure shortest, average, and longest QRS durations and the QRS shortening (ΔQRS) of the shortest QRS duration were significantly associated with the response to CRT in a univariate logistic regression analysis (P = 0.002, P = 0.03, P = 0.04 and P = 0.04, respectively). Based on the measurement of the area under curve of the receiver operating characteristic curve, only the pre-procedure shortest QRS duration and the ΔQRS of the shortest QRS duration showed significant discrimination for the response to CRT (P = 0.002 and P = 0.038, respectively). Multivariable logistic regression showed the pre-procedure shortest QRS duration is an independent predictor for the response to CRT.The shortest QRS duration from the 12 leads of the electrocardiogram might be an optimal measurement to predict the response to CRT.

Diagnostic value of fragmented QRS complex in myocardial scar detection: systematic review and meta-analysis of the literature.

Science.gov (United States)

Sadeghi, Ramin; Dabbagh, Vahid-Reza; Tayyebi, Mohammad; Zakavi, Seyed Rasoul; Ayati, Narjess

2016-01-01

The present study aimed to investigate the diagnostic value of fragmented QRS complex (fQRS) on 12-lead electrocardiogram (ECG) for myocardial scar detection, and presented the results in a systematic review and meta-analysis format. Medline, SCOPUS, and ISI Web of Knowledge were searched electronically with "Fragmented QRS" or "fQRS" as key words. All related studies that had evaluated the accuracy of fQRS for myocardial scar diagnosis were included. Eight studies (2560 patients) were finally included in the systematic review. Specificity assessment could be evaluated only by five out of these eight articles. Overall pooled sensitivity of fQRS, Q wave, and mixed Q-fQRS was 68% (65-71), 51% (47-55), and 74% (69-79) and the pooled specificity was 80% (79-81), 97% (97-98) and 92% (91-93), respectively. Fragmented QRS is a novel ECG marker with more sensitivity and less specificity than Q wave. A combination of fQRS with Q wave in a 12-lead ECG results in up to 74% sensitivity and 92% specificity. Additional studies are needed to assess the significance of this ECG parameter for regional myocardial scar detection.

Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

DEFF Research Database (Denmark)

Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.

2012-01-01

a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe......Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

Anti-tachycardia therapy can improve altered cardiac adrenergic function in tachycardia-induced cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Ohkusu, Yasuo; Takahashi, Nobukazu; Ishikawa, Toshiyuki [Yokohama City Univ. (Japan). School of Medicine] [and others

2002-11-01

We investigated whether anti-tachycardia therapy might improve the altered cardiac adrenergic and systolic function in tachycardia-induced cardiomyopathy (TC) in contrast to dilated cardiomyopathy (DCM). The subjects were 23 patients with heart failure, consisting of 8 patients with TC (43.6{+-}10.0 yrs) and 15 with DCM (45.3{+-}8.2 yrs). TC was determined as impairment of left ventricular function secondary to chronic or very frequent arrhythmia during more than 10% of the day. All patients were receiving anti-tachycardia treatment. Cardiac {sup 123}I-MIBG uptake was assessed as the heart/mediastinum activity ratio (H/M) before and after treatment. Left ventricular ejection fraction (LVEF) was also assessed. In the baseline study, H/M and LVEF showed no difference between TC and DCM (2.21{+-}0.44 vs. 2.10{+-}0.42, 35.3{+-}13.1 vs. 36.0{+-}10.9%, respectively). After treatment, the degree of change in H/M and LVEF differed significantly (0.41{+-}0.34 vs. 0.08{+-}0.20, 20.5{+-}14.4 vs. -2.1{+-}9.6%, p<0.01). In TC, heart failure improved after a shorter duration of treatment (p<0.05). In conclusion, anti-tachycardia therapy can improve altered cardiac adrenergic function and systolic function in patients with TC over a shorter period than in those with DCM. (author)

Identification of QRS complex in non-stationary electrocardiogram of sick infants.

Science.gov (United States)

Kota, S; Swisher, C B; Al-Shargabi, T; Andescavage, N; du Plessis, A; Govindan, R B

2017-08-01

Due to the high-frequency of routine interventions in an intensive care setting, electrocardiogram (ECG) recordings from sick infants are highly non-stationary, with recurrent changes in the baseline, alterations in the morphology of the waveform, and attenuations of the signal strength. Current methods lack reliability in identifying QRS complexes (a marker of individual cardiac cycles) in the non-stationary ECG. In the current study we address this problem by proposing a novel approach to QRS complex identification. Our approach employs lowpass filtering, half-wave rectification, and the use of instantaneous Hilbert phase to identify QRS complexes in the ECG. We demonstrate the application of this method using ECG recordings from eight preterm infants undergoing intensive care, as well as from 18 normal adult volunteers available via a public database. We compared our approach to the commonly used approaches including Pan and Tompkins (PT), gqrs, wavedet, and wqrs for identifying QRS complexes and then compared each with manually identified QRS complexes. For preterm infants, a comparison between the QRS complexes identified by our approach and those identified through manual annotations yielded sensitivity and positive predictive values of 99% and 99.91%, respectively. The comparison metrics for each method are as follows: PT (sensitivity: 84.49%, positive predictive value: 99.88%), gqrs (85.25%, 99.49%), wavedet (95.24%, 99.86%), and wqrs (96.99%, 96.55%). Thus, the sensitivity values of the four methods previously described, are lower than the sensitivity of the method we propose; however, the positive predictive values of these other approaches is comparable to those of our method, with the exception of the wqrs approach, which yielded a slightly lower value. For adult ECG, our approach yielded a sensitivity of 99.78%, whereas PT yielded 99.79%. The positive predictive value was 99.42% for both our approach as well as for PT. We propose a novel method for

Mechanism of polyuria and natriuresis in atrioventricular nodal tachycardia.

Science.gov (United States)

Canepa-Anson, R; Williams, M; Marshall, J; Mitsuoka, T; Lightman, S; Sutton, R

1984-01-01

A woman with tachycardia associated with polyuria was investigated. Electrophysiological analysis showed that the tachycardia was an atrioventricular nodal re-entrant tachycardia. Programmed stimulation was then used to provoke and sustain the tachycardia for 40 minutes. Polyuria, with an appreciable increase in free water clearance, was observed. This was associated with reduction in plasma and urinary arginine vasopressin concentrations. Appreciable natriuresis also developed. These results support the hypothesis that the polyuria with increased free water clearance and the natriuresis occurring during sustained tachycardia in man are due to inhibition of secretion of vasopressin and the release of natriuretic factor. PMID:6434116

QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: a prospective pilot study.

Science.gov (United States)

Vassilikos, Vassilios P; Mantziari, Lilian; Dakos, Georgios; Kamperidis, Vasileios; Chouvarda, Ioanna; Chatzizisis, Yiannis S; Kalpidis, Panagiotis; Theofilogiannakos, Efstratios; Paraskevaidis, Stelios; Karvounis, Haralambos; Mochlas, Sotirios; Maglaveras, Nikolaos; Styliadis, Ioannis H

2014-01-01

Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT. Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation. Thirty eight patients (age 65±10years, 31 males) were studied. CRT responders (n=28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p=0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p=0.004). Wavelet transformation of the QRS complex is useful in predicting response to CRT. © 2013.

QRS complex detection based on continuous density hidden Markov models using univariate observations

Science.gov (United States)

Sotelo, S.; Arenas, W.; Altuve, M.

2018-04-01

In the electrocardiogram (ECG), the detection of QRS complexes is a fundamental step in the ECG signal processing chain since it allows the determination of other characteristics waves of the ECG and provides information about heart rate variability. In this work, an automatic QRS complex detector based on continuous density hidden Markov models (HMM) is proposed. HMM were trained using univariate observation sequences taken either from QRS complexes or their derivatives. The detection approach is based on the log-likelihood comparison of the observation sequence with a fixed threshold. A sliding window was used to obtain the observation sequence to be evaluated by the model. The threshold was optimized by receiver operating characteristic curves. Sensitivity (Sen), specificity (Spc) and F1 score were used to evaluate the detection performance. The approach was validated using ECG recordings from the MIT-BIH Arrhythmia database. A 6-fold cross-validation shows that the best detection performance was achieved with 2 states HMM trained with QRS complexes sequences (Sen = 0.668, Spc = 0.360 and F1 = 0.309). We concluded that these univariate sequences provide enough information to characterize the QRS complex dynamics from HMM. Future works are directed to the use of multivariate observations to increase the detection performance.

Failed anti-tachycardia pacing can be used to differentiate atrial arrhythmias from ventricular tachycardia in implantable cardioverter-defibrillators.

Science.gov (United States)

Michael, Kevin A; Enriquez, Andres; Baranchuk, Adrian; Haley, Charlotte; Caldwell, Jane; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

2015-01-01

Atrial fibrillation/tachycardia (AF/AT) may result in inappropriate therapies in implantable cardioverter-defibrillators (ICDs). The post-pacing interval (PPI) and tachycardia cycle length difference (PPI - TCL) has been previously demonstrated to indicate the proximity of the pacing site to a tachycardia origin. We postulated that the PPI and PPI - TCL would be greater in AT/AF vs. ventricular tachycardia (VT) after episodes of failed anti-tachycardia pacing (ATP). This was a single-centre, retrospective study evaluating consecutive patients implanted with dual (DR)/biventricular (BIV) ICDs. Stored electrograms were used to determine whether the ATP captured the arrhythmia and the arrhythmia did not present with primary or secondary termination. Measurements were done using manual calipers. A total of 155 patients were included. There were 79 BIV and 76 DR devices. In total, 39 episodes were identified in 20 patients over a 23-month follow-up period. A total of 76 sequences of ATP (burst/ramp) were delivered, 28 (37%) of them inappropriate. Fifty-one events (18 AT/AF and 33 VT) were compared. The mean PPI was 693 ± 96 vs. 512 ± 88 ms (P failed ATP differs significantly between AF/AT and VT and are therefore useful indices to discriminate between supraventricular tachycardia and VT in ICDs. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

On-Line QRS Complex Detection Using Wavelet Filtering

National Research Council Canada - National Science Library

Szilagyi, L

2001-01-01

...: first a wavelet transform filtering is applied to the signal, then QRS complex localization is performed using a maximum detection and peak classification algorithm The algorithm has been tested...

The Variability of Automated QRS Duration Measurement

Czech Academy of Sciences Publication Activity Database

Vančura, V.; Wichterle, D.; Ulč, I.; Šmíd, J.; Brabec, Marek; Zárybnická, M.; Rokyta, R.

2017-01-01

Roč. 19, č. 4 (2017), s. 636-643 ISSN 1099-5129 Institutional support: RVO:67985807 Keywords : ECG * QRS complex * automated measurement Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery OBOR OECD: Statistics and probability Impact factor: 4.530, year: 2016

Correlation of Fragmented QRS with Right Ventricular Indexes and Fibrosis in Patients with Repaired Tetralogy of Fallot, by Cardiac Magnetic Resonance Imaging

Directory of Open Access Journals (Sweden)

Zahra Alizadeh Sani

2017-09-01

Full Text Available Background: Repair of tetralogy of fallot (TOF is associated with diffuse myocardial fibrosis. Cardiac magnetic resonance imaging (CMR can visualize the areas with myocardial fibrosis. Presence of fragmented QRS (fQRS implies the presence of the underlying myocardial scar. Despite the strong association between fQRS and myocardial pathologies, the impact of fQRS with myocardial fibrosis in post-TOF correction is unknown. Objectives: Here, we evaluated the possible predictive role of fQRS in repaired TOF cases and its relationship with cardiac function. Patients and Methods: Thirty two patients with previous history of repaired TOF were enrolled. The extent of fQRS was evaluated according to the number of leads with fQRS. After electrocardiographic evaluation, the participants underwent CMR. Results: Results showed a significant relationship between the right ventricular (RV systolic diameter and fQRS (P = 0.014. Also, an inverse linear relationship was found between the number of fQRS edges and RVEF (r = 0.77, P = 0.0001. The mean QRS duration in those with positive and negative fQRS was 132 mm and 115.8 mm (P = 0.0001. Furthermore, a linear correlation was observed between the number of edges and the percentage of scar tissue (r = 0.88, P = 0.001. However, no relevance between gender and fQRS was detected (P = 0.26, and the relationship between RV diastolic diameter and fQRS was not significant (P = 0.1. Thus, fQRS could be used as a marker of RV systolic dysfunction in patients with tetralogy of fallot. Conclusions: We suggested the fQRS as a surrogate indicator of RV dysfunction in repaired TOF patients and showed that diagnostic and prognostic information of the patients were available by fQRS.

Prognostic Significance of Frontal QRS-T Angle in Patients with Idiopathic Dilated Cardiomyopathy

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Sheng-Na Li

2016-01-01

Conclusions: The frontal QRS-T angle is a powerful predictor of all-cause mortality, cardiac mortality, and worsening heart failure in IDC patients, independent of well-established prognostic factors. Optimized therapy significantly narrows the QRS-T angle, which might be an indicator of medication compliance, but this requires further investigation.

Pharmacokinetic-pharmacodynamic modeling of QRS-prolongation by flecainide: heart rate-dependent effects during sinus rhythm in conscious telemetered dogs.

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Sällström, Johan; Al-Saffar, Ahmad; Pehrson, Rikard

2014-01-01

The duration of the QRS interval is determined by the ion currents involved in cardiac depolarization. Class I antiarrhythmic drugs reduce cardiac excitability and conduction by inhibiting Nav1.5 channels responsible for I(Na), thus increasing the QRS interval. Previous studies in humans as well as in animal models have demonstrated a more pronounced effect on QRS-prolongation during higher heart rates. In the present study, the effects of the Nav1.5 inhibitor flecainide on cardiovascular parameters, were studied in the telemetered beagle dog under normal autonomic control. The heart rate dependency of QRS prolongation was characterized using pharmacokinetic-pharmacodynamic (PKPD) modeling. Four male telemetered beagle dogs were administered placebo or flecainide (100, 150 and 200 mg) in a Latin square design. The QRS interval and heart rate were recorded, and blood samples were taken. Plasma concentrations of flecainide were fitted to a one compartment oral model and the intrapolated plasma concentrations were fitted to QRS and heart rate data sampled during 5 h after dosing. Flecainide increased the QRS interval in all dogs, whereas there were no effects on heart rate. Using the PKPD model, a statistically significant heart rate-dependent QRS prolongation was linked to individual concentration-time profiles of flecainide. PKPD analysis of QRS interval data from unrestrained dogs with sinus rhythm can elucidate mechanisms previously only described during controlled heart rhythm. Specific questions can therefore be addressed in generically designed cardiovascular telemetry safety studies and different types of relationships between parameters can be uncovered. In addition, the present approach can be used to better characterize drug-induced QRS effects in cardiovascular dog models. © 2013.

QRS slopes for assessment of myocardial damage in chronic chagasic patients

International Nuclear Information System (INIS)

Pueyo, E; Laciar, E; Anzuola, E; Laguna, P; Jane, R

2007-01-01

In this study the slopes of the QRS complex are evaluated for determination of the degree of myocardial damage in chronic chagasic patients. Previous studies have demonstrated the ability of the slope indices to reflect alterations in the conduction velocity of the cardiac impulse. Results obtained in the present study show that chronic chagasic patients have significantly flatter QRS slopes as compared to healthy subjects. Not only that but the extent of slope lessening turns out to be proportional to the degree of myocardial damage caused by the disease. Additionally, when incorporating the slope indices into a classification analysis together with other indices indicative of the presence of ventricular late potentials obtained from high resolution electrocardiography, results show that the percentages of correct classification increase up to 62.5%, which means eight points above the percentages obtained prior to incorporation of the slope indices. It can be concluded that QRS slopes have great potential for assessing the degree of severity associated with Chagas' disease

New Mexico Look for the STARS--AIM HIGH: QRS Profile. The Child Care Quality Rating System (QRS) Assessment

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Child Trends, 2010

2010-01-01

This paper presents a profile of New Mexico's Look for the STARS--AIM HIGH prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4)…

Comparison between fragmented QRS and Q waves in myocardial scar detection using myocardial perfusion single photon emission computed tomography.

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Dabbagh Kakhki, Vahid Reza; Ayati, Narjess; Zakavi, Seyed Rasoul; Sadeghi, Ramin; Tayyebi, Mohammad; Shariati, Farzaneh

2015-01-01

Accurate diagnosis of myocardial infarction (MI) is of paramount importance in patient management, which necessitates the development of efficient and accurate diagnostic methods. Q wave is not present in all patients with MI, and its prevalence is declining. Recently, fragmented QRS (fQRS) complex has been introduced as a marker of prior MI. To investigate diagnostic value of fQRS compared to Q wave. We included 500 consecutive patients with known or suspected coronary artery disease who underwent two days of gated myocardial perfusion imaging using dipyridamole pharmacologic stress. Electrocardiogram (ECG) was evaluated to detect fQRS as well as Q-wave. Finally, subjects were compared in terms of ventricular perfusion and function indices. A total of 207 men and 269 women with mean age of 57.06 ± 12 years were studied. ECG analysis showed that 14.3% of the patients had both fQRS and Q waves, 30.7% had fQRS, and 3.8% had Q waves. Fixed myocardial perfusion defect was noted in 22.3% of patients according to MPIs. Sensitivity, specificity, and positive and negative predictive values for myocardial scar detection were 78%, 65%, 39%, and 91%, respectively, for fQRS and 61%, 94%, 76%, and 89%, respectively, for Q wave. Although fQRS had lower specificity compared to Q wave in the detection of myocardial scar, due to higher sensitivity and negative predictive value can be an invaluable diagnostic index. There is also an incremental value for fQRS in association with Q-wave in myocardial scar assessment.

Toxic adenoma of the thyroid gland and Wolff-Parkinson-White syndrome

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Naço, M; Çeliku, E; Llukaçaj, A; Shehaj, J; Kameniku, R

2009-01-01

We report the case of a 17-year-old girl with toxic adenoma scheduled for surgery right lobectomy and isthmectomy of thyroid gland. During the examination before surgery, patient was diagnosed for the first time as having with Wolff – Parkinson – White (WPW) syndrome. In the operating room, after the induction of anesthesia, the electrocardiogram showed wide QRS complex tachycardia with a rate of 180 beats/min, which was diagnosed as paroxysmal supraventricular tachycardia. The patient was treated immediately with antiarrhythmic drugs: adenosine iv three times (at doses of 6 mg, 12mg, 12mg bolus) and esmolol iv twice (at doses 28.5 mg). This approach resulted in disappearance of the delta wave and tachycardia for the whole surgery period. In this case report we discuss the role of induction of anesthesia and presence of toxic adenoma in a patient with WPW. PMID:19561784

Data fusion for QRS complex detection in multi-lead electrocardiogram recordings

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Ledezma, Carlos A.; Perpiñan, Gilberto; Severeyn, Erika; Altuve, Miguel

2015-12-01

Heart diseases are the main cause of death worldwide. The first step in the diagnose of these diseases is the analysis of the electrocardiographic (ECG) signal. In turn, the ECG analysis begins with the detection of the QRS complex, which is the one with the most energy in the cardiac cycle. Numerous methods have been proposed in the bibliography for QRS complex detection, but few authors have analyzed the possibility of taking advantage of the information redundancy present in multiple ECG leads (simultaneously acquired) to produce accurate QRS detection. In our previous work we presented such an approach, proposing various data fusion techniques to combine the detections made by an algorithm on multiple ECG leads. In this paper we present further studies that show the advantages of this multi-lead detection approach, analyzing how many leads are necessary in order to observe an improvement in the detection performance. A well known QRS detection algorithm was used to test the fusion techniques on the St. Petersburg Institute of Cardiological Technics database. Results show improvement in the detection performance with as little as three leads, but the reliability of these results becomes interesting only after using seven or more leads. Results were evaluated using the detection error rate (DER). The multi-lead detection approach allows an improvement from DER = 3:04% to DER = 1:88%. Further works are to be made in order to improve the detection performance by implementing further fusion steps.

Fetal QRS detection and heart rate estimation: a wavelet-based approach

International Nuclear Information System (INIS)

Almeida, Rute; Rocha, Ana Paula; Gonçalves, Hernâni; Bernardes, João

2014-01-01

Fetal heart rate monitoring is used for pregnancy surveillance in obstetric units all over the world but in spite of recent advances in analysis methods, there are still inherent technical limitations that bound its contribution to the improvement of perinatal indicators. In this work, a previously published wavelet transform based QRS detector, validated over standard electrocardiogram (ECG) databases, is adapted to fetal QRS detection over abdominal fetal ECG. Maternal ECG waves were first located using the original detector and afterwards a version with parameters adapted for fetal physiology was applied to detect fetal QRS, excluding signal singularities associated with maternal heartbeats. Single lead (SL) based marks were combined in a single annotator with post processing rules (SLR) from which fetal RR and fetal heart rate (FHR) measures can be computed. Data from PhysioNet with reference fetal QRS locations was considered for validation, with SLR outperforming SL including ICA based detections. The error in estimated FHR using SLR was lower than 20 bpm for more than 80% of the processed files. The median error in 1 min based FHR estimation was 0.13 bpm, with a correlation between reference and estimated FHR of 0.48, which increased to 0.73 when considering only records for which estimated FHR > 110 bpm. This allows us to conclude that the proposed methodology is able to provide a clinically useful estimation of the FHR. (paper)

Revisiting QRS Detection Methodologies for Portable, Wearable, Battery-Operated, and Wireless ECG Systems

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Elgendi, Mohamed; Eskofier, Björn; Dokos, Socrates; Abbott, Derek

2014-01-01

Cardiovascular diseases are the number one cause of death worldwide. Currently, portable battery-operated systems such as mobile phones with wireless ECG sensors have the potential to be used in continuous cardiac function assessment that can be easily integrated into daily life. These portable point-of-care diagnostic systems can therefore help unveil and treat cardiovascular diseases. The basis for ECG analysis is a robust detection of the prominent QRS complex, as well as other ECG signal characteristics. However, it is not clear from the literature which ECG analysis algorithms are suited for an implementation on a mobile device. We investigate current QRS detection algorithms based on three assessment criteria: 1) robustness to noise, 2) parameter choice, and 3) numerical efficiency, in order to target a universal fast-robust detector. Furthermore, existing QRS detection algorithms may provide an acceptable solution only on small segments of ECG signals, within a certain amplitude range, or amid particular types of arrhythmia and/or noise. These issues are discussed in the context of a comparison with the most conventional algorithms, followed by future recommendations for developing reliable QRS detection schemes suitable for implementation on battery-operated mobile devices. PMID:24409290

Treatment of out-of-hospital supraventricular tachycardia: adenosine vs verapamil.

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Brady, W J; DeBehnke, D J; Wickman, L L; Lindbeck, G

1996-06-01

To compare the use of adenosine and the use of verapamil as out-of-hospital therapy for supraventricular tachycardia (SVT). A period of prospective adenosine use (March 1993 to February 1994) was compared with a historical control period of verapamil use (March 1990 to February 1991) for SVT. Data were obtained for SVT patients treated in a metropolitan, fire-department-based paramedic system serving a population of approximately 1 million persons. Standard drug protocols were used and patient outcomes (i.e., conversion rates, complications, and recurrences) were monitored. During the adenosine treatment period, 105 patients had SVT; 87 (83%) received adenosine, of whom 60 (69%) converted to a sinus rhythm (SR). Vagal maneuvers (VM) resulted in restoration of SR in 8 patients (7.6%). Some patients received adenosine for non-SVT rhythms: 7 sinus tachycardia, 18 atrial fibrilation, 7 wide-complex tachycardia (WCT), and 2 ventricular tachycardia; no non-SVT rhythm converted to SR and none of these patients experienced an adverse effect. Twenty-five patients were hemodynamically unstable (systolic blood pressure fibrillation). Recurrence of SVT was noted in 2 adenosine patients and 2 verapamil patients in the out-of-hospital setting and in 23 adenosine patients and 15 verapamil patients after ED arrival, necessitating additional therapy (p = 0.48 and 0.88, for recurrence rates and types of additional therapies, respectively). Hospital diagnoses, outcomes, and ED dispositions were similar for the 2 groups. Adenosine and verapamil were equally successful in converting out-of-hospital SVT in patients with similar etiologies responsible for the SVT. Recurrence of SVT occurred at similar rates for the 2 medications. Rhythm misidentification remains a common issue in out-of-hospital cardiac care in this emergency medical services system.

Robust QRS peak detection by multimodal information fusion of ECG and blood pressure signals.

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Ding, Quan; Bai, Yong; Erol, Yusuf Bugra; Salas-Boni, Rebeca; Zhang, Xiaorong; Hu, Xiao

2016-11-01

QRS peak detection is a challenging problem when ECG signal is corrupted. However, additional physiological signals may also provide information about the QRS position. In this study, we focus on a unique benchmark provided by PhysioNet/Computing in Cardiology Challenge 2014 and Physiological Measurement focus issue: robust detection of heart beats in multimodal data, which aimed to explore robust methods for QRS detection in multimodal physiological signals. A dataset of 200 training and 210 testing records are used, where the testing records are hidden for evaluating the performance only. An information fusion framework for robust QRS detection is proposed by leveraging existing ECG and ABP analysis tools and combining heart beats derived from different sources. Results show that our approach achieves an overall accuracy of 90.94% and 88.66% on the training and testing datasets, respectively. Furthermore, we observe expected performance at each step of the proposed approach, as an evidence of the effectiveness of our approach. Discussion on the limitations of our approach is also provided.

Organized Atrial Tachycardias after Atrial Fibrillation Ablation

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Castrejón-Castrejón, Sergio; Ortega, Marta; Pérez-Silva, Armando; Doiny, David; Estrada, Alejandro; Filgueiras, David; López-Sendón, José L.; Merino, José L.

2011-01-01

The efficacy of catheter-based ablation techniques to treat atrial fibrillation is limited not only by recurrences of this arrhythmia but also, and not less importantly, by new-onset organized atrial tachycardias. The incidence of such tachycardias depends on the type and duration of the baseline atrial fibrillation and specially on the ablation technique which was used during the index procedure. It has been repeatedly reported that the more extensive the left atrial surface ablated, the higher the incidence of organized atrial tachycardias. The exact origin of the pathologic substrate of these trachycardias is not fully understood and may result from the interaction between preexistent regions with abnormal electrical properties and the new ones resultant from radiofrequency delivery. From a clinical point of view these atrial tachycardias tend to remit after a variable time but in some cases are responsible for significant symptoms. A precise knowledge of the most frequent types of these arrhythmias, of their mechanisms and components is necessary for a thorough electrophysiologic characterization if a new ablation procedure is required. PMID:21941669

Hardware Implementation of a Modified Delay-Coordinate Mapping-Based QRS Complex Detection Algorithm

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Andrej Zemva

2007-01-01

Full Text Available We present a modified delay-coordinate mapping-based QRS complex detection algorithm, suitable for hardware implementation. In the original algorithm, the phase-space portrait of an electrocardiogram signal is reconstructed in a two-dimensional plane using the method of delays. Geometrical properties of the obtained phase-space portrait are exploited for QRS complex detection. In our solution, a bandpass filter is used for ECG signal prefiltering and an improved method for detection threshold-level calculation is utilized. We developed the algorithm on the MIT-BIH Arrhythmia Database (sensitivity of 99.82% and positive predictivity of 99.82% and tested it on the long-term ST database (sensitivity of 99.72% and positive predictivity of 99.37%. Our algorithm outperforms several well-known QRS complex detection algorithms, including the original algorithm.

Prevalence and inter-relationship of different Doppler measures of dyssynchrony in patients with heart failure and prolonged QRS: a report from CARE-HF

DEFF Research Database (Denmark)

Edner, Magnus; Kim, Yong; Hansen, Knud Norregaard

2009-01-01

. 3(1, 4), p = 0.002, compared to patients with ischemic heart disease. CONCLUSION: The prevalence of intra-ventricular dyssynchrony is high in patients with heart failure, wide QRS and depressed systolic function. Most important, TSI appears to be a fast and reliable method to identify patients...

Performance Analysis of Ten Common QRS Detectors on Different ECG Application Cases

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Feifei Liu

2018-01-01

Full Text Available A systematical evaluation work was performed on ten widely used and high-efficient QRS detection algorithms in this study, aiming at verifying their performances and usefulness in different application situations. Four experiments were carried on six internationally recognized databases. Firstly, in the test of high-quality ECG database versus low-quality ECG database, for high signal quality database, all ten QRS detection algorithms had very high detection accuracy (F1 >99%, whereas the F1 results decrease significantly for the poor signal-quality ECG signals (all 95% except RS slope algorithm with 94.24% on normal ECG database and 94.44% on arrhythmia database. Thirdly, for the paced rhythm ECG database, all ten algorithms were immune to the paced beats (>94% except the RS slope method, which only output a low F1 result of 78.99%. At last, the detection accuracies had obvious decreases when dealing with the dynamic telehealth ECG signals (all <80% except OKB algorithm with 80.43%. Furthermore, the time costs from analyzing a 10 s ECG segment were given as the quantitative index of the computational complexity. All ten algorithms had high numerical efficiency (all <4 ms except RS slope (94.07 ms and sixth power algorithms (8.25 ms. And OKB algorithm had the highest numerical efficiency (1.54 ms.

PKPD modelling of PR and QRS intervals in conscious dogs using standard safety pharmacology data.

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Bergenholm, Linnéa; Collins, Teresa; Evans, Neil D; Chappell, Michael J; Parkinson, Joanna

2016-01-01

Pharmacokinetic-pharmacodynamic (PKPD) modelling can improve safety assessment, but few PKPD models describing drug-induced QRS and PR prolongations have been published. This investigation aims to develop and evaluate PKPD models for describing QRS and PR effects in routine safety studies. Exposure and telemetry data from safety pharmacology studies in conscious beagle dogs were acquired. Mixed effects baseline and PK-QRS/PR models were developed for the anti-arrhythmic compounds AZD1305, flecainide, quinidine and verapamil and the anti-muscarinic compounds AZD8683 and AZD9164. RR interval correction and circadian rhythms were investigated for predicting baseline variability. Individual PK predictions were used to drive the pharmacological effects evaluating linear and non-linear direct and effect compartment models. Conduction slowing induced by the tested anti-arrhythmics was direct and proportional at low exposures, whilst time delays and non-linear effects were evident for the tested anti-muscarinics. AZD1305, flecainide and quinidine induced QRS widening with 4.2, 10 and 5.6% μM(-1) unbound drug. AZD1305 and flecainide also prolonged PR with 13.5 and 11.5% μM(-1). PR prolongations induced by the anti-muscarinics and verapamil were best described by Emax models with maximal effects ranging from 55 to 95%. RR interval correction and circadian rhythm improved PR but not QRS modelling. However, circadian rhythm had minor impact on estimated drug effects. Baseline and drug-induced effects on QRS and PR intervals can be effectively described with PKPD models using routine data, providing quantitative safety information to support drug discovery and development. Copyright © 2016 Elsevier Inc. All rights reserved.

QRS detection based ECG quality assessment

International Nuclear Information System (INIS)

Hayn, Dieter; Jammerbund, Bernhard; Schreier, Günter

2012-01-01

Although immediate feedback concerning ECG signal quality during recording is useful, up to now not much literature describing quality measures is available. We have implemented and evaluated four ECG quality measures. Empty lead criterion (A), spike detection criterion (B) and lead crossing point criterion (C) were calculated from basic signal properties. Measure D quantified the robustness of QRS detection when applied to the signal. An advanced Matlab-based algorithm combining all four measures and a simplified algorithm for Android platforms, excluding measure D, were developed. Both algorithms were evaluated by taking part in the Computing in Cardiology Challenge 2011. Each measure's accuracy and computing time was evaluated separately. During the challenge, the advanced algorithm correctly classified 93.3% of the ECGs in the training-set and 91.6 % in the test-set. Scores for the simplified algorithm were 0.834 in event 2 and 0.873 in event 3. Computing time for measure D was almost five times higher than for other measures. Required accuracy levels depend on the application and are related to computing time. While our simplified algorithm may be accurate for real-time feedback during ECG self-recordings, QRS detection based measures can further increase the performance if sufficient computing power is available. (paper)

Correlation of QRS complex after percutaneous coronary intervention with myocardial ischemia reperfusion injury and apoptosis molecule contents

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Ming-Min Jiang

2017-11-01

Full Text Available Objective: To study the correlation of QRS complex after percutaneous coronary intervention (PCI with myocardial ischemia reperfusion injury and apoptosis molecule contents. Methods: Patients with non-ST-segment elevation myocardial infarction who were treated in Nanchong Central Hospital between June 2014 and August 2016 were selected and divided into the PCI group who received emergency PCI surgery and the control group who accepted selective PCI or refused emergency PCI after the medical data were retrospectively analyzed. The fQRS as well as the contents of ischemia reperfusion injury indexes and apoptosis molecules was determined after 1 week of treatment. Results: The incidence of fQRS in PCI group was significantly lower than that in control group; serum MDA, cTnI, H-FABP, sTWEAK, sFas, sTRAIL and Caspase-3 contents as well as peripheral blood Nrf-2 and HO-1 expression of PCI group were greatly lower than those of control group; serum MDA, cTnI, H-FABP, sTWEAK, sFas, sTRAIL and Caspase-3 contents as well as peripheral blood Nrf-2 and HO-1 expression of PCI group of patients with fQRS complex (+ were greatly higher than those of patients with fQRS complex (-. Conclusion: The occurrence of fQRS after PCI is closely related to myocardial ischemia reperfusion injury and apoptosis.

When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?

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Schlegel, Todd T.; Cortez, Daniel

2010-01-01

Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

Surgical treatment for ectopic atrial tachycardia.

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Graffigna, A; Vigano, M; Pagani, F; Salerno, G

1992-08-01

Atrial tachycardia is an infrequent but potentially dangerous arrhythmia which often determines cardiac enlargement. Surgical ablation of the arrhythmia is effective and safe, provided a careful atrial mapping is performed and the surgical technique is tailored to the individual focus location. Eight patients underwent surgical ablation of ectopic atrial tachycardia between 1977 and 1990. Different techniques were adopted for each patient according to the anatomical location of the focus and possibly associated arrhythmias. Whenever possible, a closed heart procedure was chosen. In 1 patient a double focal origin was found and treated by separate procedures. In 1 patient with ostium secundum atrial septal defect and atrial flutter, surgical isolation of the right appendage and the ectopic focus was performed. In all patients ectopic atrial tachycardia was ablated with maintenance of the sinoatrial and atrioventricular nodal function as well as internodal conduction. In follow-up up to December 1991, no recurrency was recorded.

Predictors of ventricular tachyarrhythmia occurring late after intracardiac repair of tetralogy of Fallot: combination of QRS duration change rate and tricuspid regurgitation pressure gradient

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Takahashi, Masashi; Sugimoto, Ai; Tsuchida, Masanori

2017-01-01

Background To determine potential predictors of ventricular tachyarrhythmia and sudden cardiac death (SCD) occurring late after repair of tetralogy of Fallot (TOF). Methods Since 1964, 415 patients had undergone total repair for TOF at Niigata University Hospital. Of these, 89 patients who were followed for more than 10 years at our institute were retrospectively reviewed. Results The mean follow-up period was 24.3 years. During the study period, one patient died of cerebral bleeding, and two patients had SCD. The overall survival rates at 20, 30, and 40 years were 100%, 94.6%, and 94.6%, respectively. Eight (9.0%) patients required re-intervention during the late period associated with right ventricular outflow (n=4), tricuspid valve (n=3), aortic valve (n=2), and others (n=2). Ten (11.2%) patients had a history of ventricular tachycardia (VT) or ventricular fibrillation (VF), and six underwent implantation of an implantable cardiac defibrillator. Multivariate analysis selected the change rate of QRS duration [ms/year; odds ratio (OR), 2.44; 95% confidence interval (CI): 1.28–4.65; P=0.007] and the pressure gradient at tricuspid valve regurgitation on echocardiography (OR, 1.12; 95% CI: 1.02–1.22; P=0.017) as risk factors for VT/VF or SCD. Trans-annular patch (TAP) repair was not an independent risk factor for ventricular arrhythmia. Conclusions The combination of rapid change rate of QRS duration and higher-pressure gradient at tricuspid regurgitation were risk factors for ventricular tachyarrhythmia late after TOF repair. Adequate surgical or catheter intervention for pressure and volume load in the right ventricle might decrease the prevalence of VT/VF and SCD. PMID:29312717

Data on association between QRS duration on prehospital ECG and mortality in patients with confirmed STEMI

DEFF Research Database (Denmark)

Hansen, Rikke; Frydland, Martin; Møller-Helgestad, Ole Kristian

2017-01-01

Data presented in this article relates to the research article entitled “Association between QRS duration on prehospital ECG and mortality in patients with suspected STEMI” (Hansen et al., in press) [1]. Data on the prognostic effect of automatically recoded QRS duration on prehospital ECG...

Bidirectional ventricular tachycardia of unknown etiology

International Nuclear Information System (INIS)

Ali, M.; Khan, J.A.; Masood, T.; Shamsi, F.; Dero, M.H.; Khan, S.

2013-01-01

A 45 years old male presented to the emergency department with palpitations, headache and apprehension. His electrocardiogram revealed bidirectional ventricular tachycardia. He remained vitally stable and responded to intravenous beta-blocker. Initially digitalis toxicity was suspected but history was negative for digitalis intake. The cause remained unidentified in patient despite detailed investigations. During a short follow-up (of 6 months) he remained asymptomatic and no cause was further identified during this period. Some other unseen causes of bidirectional ventricular tachycardia need to be explored. (author)

An approach to the patient with a suspected tachycardia in the ...

African Journals Online (AJOL)

ectopic tachycardia (JET). AVJRT can be due to atrioventricular nodal re-entrant tachycardia. (AVNRT), where the antegrade limb is the slow pathway of the atrioventricular (AV) node and the retrograde limb the fast pathway, or atrioventricular re-entrant tachycardia (AVRT), where the antegrade limb is the AV node and.

Distribution and determinants of QRS rotation of black and white persons in the general population.

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Prineas, Ronald J; Zhang, Zhu-Ming; Stevens, Cladd E; Soliman, Elsayed Z

The prevalence and determinants of QRS transition zones are not well established. We examined the distributions of Normal, clockwise (CW) and counterclockwise (CCW)) QRS transition zones and their relations to disease, body size and demographics in 4624 black and white men and women free of cardiovascular disease and major ECG abnormalities enrolled in the NHANES-III survey. CW transition zones were least observed (6.2%) and CCW were most prevalent (60.1%) with Normal in an intermediate position (33.7%). In multivariable logistic regression analysis, the adjusted, significant predictors for CCW compared to Normal were a greater proportion of blacks and women, fewer thin people (BMI<20, thin), a greater ratio of chest depth to chest width, and an LVMass index <80g. By contrast, CW persons were older, had larger QRS/T angles, smaller ratio of chest depth to chest width, had a greater proportion of subjects with low voltage QRS, more pulmonary disease, a greater proportion with high heart rates, shorter QRS duration and were more obese (BMI≥30). Normal rather than being the most prevalent transition zone was intermediate in frequency between the most frequently encountered CCW and the least frequently encountered transition zone CW. Differences in the predictors of CW and CCW exist. This requires further investigation to examine how far these differences explain the differences in the published prognostic differences between CW and CCW. Copyright © 2017 Elsevier Inc. All rights reserved.

Low QRS Voltage on Presenting Electrocardiogram Predicts Multi-vessel Disease in Anterior ST-segment Elevation Myocardial Infarction.

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Kobayashi, Akihiro; Misumida, Naoki; Aoi, Shunsuke; Kanei, Yumiko

Low QRS voltage was reported to predict adverse outcomes in acute myocardial infarction in the pre-thrombolytic era. However, the association between low voltage and angiographic findings has not been fully addressed. We performed a retrospective analysis of patients with anterior ST-segment elevation myocardial infarction (STEMI). Low QRS voltage was defined as either peak to peak QRS complex voltage voltage. Patients with low voltage had a higher rate of multi-vessel disease (MVD) (76% vs. 52%, p=0.01). Patients with low voltage were more likely to undergo coronary artery bypass grafting (CABG) during admission (11% vs. 2%, p=0.028). Low voltage was an independent predictor for MVD (OR 2.50; 95% CI 1.12 to 6.03; p=0.032). Low QRS voltage was associated with MVD and in-hospital CABG in anterior STEMI. Copyright © 2017 Elsevier Inc. All rights reserved.

Efeitos agudos de levosimendana e dobutamina na duração do QRS em Pacientes com insuficiência cardíaca Efectos agudos de levosimendana y dobutamina en la duración del QRS en pacientes con insuficiencia cardíaca Acute effects of levosimendan and dobutamine on QRS duration in patients with heart failure

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Osman Can Yontar

2010-12-01

Full Text Available FUNDAMENTO: A levosimendana é um novo agente inotrópico que aumenta a contratilidade cardíaca sem aumentar a captação celular de cálcio, de forma a não causar sobrecarga de cálcio e arritmias relacionadas. Em pacientes com insuficiência cardíaca (IC, a duração prolongada do QRS está associada com um aumento no risco de mortalidade e morte súbita cardíaca. Mudanças estruturais no ventrículo esquerdo podem levar à contração assíncrona, causando atraso de condução e um QRS prolongado no ECG de superfície. OBJETIVO: O objetivo do presente estudo foi comparar os efeitos agudos de levosimendana e dobutamina na duração do QRS em pacientes com IC grave e ritmo sinusal. MÉTODOS: 60 pacientes consecutivos com IC isquêmica foram incluídos no estudo e randomizados em dois grupos para infusão de levosimendana (n=37 ou dobutamina (n=23. 67,2 % eram homens; a média da idade era 66,4 ± 9,2 anos para todos os pacientes. A duração basal do QRS nos grupos levosimendana e dobutamina foi 120,44 ± 23,82 ms vs 116,59 ± 13,80 ms respectivamente. A fração de ejeção do ventrículo esquerdo (FEVE estava diminuída em ambos os grupos (23,15 ± 8,3 vs 24,56 ± 7,5%. RESULTADOS: No grupo levosimendana, a duração do QRS diminuiu do valor basal para 116,47 ± 24,56 ms (p=0,006, enquanto não houve diferença significante no grupo dobutamina (p=0,605. Ambos os medicamentos causaram um aumento na FEVE, mas este foi significante apenas no grupo levosimendana (27,95 ± 8,9% p=0,003 vs 26,67 ± 7,6%, p=0,315. CONCLUSÃO: O estudo sugere que a administração de levosimendana, mas não de dobutamina, encurta a duração do QRS no ECG de superfície, possivelmente por causar uma contração coletiva nas fibras do músculo do ventrículo esquerdo. A base molecular desse efeito ainda precisa ser esclarecida.FUNDAMENTO: La levosimendana es un nuevo agente inotrópico que aumenta la contractibilidad cardíaca sin aumentar la captación celular de

Ventricular tachycardia induced by weight loss pills

DEFF Research Database (Denmark)

Pareek, Manan; Hansson, Nils Henrik; Grove, Erik Lerkevang

2013-01-01

A previously healthy 29-year-old man was admitted with palpitations, dizziness, and near-syncope after he had recently started taking weight loss pills purchased on the internet. The pills contained caffeine and ephedrine. An electrocardiogram and telemetry revealed multiple episodes of non......-sustained monomorphic ventricular tachycardia, which was successfully treated with amiodarone. In conclusion, unauthorized weight loss pills can be harmful. In particular, ephedrine-containing drugs carry a risk of ventricular tachycardia and should be discouraged....

Comparison of QRS Duration and Associated Cardiovascular Events in American Indian Men Versus Women (The Strong Heart Study).

Science.gov (United States)

Deen, Jason F; Rhoades, Dorothy A; Noonan, Carolyn; Best, Lyle G; Okin, Peter M; Devereux, Richard B; Umans, Jason G

2017-06-01

Electrocardiographic QRS duration at rest is associated with sudden cardiac death and death from coronary heart disease in the general population. However, its relation to cardiovascular events in American Indians, a population with persistently high cardiovascular disease mortality, is unknown. The relation of QRS duration to incident cardiovascular disease during 17.2 years of follow-up was assessed in 1,851 male and female Strong Heart Study participants aged 45 to 74 years without known cardiovascular disease at baseline. Cox regression with robust standard error estimates was used to determine the association between quintiles of QRS duration and incident cardiovascular disease in gender-stratified analyses, adjusted for age, systolic blood pressure, hypertension, antihypertensive medication use, body mass index, current smoking, diabetes, total cholesterol, high-density lipoprotein cholesterol, and albuminuria. In women only, QRS duration in the highest quintile (≥105 ms) conferred significantly higher risk of cardiovascular disease than QRS duration in the lowest quintile (64 to 84 ms) (hazard ratio 1.6, 95% CI 1.1 to 2.4) likely because of higher risks of coronary heart disease (hazard ratio 1.8, 95% CI 1.1 to 3.1) and myocardial infarction (hazard ratio 2.1, 95% CI 1.0 to 4.7). Furthermore, when added to the Strong Heart Study Coronary Heart Disease Risk Calculator, QRS duration significantly improved prediction of future coronary heart disease events in women (Net Reclassification Index 0.17, 95% CI 0.06 to 0.47). In conclusion, QRS duration is an independent predictor of cardiovascular disease in women in the Strong Heart Study cohort and may have value in estimating risk in populations with similar risk profiles and a high lifetime incidence of cardiovascular disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term effectiveness of surgical treatment of ectopic atrial tachycardia.

Science.gov (United States)

Prager, N A; Cox, J L; Lindsay, B D; Ferguson, T B; Osborn, J L; Cain, M E

1993-07-01

The purpose of this study was to determine the long-term clinical outcome of patients with ectopic atrial tachycardias treated surgically. Ectopic atrial tachycardia is an uncommon arrhythmia that can be symptomatic and is associated with the development of a cardiomyopathy. Management strategies are not well defined because of the paucity of data on the long-term effectiveness of pharmacologic and nonpharmacologic therapies. The long-term clinical impact of medical and surgical therapy was determined in 15 consecutive patients with ectopic atrial tachycardia. All 15 patients were initially treated with antiarrhythmic drugs (mean 5.7 +/- 2.2 drugs/patient). An effective drug regimen was identified in only 5 (33%) of the 15 patients; the remaining 10 patients were treated surgically. In each, individualized surgical procedures were guided by computer-assisted intraoperative mapping, with atrial plaques comprising up to 156 electrodes. Focal ablation was performed in four patients and atrial isolation procedures in six. The 10 patients treated surgically were followed up a mean of 4 +/- 3.2 years. Ectopic atrial tachycardia recurred in one patient. A permanent pacemaker was implanted in two patients, one of whom also required reoperation for constrictive pericarditis. There were no operative deaths. Ectopic atrial tachycardia recurred in three (60%) of the five patients discharged on antiarrhythmic drug therapy during a mean follow-up interval of 6.4 +/- 4.3 years. There was one nonarrhythmic death. Map-guided surgery demonstrated long-term efficacy in abolishing symptoms in 9 of the 10 patients with ectopic atrial tachycardia. Results demonstrate that surgery is effective for patients with ectopic atrial tachycardias who are not easily treated with antiarrhythmic drugs.

Real-time QRS detection using integrated variance for ECG gated cardiac MRI

Directory of Open Access Journals (Sweden)

Schmidt Marcus

2016-09-01

Full Text Available During magnetic resonance imaging (MRI, a patient’s vital signs are required for different purposes. In cardiac MRI (CMR, an electrocardiogram (ECG of the patient is required for triggering the image acquisition process. However, a reliable QRS detection of an ECG signal acquired inside an MRI scanner is a challenging task due to the magnetohydrodynamic (MHD effect which interferes with the ECG. The aim of this work was to develop a reliable QRS detector usable inside the MRI which also fulfills the standards for medical devices (IEC 60601-2-27. Therefore, a novel real-time QRS detector based on integrated variance measurements is presented. The algorithm was trained on ANSI/AAMI EC13 test waveforms and was then applied to two databases with 12-lead ECG signals recorded inside and outside an MRI scanner. Reliable results for both databases were achieved for the ECG signals recorded inside (DBMRI: sensitivity Se = 99.94%, positive predictive value +P = 99.84% and outside (DBInCarT: Se = 99.29%, +P = 99.72% the MRI. Due to the accurate R-peak detection in real-time this can be used for monitoring and triggering in MRI exams.

The Postural Tachycardia Syndrome (POTS: Pathophysiology, Diagnosis & Management

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Satish R Raj

2006-04-01

Full Text Available Postural tachycardia syndrome (POTS, characterized by orthostatic tachycardia in the absence of orthostatic hypotension, has been the focus of increasing clinical interest over the last 15 years 1. Patients with POTS complain of symptoms of tachycardia, exercise intolerance, lightheadedness, extreme fatigue, headache and mental clouding. Patients with POTS demonstrate a heart rate increase of ≥30 bpm with prolonged standing (5-30 minutes, often have high levels of upright plasma norepinephrine (reflecting sympathetic nervous system activation, and many patients have a low blood volume. POTS can be associated with a high degree of functional disability. Therapies aimed at correcting the hypovolemia and the autonomic imbalance may help relieve the severity of the symptoms. This review outlines the present understanding of the pathophysiology, diagnosis, and management of POTS.

Significance of fragmented QRS complexes for identifying culprit lesions in patients with non-ST-elevation myocardial infarction: a single-center, retrospective analysis of 183 cases

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Guo Rong

2012-06-01

Full Text Available Abstract Background Fragmented QRS (fQRS complexes are novel electrocardiographic signals, which reflect myocardial conduction delays in patients with coronary artery disease (CAD. The importance of fQRS complexes in identifying culprit vessels was evaluated in this retrospective study. Methods A 12-lead surface electrocardiogram was obtained in 183 patients who had non-ST-elevation myocardial infarction (NSTEMI and subsequently underwent coronary angiography (CAG. On the basis of the frequency of fQRS complexes, indices such as sensitivity, specificity, positive and negative predictive values, and likelihood ratio were evaluated to determine the ability of fQRS complexes to identify the culprit vessels. Results Among the patients studied, elderly patients (age ≥ 65 years and those with diabetes had a significantly higher frequency of fQRS complexes (p = 0.005, p = 0.003, respectively. The fQRS complexes recorded in the 4 precordial leads had the highest specificity (81.8% for indentifying the culprit vessel (left anterior descending artery. However, the specificity of fQRS complexes to identify lesions in the left circumflex and right coronary arteries was lower for the inferior and lateral leads than for the limb leads (65.5% versus 71.7%; however, the limb leads had higher sensitivity (92.3% versus 89.4%. And the total sensitivity and specificity of fQRS (77.1% and 71.5% were higher than those values for ischemic T-waves. Conclusions The frequency of fQRS complexes was higher in elderly and diabetic patients with NSTEMI. The frequency of fQRS complexes recorded in each of the ECG leads can be used to identify culprit vessels in patients with NSTEMI.

EXERCISE-INDUCED VENTRICULAR-TACHYCARDIA - A RARE MANIFESTATION OF DIGITALIS TOXICITY

NARCIS (Netherlands)

GOSSELINK, ATM; CRIJNS, HJGM; WIESFELD, ACP; LIE, KI

Digitalis intoxication is one of the most common adverse drug reactions. Although some arrhythmias are seen more frequently than others, virtually any rhythm disturbance, including ventricular tachycardia, may occur. However, to our knowledge, exercise-induced ventricular tachycardia as a

Prolonged Atrioventricular Block and Ventricular Standstill Following Adenosine Triphosphate Injection in a Patient Taking Dipyridamole and Antiarrhythmic Agents: A Case Report

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Kotaro Oe, MD

2009-01-01

Full Text Available An 83-year-old woman was admitted to our hospital because of palpitation. She had hypertension and paroxysmal atrial fibrillation, treated with digoxin and cibenzoline, and took dipyridamole for microalbuminuria. Before admission, she had taken pilsicainide pills in addition. On admission, electrocardiogram showed regular tachycardia with mildly prolonged QRS width. For the purpose of terminating tachycardia, 10 mg of adenosine triphosphate (ATP was rapidly injected. About 20 sec later, atrioventricular block and ventricular standstill occurred. She presented loss of consciousness and convulsion, and chest compression was performed. About 30 sec later, the QRS complex reappeared, and she became alert. Serum concentration of digoxin, cibenzoline and pilsicainide was within therapeutic level, respectively. We should be cautious in using ATP for a patient taking dipyridamole and antiarrhythmic agents.

Analysis Spectrum of ECG Signal and QRS Detection during Running on Treadmill

Science.gov (United States)

Agung Suhendra, M.; Ilham R., M.; Simbolon, Artha I.; Faizal A., M.; Munandar, A.

2018-03-01

The heart is an important organ in our metabolism in which it controls circulatory and oxygen. The heart exercise is needed one of them using the treadmill to prevent health. To analysis, it using electrocardiograph (ECG) to investigating and diagnosing anomalies of the heart. In this paper, we would like to analysis ECG signals during running on the treadmill with kinds of speeds. There are two analysis ECG signals i.e. QRS detection and power spectrum density (PSD). The result of PSD showed that subject 3 has highly for all subject and the result of QRS detection using pan Tomkins algorithm that a percentage of failed detection is an approaching to 0 % for all subject.

Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep?

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Guido Wassink

2014-01-01

Full Text Available T/QRS ratio monitoring is used to help identify fetal asphyxia. However, immature animals have greater capacity to maintain blood pressure during severe asphyxia, raising the possibility that they may show an attenuated T/QRS increase during asphyxia. Chronically instrumented fetal sheep at 0.6 of gestation (0.6 GA; n = 12, 0.7 GA (n = 12, and 0.8 GA (n = 8 underwent complete umbilical cord occlusion for 30 min, 25 min, or 15 min, respectively. Cord occlusion was associated with progressive metabolic acidosis and initial hypertension followed by severe hypotension, with a more rapid fall in mean arterial blood pressure (MAP and carotid blood flow (CaBF with advancing gestation. T/QRS ratio rose after occlusion more rapidly at 0.8 GA than in immature fetuses, to a similar final peak at all ages, followed by a progressive fall that was slower at 0.8 GA than in the immature fetuses. The increase in T/QRS ratio correlated with initial hypertension at 0.8 GA (P<0.05, R2 = 0.38, and conversely, its fall correlated closely with falling MAP in all gestational groups (P<0.01, R2 = 0.67. In conclusion, elevation of the T/QRS ratio is an index of onset of severe asphyxia in the last third of gestation, but not of fetal compromise.

Tachycardia-Induced Cardiomyopathy in a 12-Year-Old Child With Long QT Syndrome

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Ghandi

2016-05-01

Full Text Available Introduction Tachycardia-induced cardiomyopathy (TIC is a ventricular dysfunction secondary to chronic and persistent tachycardia that can regress partially or completely following heart rate normalization. Paroxysmal atrial tachycardia and permanent junctional reciprocating tachycardia are two types of frequent arrhythmias that can cause cardiomyopathy in children. Case Presentation A 12-year-old child with obesity (body mass index > 26.8 was admitted with fatigue, pallor and tachypnea to the clinic. He had palpitation for the past 24 hours. On the cardiac auscultation, holosystolic 2/6 murmur was heard in the apex as well as gallop rhythm. Electrocardiogram revealed heart rate of 150 - 160 bpm and negative P waves in II, III and AVF leads. The echocardiography revealed dilated cardiomyopathy with an ejection fraction of 30%. Conclusions Diagnosis of tachycardia-induced cardiomyopathy in children is important, since appropriate treatment improves the prognosis. Every child with recurrent and persistent palpitation with the first episode of congestive heart failure should be evaluated for tachycardia- induced cardiomyopathy.

Comparison of Selvester QRS score with magnetic resonance imaging measured infarct size in patients with ST elevation myocardial infarction

DEFF Research Database (Denmark)

Carlsen, Esben A; Bang, Lia E; Ahtarovski, Kiril A

2012-01-01

Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates...

Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

Science.gov (United States)

Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

2004-01-01

Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

Tachycardia may prognosticate life- or organ-threatening diseases in children with abdominal pain.

Science.gov (United States)

Hayakawa, Itaru; Sakakibara, Hiroshi; Atsumi, Yukari; Hataya, Hiroshi; Terakawa, Toshiro

2017-06-01

Abdominal pain is common in children, but expeditious diagnosis of life- or organ-threatening diseases can be challenging. An evidence-based definition of tachycardia in children was established recently, but its diagnostic utility has not yet been studied. To test the hypothesis that abdominal pain with tachycardia may pose a higher likelihood of life- or organ-threatening diseases in children. A nested case-control study was conducted in a pediatric emergency department in 2013. Tachycardia was defined as a resting heart rate of more than 3 standard deviations above the average for that age. Life- or organ-threatening diseases were defined as "disorders that might result in permanent morbidity or mortality without appropriate intervention." A triage team recorded vital signs before emergency physicians attended patients. Patients with tachycardia (cases) and without tachycardia (controls) were systematically matched for age, sex, and month of visit. The groups were compared for the presence of life- or organ-threatening diseases. There were 1683 visits for abdominal pain, 1512 of which had vital signs measured at rest. Eighty-three patients experienced tachycardia, while 1429 did not. Fifty-eight cases and 58 controls were matched. Life- or organ-threatening diseases were more common in the case group (19%) than the control group (5%, p=0.043). The relative risk of tachycardia to the presence of the diseases was 3.7 (95% confidence interval 1.2-12.0). Tachycardia significantly increased the likelihood of life- or organ-threatening diseases. Tachycardia in children with abdominal pain should alert emergency physicians to the possibility of serious illness. Copyright © 2017 Elsevier Inc. All rights reserved.

Mahaim Fibre Tachycardia: Recognition and Management

Directory of Open Access Journals (Sweden)

Eduardo Back Sternick

2003-04-01

regular QRS tachycardias with ventriculoatrial dissociation. The last variety which is known as fasciculoventricular pathway22 seems to play no role in clinical tachycardias but as long as it is very often associated with bypass tracts they should be correctly recognized and not targeted for ablation, avoiding unnecessary damage to the A-V node-His bundle conduction system.

Electrocardiogram voltage discordance: Interpretation of low QRS voltage only in the precordial leads.

Science.gov (United States)

Kim, Diana H; Verdino, Ralph J

To define clinical correlates of low voltage isolated to precordial leads on the surface electrocardiogram (ECG). Low voltage (V) on the ECG is defined as QRS Vvoltage isolated to the precordial leads with normal limb lead voltages is unclear. Twelve-lead ECGs with QRS V>5mm in one or more limb leads and voltage was found in 256 of 150,000 ECGs (~0.2%). 50.4% of patients had discordant ECGs that correlated with classic etiologies, with a higher incidence of LV dilation in those with classic etiologies than those without. Low precordial voltage is associated with classic etiologies and LV dilation. Copyright © 2017 Elsevier Inc. All rights reserved.

Noninvasive fetal QRS detection using an echo state network and dynamic programming.

Science.gov (United States)

Lukoševičius, Mantas; Marozas, Vaidotas

2014-08-01

We address a classical fetal QRS detection problem from abdominal ECG recordings with a data-driven statistical machine learning approach. Our goal is to have a powerful, yet conceptually clean, solution. There are two novel key components at the heart of our approach: an echo state recurrent neural network that is trained to indicate fetal QRS complexes, and several increasingly sophisticated versions of statistics-based dynamic programming algorithms, which are derived from and rooted in probability theory. We also employ a standard technique for preprocessing and removing maternal ECG complexes from the signals, but do not take this as the main focus of this work. The proposed approach is quite generic and can be extended to other types of signals and annotations. Open-source code is provided.

Electrical storm in a patient with dilated non-ischaemic cardiomyopathy.

Science.gov (United States)

De Meyer, Grim; Van Beeumen, Katarina; Duytschaever, Mattias

2009-10-01

Bundle-branch re-entrant ventricular tachycardia (BBRVT) is usually seen in patients with dilated cardiomyopathy. The diagnosis should be suspected in case the QRS morphology during the tachycardia is identical to that in sinus rhythm. Identifying patients with BBRVT is important because they can be easily treated by catheter ablation. This report describes a patient previously implanted with a cardiac resynchronization therapy defibrillator (CRT-D) presenting with an electrical storm due to BBRVT.

[AV-reentrant tachycardia and Wolff-Parkinson-White syndrome : Diagnosis and treatment].

Science.gov (United States)

Voss, Frederik; Eckardt, Lars; Busch, Sonia; Estner, Heidi L; Steven, Daniel; Sommer, Philipp; von Bary, Christian; Neuberger, Hans-Ruprecht

2016-12-01

The AV-reentrant tachycardia (AVRT) is a supraventricular tachycardia with an incidence of 1-3/1000. The pathophysiological basis is an accessory atrioventricular pathway (AP). Patients with AVRT typically present with palpitations, an on-off characteristic, anxiety, dyspnea, and polyuria. This type of tachycardia may often be terminated by vagal maneuvers. Although the clinical presentation of AVRT is quite similar to AV-nodal reentrant tachycardias, the correct diagnosis is often facilitated by analyzing a standard 12-lead ECG at normal heart rate showing ventricular preexcitation. Curative catheter ablation of the AP represents the therapy of choice in symptomatic patients. This article is the fourth part of a series written to improve the professional education of young electrophysiologists. It explains pathophysiology, symptoms, and electrophysiological findings of an invasive EP study. It focusses on mapping and ablation of accessory pathways.

Noninvasive fetal QRS detection using an echo state network and dynamic programming

International Nuclear Information System (INIS)

Lukoševičius, Mantas; Marozas, Vaidotas

2014-01-01

We address a classical fetal QRS detection problem from abdominal ECG recordings with a data-driven statistical machine learning approach. Our goal is to have a powerful, yet conceptually clean, solution. There are two novel key components at the heart of our approach: an echo state recurrent neural network that is trained to indicate fetal QRS complexes, and several increasingly sophisticated versions of statistics-based dynamic programming algorithms, which are derived from and rooted in probability theory. We also employ a standard technique for preprocessing and removing maternal ECG complexes from the signals, but do not take this as the main focus of this work. The proposed approach is quite generic and can be extended to other types of signals and annotations. Open-source code is provided. (paper)

A real time QRS detection using delay-coordinate mapping for the microcontroller implementation.

Science.gov (United States)

Lee, Jeong-Whan; Kim, Kyeong-Seop; Lee, Bongsoo; Lee, Byungchae; Lee, Myoung-Ho

2002-01-01

In this article, we propose a new algorithm using the characteristics of reconstructed phase portraits by delay-coordinate mapping utilizing lag rotundity for a real-time detection of QRS complexes in ECG signals. In reconstructing phase portrait the mapping parameters, time delay, and mapping dimension play important roles in shaping of portraits drawn in a new dimensional space. Experimentally, the optimal mapping time delay for detection of QRS complexes turned out to be 20 ms. To explore the meaning of this time delay and the proper mapping dimension, we applied a fill factor, mutual information, and autocorrelation function algorithm that were generally used to analyze the chaotic characteristics of sampled signals. From these results, we could find the fact that the performance of our proposed algorithms relied mainly on the geometrical property such as an area of the reconstructed phase portrait. For the real application, we applied our algorithm for designing a small cardiac event recorder. This system was to record patients' ECG and R-R intervals for 1 h to investigate HRV characteristics of the patients who had vasovagal syncope symptom and for the evaluation, we implemented our algorithm in C language and applied to MIT/BIH arrhythmia database of 48 subjects. Our proposed algorithm achieved a 99.58% detection rate of QRS complexes.

Accuracy of computer-calculated and manual QRS duration assessments: Clinical implications to select candidates for cardiac resynchronization therapy.

Science.gov (United States)

De Pooter, Jan; El Haddad, Milad; Stroobandt, Roland; De Buyzere, Marc; Timmermans, Frank

2017-06-01

QRS duration (QRSD) plays a key role in the field of cardiac resynchronization therapy (CRT). Computer-calculated QRSD assessments are widely used, however inter-manufacturer differences have not been investigated in CRT candidates. QRSD was assessed in 377 digitally stored ECGs: 139 narrow QRS, 140 LBBB and 98 ventricular paced ECGs. Manual QRSD was measured as global QRSD, using digital calipers, by two independent observers. Computer-calculated QRSD was assessed by Marquette 12SL (GE Healthcare, Waukesha, WI, USA) and SEMA3 (Schiller, Baar, Switzerland). Inter-manufacturer differences of computer-calculated QRSD assessments vary among different QRS morphologies: narrow QRSD: 4 [2-9] ms (median [IQR]), p=0.010; LBBB QRSD: 7 [2-10] ms, p=0.003 and paced QRSD: 13 [6-18] ms, p=0.007. Interobserver differences of manual QRSD assessments measured: narrow QRSD: 4 [2-6] ms, p=non-significant; LBBB QRSD: 6 [3-12] ms, p=0.006; paced QRSD: 8 [4-18] ms, p=0.001. In LBBB ECGs, intraclass correlation coefficients (ICCs) were comparable for inter-manufacturer and interobserver agreement (ICC 0.830 versus 0.837). When assessing paced QRSD, manual measurements showed higher ICC compared to inter-manufacturer agreement (ICC 0.902 versus 0.776). Using guideline cutoffs of 130ms, up to 15% of the LBBB ECGs would be misclassified as <130ms or ≥130ms by at least one method. Using a cutoff of 150ms, this number increases to 33% of ECGs being misclassified. However, by combining LBBB-morphology and QRSD, the number of misclassified ECGs can be decreased by half. Inter-manufacturer differences in computer-calculated QRSD assessments are significant and may compromise adequate selection of individual CRT candidates when using QRSD as sole parameter. Paced QRSD should preferentially be assessed by manual QRSD measurements. Copyright © 2017 Elsevier B.V. All rights reserved.

Management of paroxysmal ectopic atrial tachycardia with long sinus pauses in a teenager

OpenAIRE

Seshadri Balaji

2015-01-01

Sinus pauses in the setting of supraventricular tachycardia is rare in children. We describe an asymptomatic teen with irregular heart rate detected during an incidental exam who was found to have short runs of a slow ectopic atrial tachycardia on electrocardiogram and prolonged sinus pauses on routine ambulatory ECG. Successful catheter ablation of the ectopic atrial tachycardia led to resolution of the sinus pauses.

QRS Score at Presentation Electrocardiogram Is Correlated With Infarct Size and Mortality in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention.

Science.gov (United States)

Shiomi, Hiroki; Kosuge, Masami; Morimoto, Takeshi; Watanabe, Hiroki; Taniguchi, Tomohiko; Nakatsuma, Kenji; Toyota, Toshiaki; Yamamoto, Erika; Shizuta, Satoshi; Tada, Tomohisa; Furukawa, Yutaka; Nakagawa, Yoshihisa; Ando, Kenji; Kadota, Kazushige; Kimura, Kazuo; Kimura, Takeshi

2017-07-25

In ST-segment elevation myocardial infarction (STEMI), QRS score at presentation ECG may reflect the progression of infarction and facilitate prediction of the degree of myocardial salvage achieved by reperfusion therapy.Methods and Results:Admission electrocardiogram (ECG) was studied in 2,607 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) within 24 h of symptom onset. Patients were classified into 3 groups according to QRS score: low (0-3, n=1,227), intermediate (4-7, n=810), and high (≥8, n=570). An increase of infarct size estimated by median peak creatine phosphokinase was observed as QRS score increased (low score, 1,836 IU/L; inter-quartile range (IQR), 979-3,190 IU/L; intermediate score, 2,488 IU/L; IQR, 1,126-4,640 IU/L; high score, 3,454 IU/L; IQR, 1,759-5,639 IU/L; P<0.001). Higher QRS score was associated with higher long-term mortality (low, intermediate, and high score, 15.6%, 19.7%, and 23.7% at 5 years, respectively; log-rank P<0.001). The positive relationship of QRS score with mortality was consistently seen when stratified by infarct location. The association of high QRS score with increased mortality was most remarkably seen in patients with early (≤2 h) presentation (low, intermediate, and high score: 16.7%, 16.6%, and 28.1% at 5 years, respectively; log-rank P<0.001). Higher QRS score at presentation ECG was associated with larger infarct size, and higher long-term mortality in patients with STEMI undergoing primary PCI. QRS score appears to be important in the early risk stratification for STEMI.

Fetal QRS extraction from abdominal recordings via model-based signal processing and intelligent signal merging

International Nuclear Information System (INIS)

Haghpanahi, Masoumeh; Borkholder, David A

2014-01-01

Noninvasive fetal ECG (fECG) monitoring has potential applications in diagnosing congenital heart diseases in a timely manner and assisting clinicians to make more appropriate decisions during labor. However, despite advances in signal processing and machine learning techniques, the analysis of fECG signals has still remained in its preliminary stages. In this work, we describe an algorithm to automatically locate QRS complexes in noninvasive fECG signals obtained from a set of four electrodes placed on the mother’s abdomen. The algorithm is based on an iterative decomposition of the maternal and fetal subspaces and filtering of the maternal ECG (mECG) components from the fECG recordings. Once the maternal components are removed, a novel merging technique is applied to merge the signals and detect the fetal QRS (fQRS) complexes. The algorithm was trained and tested on the fECG datasets provided by the PhysioNet/CinC challenge 2013. The final results indicate that the algorithm is able to detect fetal peaks for a variety of signals with different morphologies and strength levels encountered in clinical practice. (paper)

Magnetic electroanatomical mapping for ablation of focal atrial tachycardias.

Science.gov (United States)

Marchlinski, F; Callans, D; Gottlieb, C; Rodriguez, E; Coyne, R; Kleinman, D

1998-08-01

Uniform success for ablation of focal atrial tachycardias has been difficult to achieve using standard catheter mapping and ablation techniques. In addition, our understanding of the complex relationship between atrial anatomy, electrophysiology, and surface ECG P wave morphology remains primitive. The magnetic electroanatomical mapping and display system (CARTO) offers an on-line display of electrical activation and/or signal amplitude related to the anatomical location of the recorded sites in the mapped chamber. A window of electrical interest is established based on signals timed from an electrical reference that usually represents a fixed electrogram recording from the coronary sinus or the atrial appendage. This window of electrical interest is established to include atrial activation prior to the onset of the P wave activity associated with the site of origin of a focal atrial tachycardia. Anatomical and electrical landmarks are defined with limited fluoroscopic imaging support and more detailed global chamber and more focal atrial mapping can be performed with minimal fluoroscopic guidance. A three-dimensional color map representing atrial activation or voltage amplitude at the magnetically defined anatomical sites is displayed with on-line data acquisition. This display can be manipulated to facilitate viewing from any angle. Altering the zoom control, triangle fill threshold, clipping plane, or color range can all enhance the display of a more focal area of interest. We documented the feasibility of using this single mapping catheter technique for localizing and ablating focal atrial tachycardias. In a consecutive series of 8 patients with 9 focal atrial tachycardias, the use of the single catheter CARTO mapping system was associated with ablation success in all but one patient who had a left atrial tachycardia localized to the medial aspect of the orifice of the left atrial appendage. Only low power energy delivery was used in this patient because of the

[Catheter ablation of ectopic incessant atrial tachycardia using radiofrequency. Reversion of tachycardiomyopathy].

Science.gov (United States)

de Paola, A A; Mendonça, A; Balbão, C E; Tavora, M Z; da Silva, R M; Hara, V M; Guiguer Júnior, N; Vattimo, A C; Souza, I A; Portugal, O P

1993-10-01

A 8-year-old female patient with refractory incessant atrial tachycardia, very symptomatic and with left ventricular ejection fraction of 0.25. Electrophysiological study and endocardial mapping localized the site of the origin of atrial tachycardia in the superior right atrium. In this site 2 applications of radiofrequency current (25V, 20 and 50 seconds) resulted in termination of the atrial tachycardia. She was discharged off antiarrhythmic drugs and after 2 months ejection fraction was 0.52. She was completely asymptomatic 6 months after ablation procedure.

Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection

Science.gov (United States)

Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

2009-01-01

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as ''RAZs''. RAZs are displayed as ''go, no-go'' signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

Improved symptoms, physical limitation, and self-efficacy after resynchronization in a patient with heart failure and a prolonged QRS duration.

Science.gov (United States)

Conaway, Darcy G; Sullivan, Robbie; McCullough, Peter A

2004-01-01

This report examines the impact of resynchronization therapy in a patient with class IV heart failure and a prolonged QRS duration on electrocardiogram. The Kansas City Cardiomyopathy Questionnaire (KCCQ) was used to assess the patient's health status prior to, immediately after, and 2 months after placement of a biventricular pacemaker. B-type natriuretic peptide (BNP) values and electrocardiogram QRS duration were recorded to further document clinical status. Our patient experienced statistically significant improvements in 7 of 10 KCCQ domains after resynchronization. QRS duration narrowed following the procedure and BNP values decreased. Resynchronization therapy improved this patient's symptoms, physical limitations, and self-efficacy when maximal medical therapy failed.

Depolarization changes during acute myocardial ischemia by evaluation of QRS slopes: standard lead and vectorial approach.

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Romero, Daniel; Ringborn, Michael; Laguna, Pablo; Pahlm, Olle; Pueyo, Esther

2011-01-01

Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward ( ℑ(US)) and downward ( ℑ(DS) ) slopes of the R wave as well as the upward ( ℑ(TS)) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of ℑ(US), ℑ(DS), and ℑ(TS) that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that ℑ(US), ℑ(DS), and ℑ(TS) present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change ( ℜ(ℑ)) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for ℑ(US) and ℑ(DS), respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The ℑ(TS) index presented a similar behavior to that of ℑ(DS). The timing for the occurrence of significant changes in ℑ(US) and ℑ(DS) varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative ℑ(DS) changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.

Computerized analysis of the 12-lead electrocardiogram to identify epicardial ventricular tachycardia exit sites.

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Yokokawa, Miki; Jung, Dae Yon; Joseph, Kim K; Hero, Alfred O; Morady, Fred; Bogun, Frank

2014-11-01

Twelve-lead electrocardiogram (ECG) criteria for epicardial ventricular tachycardia (VT) origins have been described. In patients with structural heart disease, the ability to predict an epicardial origin based on QRS morphology is limited and has been investigated only for limited regions in the heart. The purpose of this study was to determine whether a computerized algorithm is able to accurately differentiate epicardial vs endocardial origins of ventricular arrhythmias. Endocardial and epicardial pace-mapping were performed in 43 patients at 3277 sites. The 12-lead ECGs were digitized and analyzed using a mixture of gaussian model (MoG) to assess whether the algorithm was able to identify an epicardial vs endocardial origin of the paced rhythm. The MoG computerized algorithm was compared to algorithms published in prior reports. The computerized algorithm correctly differentiated epicardial vs endocardial pacing sites for 80% of the sites compared to an accuracy of 42% to 66% of other described criteria. The accuracy was higher in patients without structural heart disease than in those with structural heart disease (94% vs 80%, P = .0004) and for right bundle branch block (82%) compared to left bundle branch block morphologies (79%, P = .001). Validation studies showed the accuracy for VT exit sites to be 84%. A computerized algorithm was able to accurately differentiate the majority of epicardial vs endocardial pace-mapping sites. The algorithm is not region specific and performed best in patients without structural heart disease and with VTs having a right bundle branch block morphology. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Animal model of neuropathic tachycardia syndrome

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Carson, R. P.; Appalsamy, M.; Diedrich, A.; Davis, T. L.; Robertson, D.

2001-01-01

Clinically relevant autonomic dysfunction can result from either complete or partial loss of sympathetic outflow to effector organs. Reported animal models of autonomic neuropathy have aimed to achieve complete lesions of sympathetic nerves, but incomplete lesions might be more relevant to certain clinical entities. We hypothesized that loss of sympathetic innervation would result in a predicted decrease in arterial pressure and a compensatory increase in heart rate. Increased heart rate due to loss of sympathetic innervation is seemingly paradoxical, but it provides a mechanistic explanation for clinical autonomic syndromes such as neuropathic postural tachycardia syndrome. Partially dysautonomic animals were generated by selectively lesioning postganglionic sympathetic neurons with 150 mg/kg 6-hydroxydopamine hydrobromide in male Sprague-Dawley rats. Blood pressure and heart rate were monitored using radiotelemetry. Systolic blood pressure decreased within hours postlesion (Delta>20 mm Hg). Within 4 days postlesion, heart rate rose and remained elevated above control levels. The severity of the lesion was determined functionally and pharmacologically by spectral analysis and responsiveness to tyramine. Low-frequency spectral power of systolic blood pressure was reduced postlesion and correlated with the diminished tyramine responsiveness (r=0.9572, P=0.0053). The tachycardia was abolished by treatment with the beta-antagonist propranolol, demonstrating that it was mediated by catecholamines acting on cardiac beta-receptors. Partial lesions of the autonomic nervous system have been hypothesized to underlie many disorders, including neuropathic postural tachycardia syndrome. This animal model may help us better understand the pathophysiology of autonomic dysfunction and lead to development of therapeutic interventions.

A ±6 ms-Accuracy, 0.68 mm2, and 2.21 μW QRS Detection ASIC

Directory of Open Access Journals (Sweden)

Sheng-Chieh Huang

2012-01-01

Full Text Available Healthcare issues arose from population aging. Meanwhile, electrocardiogram (ECG is a powerful measurement tool. The first step of ECG is to detect QRS complexes. A state-of-the-art QRS detection algorithm was modified and implemented to an application-specific integrated circuit (ASIC. By the dedicated architecture design, the novel ASIC is proposed with 0.68 mm2 core area and 2.21 μW power consumption. It is the smallest QRS detection ASIC based on 0.18 μm technology. In addition, the sensitivity is 95.65% and the positive prediction of the ASIC is 99.36% based on the MIT/BIH arrhythmia database certification.

Spontaneous Transition of Double Tachycardias with Atrial Fusion in a Patient with Wolff-Parkinson-White Syndrome.

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Kim, Dongmin; Lee, Myung-Yong

2016-07-01

Among patients with Wolff-Parkinson-White syndrome, atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) can coexist in a single patient. Direct transition of both tachycardias is rare; however, it can occur after premature atrial or ventricular activity if the cycle lengths of the two tachycardias are similar. Furthermore, persistent atrial activation by an accessory pathway (AP) located outside of the AV node during ongoing AVNRT is also rare. This article describes a case of uncommon atrial activation by an AP during AVNRT and gradual transition of the two supraventricular tachycardias without any preceding atrial or ventricular activity in a patient with preexcitation syndrome.

Atrial flutter with 1:1 conduction in undiagnosed Wolff-Parkinson-White syndrome.

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Nelson, Jessie G; Zhu, Dennis W

2014-05-01

Atrial flutter with 1:1 atrioventricular conduction via an accessory pathway is an uncommon presentation of Wolff-Parkinson-White syndrome not previously reported in the emergency medicine literature. Wolff-Parkinson-White syndrome, a form of ventricular preexcitation sometimes initially seen and diagnosed in the emergency department (ED), can present with varied tachydysrhythmias for which certain treatments are contraindicated. For instance, atrial fibrillation with preexcited conduction needs specific consideration of medication choice to avoid potential degeneration into ventricular fibrillation. We describe an adult female presenting with a very rapid, regular wide complex tachycardia successfully cardioverted in the ED followed by a normal electrocardiogram (ECG). Electrophysiology study confirmed atrial flutter with 1:1 conduction and revealed an accessory pathway consistent with Wolff-Parkinson-White syndrome, despite lack of ECG findings of preexcitation during sinus rhythm. Why should an emergency physician be aware of this? Ventricular tachycardia must be the first consideration in patients with regular wide complex tachycardia. However, clinicians should consider atrial flutter with 1:1 conduction related to an accessory pathway when treating patients with the triad of very rapid rate (>250 beats/min), wide QRS complex, and regular rhythm, especially when considering pharmacologic treatment. Emergency physicians also should be aware of electrocardiographically concealed accessory pathways, and that lack of delta waves does not rule out preexcitation syndromes such as Wolff-Parkinson-White syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

Summation and Cancellation Effects on QRS and ST-Segment Changes Induced by Simultaneous Regional Myocardial Ischemia.

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Vives-Borrás, Miquel; Jorge, Esther; Amorós-Figueras, Gerard; Millán, Xavier; Arzamendi, Dabit; Cinca, Juan

2018-01-01

Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries ( n = 4); Group 2: left anterior descending artery (LAD) and LCX ( n = 4) and; Group 3: LAD and RCA ( n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.

[Radioisotopic mapping of the arrhythmogenic focus in patients with chronic chagasic cardiomyopathy and sustained ventricular tachycardia].

Science.gov (United States)

de Paola, A A; Balbão, C E; Castiglioni, M L; Barbieri, A; Mendonça, A; Netto, O S; Guiguer Júnior, N; Vattimo, A C; Souza, I A; Portugal, O P

1993-06-01

To localize the site of the origin of sustained ventricular tachycardia in chronic chagasic cardiomyopathy patients refractory to antiarrhythmic therapy by radionuclide angiography techniques. Five patients underwent radionuclide angiography by intravenous administration of 25mCi 99mTc. The images were obtained in sinus rhythm and during sustained ventricular tachycardia induced in the electrophysiologic laboratory for endocardial mapping. Amplitude and phase images were obtained resulting in a contraction wave synchronic to ventricular dispolarization. All patients had haemodynamic stability during the arrhythmia. One patient had incessant ventricular tachycardia. Mean ejection fraction was 0.38. In 4 patients the site of the origin of ventricular tachycardia was posterior and in one it was localized in the interventricular septum. There was identity in the site of the origin of ventricular tachycardia obtained by endocardial mapping or radionuclide angiography in all patients. The therapy was chemical ablation in 3 patients, surgical aneurysmectomy in one and pharmacologic therapy in the last patient. The site of the origin of ventricular tachycardia can be estimated by analyzing the contraction wave obtained by radionuclide angiography techniques in patients with hemodynamic stable sustained ventricular tachycardia.

Auricular tachycardia: therapeutic and pathophysiologic news concepts: literature review and casuistic Service presentation

International Nuclear Information System (INIS)

Horta, J. de; Reyes, W.; Calleriza, F.; Pouso, J.; Besada, E.

1998-01-01

The auricular tachycardia are the supraventricular tachycardias whose origin mechanism and maintenance is located at level exclusively auricular. It show diagnostic and therapeutics difficulties.The inadequate handling can cause commitment of the ventricular function and to commit the predict vital.The pharmacological treatment, is more used is few effective.The ablation for catheter with radiofrequency is a new weapon transcendent therapy for the resolution of a significant group of these patients. A review of the concept of auricular tachycardias, it upgrades its classification and the mechanisms pathophysiologic.It describes the techniques of ablation for catheter in these arrhythmias and their results are revised in the literature. In the end it presents the casuistry of the Service in the treatment of the auricular tachycardias focal s,incision ales and atrial flutter by means of ablation for catheter with radiofrequency [es

A New Association or Coincidence: Supraventricular Tachycardia in a Child Receiving Hyoscine N-Butylbromide

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Eyup Aslan

2014-12-01

Full Text Available Hyoscine N-Butylbromide, is a peripherally acting antimuscarinic, anticholinergic agent. It is used for spasms of gastrointestinal and genitourinary trackt. Because of anticholinergic effects, it exerts positive chronotropic agent like atropine, may lead to sinus tachycardia. However, there has been no reported an association of supraventricular tachycardia and hyoscine n-butylbromide. In this report, we report a case that developed supraventricular tachycardia during hyoscine n-butylbromide therapy for his abdominal pain.

The treatment of malignant ventricular tachycardia by aorto-coronary saphenous vein bypass graft

Science.gov (United States)

Ikram, H.; Jeffery, R. M.; Parkins, R. A.; Makey, A. R.; Emery, E. R. J.; Stone, D. L.

1974-01-01

A 61-year-old man with a previous cardiac infarction had at least fifteen attacks of ventricular tachycardia which finally did not respond to either drug or electrical therapy. Angiography showed a blocked right coronary artery and a non-contractile portion of postero-inferior left ventricular wall. An aorto to right coronary saphenous vein bypass graft was inserted, and although attacks of tachycardia occurred following the operation these were of short duration and reverted spontaneously. He has been free of tachycardia for 5 weeks, with a greatly improved effort tolerance. ImagesFig. 2Fig. 3

Analysis of the temporal regression of the QRS widening induced by bupivacaine after Intralipid administration. Study in an experimental porcine model.

Science.gov (United States)

Zaballos, M; Sevilla, R; González, J; Callejo, D; de Diego, C; Almendral, J; Quintela, O; Anadón, M J

2016-01-01

The principal mechanism of cardiac toxicity of bupivacaine relates to the blockade of myocardial sodium channels, which leads to an increase in the QRS duration. Recently, experimental studies suggest that lipid emulsion is effective in reversing bupivacaine cardiac toxicity. We aimed to evaluate the temporal evolution of the QRS widening induced by bupivacaine with the administration of Intralipid. Twelve pigs were anesthetized with intravenous sodium thiopental 5mg kg(-1) and sevoflurane 1 MAC (2.6%). Femoral artery and vein were canalized for invasive monitoring, analysis of blood gases and determination of bupivacaine levels. After instrumentation and monitoring, a bupivacaine bolus of 4-6 mg kg(-1) was administered in order to induce a 150% increase in QRS duration (defined as the toxic point). The pigs were randomized into two groups of six individuals. Intralipid group (IL) received 1.5 mL kg(-1)of IL over one minute, followed by an infusion of 0.25 mL kg min(-1). Control group (C) received the same volume of a saline solution. The electrocardiographic parameters were recorded, and blood samples were taken after bupivacaine and 1, 5, 10 and 30 minutes after Intralipid/saline administration. Bupivacaine (4.33±0.81 mg/kg in IL group and 4.66±1.15 mg/kg in C group) induced similar electrocardiographic changes in both groups; mean maximal percent increase in QRS interval was 184±62% in IL group, and 230±56% in control group (NS). Lipid administration reversed the QRS widening previously impaired by bupivacaine. After ten minutes of the administration of IL, the mean QRS interval decreased to 132±56% vs. 15±76% relative to the maximum widening induced by bupivacaine, in IL and C group, respectively. Intralipid reversed the lengthening of QRS interval induced by the injection of bupivacaine. Time to normalization of electrocardiographic parameters can last more than 10 minutes. While the phenomena of cardiac toxicity persist, resuscitation measures and

Supraventricular tachycardia induced by chocolate: is chocolate too sweet for the heart?

Science.gov (United States)

Parasramka, Saurabh; Dufresne, Alix

2012-09-01

Conflicting studies have been published concerning the association between chocolate and cardiovascular diseases. Fewer articles have described the potential arrhythmogenic risk related to chocolate intake. We present a case of paroxysmal supraventricular tachycardia in a woman after consumption of large quantity of chocolate. A 53-year-old woman with no significant medical history presented to us with complaints of palpitations and shortness of breath after consuming large amounts of chocolate. Electrocardiogram showed supraventricular tachycardia at 165 beats per minute, which was restored to sinus rhythm after adenosine bolus injection. Electrophysiology studies showed atrioventricular nodal reentry tachycardia, which was treated with radiofrequency ablation. Chocolate contains caffeine and theobromine, which are methylxanthines and are competitive antagonists of adenosine and can have arrhythmogenic potential. Our case very well describes an episode of tachycardia precipitated by large amount of chocolate consumption in a patient with underlying substrate. There are occasional case reports describing association between chocolate, caffeine, and arrhythmias. A large Danish study, however, did not find any association between amount of daily caffeine consumption and risk of arrhythmia.

[Ventricular tachycardia in a patient with rate-responsive cardiac pacemaker].

Science.gov (United States)

Himbert, C; Lascault, G; Tonet, J; Coutte, R; Busquet, P; Frank, R; Grosgogeat, Y

1992-11-01

The authors report a case of syncopal ventricular tachycardia in a patient with a respiratory-dependent rate responsive pacemaker, followed-up for valvular heart disease with severe left ventricular dysfunction and sustained atrial and ventricular arrhythmias. The introduction of low dose betablocker therapy with reinforcement of the treatment of cardiac failure controlled the ventricular arrhythmia, after suppression of the data responsive function had been shown to be ineffective. The authors discuss the role of the rate responsive function in the triggering of the ventricular tachycardias.

Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping

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Távora Maria Zildany P.

1999-01-01

Full Text Available OBJECTIVE: To study electrophysiological characteristics that enable the identification and ablation of sites of chagasic tachycardia. METHODS: Thirty-one patients with chronic Chagas' heart disease and sustained ventricular tachycardia (SVT underwent electrophysiological study to map and ablate that arrhythmia. Fifteen patients had hemodinamically stable SVT reproducible by programmed ventricular stimulation, 9 men and 6 women with ages ranging from 37 to 67 years and ejection fraction varying from 0.17 to 0.64. Endocardial mapping was performed during SVT in all patients. Radiofrequency (RF current was applied to sites of presystolic activity of at least 30 ms. Entrainment was used to identify reentrant circuits. In both successful and unsuccessful sites of RF current application, electrogram and entrainment were analyzed. RESULTS: Entrainment was obtained during all mapped SVT. In 70.5% of the sites we observed concealed entrainment and ventricular tachycardia termination in the first 15 seconds of RF current application. In the unsuccessful sites, significantly earlier electrical activity was seen than in the successful ones. Concealed entrainment was significantly associated with ventricular tachycardia termination. Bystander areas were not observed. CONCLUSION: The reentrant mechanism was responsible for the genesis of all tachycardias. In 70.5% of the studied sites, the endocardial participation of the slow conducting zone of reentrant circuits was shown. Concealed entrainment was the main electrophysiological parameter associated with successful RF current application. There was no electrophysiological evidence of bystander regions in the mapped circuits of SVT.

Electrocardiographic spatial QRS-T angle and incident cardiovascular disease in HIV-infected patients (from the Strategies for the Management of Antiretroviral Therapy [SMART] study)

DEFF Research Database (Denmark)

Dawood, Farah Z; Khan, Faraaz; Roediger, Mollie P

2013-01-01

the baseline resting 12-lead electrocardiogram of 4,453 HIV-infected patients aged 43.5 ± 9.3 years from the Strategies for Management of Antiretroviral Therapy (SMART) trial. CVD events were identified during a median follow-up of 28.7 months. Quartiles of the spatial QRS-T angle was calculated for men......Widening of the electrocardiographic (ECG) spatial QRS-T angle has been predictive of cardiovascular disease (CVD) events in the general population. However, its prognostic significance in human immunodeficiency virus (HIV)-infected patients remains unknown. The spatial QRS-T angle was derived from...... and women separately, and values in the upper quartile were considered as a widened angle (values >74° for women and >93° for men). A multivariate Cox proportional hazards analysis was used to examine the association between a widened baseline spatial QRS-T angle and incident CVD events. During 11...

Prognostic Estimation of Advanced Heart Failure With Low Left Ventricular Ejection Fraction and Wide QRS Interval.

Science.gov (United States)

Oh, Changmyung; Chang, Hyuk-Jae; Sung, Ji Min; Kim, Ji Ye; Yang, Wooin; Shim, Jiyoung; Kang, Seok-Min; Ha, Jongwon; Rim, Se-Joong; Chung, Namsik

2012-10-01

Cardiac resynchronization therapy (CRT) has been known to improve the outcome of advanced heart failure (HF) but is still underutilized in clinical practice. We investigated the prognosis of patients with advanced HF who were suitable for CRT but were treated with conventional strategies. We also developed a risk model to predict mortality to improve the facilitation of CRT. Patients with symptomatic HF with left ventricular ejection fraction ≤35% and QRS interval >120 ms were consecutively enrolled at cardiovascular hospital. After excluding those patients who had received device therapy, 239 patients (160 males, mean 67±11 years) were eventually recruited. During a follow-up of 308±236 days, 56 (23%) patients died. Prior stroke, heart rate >90 bpm, serum Na ≤135 mEq/L, and serum creatinine ≥1.5 mg/dL were identified as independent factors using Cox proportional hazards regression. Based on the risk model, points were assigned to each of the risk factors proportional to the regression coefficient, and patients were stratified into three risk groups: low- (0), intermediate-(1-5), and high-risk (>5 points). The 2-year mortality rates of each risk group were 5, 31, and 64 percent, respectively. The C statistic of the risk model was 0.78, and the model was validated in a cohort from a different institution where the C statistic was 0.80. The mortality of patients with advanced HF who were managed conventionally was effectively stratified using a risk model. It may be useful for clinicians to be more proactive about adopting CRT to improve patient prognosis.

Left anterior descending coronary artery dissection during ventricular tachycardia ablation – case report

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Kordic Kresimir

2018-03-01

Full Text Available Fascicular left ventricular tachycardia (VT is the second most frequent idiopathic left VT in the setting of a structurally normal heart. Catheter ablation is curative in most patients with low complication rates. We report a case of ostial left anterior descending coronary artery (LAD occlusion during fascicular ventricular tachycardia ablation.

Quick detection of QRS complexes and R-waves using a wavelet transform and K-means clustering.

Science.gov (United States)

Xia, Yong; Han, Junze; Wang, Kuanquan

2015-01-01

Based on the idea of telemedicine, 24-hour uninterrupted monitoring on electrocardiograms (ECG) has started to be implemented. To create an intelligent ECG monitoring system, an efficient and quick detection algorithm for the characteristic waveforms is needed. This paper aims to give a quick and effective method for detecting QRS-complexes and R-waves in ECGs. The real ECG signal from the MIT-BIH Arrhythmia Database is used for the performance evaluation. The method proposed combined a wavelet transform and the K-means clustering algorithm. A wavelet transform is adopted in the data analysis and preprocessing. Then, based on the slope information of the filtered data, a segmented K-means clustering method is adopted to detect the QRS region. Detection of the R-peak is based on comparing the local amplitudes in each QRS region, which is different from other approaches, and the time cost of R-wave detection is reduced. Of the tested 8 records (total 18201 beats) from the MIT-BIH Arrhythmia Database, an average R-peak detection sensitivity of 99.72 and a positive predictive value of 99.80% are gained; the average time consumed detecting a 30-min original signal is 5.78s, which is competitive with other methods.

2D.03: IMPROVING DIAGNOSTIC STRATEGY IN PATIENTS WITH LONG-STANDING HYPERTENSION, CHEST PAIN AND NORMAL RESTING ECG: VALUE OF THE EXERCISE HIGH-FREQUENCY QRS VERSUS ST-SEGMENT ANALYSIS.

Science.gov (United States)

Conti, A; Bianchi, S; Grifoni, C; Trausi, F; Angeli, E; Paolini, D; Catarzi, S; Perrotta, M E; Covelli, A; Renzi, N; Bertolini, P; Mazzucchelli, M

2015-06-01

The novel exercise computer-assisted high-frequency QRS-analysis (ex-HF/QRS) has demonstrated improved sensitivity and specificity over the conventional exercise-ST/ECG-segment-analysis (ex-ST/ECG) in the detection of myocardial ischemia. The aim of the present study was to test the implementation in diagnostic value of the ex-HF/QRS in patient with hypertension and chest pain (CP) versus the conventional ex-ST/ECG anlysis alone. Patients with long-standing hypertension, CP, normal ECG, troponin and echocardiography were enrolled. All patients underwent the ex-ST/ECG and ex-HF/QRS. A decrease >/=50% of the signal of ex-HF/QRS intensity recorded in two contiguous leads, at least, was considered as index of ischaemia, as ST-segment depression >/=2 mm or >/=1 mm and CP on ex-ST/ECG. Exclusion criteria were QRS duration >/=120 msec and inability to exercise. The end-point was the composite of coronary stenosis >50% or acute coronary syndrome, revascularization, cardiovascular death at 3-month follow-up. Six-hundred thirty-one patients were enrolled (age 61+/-15 y). The percentage of age-adjusted maximal predicted heart rate was 88+/-10 beat-per-minute and the maximal systolic blood pressure was 169+/-22 mmHg. Twenty-seven patients achieved the end-point. On multivariate analysis, both the ex-ST/ECG and ex-HF/QRS were predictors of the end-point. The ex-HF/QRS showed higher sensitivity (88% vs 50%; p = 0.003), lower specificity (77% vs 97%; p = 0.245) and comparable negative predictive value (99% vs 99%; p = NS) when compared to ex-ST/ECG. Receiver operator characteristics (ROC) analysis showed the incremental diagnostic value of the ex-HF/QRS (area: 0.64, 95% Confidence Intervals, CI 0.51-0.77) over conventional ex-ST/ECG (0.60, CI 0.52-0.66) and Chest Pain Score (0.53, CI 0.48-0.59); p = NS on pairwise C-statistic. In patients with long-standing hypertension and CP submitted to risk stratification with exercise tolerance test, the novel ex-HF/QRS

[Basic mechanisms of QRS voltage changes on ECG of healthy subjects during the exercise test].

Science.gov (United States)

Saltykova, M M

2015-01-01

Electrocardiography is the most commonly used technique for detection stress-induced myocardial ischemia. However, the sensitivity of ECG-criteria is not high. One of the major problem is the difficulty in differentiating ECG changes caused by various factors. The aim of this study was to evaluate the dependence of the QRS voltage changes during exercise on parameters of central hemodynamics, gender particularities and to reveal mechanisms causing these changes. To eliminate the effect of changes in cardiomyocytes transmembrane potentials under the influence of the neurotransmitters of the autonomic nervous system during stepwise increasing exercises and/or due to a lack of ATP results from inadequate myocardial blood flow only healthy subjects not older than 35 years were included in the study (7 men and 7 women) and only periods of ventricular depolarization (QRS complex on the ECG) were included in the analysis. We compared the changes of QRS waves during exercise sessions with two upper and one lower limbs in both men and women. The exercise load was twice bigger in exercise with one leg relative to exercise with two arms. Responses of heart rate and systolic arterial pressure were similar. Amplitude of S-wave in left chest leads significantly increased in both sessions without significant difference between augmentations in the sessions and in groups of men and women. Significant relationship between the S wave augmentation and the peak systolic arterial pressure were revealed. Furthermore, the QRS changes during the exercise with vertical and a horizontal torso position were compared to assess the impact of diastolic arterial pressure and displacement of the diaphragm and heart rotation due to increase of abdominal pressure during the last steps of exercise. The obtained results allow us to exclude the impact of the heart position and size changes, as well as the exercise load on S-wave changes and make a conclusion about the dependence of this parameter on

Cadmium stress assessment based on the electrocardiogram characteristics of zebra fish (Danio rerio): QRS complex could play an important role.

Science.gov (United States)

Xing, Na; Ji, Lizhen; Song, Jie; Ma, Jingchun; Li, Shangge; Ren, Zongming; Xu, Fei; Zhu, Jianping

2017-10-01

The electrocardiogram (ECG) of zebra fish (Danio rerio) expresses cardiac features that are similar to humans. Here we use sharp microelectrode measurements to obtain ECG characteristics in adult zebra fish and analyze the effects of cadmium chloride (CdCl 2 ) on the heart. We observe the overall changes of ECG parameters in different treatments (0.1 TU, 0.5 TU and 1.0 TU CdCl 2 ), including P wave, Q wave, R wave, S wave, T wave, PR interval (atrial contraction), QRS complex (ventricular depolarization), ST segment, and QT interval (ventricular repolarization). The trends of the ECG parameters showed some responses to the concentration and exposure time of CdCl 2 , but it was difficult to obtain more information about the useful indicators in water quality assessment depending on tendency analysis alone. A self-organizing map (SOM) showed that P values, R values, and T values were similar; R wave and T wave amplitude were similar; and most important, QRS value was similar to the CdCl 2 stress according to the classified data patterns including CdCl 2 stress (E) and ECG components based on the Ward linkage. It suggested that the duration of QRS complex was related to environmental stress E directly. The specification and evaluation of ECG parameters in Cd 2+ pollution suggested that there is a markedly significant correlation between QRS complex and CdCl 2 stress with the highest r (0.729) and the smallest p (0.002) among all ECG characteristics. In this case, it is concluded that QRS complex can be used as an indicator in the CdCl 2 stress assessment due to the lowest AIC data abased on the linear regression model between the CdCl 2 stress and ECG parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

Perioperative care of an adolescent with postural orthostatic tachycardia syndrome

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Kernan Scott

2010-01-01

Full Text Available Postural orthostatic tachycardia syndrome (POTS is a disorder characterized by postural tachycardia in combination with orthostatic symptoms without associated hypotension. Symptoms include light-headedness, palpitations, fatigue, confusion, and anxiety, which are brought on by assuming the upright position and usually relieved by sitting or lying down. Given the associated autonomic dysfunction that occurs with POTS, various perioperative concerns must be considered when providing anesthetic care for such patients. We present an adolescent with POTS who required anesthetic care during posterior spinal fusion for the treatment of scoliosis. The potential perioperative implications of this syndrome are discussed.

Automatic QRS complex detection algorithm designed for a novel wearable, wireless electrocardiogram recording device

DEFF Research Database (Denmark)

Saadi, Dorthe Bodholt; Egstrup, Kenneth; Branebjerg, Jens

2012-01-01

We have designed and optimized an automatic QRS complex detection algorithm for electrocardiogram (ECG) signals recorded with the DELTA ePatch platform. The algorithm is able to automatically switch between single-channel and multi-channel analysis mode. This preliminary study includes data from ...

Surgical ablation of ventricular tachycardia secondary to congenital ventricular septal aneurysm.

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Graffigna, A; Minzioni, G; Ressia, L; Vigano, M

1994-04-01

Three patients underwent surgical ablation for ventricular tachycardia resulting from an aneurysm of the membranous portion of the ventricular septum. Two patients had a definite history of cardiac murmur during infancy, and one of them was found at the time of operation to have a left-to-right shunt through the apex of the aneurysm. The earliest ventricular activation sites were located around the neck of the aneurysm and were ablated in 1 patient by encircling the endocardial ventriculotomy and by cryoablation in the remaining 2. After focus resection had been completed, aneurysm resection and ventricular septal reconstruction were performed. All patients were alive and free of ventricular tachycardia and did not need medication as of 61, 66, and 88 months postoperatively. Spontaneous closure of a ventricular septal defect may lead to the formation of an aneurysm in the ventricular septum that may sustain ventricular tachycardias. Such arrhythmias can be effectively treated using electrically guided surgical techniques.

Resolution of Postural Orthostatic Tachycardia Syndrome After CT-Guided, Percutaneous T2 Ethanol Ablation for Hyperhidrosis

Energy Technology Data Exchange (ETDEWEB)

Brock, Malcolm, E-mail: mabrock@jhmni.edu [Johns Hopkins University, Department of Thoracic Surgery, Center for Sweat Disorders (United States); Chung, Tae Hwan, E-mail: Tchang7@jhmi.edu [Johns Hopkins University, Physical Medicine and Rehabilitation (United States); Gaddam, Sathvika Reddy, E-mail: drsathvikareddy@yahoo.com; Kathait, Anjaneya Singh, E-mail: askathait@gmail.com [Johns Hopkins University, Vascular & Interventional Radiology (United States); Ober, Cecily, E-mail: ceober21@gmail.com [Johns Hopkins University, Department of Thoracic Surgery (United States); Georgiades, Christos, E-mail: cgeorgi@jhmi.edu [Johns Hopkins University, Vascular & Interventional Radiology (United States)

2016-12-15

Postural orthostatic tachycardia syndrome is characterized by orthostatic intolerance. Orthostasis (or other mild physical stress) triggers a cascade of inappropriate tachycardia, lightheadedness, palpitations, and often fainting. The underlying defect is sympathetic dysregulation of the heart, which receives its sympathetic tone from the cervical and upper thoracic sympathetic ganglia. Primary hyperhidrosis is also thought to be the result of sympathetic dysregulation. We present the case of a patient treated with CT-guided, percutaneous T2 EtOH sympatholysis for craniofacial hyperhidrosis. The patient also suffered from postural orthostatic tachycardia syndrome for many years and was unresponsive to treatment. Immediately after sympatholysis, the patient experienced resolution of both craniofacial hyperhidrosis and postural orthostatic tachycardia syndrome.

QRS Width as a Predictor of Right Ventricular Remodeling After Percutaneous Pulmonary Valve Implantation.

Science.gov (United States)

Paech, C; Dähnert, I; Riede, F T; Wagner, R; Kister, T; Nieschke, K; Wagner, F; Gebauer, R A

2017-08-01

Recent data showed a right ventricular dyssynchrony in patients with tetralogy of Fallot (TOF). Percutaneous pulmonary valve implantation (PPVI) has become an important procedure to treat a pulmonary stenosis and/or regurgitation of the right ventricular outflow tract in these patients. Despite providing good results, there is still a considerable number of nonresponders to PPVI. The authors speculated that electrical dysfunction of the right ventricle plays an underestimated role in the outcome of patients after PPVI. This study aimed to investigate the influence of right ventricular electrical dysfunction, i.e., right bundle branch block (RBBB) on the RV remodeling after PPVI. The study included consecutive patients after correction of TOF with or without RBBB, who had received a PPVI previously at the Heart Center of the University of Leipzig, Germany during the period from 2012 to 2015. 24 patients were included. Patients without RBBB, i.e., with narrow QRS complexes pre-intervention, had significantly better RV function and had smaller right ventricular volumes. Patients with pre-interventionally QRS width below 150 ms showed a post-interventional remodeling of the right ventricle with the decreasing RV volumes (p = 0.001). The parameters of LV function and volume as well as RV ejection fraction remained unaffected by RBBB. The presented data indicate that the QRS width seems to be a valuable parameter in the prediction of right ventricular remodeling after PPVI, as it represents both electrical and mechanical functions of the right ventricle and may serve as an additional parameter for optimal timing of a PPVI.

Signal averaging technique for noninvasive recording of late potentials in patients with coronary artery disease

Science.gov (United States)

Abboud, S.; Blatt, C. M.; Lown, B.; Graboys, T. B.; Sadeh, D.; Cohen, R. J.

1987-01-01

An advanced non invasive signal averaging technique was used to detect late potentials in two groups of patients: Group A (24 patients) with coronary artery disease (CAD) and without sustained ventricular tachycardia (VT) and Group B (8 patients) with CAD and sustained VT. Recorded analog data were digitized and aligned using a cross correlation function with fast Fourier transform schema, averaged and band pass filtered between 60 and 200 Hz with a non-recursive digital filter. Averaged filtered waveforms were analyzed by computer program for 3 parameters: (1) filtered QRS (fQRS) duration (2) interval between the peak of the R wave peak and the end of fQRS (R-LP) (3) RMS value of last 40 msec of fQRS (RMS). Significant change was found between Groups A and B in fQRS (101 -/+ 13 msec vs 123 -/+ 15 msec; p < .0005) and in R-LP vs 52 -/+ 11 msec vs 71-/+18 msec, p <.002). We conclude that (1) the use of a cross correlation triggering method and non-recursive digital filter enables a reliable recording of late potentials from the body surface; (2) fQRS and R-LP durations are sensitive indicators of CAD patients susceptible to VT.

Successful Ablation for Atrial Tachycardia Originated from Sinus Venosa with Tachycardia-Induced Cardiomyopathy

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Sou Takenaka

2016-01-01

Full Text Available A 74-year-old male suffering from congestive heart failure with atrial tachycardia (AT with 2 : 1 atrioventricular conduction was admitted to our hospital. After the therapy with diuretics and β-blocker, his rapid AT was still sustained. He took the catheter ablation for his AT. Postpacing interval mapping from entrainment and noncontact mapping system revealed the mechanism of his AT, originated from sinus venosa. His AT was successfully terminated and eliminated by radiofrequency catheter ablation. After the successful ablation, he has been free from any AT, and his cardiac function was also improved.

Torsades de Pointes

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Richard J Chen, MD

2018-04-01

Full Text Available History of present illness: 70-year-old male with a history ventricular arrhythmia, AICD (automated implantable cardioverter defibrillator, coronary artery disease and cardiac stents presented to the Emergency Department after three AICD discharges with dyspnea but no chest pain. During triage, he was found to have an irregular radial pulse and was placed on a cardiac monitor. Significant findings: The patient was found to be in a polymorphic ventricular tachycardia; he was alert, awake and asymptomatic. A rhythm strip showed a wide complex tachycardia with the QRS complex varying in amplitude around the isoelectric line consistent with Torsades de Pointes. Discussion: Torsades de Pointes (TdP is a specific type of polymorphic ventricular tachycardia. The arrhythmia’s characteristic morphology consists of the QRS complex “twisting” around the isoelectric line with gradual variation of the amplitude, reflecting its literal translation of “twisting of the points.”1 This arrhythmia occurs in the context of prolonged QT. The most common form of acquired QT prolongation is medication induced. Common causes include antiarrhythmics, antipsychotics, antiemetics, and antibiotics.2 Patient specific risk factors include female sex, bradycardia, hypokalemia, hypomagnesemia, hypocalcemia, hypothermia and heart disease.3 In the setting of prolonged QT, the repolarization phase is extended. TdP is initiated when a PVC (premature ventricular contraction occurs during this repolarization, known as an ‘R on T’ phenomenon. TdP is often asymptomatic and self-limited. The danger in TdP is its potential to deteriorate into ventricular fibrillation. A mainstay of management of TdP is prevention of risk factors when possible.4 Unstable patients should be treated with synchronized cardioversion. Magnesium sulfate should be administered in all cases of TdP.1 If a patient is not responsive to magnesium, consider isoproterenol, amiodarone, and overdrive

A 410-nW Efficient QRS Processor for Mobile ECG Monitoring in 0.18-μm CMOS.

Science.gov (United States)

Li, Peng; Zhang, Xu; Liu, Ming; Hu, Xiaohui; Pang, Bo; Yao, Zhaolin; Jiang, Hanjun; Chen, Hongda

2017-12-01

This paper proposes a low power and efficient QRS processor for real-time and continuous mobile ECG monitoring. The QRS detector contains the wavelet transform (WT), the modulus maxima pair identification (MMPI), and the R position modification (RPM). In order to reduce power consumption, we choose the Haar function as the mother wavelet of WT. It is implemented by an optimized FIR filter structure where none of the multiplier is used. The MMPI processes the wavelet coefficients at scale 2 4 and provides candidate R peak positions for the RPM. To improve the accuracy and robust performance, a number of modules have been designed in MMPI, including the preprocessing unit, the automatic threshold updating, and the decision state machine. The RPM is designed to eliminate digital time delay in wavelet transform and locate the R peak position precisely. Raw ECG signals and QRS detection results are output simultaneously. Fabricated in 0.18-μm N-well CMOS 1P6M technology, the power consumption of this chip is only about 410 nW in 1 V voltage supply. Validated by all 48 sets of data in the MIT-BIH arrhythmia database, the sensitive and the positive prediction are 99.60% and 99.77% respectively.

Effect of study design on the reported effect of cardiac resynchronization therapy (CRT) on quantitative physiological measures: stratified meta-analysis in narrow-QRS heart failure and implications for planning future studies.

Science.gov (United States)

Jabbour, Richard J; Shun-Shin, Matthew J; Finegold, Judith A; Afzal Sohaib, S M; Cook, Christopher; Nijjer, Sukhjinder S; Whinnett, Zachary I; Manisty, Charlotte H; Brugada, Josep; Francis, Darrel P

2015-01-06

Biventricular pacing (CRT) shows clear benefits in heart failure with wide QRS, but results in narrow QRS have appeared conflicting. We tested the hypothesis that study design might have influenced findings. We identified all reports of CRT-P/D therapy in subjects with narrow QRS reporting effects on continuous physiological variables. Twelve studies (2074 patients) met these criteria. Studies were stratified by presence of bias-resistance steps: the presence of a randomized control arm over a single arm, and blinded outcome measurement. Change in each endpoint was quantified using a standardized effect size (Cohen's d). We conducted separate meta-analyses for each variable in turn, stratified by trial quality. In non-randomized, non-blinded studies, the majority of variables (10 of 12, 83%) showed significant improvement, ranging from a standardized mean effect size of +1.57 (95%CI +0.43 to +2.7) for ejection fraction to +2.87 (+1.78 to +3.95) for NYHA class. In the randomized, non-blinded study, only 3 out of 6 variables (50%) showed improvement. For the randomized blinded studies, 0 out of 9 variables (0%) showed benefit, ranging from -0.04 (-0.31 to +0.22) for ejection fraction to -0.1 (-0.73 to +0.53) for 6-minute walk test. Differences in degrees of resistance to bias, rather than choice of endpoint, explain the variation between studies of CRT in narrow-QRS heart failure addressing physiological variables. When bias-resistance features are implemented, it becomes clear that these patients do not improve in any tested physiological variable. Guidance from studies without careful planning to resist bias may be far less useful than commonly perceived. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Prognostic significance of nonsustained ventricular tachycardia after revascularization.

Science.gov (United States)

Mittal, Suneet; Lomnitz, David J; Mirchandani, Sunil; Stein, Kenneth M; Markowitz, Steven M; Slotwiner, David J; Iwai, Sei; Das, Mithilesh K; Lerman, Bruce B

2002-04-01

Two randomized trials (Multicenter Automatic Defibrillator Implantation Trial [MADIT] and Multicenter Unsustained Tachycardia Trial [MUSTT]) suggest that implantable cardioverter defibrillator (ICD) placement is associated with improved survival in patients with coronary artery disease, depressed left ventricular function, and nonsustained ventricular tachycardia (VT) who also have inducible sustained VT. However, neither study directly addresses the management of such patients who develop nonsustained VT early after revascularization. We evaluated 109 consecutive patients who underwent electrophysiologic testing to evaluate nonsustained VT, which occurred 5 +/- 4 days following revascularization. Sustained monomorphic VT was inducible in 46 (42%) patients; these patients received an ICD. The remaining 63 (58%) noninducible patients received neither antiarrhythmic drug therapy nor an ICD. During 27 +/- 12 months of follow-up, 15 (33%) of 45 patients with an implanted ICD received at least one appropriate therapy from the device and 26 (24%) of the 109 study patients died. The 1- and 2-year freedom from ventricular tachycardia/fibrillation or sudden death in noninducible patients (97% and 93%) was significantly greater than that of inducible patients (84% and 71%; P = 0.001). However, no difference was observed in total mortality. Patients with nonsustained VT during the early postrevascularization period who have inducible VT have a high incidence of arrhythmic events. Although this study was not designed to assess the impact of ICD placement on the total mortality of inducible patients, the finding that one third of these patients received appropriate ICD therapy suggests that the device may have a protective effect in these patients.

A multi-step method with signal quality assessment and fine-tuning procedure to locate maternal and fetal QRS complexes from abdominal ECG recordings

International Nuclear Information System (INIS)

Liu, Chengyu; Li, Peng; Zhao, Lina; Di Maria, Costanzo; Zhang, Henggui; Chen, Zhiqing

2014-01-01

Non-invasive monitoring of fetal electrocardiogram (fECG) plays an important role in detecting and diagnosing fetal diseases. This study aimed to develop a multi-step method for locating both maternal and fetal QRS complexes from abdominal ECG (aECG) recordings. The proposed method included four major steps: abdominal ECG pre-processing, maternal QRS complex locating, maternal ECG cancellation and fetal QRS complex locating. Signal quality assessment (SQA) and fine-tuning for maternal ECG (FTM) were implemented in the first and third steps, respectively. The method was then evaluated using 75 non-invasive 4-channel aECG recordings provided by the PhysioNet/Computing in Cardiology Challenge 2013. The F 1 measure, which is a new index introduced by Behar et al (2013 Proc. Comput. Cardiol. 40 297–300), was used to assess the locating accuracy. The other two indices, mean squared error of heart rate (MSE H R) between the fetal HR signals estimated from the reference and our method (MSE H R in bpm 2 ) and root mean squared difference between the corresponding fetal RR intervals (MSE R R in ms) were also used to assess the locating accuracy. Overall, for the maternal QRS complex, the F 1 measure was 98.4% from the method without the implementation of SQA, and it was improved to 99.8% with SQA. For the fetal QRS complex, the F 1 measure, MSE H R and MSE R R were 84.9%, 185.6 bpm 2 and 19.4 ms for the method without both SQA and FTM procedures. They were improved to 93.9%, 47.5 bpm 2 and 7.6 ms with both SQA and FTM procedures. These improvements were observed from each individual subject. It can be concluded that implementing both SQA and FTM procedures could achieve better performance for locating both maternal and fetal QRS complexes. (paper)

A Case of Multiple Cardiovascular and Tracheal Anomalies Presented with Wolff-Parkinson-White Syndrome in a Middle-aged Adult.

Science.gov (United States)

Shi, Hyejin; Sohn, Sungmin; Wang, SungHo; Park, Sungrock; Lee, SangKi; Kim, Song Yi; Jeong, Sun Young; Kim, Changhwan

2017-12-01

Congenital cardiovascular anomalies, such as dextrocardia, persistent left superior vena cava (SVC), and pulmonary artery (PA) sling, are rare disorders. These congenital anomalies can occur alone, or coincide with other congenital malformations. In the majority of cases, congenital anomalies are detected early in life by certain signs and symptoms. A 56-year-old man with no previous medical history was admitted due to recurrent wide QRS complex tachycardia with hemodynamic collapse. A chest radiograph showed dextrocardia. After synchronized cardioversion, an electrocardiogram revealed Wolff-Parkinson-White (WPW) syndrome. Persistent left SVC, PA sling, and right tracheal bronchus were also detected by a chest computed tomography (CT) scan. He was diagnosed with paroxysmal supraventricular tachycardia (PSVT) associated with WPW syndrome, and underwent radiofrequency ablation. We reported the first case of situs solitus dextrocardia coexisting with persistent left SVC, PA sling and right tracheal bronchus presented with WPW and PSVT in a middle-aged adult. In patients with a cardiovascular anomaly, clinicians should consider thorough evaluation of possibly combined cardiovascular and airway malformations and cardiac dysrhythmia. © 2017 The Korean Academy of Medical Sciences.

Supraventricular Tachycardia Atackt Due to Losewieght Drug

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Murat Yalcin

2016-01-01

Full Text Available Obesity is an important health problem. Treatment of obesity includes diet, exercise and drugs. Some of these drugs are out of prescription. Advers effects of these drugs have not been known. In this report; we present a case with supraventricular tachycardia attack due to loseweight drug containing mangostana (mango, hibiscus, citrus mate, L-karnitin, guarana.

Cardiac Rehabilitation Improves the QRS Fragmentation in Patients With ST Elevatıon Myocardial Infarction

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Mustafa Bulut

2015-09-01

Conclusion: The existence of the fQRS decreases after CR in patients with STEMI especially in hypertensive individuals, which may be related to improved electrical stability in the myocardium as a predictor of increase in survival and decrease in major cardiac events.

Electrocardiogram artifact caused by rigors mimicking narrow complex tachycardia: a case report.

Science.gov (United States)

Matthias, Anne Thushara; Indrakumar, Jegarajah

2014-02-04

The electrocardiogram (ECG) is useful in the diagnosis of cardiac and non-cardiac conditions. Rigors due to shivering can cause electrocardiogram artifacts mimicking various cardiac rhythm abnormalities. We describe an 80-year-old Sri Lankan man with an abnormal electrocardiogram mimicking narrow complex tachycardia during the immediate post-operative period. Electrocardiogram changes caused by muscle tremor during rigors could mimic a narrow complex tachycardia. Identification of muscle tremor as a cause of electrocardiogram artifact can avoid unnecessary pharmacological and non-pharmacological intervention to prevent arrhythmias.

Junctional ectopic tachycardia following repair of congenital heart ...

African Journals Online (AJOL)

Background: Postoperative junctional ectopic tachycardia (JET) is a rare and transient phenomenon occurring after repair of congenital heart defects. Report on this arrhythmia in the subregion is rare. We set out to determine the incidence of this arrhythmia and review the treatment and outcomes of treatment in our centre.

Surgical correction of mitral valve prolapse : a cure for recurrent ventricular tachycardia in Marfan syndrome?

Science.gov (United States)

Beroukhim, Rebecca S; Reed, John H; Schaffer, Michael S; Yetman, Anji T

2006-01-01

We describe the case of a 3-year-old child with neonatal Marfan syndrome complicated by mitral valve prolapse with regurgitation, marked aortic root dilatation, and ventricular tachycardia. The patient had resolution of ventricular tachycardia following surgical intervention consisting of a valve-sparing aortic root replacement and mitral valve annuloplasty.

Left cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia

NARCIS (Netherlands)

Wilde, Arthur A. M.; Bhuiyan, Zahurul A.; Crotti, Lia; Facchini, Mario; de Ferrari, Gaetano M.; Paul, Thomas; Ferrandi, Chiara; Koolbergen, Dave R.; Odero, Attilio; Schwartz, Peter J.

2008-01-01

Catecholaminergic polymorphic ventricular tachycardia is a potentially lethal disease characterized by adrenergically mediated ventricular arrhythmias manifested especially in children and teenagers. Beta-blockers are the cornerstone of therapy, but some patients do not have a complete response to

Wolff-Parkinson-White Syndrome: Electrocardiogram

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Brianna Miner

2016-09-01

Full Text Available History of present illness: A 26-year-old male with no significant past medical history presented to the emergency department with palpitations. The patient experienced these symptoms five times before in his life, but they had self-resolved with squatting or raising his arms. He denied chest pain, shortness of breath, dizziness, syncope, or pre-syncope symptoms. He denied any recent illnesses, cough, chest pain, drug use, or infections. Significant findings: The initial EKG showed wide complex, irregular tachycardia > 200 bpm (EKG 1. Given the possibility of Wolff-Parkinson-White (WPW, procainamide was given to the patient. The patient’s heart rate responded and decreased to 120-140 bpm with narrowing of the QRS complex. A repeat EKG showed narrow complex tachycardia without P waves approximately 120 bpm (EKG 2. Once the procainamide infusion was complete, the patient had converted to sinus rhythm with a delta wave now apparent, consistent with WPW (EKG 3. Discussion: Wolff-Parkinson-White syndrome is a combination of the presence of a certain congenital accessory pathway (Bundle of Kent and episodes of tachyarrhythmia.1 The incidence is less than one percent of the general population,2 but it is associated with the risk of sudden cardiac death, making the diagnosis imperative. When examining a wide-based tachycardia, it is important to consider WPW when choosing medications for rate control or chemical cardioversion. The first EKG shows an example of atrial fibrillation with WPW. While procainamide blocks the accessory pathway, other drugs such as beta blockers and calcium channel blockers can inhibit the AV node resulting in increased use of the accessory pathway. This can worsen the tachyarrhythmia and potentially lead to ventricular fibrillation, ventricular tachycardia, or asystole.

Phase analysis of gated blood pool SPECT for multiple stress testing assessments of ventricular mechanical dyssynchrony in a tachycardia-induced dilated cardiomyopathy canine model.

Science.gov (United States)

Salimian, Samaneh; Thibault, Bernard; Finnerty, Vincent; Grégoire, Jean; Harel, François

2017-02-01

Stress-induced dyssynchrony has been shown to be independently correlated with clinical outcomes in patients with dilated cardiomyopathy (DCM) and narrow QRS complexes. However, the extent to which stress levels affect inter- and intraventricular dyssynchrony parameters remains unknown. Ten large dogs were submitted to tachycardia-induced DCM by pacing the right ventricular apex for 3-4 weeks to reach a target ejection fraction (EF) of 35% or less. Stress was then induced in DCM dogs by administering intravenous dobutamine up to a maximum of 20 μg·kg -1 ·min -1 . Hemodynamic and ventricular dyssynchrony data were analyzed by left ventricular (LV) pressure measurements and gated blood pool SPECT (GBPS) imaging. In order to assess mechanical dyssynchrony in DCM subjects and compare it with that of 8 normal counterparts, we extracted the following data: count-based indices of LV contraction homogeneity index (CHI), entropy and phase standard deviation, and interventricular dyssynchrony index. A significant LV intraventricular dyssynchrony (CHI: 96.4 ± 1.3% in control vs 78.6% ± 10.9% in DCM subjects) resulted in an intense LV dysfunction in DCM subjects (EF: 49.5% ± 8.4% in control vs 22.6% ± 6.0% in DCM), compared to control subjects. However, interventricular dyssynchrony did not vary significantly between the two groups. Under stress, DCM subjects showed a significant improvement in ventricular functional parameters at each level (EF: 22.6% ± 6.0% at rest vs 48.1% ± 5.8% at maximum stress). All intraventricular dyssynchrony indices showed a significant increase in magnitude of synchrony from baseline to stress levels of greater than or equal to 5 μg·kg -1 ·min -1 dobutamine. There were individual differences in the magnitude and pattern of change in interventricular dyssynchrony during the various levels of stress. Based on GBPS analyses, different levels of functional stress, even in close intervals, can have a significant impact on

Left ventricular outflow tract arrhythmias with divergent QRS morphology: mapping of different exits and ablation strategy.

Science.gov (United States)

Reithmann, Christopher; Fiek, Michael

2018-01-01

Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) can have multiple exits exhibiting divergent ECG features. In a series of 131 patients with VAs with LVOT origin, 10 patients presented with divergent QRS morphologies. Multisite endo- and epicardial mapping of different exit sites was performed. The earliest ventricular activity of 23 LVOT VAs in 10 patients was detected in the endocardium of the LV in 7 patients, the aortic sinuses of Valsalva (SoV) in 3 patients, the distal coronary sinus in 6 patients, the anterior interventricular vein in 3 patients, and the posterior right ventricular outflow tract (RVOT) in 4 patients. Simultaneous elimination of two divergent QRS morphologies of LVOT VAs by ablation from a single site was achieved in 5 patients (aorto-mitral continuity in 3 patients, SoV and RVOT in each 1 patient) using a mean maximum ablation energy of 46 ± 5 W. Sequential ablation from two or three different sites, including trans-pericardial and distal coronary sinus ablation in each 2 patients, led to elimination of the divergent VA QRS morphologies in the other 5 patients. During the follow-up of 28 ± 29 months, 4 of the 10 patients had recurrence of at least one LVOT VA. A 43-year-old patient with muscular dystrophy Curschmann-Steinert had recurrence of sustained LVOT VTs and died of sudden cardiac death. Multisite mapping of different exit sites of LVOT VAs can guide ablation of intramural foci but the recurrence rate after initially successful ablation was high.

Role of ventricular tachycardia ablation in arrhythmogenic right ventricular cardiomyopathy

Directory of Open Access Journals (Sweden)

Alberto Cipriani

2017-11-01

Full Text Available Arrhythmogenic right ventricular cardiomyopathy (ARVC is characterized by progressive fibro-fatty replacement of the myocardium that represents the substrate for recurrent sustained ventricular tachycardia (VT. These arrhythmias characterize the clinical course of a sizeable proportion of patients and have significant implications for their quality of life and long-term prognosis. Antiarrhythmic drugs are often poorly tolerated and usually provide incomplete control of arrhythmia relapses. Catheter ablation is a potentially effective strategy to treat frequent VT episodes and ICD shocks in ARVC patients. The aims of this review are to discuss the electrophysiological and electroanatomic substrates of ventricular tachycardia in patients with ARVC and to analyze the role of catheter ablation in their management with particular reference to selection of patients, technical issues, potential complications and outcomes.

Atriofascicular Mahaim with Ebstein anomaly: A case report

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Kazushi Ueshima, MD

2017-10-01

Full Text Available We report a case of a 7-year-old girl with atriofascicular Mahaim (AFM pathway concomitant with Ebstein's anomaly. The QRS wave showed left bundle branch block pattern on electrocardiogram. Holter electrocardiogram showed prolongation of the PR interval and QRS morphological change during sinus tachycardia. An electrophysiological study demonstrated that the distal His potential appeared earlier than the proximal His potential, which suggested retrograde His conduction toward the atrioventricular node. Conduction from the Mahaim fiber to the His bundle was faster than that from the atrioventricular node towards the His bundle. The findings of this important case allowed a differential diagnosis between AFM and Wolff-Parkinson-White (WPW syndrome.

Effect of newly synthesized compounds 44Bu and 444 on QRS -complex width and fast sodium current

Czech Academy of Sciences Publication Activity Database

Kilianová, A.; Bébarová, M.; Beránková, K.; Opatřilová, R.; Pásek, Michal; Bartošová, L.

2010-01-01

Roč. 79, č. 1 (2010), s. 41-49 ISSN 0001-7213 Institutional research plan: CEZ:AV0Z20760514 Keywords : 444 * 44Bu * QRS-complex * sodium current * rat Subject RIV: BO - Biophysics Impact factor: 0.534, year: 2010

Sick sinus syndrome, progressive cardiac conduction disease, atrial flutter and ventricular tachycardia caused by a novel SCN5A mutation

DEFF Research Database (Denmark)

Holst, Anders G; Liang, Bo; Jespersen, Thomas

2010-01-01

father carried the same mutation, but had a milder phenotype, presenting with progressive cardiac conduction later in life. The mutation was found to result in a loss-of-function in the sodium current. In conclusion, the same SCN5A mutation can result in a wide array of clinical phenotypes and perhaps......Mutations in the cardiac sodium channel encoded by the gene SCN5A can result in a wide array of phenotypes. We report a case of a young male with a novel SCN5A mutation (R121W) afflicted by sick sinus syndrome, progressive cardiac conduction disorder, atrial flutter and ventricular tachycardia. His...

Shortening of ventriculoatrial interval after ablation of an accessory pathway

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Mohammad Alasti

2006-10-01

Full Text Available A 21-year old man with history of 8 year palpitation was referred for electrophysiologic study and possible radiofrequency ablation. Physical examination and transthoracic echocardiographic study did not disclose any abnormality. Baseline ECG showed normal sinus rhythm with normal PR and QRS intervals and no evidence of preexcitation. Antiarrhythmic drugs (propranolol and verapamil were discontinued two days before the procedure. Baseline intervals in sinus rhythm were as follows: sinus cycle length=690 msec, AH=74 msec, HV=37 msec, QRS=90 msec, PR=133 msec. The minimal pacing cycle length maintaining 1:1 antegrade conduction (AVWP was 320 msec and the minimal pacing cycle length maintaining 1:1 retrograde conduction (VAWP was 400 msec. Single extrastimulus testing in the right atrium and the right ventricular apex leaded to a sustained narrow complex tachycardia. The arrhythmia was a short PR- long RP tachycardia with following characteristics: cycle length=376 msec, AH=141 msec, HV=42 msec, VA=200 msec, HA (HRA =236 msec, HA (His =243 msec and eccentric atrial activation during the arrhythmia (Figure 1. The arrhythmia was easily reproducible with stable hemodynamic.

Efficacy of dexmedetomidine for the control of junctional ectopic tachycardia after repair of tetralogy of Fallot

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Randhir S Rajput

2014-01-01

Full Text Available Background: Junctional ectopic tachycardia occurs frequently after congenital cardiac surgery and can be a cause of increased morbidity and mortality. Dexmedetomidine (DEX is an a2 adrenoreceptor agonist, has properties of controlling tachyarrhythmia by regulating the sympatho-adrenal system. Objective: To evaluate the efficacy of DEX for control of junctional ectopic tachycardia after repair of Tetralogy of Fallot (TOF. Materials and Methods: Two hundred and twenty pediatric cardiac patients with TOFs were enrolled in a prospective randomized control study. Patients underwent correction surgery. They were divided into two groups, i.e., Group 1 (DEX and Group 2 (control. Heart rate, rhythm, mean arterial pressure (MAP were recorded after the anesthetic induction (T1, after termination of bypass (T2, after 04 hours (T3, and 08 hours after transferring the patient to intensive care unit (ICU; T4. Results: Heart rate was comparable between two groups before starting the drug but statistically significant after bypass until 08 hours after transferring the patient to ICU. Junctional ectopic tachycardia occurred more in Group-2 (20% as compared to Group-1 (9.09%; P = 0.022. Junctional ectopic tachycardia occurs early in Group-2 (0.14 ± 0.527 hours as compared to Group 1 (0.31 ± 1.29 hours; P = 0.042. The duration of junctional ectopic tachycardia was more prolonged in Group-2 (1.63 ± 3.64 hours as compared to Group-1 (0.382 ± 1.60 hours; P = 0.012. The time to withdraw from mechanical ventilation and ICU stay of Group 1 patient was less than of Group 2 patients (P = <0.001. Conclusion: DEX had a therapeutic role in the prevention of junctional ectopic tachycardia in patients undergoing repair for TOF.

Cryoablation of focal tachycardia originating from the right atrial free wall during upstream phrenic pacing to avoid phrenic nerve injury.

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Johnsrude, Christopher

2015-01-01

Recognition of the potential for phrenic nerve injury (PNI) often prompts less aggressive attempts at catheter ablation of multiple forms of tachycardia or abandoning ablation altogether. Some novel techniques to avoid PNI during catheter ablation have been described. Five patients (age: 13-57 years, three females) with ectopic atrial tachycardia originating from the right atrial free wall (RAFW) near the phrenic nerve underwent electrophysiology study with three-dimensional mapping and endocardial cryoablation. Upstream phrenic pacing was performed after cryoadherence was achieved, and cryoablation of ectopic foci was performed during close observation for occurrence of PNI and tachycardia elimination. Cryoablation acutely eliminated five of six atrial tachycardias originating close to the phrenic nerve. Transient PNI during cryothermy occurred in two patients, and resolved within 3 minutes. Patients were observed overnight on telemetry, with no early recurrences of targeted atrial tachycardias and no evidence of PNI. At last follow-up of 1-39 months, four patients were arrhythmia free on no medications. Catheter cryoablation during simultaneous upstream phrenic nerve pacing can lead to safe and effective elimination of focal atrial tachycardias originating from the RAFW close to the phrenic nerve. ©2014 Wiley Periodicals, Inc.

Radiation exposure to patients and operator during radiofrequency ablation for supraventricular tachycardia

International Nuclear Information System (INIS)

Kovoor, P.; Ricciardello, M.; Collins, L.; Uther, J.B.; Ross, D.L.

1995-01-01

Radiofrequency (RF) ablation has become the primary method of treatment for supraventricular tachycardia and often requires prolonged fluoroscopy times. The aim of this study was to quantitate radiation exposure to patient and operator during RF ablation for supra- ventricular tachycardia. Thermoluminescent dosemeters were used to monitor radiation at seven sites. Positions were: patient's thyroid, left scapula, T9 vertebra, right scapula and L4-L5 vertebra and the operator's thyroid and left hand. Monitoring was performed during 22 procedures. Of the patients studied 10 (45%) had atrioventricular junctional re-entry tachycardia (AVJRT) and 12 (55%) had accessory pathway tachycardia. The median fluoroscopy times (minutes) and inter-quartile ranges were 46 (39-65) for AVJRT, 55 (52-60) for left free wall accessory pathway (LFW), 107 (89-140) for septal and 166 (128-176) for RFW pathways. The mean radiation doses (mGy) to the chest wall were 50 for AVJRT, 47 for LFW, 87 for septal and 151 for RFW pathways. The mean radiation to the chest wall of the patient per case was found to be 3.9 times that reported for diagnostic cardiac catheterisation and 1.5 times that reported for angioplasty. It is concluded that radiofrequency ablation is associated with significant irradiation of the patient and operator. All precautions should be taken to decrease this exposure. If eye irradiation is assumed to be equal to that to the thyroid, more than 45 procedures per month by a single operator (using ceiling-suspended lead glass shielding) may result in exceeding the recommended dose limit to the eye. 32 refs., 3 tabs

Financial audit of antitachycardia pacing for the control of recurrent supraventricular tachycardia.

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Griffith, M J; Bexton, R S; McComb, J M

1993-03-01

To assess the financial implications of antitachycardia pacing in patients with frequent supraventricular tachycardia. Intertach pacemakers were implanted in 25 patients (mean age 47 years, five men): 22 had atrioventricular nodal reentry tachycardia. The patients had failed a mean of 4.9 (range zero to eight) drugs and had been admitted to hospital 3.7 (zero to 31) times over a symptomatic period of 13.9 years (two months to 54 years). The mean admission time for implantation was 2.8 (two to seven) days. One patient with Wolff-Parkinson-White syndrome subsequently underwent surgery. Infection occurred in two patients, and pain over the pacemaker required its resiting in two. Two patients have had one admission each for tachycardia. Six patients remain on anti-arrhythmic drugs. Costs were calculated including value added tax, capital charges, and allocated overheads. The cost a year before pacing was 1174 pounds including drug costs, clinic visits, and hospital admissions. The mean cost of pacemaker implantation was 3364.22 pounds, including the pacemaker and lead, admission and procedure, readmissions and first pacing check. Subsequent annual follow up cost was 73.72 pounds including annual clinic visits and drug costs. The cost of pacing is 4241 pounds whereas medical management costs 7044 pounds assuming pacemaker life of six years: with a 10 year life the cost is 4537 pounds compared with 11,740 pounds: with a 12 year life the cost is 4685 pounds compared with 14,088 pounds. The excess cost of implantation of an antitachycardia pacemaker is minimal in patients with frequent supraventricular tachycardia despite drug treatment and is justified by excellent control of symptoms and reduction of drug use and hospital admissions.

The radio frequency catheter ablation of inter-fascicular reentrant tachycardia: new insights into the electrophysiological and anatomical characteristics

NARCIS (Netherlands)

Okishige, Kaoru; Sakurada, Harumizu; Mizusawa, Yuka; Yamauchi, Yasuteru; Fukamizu, Seiji; Aoyagi, Hideshi; Okano, Yoshifumi; Azegami, Koji; Sasano, Tetsuo; Hirao, Kenzo

2014-01-01

Macro-reentrant ventricular tachycardias (VT) utilizing the bundle branches and Purkinje fibers have been reported as verapamil sensitive VT (idiopathic left VT), bundle branch reentrant VT (BBRT) and inter-fascicular reentrant tachycardia (inter-fascicular VT). However, diagnostic confusion exists

Dose-related ethanol intake, Cx43 and Nav1.5 remodeling: Exploring insights of altered ventricular conduction and QRS fragmentation in excessive alcohol users.

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Hung, Chung-Lieh; Lai, Yu-Jun; Chi, Po-Ching; Chen, Liang-Chia; Tseng, Ya-Ming; Kuo, Jen-Yuan; Lin, Cheng-I; Chen, Yao-Chang; Lin, Shing-Jong; Yeh, Hung-I

2018-01-01

Chronic, excessive ethanol intake has been linked with various electrical instabilities, conduction disturbances, and even sudden cardiac death, but the underlying cause for the latter is insufficiently delineated. We studied surface electrocardiography (ECG) in a community-dwelling cohort with moderate-to-heavy daily alcohol intake (grouped as >90g/day, ≤90g/day, and nonintake). Compared with nonintake, heavier alcohol users showed markedly widened QRS duration and higher prevalence of QRS fragmentation (64.3%, 50.9%, and 33.7%, respectively, χ 2 12.0, both pchronically given a 4% or 6% alcohol diet and showed dose-related slower action potential upstroke, reduced resting membrane potential, and disorganized or decreased intraventricular conduction (all pChronic excessive alcohol ingestion is associated with dose-related phenotypic intraventricular conduction disturbances and QRS fragmentation that can be recapitulated in mice. The mechanisms may involve suppressed gap junction and sodium channel functions, together with enhanced cardiac fibrosis that may contribute to arrhythmogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

V–V delay interval optimization in CRT using echocardiography compared to QRS width in surface ECG

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Amr Nawar

2012-09-01

Conclusion: Significant correlation appeared to exist during optimization of CRT between VV programming based on the shortest QRS interval at 12-lead ECG pacing and that based on highest LVOT VTI by echocardiography. A combined ECG and echocardiographic approach could be a more convenient solution in performing V–V optimization.

Tachydysrhythmia treatment and adverse events in patients with wolff-Parkinson-white syndrome.

Science.gov (United States)

Siegelman, Jeffrey N; Marill, Keith A; Adler, Jonathan N

2014-09-01

Current guidelines recommend avoiding atrioventricular-nodal blocking agents (AVNB) when treating tachydysrhythmias in Wolff-Parkinson-White syndrome (WPW) patients. We investigated medications selected and resulting outcomes for patients with tachydysrhythmias and WPW. In this single-center retrospective cohort study, we searched a hospital-wide database for the following inclusion criteria: WPW, tachycardia, and intravenous antidysrhythmics. The composite outcome of adverse events was acceleration of tachycardia, new hypotension, new malignant dysrhythmia, and cardioversion. The difference in binomial proportions of patients meeting the composite outcome after AVNB or non-AVNB (NAVNB) treatment was calculated after dividing the groups by QRS duration. A random-effects mixed linear analysis was performed to analyze the vital sign response. The initial database search yielded 1158 patient visits, with 60 meeting inclusion criteria. Patients' median age was 52.5 years; 53% were male, 43% presented in wide complex tachycardia (WCT), with 75% in atrial fibrillation (AF) or flutter. AVNBs were administered in 42 (70%) patient visits. For those patients with WCT in AF, the difference in proportions of patients meeting the composite outcome after AVNBs vs. NAVNBs treatment was an increase of 3% (95% confidence interval [CI] -39%-49%), and for those with narrow complex AF it was a decrease of 13% (95% CI -37%-81%). No instances of malignant dysrhythmia occurred. Mixed linear analysis showed no statistically significant effects on heart rate, though suggested a trend toward increasing heart rate after AVNB in wide complex AF. In this sample of WPW-associated tachydysrhythmia patients, many were treated with AVNBs. The composite outcome was similarly met after use of either AVNB or NAVNB, and no malignant dysrhythmias were observed. Copyright © 2014 Elsevier Inc. All rights reserved.

[Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease.

DEFF Research Database (Denmark)

Holst, Anders Gaarsdal; Tfelt-Hansen, 1jacob; Olesen, Morten S

2010-01-01

Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease, which can lead to life-threatening ventricular arrhythmias in patients with a structurally normal heart. The age of onset is usually between two and 12 years and the initial symptom is frequently syncope...

Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration: the Karolinska approach.

Science.gov (United States)

Sartipy, Ulrik; Albåge, Anders; Insulander, Per; Lindblom, Dan

2007-09-01

This article presents a review on the efficacy of surgical ventricular restoration and direct surgery for ventricular tachycardia in patients with left ventricular aneurysm or dilated ischemic cardiomyopathy. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. A practical guide to the pre- and postoperative management of these patients is provided.

Inadvertent puncture of the aortic noncoronary cusp during postoperative left atrial tachycardia ablation

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Dursun Aras, MD

2015-08-01

Full Text Available Transseptal catheterization has become part of the interventional electrophysiologist׳s technical armamentarium since the development of left atrial catheter ablation and percutaneous technologies for treating mitral and aortic valve disease. Although frequently performed, the procedure׳s most feared complication is aortic root penetration. Focal atrial tachycardia has been described as the most common late sequela of surgical valve replacements. We present a complicated case involving the inadvertent delivery of an 8 French sheath across the noncoronary cusp during radiofrequency catheter ablation for left atrial tachycardia originating from the mitral annulus in a patient with prior mitral valve replacement.

Next-generation sequencing of AV nodal reentrant tachycardia patients identifies broad spectrum of variants in ion channel genes

DEFF Research Database (Denmark)

Andreasen, Laura; Ahlberg, Gustav; Tang, Chuyi

2018-01-01

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common form of regular paroxysmal supraventricular tachycardia. This arrhythmia affects women twice as frequently as men, and is often diagnosed in patients <40 years of age. Familial clustering, early onset of symptoms and lack of st...

Analysis of the High-Frequency Content in Human QRS Complexes by the Continuous Wavelet Transform: An Automatized Analysis for the Prediction of Sudden Cardiac Death.

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García Iglesias, Daniel; Roqueñi Gutiérrez, Nieves; De Cos, Francisco Javier; Calvo, David

2018-02-12

Fragmentation and delayed potentials in the QRS signal of patients have been postulated as risk markers for Sudden Cardiac Death (SCD). The analysis of the high-frequency spectral content may be useful for quantification. Forty-two consecutive patients with prior history of SCD or malignant arrhythmias (patients) where compared with 120 healthy individuals (controls). The QRS complexes were extracted with a modified Pan-Tompkins algorithm and processed with the Continuous Wavelet Transform to analyze the high-frequency content (85-130 Hz). Overall, the power of the high-frequency content was higher in patients compared with controls (170.9 vs. 47.3 10³nV²Hz -1 ; p = 0.007), with a prolonged time to reach the maximal power (68.9 vs. 64.8 ms; p = 0.002). An analysis of the signal intensity (instantaneous average of cumulative power), revealed a distinct function between patients and controls. The total intensity was higher in patients compared with controls (137.1 vs. 39 10³nV²Hz -1 s -1 ; p = 0.001) and the time to reach the maximal intensity was also prolonged (88.7 vs. 82.1 ms; p content of the QRS complexes was distinct between patients at risk of SCD and healthy controls. The wavelet transform is an efficient tool for spectral analysis of the QRS complexes that may contribute to stratification of risk.

Adaptación de la forma abreviada del “cuestionario de recursos y estrés (QRS-F, 1983, para padres de personas con autismo / Adaptation of the been brief form of the the

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Soto Calderón, Ronald

2008-04-01

Full Text Available Resumen: Medir el estrés en padres de personas con discapacidad ha sido una tarea muy difícil. En 1974, Holroyd desarrollo el “Cuestionario de recursos y estrés (QRS (de 289 ítemes, para solventar esta necesidad. No obstante, por su longitud y dificultad de análisis psicométrico, se ha dificultado su empleo en diferentes estudios. Friedrich y otros, en 1983, realizaron un estudio de los 289 ítemes del cuestionario QRS y obtuvieron la “Forma abreviada del Cuestionario de Recursos y Estrés (QRS-F”, la cual consta de 52 ítemes representativos de la prueba original. El análisis de factores aplicado tuvo como resultado que emergieran cuatro factores, a saber: Problemas de los padres y la familia, Pesimismo, Características del niño e incapacidad física. En el presente estudio se hizo la adaptación del QRS-F para padres de personas con Autismo en nuestro país.Abstract: To measure stress in parents of people with disability has been a very difficult task. To resolve this necessity, in 1974, Holroyd develop the Questionnaire of Resources and Stress (QRS (of 289 items. However, by its length and difficulty of psychometric analysis, its use in different studies has become difficult. Friedrich and others, in 1983, made a study of the 289 items of the questionnaire QRS and obtained the "been brief Form of the Questionnaire of Resources and Stress (QRS-F", which consists of 52 items representative of the original test. The analysis of factors applied had as result that emerged four factors, that is to say: Problems of the parents and the family, Pessimism, Characteristics of the boy and physical incapacity. In the present study the adaptation was made of the QRS-F for parents of people with Autism in our country.

Differential prognostic importance of QRS duration in heart failure and acute myocardial infarction associated with left ventricular dysfunction

DEFF Research Database (Denmark)

Fosbøl, Emil Loldrup; Seibaek, Marie; Brendorp, Bente

2007-01-01

BACKGROUND/AIMS: Studies of the prognostic importance of QRS duration in patients with heart failure (HF) have shown conflicting results and few studies have estimated the importance after myocardial infarction (MI). METHODS: The Danish Investigations and Arrhythmia ON Dofetilide (DIAMOND) study...

Pseudo ventricular tachycardia: a case report.

LENUS (Irish Health Repository)

Riaz, A

2012-02-01

BACKGROUND: Dramatic artifacts of pseudo flutter have been reported in the past secondary to various factors including tremor (Handwerker and Raptopoulos in N Engl J Med 356:503, 2007) and dialysis machines (Kostis et al. in J Electrocardiol 40(4):316-318, 2007). METHODS: We present this unusual case where the artifact, produced by tremor, was so pronounced to be misdiagnosed and treated as ventricular tachycardia. CONCLUSION: This case highlights the importance of correlating ECG findings with history and clinical examination and of using 12 lead ECGs for rhythm interpretation especially to confirm consistence of arrhythmias in all leads.

Catecholaminergic polymorphic ventricular tachycardia in 2012

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Christian van der Werf

2011-12-01

Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a rare, potentially lethal inherited arrhythmia syndrome characterized by stress or emotion-induced ventricular arrhythmias. CPVT was first described in 1960, while the genetic basis underlying this syndrome was discovered in 2001. The past decade has seen substantial advances in understanding the pathophysiology of CPVT. In addition, significant advances have been made in elucidating clinical characteristics of CPVT patients and new treatment options have become available. Here, we review current literature on CPVT to present state-of-the-art knowledge on the subject of the genetic basis, pathophysiology, clinical presentation, diagnosis, treatment and prognosis.

Ventricular tachycardia in ischemic heart disease substrates

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Olujimi A. Ajijola

2014-01-01

This review will discuss the central role of the ischemic heart disease substrate in the development MMVT. Electrophysiologic characterization of the post-infarct myocardium using bipolar electrogram amplitudes to delineate scar border zones will be reviewed. Functional electrogram determinants of reentrant circuits such as isolated late potentials will be discussed. Strategies for catheter ablation of reentrant ventricular tachycardia, including structural and functional targets will also be examined, as will the role of the epicardial mapping and ablation in the management of recurrent MMVT.

Effect of novel mucoadhesive buccal patches of carvedilol on isoprenaline-induced tachycardia

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Navneet Verma

2014-01-01

Full Text Available The main aim of the study was designed to develop bioadhesive buccal patches of carvedilol (CR and evaluate for isoprenaline-induced tachycardia. Buccal patches of carvedilol were prepared by using chitosan (CH, sodium salt of carboxy methyl cellulose (NaCMC, and polyvinyl alcohol (PVA as mucoadhesive polymers. The solvent evaporation method was used for the preparation of buccal patches. The patches were evaluated for their physical characteristics like patch thickness, weight variation, content uniformity, folding endurance, surface pH, residence time, in vitro drug release, and in vivo pharmacodynamic study. The swelling index of the patches was found to be proportional to the polymer concentration, whereas surface pH of all the formulated bioadhesive patches was found to lie between neutral ranges. In-vitro release study shows that 94.75% drug was release in 8 hours from the patch, which containing 2% w/v chitosan. The folding endurance result shows good elasticity in all the patches.Application of buccal patches on buccal mucosa of rabbit shows a significant result in % inhibition of isoprenaline-induced tachycardia. Prepared buccal patches of chitosan, NaCMC, and PVA containing Carvedilol meet the ideal requirement for the delivery of cardiovascular drugs and inhibit the isoprenaline tachycardia.

Imaging QRS complex and ST segment in myocardial infarction

DEFF Research Database (Denmark)

Bacharova, Ljuba; Bang, Lia E; Szathmary, Vavrinec

2014-01-01

BACKGROUND: Acute myocardial infarction creates regions of altered electrical properties of myocardium resulting in typical QRS patterns (pathological Q waves) and ST segment deviations observed in leads related to the MI location. The aim of this study was to present a graphical method for imaging...... the changes in the sequence of depolarization and the ST segment deviations in myocardial infarction using the Dipolar ElectroCARdioTOpography (DECARTO) method. MATERIAL AND METHODS: Simulated ECG data corresponding to intramural, electrically inactive areas encircled by transmural areas with slowed impulse...... propagation velocity in anteroseptal and inferior locations were used for imaging the altered sequence of depolarization and the ST vector. The ECGs were transformed to areas projected on the image surface so as to image the process of ventricular depolarization based on the orientation and magnitude...

Right Ventricular Endomyocardial Fibrosis Presenting With Ventricular Tachycardia And Apical Thrombus - An Interesting Presentation

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Amitesh Aggarwal

2009-11-01

Full Text Available Endomyocardial fibrosis is a progressive disease of unknown origin affecting children and young adults. It involves inflow portion of right and/or left ventricle and apex. It may be associated with thrombus. Literature regarding right ventricular endomyocardial fibrosis with thrombus is scarce. Here we report a rare case of right ventricular endomyocardial fibrosis presenting as ventricular tachycardia and echocardiographic evidence of apical thrombus. Interestingly there was no pulmonary involvement or evidence of deep venous thrombosis. This case also underscores the importance of urgent echocardiography in diagnosis of obscure cases of ventricular tachycardia.

Right Atrial Dual-loop Reentry Tachycardia after Cardiac Surgery: Prevalence, Electrophysiologic Characteristics and Ablation Outcomes.

Science.gov (United States)

Yang, Jian-du; Sun, Qi; Guo, Xiao-Gang; Zhou, Gong-Bu; Liu, Xu; Luo, Bin; Wei, Hui-Qiang; Santangeli, Pasquale; Liang, Jackson J; Ma, Jian

2018-04-03

Right atrial dual-loop reentry tachycardia has been described in patients with open-heart surgery. However, the prevalence, electrophysiologic substrate and ablation outcomes have been poorly characterized. We aimed to investigate the prevalence, electrophysiologic substrate and ablation outcomes for RA dual-loop reentry tachycardia following cardiac surgery. We identified all patients with atrial tachycardia after cardiac surgery. We compared electrophysiologic findings and outcomes of those with RA dual-loop reentry tachycardia versus a control group of patients with RA macro-reentrant arrhythmias in the setting of linear RA free wall (FW) scar. Out of 127 patients with 152 post-surgical atrial tachycardias (ATs), 28 (18.4%) had diagnosis of RA dual-loop reentry and 24/28 (85.7%) had tricuspid annular (TA) reentry combined with FW incisional reentry. An incision length > 51.5mm along the FW predicted the substrate for a second loop. In 22/23 patients (95.7%) with initial ablation in the cavo-tricuspid isthmus, a change in the interval between Halo d to CS p could be recorded, while 15/23 patients (65.2%) had CS activation pattern change. Complete success was achieved in 25/28 (89.3%) and 64/69 (92.8%) in the dual-loop reentry and control groups, respectively. After mean follow-up of 33.9±24.2 months, 24/28 (85.7%) and 60/69 (86.95%) were free of arrhythmias after initial procedure in two groups. The prevalence of RA dual-loop reentry is 18.4% among ATs with prior atriotomy scar. A long incision should alert physician the possibility of the second loop at the FW. Halo and CS activation pattern are important clues for circuit transformation. Copyright © 2018. Published by Elsevier Inc.

INTERMITTENT ANTIARYTHMIC THERAPY OF ARIOVENTICULAR NODAL REENTRY TACHYCARDIA IN CHILDREN

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Boris Djindjic

2008-04-01

Full Text Available Until recent advances in pharmacology and clinical cardiology regarding farmacodynamics of antiarrhythmic drugs and their efficiency in patients with refractory paroxysmal supraventricular tachycardia, chronic prophylactic therapy was the only treatment option for patients refusing catheter ablation. Another treatment option, also known by eponym “pill in pocket” have been shown to be equally useful and efficacious.The aim of our study was prospective examination of children with refractory atrioventricular nodal reentry tachycardia (AVNRT who were withdrawn from chronic antiarrhythmic prophylactic therapy and started with intermittent oral beta blocker treatment (propranolol at dosage 1 mg/kg - max 80 mg.Twelve children (8 boys and 4 girls with AVNRT were included in the study. Four children did not have arrhythmia during first six months after withdrawal and 7 were successfully treated without complication.Intermittent antiarrhythmic therapy in children with AVNRT could be very efficacious and useful treatment option which significantly improves their quality of life.

Bidirectional Tachycardia after an Acute Intravenous Administration of Digitalis for a Suicidal Gesture

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Diletta Sabatini

2014-01-01

Full Text Available Acute digoxin intoxication is a life-threating condition associated with severe cardiotoxicity. Female gender, age, low lean body mass, hypertension, and renal insufficiency may worsen the prognosis. Arrhythmias caused by digitalis glycosides are characterized by an increased automaticity coupled with concomitant conduction delay. Bidirectional tachycardia is pathognomonic of digoxin intoxication, but it is rarely observed. An 83-year-old woman was admitted to the Emergency Department after self-administration of 5 mg of digoxin i.v. for suicidal purpose. Her digoxin serum concentration was 17.4 ng/mL. The patient developed a bidirectional tachycardia and the Poison Control Center of the hospital provided digoxin immune fab. Bidirectional tachycardia quickly reversed and the patient remained stable throughout the hospital stay. This case shows that a multiple disciplinary approach, involving cardiologists and toxicologists, is essential for the management of digoxin intoxication. The optimal treatment of this rare event depends on the clinical conditions and on the serum drug concentration of the patient. Digoxin immune fab represents a safe, effective, and specific method for rapidly reversing digitalis cardiotoxicity and should be started as soon as the diagnosis is defined.

Familial atrioventricular nodal re-entrant tachycardia: A case seriers and a systematic review

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Muthiah Subramanian

2017-11-01

Full Text Available Multiple reports of familial clustering suggest that genetic factors may contribute in the pathogenesis of atrioventricular nodal re-entrant tachycardia (AVNRT. We report three cases of AVNRT in a father and his two sons along with a review of literature of other similar cases. Electrophysiological studies induced typical AVNRT, which was successfully eliminated by radiofrequency ablation in all of them. Of the 22 reported cases, 96% had typical (slow-fast variant of AVNRT. The predominant pattern of inheritance appears to be autosomal dominant, though other patterns may exist. Further research is needed to understand the genetic influence of AVNRT and its pathophysiology. Keywords: Familial, AVNRT, Tachycardia

Interaction of Left Ventricular Size and Sex on Outcome of Cardiac Resynchronization Therapy Among Patients With a Narrow QRS Duration in the EchoCRT Trial

DEFF Research Database (Denmark)

Varma, Niraj; Sogaard, Peter; Bax, Jeroen J

2018-01-01

BACKGROUND: Longer QRS duration (QRSd) improves, but increased left ventricular (LV) end-diastolic volume (LVEDV) reduces, efficacy of cardiac resynchronization therapy (CRT). QRSd/LVEDV ratios differ between sexes. We hypothesized that in the EchoCRT (Echocardiography Guided Cardiac Resynchroniz......BACKGROUND: Longer QRS duration (QRSd) improves, but increased left ventricular (LV) end-diastolic volume (LVEDV) reduces, efficacy of cardiac resynchronization therapy (CRT). QRSd/LVEDV ratios differ between sexes. We hypothesized that in the EchoCRT (Echocardiography Guided Cardiac...... Resynchronization Therapy) trial enrolling patients with heart failure with QRSd New York Heart Association class III, QRSd

Stream computing for biomedical signal processing: A QRS complex detection case-study.

Science.gov (United States)

Murphy, B M; O'Driscoll, C; Boylan, G B; Lightbody, G; Marnane, W P

2015-01-01

Recent developments in "Big Data" have brought significant gains in the ability to process large amounts of data on commodity server hardware. Stream computing is a relatively new paradigm in this area, addressing the need to process data in real time with very low latency. While this approach has been developed for dealing with large scale data from the world of business, security and finance, there is a natural overlap with clinical needs for physiological signal processing. In this work we present a case study of streams processing applied to a typical physiological signal processing problem: QRS detection from ECG data.

Successful Non-fluoroscopic Radiofrequency Ablation of Incessant Atrial Tachycardia in a High Risk Twin Pregnancy

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Dr Zia Zuberi, BSc PhD MRCP

2014-01-01

Full Text Available We describe a patient presenting with incessant ectopic atrial tachycardia during a high risk twin pregnancy. Tachycardia was resistant to escalating doses of beta-blockade with digoxin. Because of increasing left ventricular dysfunction early in the third trimester, catheter ablation was performed successfully at 30 weeks gestation. Electro-anatomic mapping permitted the entire procedure to be conducted without the use of ionizing radiation. The pregnancy proceeded to successful delivery near term and after three years the patient remains recurrence free with normal left ventricular function, off all medication.

Case files of the Medical Toxicology Fellowship at the Toxikon Consortium in Chicago: Cocaine-associated wide-complex dysrhythmias and cardiac arrest— treatment nuances and controversies

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Kalimullah, Ejaaz A.; Bryant, Sean M.

2008-01-01

Manifestations of cocaine poisoning range widely from mild sympathomimetic overdrive to life-threatening seizures, hyperthermia, and cardiac dysrhythmias. While supportive care, including the judicious use of benzodiazepines and cooling measures, is paramount, the management of cocaine-associated wide-complex dysrhythmias and cardiac arrest regularly includes sodium bicarbonate boluses in order to narrow QRS length. When confronted with refractory dysrhythmias, one must weigh the benefits and...

Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

Science.gov (United States)

Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

2015-10-01

Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

Ambulatory monitoring of myocardial ischemia in the 21st century-an opportunity for high frequency QRS analysis

Czech Academy of Sciences Publication Activity Database

Leinveber, Pavel; Halámek, Josef; Jurák, Pavel

2016-01-01

Roč. 49, č. 6 (2016), s. 902-906 ISSN 0022-0736 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : ambulatory monitoring * HF-QRS * myocardial Ischemia * silent Ischemia * Holter monitoring Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.514, year: 2016

Female preponderance in atrioventricular node reentrant tachycardia, but no sex related electrophysiological differences

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Claes Williamsson

2014-01-01

Full Text Available The mechanism behind the female preponderance for atrio-ventricular node reentrant tachycardia (AVNRT is not clear. We compared baseline electrophysiological measurements and clinical data in 141 consecutive patients (96 women who underwent successful AVNRT ablation at their fi rst therapeutic procedure. Women had on average 9% higher resting heart rate than men (p<0.05, but were similar in all measures of AV node function. Isoproterenol infusion was required for AVNRT induction in 69 cases (49%, and the need for isoproterenol was associated with lower resting heart rate and longer anterograde and retrograde AV node refractory periods (p<0.05 for comparisons, but not with sex. We conclude that the spectrum of baseline AV node physiology in AVNRT patients is wide, and is similar in men and women. The female preponderance for AVNRT cannot be explained from comparisons of baseline AV node electrophysiological properties.

Troponin elevation in patients with various tachycardias and normal epicardial coronaries

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Yousuf Kanjwal

2008-08-01

Full Text Available Troponin elevation is usually synonymous with acute coronary syndrome (ACS. Although sensitive for ACS, the elevation of serum troponin, in the absence of clinical evidence of ischemia, should prompt a search for other etiologies of myocardial necrosis. In fact, elevated values of troponin are correlated with myocardial necrosis even though it does not discriminate the mechanism involved. We report a series of seven patients (age range 18-67 years, who presented with complaints of chest discomfort and were found to have regular supraventricular tachycardia (5 patients and one patient each with atrial fibrillation and ventricular tachycardia. All these patients had elevated troponin I and underwent coronary angiography that revealed normal epicardial coronary arteries. This is first case series in which all patients underwent coronary angiography and none of the patients was hemodynamically unstable at the time of presentation. Patients with elevated troponin due to conditions other than ACS can receive inappropriate and delayed definitive diagnosis and treatment.

Incessant ventricular tachycardia early after acute myocardial infarction: efficacy of radiofrequency catheter ablation but not of optimal coronary revascularization.

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Bonanno, C; Ometto, R; Finocchi, G; Rulfo, F; La Vecchia, L; Vincenzi, M

1999-12-01

Incessant ventricular tachycardia is an arrhythmia refractory to conventional antiarrhythmic treatment. We describe the case of 55-year-old man who presented incessant ventricular tachycardia in the early post-acute phase of myocardial infarction. Optimal coronary revascularization was not effective, but radiofrequency catheter ablation was able to eliminate the anatomic substrate and clinical arrhythmic recurrence.

Role of Electrophysiological Study and Catheter Ablation for Recurrent Ventricular Tachycardia Complicating Myocarditis

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Emanuele Cecchi

2012-01-01

Full Text Available Here we report the case of a 31-year-old man admitted to our hospital with echocardiografic and Cardiac Magnetic Resonance signs of myocarditis complicated by ventricular tachycardia, initially resolved with direct current shock. After the recurrence of ventricular tachycardia the patient was submitted to electrophysiological study revealing a re-entrant circuit at the level of the medium segment of interventricular septum, successfully treated with transcatheter ablation. This case highlights how the presence of recurrent ventricular arrhythmias at the onset of acute myocarditis, suspected or proven, could be associated with a pre-existing arrhythmogenic substrate, therefore these patients should be submitted to electrophysiological study in order to rule out the presence of arrhythmogenic focuses that can be treated with transcatheter ablation.

Night-time heart rate cut-off point definition by resting office tachycardia in untreated hypertensive patients: data of the Spanish ABPM registry.

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Vinyoles, Ernest; de la Sierra, Alejandro; Roso, Albert; de la Cruz, Juan J; Gorostidi, Manuel; Segura, Julián; Banegas, José R; Martell-Claros, Nieves; Ruilope, Luís M

2014-05-01

Epidemiological studies have shown that an elevated resting heart rate (HR) is a risk factor for both total and cardiovascular mortality. Our aim was to estimate the night-time HR cut-off point that best predicts cardiovascular risk office tachycardia in hypertensive patients. Untreated hypertensive patients without concomitant cardiovascular diseases were included. Office and ambulatory HRs were measured. Cardiovascular risk office tachycardia was defined by office HR at least 85 beats per minute (bpm). Different night-time HR cut-offs were estimated by receiver operating characteristic curve analyses to predict cardiovascular risk office tachycardia. The best cut-off was selected on the basis of its combined sensitivity and specificity. A total of 32 569 hypertensive patients were included: 46.5% women, mean age (SD) 52 (14) years, office blood pressure 146 (16)/89 (11) mmHg, diabetes 10.3%, smoking 19.2%, BMI 29 (6.8) kg/m, office HR 77 (11.2) bpm, and night-time HR 64.9 (9.3) bpm. A total of 7070 (21.7%) patients were found to have cardiovascular risk office tachycardia. The night-time HR value that better predicted cardiovascular risk office tachycardia was more than 66 bpm. In comparison with patients with night HR below this value, those with night-time tachycardia were predominantly women, younger, with higher ambulatory blood pressure, greater BMI, and higher prevalence of diabetes and smoking. All comparisons were statistically significant (P less than 0.001). A mean night-time HR more than 66 bpm is a good predictor of cardiovascular risk office tachycardia in untreated hypertensive patients and could be considered a variable associated with an increased cardiovascular risk.

Identification of the QRS Complex in the ECG

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Martin Paralič

2016-12-01

Full Text Available The cardiovascular heart diseases are one of the most common causes of leading to death of man. Unfortunately, the symptoms vary and the most common reason for critical delays in medical treatment is lack of early warning and patient unawareness. In this paper, we present a development of the mobile application for Electrocardiogram measurements based on communication with a smart clothing using Bluetooth. The objectives of the application are a wireless data collection and analysis of ECG signal. The analysis is aimed for precise detection of QRS complex parameters plus detection of P-wave and T-wave. Measurement and evaluation of multiple PQRST parameters in a series allows detection of anomalies which leads to different heart diseases. Early warning system can help to make preventive actions to avoid severe heart disease. The recorded data are exported to format of the MIT/BIH arrhythmia database to be compatible with the professional medical software. This program will be devoted to the purposes of research and home healthcare instead of clinical diagnosis.

[Successful transcatheter ablation of fascicular potential in pediatric patients with left posterior fascicular tachycardia].

Science.gov (United States)

Zeng, Shao-ying; Shi, Ji-jun; Li, Hong; Zhang, Zhi-wei; Li, Yu-fen

2010-08-01

To simplify the methods of transcatheter mapping and ablation in the pediatric patients with left posterior fascicular tachycardia. While in sinus rhythm, the fascicular potential can be mapped at the posterior septal region (1 - 2 cm below inferior margin of orifice of coronary sinus vein), which display a biphasic wave before ventricular wave, and exist equipotential lines between them. When the fascicular potential occurs 20 ms later than the bundle of His' potential, radiofrequency was applied. Before applying radiofrequency, catheter position must be observed using double angle viewing (LAO 45°RAO 30°), and it should be made sure that the catheter is not at His' bundle. If the electrocardiogram displays left posterior fascicular block, the correct region is identified and ablation can continue for 60 s. Electrocardiogram monitoring should continue for 24 - 48 hours after operation, and notice abnormal repolarization after termination of ventricular tachycardia. Aspirin [2 - 3 mg/(kg·d)] was used for 3 months, and antiarrhythmic drug was discontinued. Surface electrocardiogram, chest X-ray and ultrasound cardiography were rechecked 1 d after operation. Follow-up was made at 1 month and 3 months post-discharge. Recheck was made half-yearly or follow-up was done by phone from then on. Fifteen pediatric patients were ablated successfully, and their electrocardiograms all displayed left posterior fascicular block after ablation. None of the patients had recurrences during the 3 to 12 months follow-up period. In one case, the electrocardiogram did not change after applying radiofrequency ablation and the ventricular tachycardia remained; however, on second attempt after remapping, the electrocardiogram did change. The radiofrequency lasted for 90 seconds and ablation was successful. This case had no recurrences at 6 months follow-up. Transcatheter ablation of the fascicular potential in pediatric patients with left posterior fascicular tachycardia can simplify

Thoracoscopic Left Cardiac Sympathetic Denervation for a Patient with Catecholaminergic Polymorphic Ventricular Tachycardia and Recurrent Implantable Cardioverter-Defibrillator Shocks

Directory of Open Access Journals (Sweden)

Woo-Sik Yu

2015-06-01

Full Text Available A patient presented with loss of consciousness and conversion. During an exercise test, catecholaminergic polymorphic ventricular tachycardia (CPVT resulted in cardiac arrest. He started taking medication (a beta-blocker and flecainide and an implantable cardioverter defibrillator (ICD was inserted, but the ventricular tachycardia did not resolve. Left cardiac sympathetic denervation (LCSD was then performed under general anesthesia, and the patient was discharged on the second postoperative day without complications. One month after the operation, no shock had been administered by the ICD, and an exercise stress test did not induce ventricular tachycardia. Although beta- blockers are the gold standard of therapy in patients with CPVT, thoracoscopic LCSD is safe and can be an effective alternative treatment option for patients with intractable CPVT.

Electrocardiographic characteristics and clinical features of acute apical infarction. Analysis by a QRS scoring system

Energy Technology Data Exchange (ETDEWEB)

Seino, Yoshihiko; Nagae, Yasuhiro; Kamei, Shinichiro; Koh, Yoshiki; Tanaka, Keiji; Katoh, Takao; Takano, Teruo; Hayakawa, Hirokazu; Okumura, Hidemasa

1986-11-01

Two-dimensional echocardiography and thallium-201 myocardial single photon emission computed tomography were used to detect infarct site in 56 consecutive patients with acute myocardial infarction (MI). The pathophysiology of apical MI at acute stage was studied in relation to ECG changes as determined by a QRS scoring system. On the first hospital day, the group with antero-apical MI (AAp group) had long Q-wave durations in leads V/sub 3/ and V/sub 4/, high QRS scores (QRSs) in leads V/sub 4/ and V/sub 5/, high QRSs in total, and large number of Q waves, as compared with the group with anterior MI (A group). On the 7th day, Q-wave durations in leads V/sub 2/ and V/sub 3/, and QRSs in leads V/sub 4/ and V/sub 5/ were significantly larger in AAp group than A group. Although there was no significant difference between the two groups with respect to blood circulation and peak creatine kinase (CK)/CK-MB at the time of admission, left ventricular ejection function was significantly lower in AAp group than A group. No finding was significantly different between the group with infero-apical MI and the group with inferior MI. QRSs in leads V/sub 4/ and V/sub 5/ was a useful means of diagnosing AAp MI. (Namekawa, K.).

Acute supraventricular tachycardia in children.

Science.gov (United States)

Paul, Siba Prosad; Blaikley, Sarah; Peevers, Camilla; Fitz-John, Lin

2012-10-01

This article describes the management in emergency departments of supraventricular tachycardia (SVT) in children. Of all forms of symptomatic arrhythmia in infants, children and adolescents, SVT is the most common. Its clinical presentation varies with the child's age, and it can be difficult to diagnose in infants and young children. It is important that the nurses in the emergency department consider a diagnosis of SVT in young children with histories of poor feeding, lethargy, irritability, excessive sweating or pallor (Zeigler 1994) and in older children with histories of palpitations, dizziness, chest pain, syncope or shortness of breath (Uzun 2010). If SVT is suspected, a 12-lead electrocardiogram should be recorded. Vagal manoeuvre may be successful but in some cases intravenous adenosine is necessary. Children with Wolff-Parkinson-White syndrome are at risk of sudden cardiac death associated with SVT, and should not be treated with calcium channel blockers or digoxin.

Overview of the management of postural tachycardia syndrome in pregnant patients.

Science.gov (United States)

Ruzieh, Mohammed; Grubb, Blair P

2018-02-16

Postural tachycardia syndrome (POTS) is a chronic condition characterized by symptoms of orthostatic intolerance. Pregnancy can cause different physiological changes in cardiovascular parameters, that could have greater impact on POTS patients. In this review, we discuss the management of POTS in the pregnant and obstetric settings. Copyright © 2018 Elsevier B.V. All rights reserved.

Postural tachycardia syndrome (POTS) and other autonomic disorders in antiphospholipid (Hughes) syndrome (APS).

Science.gov (United States)

Schofield, J R; Blitshteyn, S; Shoenfeld, Y; Hughes, G R V

2014-06-01

Antiphospholipid syndrome (APS) is an autoimmune hypercoagulable disorder that has been shown to cause a large number of cardiac and neurological manifestations. Two recent studies have demonstrated abnormalities in cardiovascular autonomic function testing in APS patients without other cardiovascular or autoimmune disease. However, an association between autonomic disorders such as postural tachycardia syndrome and APS has not previously been described. Data were obtained by retrospective chart review. We identified 15 patients who have been diagnosed with APS and an autonomic disorder. The median age of the patients at the time of data analysis was 39 years. The autonomic disorders seen in these patients included postural tachycardia syndrome, neurocardiogenic syncope and orthostatic hypotension. The majority of patients (14/15) were female and the majority (14/15) had non-thrombotic neurological manifestations of APS, most commonly migraine, memory loss and balance disorder. Many also had livedo reticularis (11/15) and Raynaud's phenomenon (nine of 15). In some patients, the autonomic manifestations improved with anticoagulation and/or anti-platelet therapy; in others they did not. Two patients with postural tachycardia syndrome who failed to improve with the usual treatment of APS have been treated with intravenous immunoglobulin with significant improvement in their autonomic symptoms. We believe that autonomic disorders in APS may represent an important clinical association with significant implications for treatment. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

[Successful treatment of fetal supraventricular tachycardia with a combination of digoxin and amiodarone].

Science.gov (United States)

Hajdú, J; Szabó, I; Német, J

1996-10-06

The supraventricular tachycardia is a life threatening state in the intrauterine life. It can cause non-immune hydrops fetalis, intrauterine death or complications during the delivery. The unexplained tachycardia can cause fetal distress and premature delivery. Usually the digoxin is the first drug of choice for transplacental cardioversion. If digitalisation does not achieve cardioversion, the second line antiarrhythmic drugs should be instituted. Amiodarone has been suggested as a therapeutic alternative after failure of digoxin-verapamil combination. We give a drug in standard therapeutic doses for four-five days and after it we determine whether it is effective or not. We should determine the newer therapy or termination of pregnancy. The transplacental administration of amiodarone may be dangerous because of fetal cretinism. Our case is the first in Hungary-in our best knowledge- and we suggest the amiodarone for transplacental therapy.

Neonatal thyrotoxicosis with severe supraventricular tachycardia: case report and review of the literature.

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Abbasoğlu, Aslıhan; Ecevit, Ayşe; Tuğcu, Ali Ulaş; Erdoğan, Lkay; Kınık, Sibel Tulgar; Tarcan, Aylin

2015-03-01

Neonatal thyrotoxicosis is a rare condition caused by the transplacental passage of thyroid stimulating immunoglobulins from mothers with Graves' disease. We report a case of neonatal thyrotoxicosis with concurrent supraventricular tachycardia (SVT). The female infant, who was born by section due to breech delivery and meconium in the amniotic fluid at 36 weeks of gestation, presented with tachycardia on day 7. Her heart rate was between 260 and 300 beats/min, and an electrocardiogram revealed ongoing SVT. Sotalol was effective after two cardioversions in maintaining sinus rhythm. Thyroid function studies revealed hyperthyroidism in the infant, and her mother was found to have Graves' disease. Since symptoms and signs can vary, especially in preterm infants with neonatal hyperthyroidism, we want to emphasize the importance of prenatal care and follow-ups of Graves' disease associated pregnancies and management of newborns after birth.

Idiopathic ventricular tachycardia and fibrillation.

Science.gov (United States)

Belhassen, B; Viskin, S

1993-06-01

Important data have recently been added to our understanding of sustained ventricular tachyarrhythmias occurring in the absence of demonstrable heart disease. Idiopathic ventricular tachycardia (VT) is usually of monomorphic configuration and can be classified according to its site of origin as either right monomorphic (70% of all idiopathic VTs) or left monomorphic VT. Several physiopathological types of monomorphic VT can be presently individualized, according to their mode of presentation, their relationship to adrenergic stress, or their response to various drugs. The long-term prognosis is usually good. Idiopathic polymorphic VT is a much rarer type of arrhythmia with a less favorable prognosis. Idiopathic ventricular fibrillation may represent an underestimated cause of sudden cardiac death in ostensibly healty patients. A high incidence of inducibility of sustained polymorphic VT with programmed ventricular stimulation has been found by our group, but not by others. Long-term prognosis on Class IA antiarrhythmic medications that are highly effective at electrophysiologic study appears excellent.

Mechanism-specific effects of adenosine on ventricular tachycardia.

Science.gov (United States)

Lerman, Bruce B; Ip, James E; Shah, Bindi K; Thomas, George; Liu, Christopher F; Ciaccio, Edward J; Wit, Andrew L; Cheung, Jim W; Markowitz, Steven M

2014-12-01

There is no universally accepted method by which to diagnose clinical ventricular tachycardia (VT) due to cAMP-mediated triggered activity. Based on cellular and clinical data, adenosine termination of VT is thought to be consistent with a diagnosis of triggered activity. However, a major gap in evidence mitigates the validity of this proposal, namely, defining the specificity of adenosine response in well-delineated reentrant VT circuits. To this end, we systematically studied the effects of adenosine in a model of canine reentrant VT and in human reentrant VT, confirmed by 3-dimensional, pace- and substrate mapping. Adenosine (12 mg [IQR 12-24]) failed to terminate VT in 31 of 31 patients with reentrant VT due to structural heart disease, and had no effect on VT cycle length (age, 67 years [IQR 53-74]); ejection fraction, 35% [IQR 20-55]). In contrast, adenosine terminated VT in 45 of 50 (90%) patients with sustained focal right or left outflow tract tachycardia. The sensitivity of adenosine for identifying VT due to triggered activity was 90% (95% CI, 0.78-0.97) and its specificity was 100% (95% CI, 0.89-1.0). Additionally, reentrant circuits were mapped in the epicardial border zone of 4-day-old infarcts in mongrel dogs. Adenosine (300-400 μg/kg) did not terminate sustained VT or have any effect on VT cycle length. These data support the concept that adenosine's effects on ventricular myocardium are mechanism specific, such that termination of VT in response to adenosine is diagnostic of cAMP-mediated triggered activity. © 2014 Wiley Periodicals, Inc.

Partial suppression of the respiratory defect of qrs1/her2 glutamyl-tRNA amidotransferase mutants by overexpression of the mitochondrial pentatricopeptide Msc6p.

Science.gov (United States)

Moda, Bruno S; Ferreira-Júnior, José Ribamar; Barros, Mario H

2016-08-01

Recently, a large body of evidences indicates the existence in the mitochondrial matrix of foci that contain different proteins involved in mitochondrial RNA metabolism. Some of these proteins have a pentatricopeptide repeat motif that constitutes their RNA-binding structures. Here we report that MSC6, a mitochondrial pentatricopeptide protein of unknown function, is a multi copy suppressor of mutations in QRS1/HER2 a component of the trimeric complex that catalyzes the transamidation of glutamyl-tRNAQ to glutaminyl-tRNAQ. This is an essential step in mitochondrial translation because of the lack of a specific mitochondrial aminoacyl glutaminyl-tRNA synthetase. MSC6 over-expression did not abolish translation of an aberrant variant form of Cox2p detected in QRS1/HER2 mutants, arguing against a suppression mechanism that bypasses Qrs1p function. A slight decrement of the mitochondrial translation capacity as well as diminished growth on respiratory carbon sources media for respiratory activity was observed in the msc6 null mutant. Additionally, the msc6 null mutant did not display any impairment in RNA transcription, processing or turnover. We concluded that Msc6p is a mitochondrial matrix protein and further studies are required to indicate the specific function of Msc6p in mitochondrial translation.

Electrocardiogram: his bundle potentials can be recorded noninvasively beat by beat on surface electrocardiogram.

Science.gov (United States)

Wang, Gaopin; Liu, Renguang; Chang, Qinghua; Xu, Zhaolong; Zhang, Yingjie; Pan, Dianzhu

2017-03-15

The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram. We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure. His bundle electrogram was collected during the procedure. Comparative analysis of PA s (PA interval recorded on surface electrocardiogram), AH s (AH interval recorded on surface electrocardiogram) and HV s (HV interval recorded on surface electrocardiogram) interval recorded on surface "new electrocardiogram" and PA, AH, HV interval recorded on His bundle electrogram was investigated. There was no difference (P > 0.05) between groups in HV s interval (49.63 ± 6.19 ms) and HV interval (49.35 ± 6.49 ms). Results of correlational analysis found that HV S interval was significantly positively associated with HV interval (r = 0.929; P electrocardiogram. Noninvasive His bundle potential tracing might represent a new method for locating the site of atrioventricular block and identifying the origin of a wide QRS complex.

A diagnostic algorithm to optimize data collection and interpretation of Ripple Maps in atrial tachycardias.

Science.gov (United States)

Koa-Wing, Michael; Nakagawa, Hiroshi; Luther, Vishal; Jamil-Copley, Shahnaz; Linton, Nick; Sandler, Belinda; Qureshi, Norman; Peters, Nicholas S; Davies, D Wyn; Francis, Darrel P; Jackman, Warren; Kanagaratnam, Prapa

2015-11-15

Ripple Mapping (RM) is designed to overcome the limitations of existing isochronal 3D mapping systems by representing the intracardiac electrogram as a dynamic bar on a surface bipolar voltage map that changes in height according to the electrogram voltage-time relationship, relative to a fiduciary point. We tested the hypothesis that standard approaches to atrial tachycardia CARTO™ activation maps were inadequate for RM creation and interpretation. From the results, we aimed to develop an algorithm to optimize RMs for future prospective testing on a clinical RM platform. CARTO-XP™ activation maps from atrial tachycardia ablations were reviewed by two blinded assessors on an off-line RM workstation. Ripple Maps were graded according to a diagnostic confidence scale (Grade I - high confidence with clear pattern of activation through to Grade IV - non-diagnostic). The RM-based diagnoses were corroborated against the clinical diagnoses. 43 RMs from 14 patients were classified as Grade I (5 [11.5%]); Grade II (17 [39.5%]); Grade III (9 [21%]) and Grade IV (12 [28%]). Causes of low gradings/errors included the following: insufficient chamber point density; window-of-interestRipple Maps in atrial tachycardias. This algorithm requires prospective testing on a real-time clinical platform. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Atrial activation during atrioventricular nodal reentrant tachycardia: studies on retrograde fast pathway conduction

NARCIS (Netherlands)

Katritsis, Demosthenes G.; Ellenbogen, Kenneth A.; Becker, Anton E.

2006-01-01

Detailed right and left septal mapping of retrograde atrial activation during typical atrioventricular nodal reentrant tachycardia (AVNRT) has not been undertaken and may provide insight into the complex physiology of AVNRT, especially the anatomic localization of the fast and slow pathways. The

Consideration of QRS complex in addition to ST-segment abnormalities in the estimated "risk region" during acute anterior myocardial infarction

DEFF Research Database (Denmark)

van Hellemond, Irene E. G.; Bouwmeester, Sjoerd; Olson, Charles W.

2011-01-01

a falsely low estimated total MaR if determined by using ST segment-based methods. The purpose of this study was to investigate if consideration of the abnormalities in the QRS complex, in addition to those in the ST segment, provides a more accurate estimated total MaR during anterior AMI than...

Design of a cardiac monitor in terms of parameters of QRS complex.

Science.gov (United States)

Chen, Zhen-cheng; Ni, Li-li; Su, Ke-ping; Wang, Hong-yan; Jiang, Da-zong

2002-08-01

Objective. To design a portable cardiac monitor system based on the available ordinary ECG machine and works on the basis of QRS parameters. Method. The 80196 single chip microcomputer was used as the central microprocessor and real time electrocardiac signal was collected and analyzed [correction of analysized] in the system. Result. Apart from the performance of an ordinary monitor, this machine possesses also the following functions: arrhythmia analysis, HRV analysis, alarm, freeze, and record of automatic papering. Convenient in carrying, the system is powered by AC or DC sources. Stability, low power and low cost are emphasized in the hardware design; and modularization method is applied in software design. Conclusion. Popular in usage and low cost made the portable monitor system suitable for use under simple conditions.

Ventricular tachycardia during arthroscopic shoulder surgery: a report of two cases.

Science.gov (United States)

Cho, Seung Hyun; Yi, Jin Woong; Kwack, Yoon Ho; Park, Sung Wook; Kim, Mi Kyeong; Rhee, Yong Girl

2010-03-01

We routinely have performed arthroscopic shoulder surgery under general anesthesia in the beach chair position using epinephrine (0.33 mg/L) saline irrigation. At a 2-week interval, two patients, a 19-year-old man scheduled to undergo an arthroscopic Bankart repair for left traumatic anterior instability and a 49-year-old woman scheduled for an arthroscopic rotator cuff repair for a left rotator cuff tear, were resuscitated by chest compression and defibrillation due to a sudden developed cardiogenic shock following ventricular tachycardia at the time of arthroscopic shoulder surgery. They were transferred to the intensive care unit because their emergent echocardiogram showed significantly decreased cardiac functions. They were fully recovered and then discharged. Epinephrine was considered to be the cause of ventricular tachycardia because the two patients showed no anaphylactic reaction to drugs or symptoms of air embolism related to the beach chair position. In addition, according to our observation of epinephrine flow patterns, it was more likely that highly concentrated epinephrine was rapidly infused into the body. This complication is very rare. However, thorough understanding of the side effects and their development of epinephrine during arthroscopic shoulder surgery should neither be overemphasized nor disregarded.

Flecainide Therapy Reduces Exercise-Induced Ventricular Arrhythmias in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia

NARCIS (Netherlands)

van der Werf, Christian; Kannankeril, Prince J.; Sacher, Frederic; Krahn, Andrew D.; Viskin, Sami; Leenhardt, Antoine; Shimizu, Wataru; Sumitomo, Naokata; Fish, Frank A.; Bhuiyan, Zahurul A.; Willems, Albert R.; van der Veen, Maurits J.; Watanabe, Hiroshi; Laborderie, Julien; Haïssaguerre, Michel; Knollmann, Björn C.; Wilde, Arthur A. M.

2011-01-01

Objectives This study evaluated the efficacy and safety of flecainide in addition to conventional drug therapy in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Background CPVT is an inherited arrhythmia syndrome caused by gene mutations that destabilize cardiac

Accessory atrioventricular myocardial connections in the developing human heart: relevance for perinatal supraventricular tachycardias

NARCIS (Netherlands)

Hahurij, Nathan D.; Gittenberger-de Groot, Adriana C.; Kolditz, Denise P.; Bökenkamp, Regina; Schalij, Martin J.; Poelmann, Robert E.; Blom, Nico A.

2008-01-01

BACKGROUND: Fetal and neonatal atrioventricular (AV) reentrant tachycardias can be life-threatening but resolve in most cases during the first year of life. The transient presence of accessory AV myocardial connections during annulus fibrosus development may explain this phenomenon. METHODS AND

Counterclockwise and Clockwise Rotation of QRS Transitional Zone: Prospective Correlates of Change and Time-Varying Associations With Cardiovascular Outcomes.

Science.gov (United States)

Patel, Siddharth; Kwak, Lucia; Agarwal, Sunil K; Tereshchenko, Larisa G; Coresh, Josef; Soliman, Elsayed Z; Matsushita, Kunihiro

2017-11-03

A few studies have recently reported clockwise and counterclockwise rotations of QRS transition zone as predictors of mortality. However, their prospective correlates and associations with individual cardiovascular disease (CVD) outcomes are yet to be investigated. Among 13 567 ARIC (Atherosclerosis Risk in Communities) study participants aged 45 to 64 years, we studied key correlates of changes in the status of clockwise and counterclockwise rotation over time as well as the association of rotation status with incidence of coronary heart disease (2408 events), heart failure (2196 events), stroke (991 events), composite CVD (4124 events), 898 CVD deaths, and 3469 non-CVD deaths over 23 years of follow-up. At baseline, counterclockwise rotation was most prevalent (52.9%), followed by no (40.5%) and clockwise (6.6%) rotation. Of patients with no rotation, 57.9% experienced counterclockwise or clockwise rotation during follow-up, with diabetes mellitus and black race significantly predicting clockwise and counterclockwise conversion, respectively. Clockwise rotation was significantly associated with higher risk of heart failure (hazard ratio, 1.20; 95% confidence interval [CI], 1.02-1.41) and non-CVD death (hazard ratio, 1.28; 95% CI, 1.12-1.46) after adjusting for potential confounders including other ECG parameters. On the contrary, counterclockwise rotation was significantly related to lower risk of composite CVD (hazard ratio, 0.93; 95% CI, 0.87-0.99]), CVD mortality (hazard ratio, 0.76; 95% CI, 0.65-0.88), and non-CVD deaths (hazard ratio, 0.92; 95% CI, 0.85-0.99 [borderline significance with heart failure]). Counterclockwise rotation, the most prevalent QRS transition zone pattern, demonstrated the lowest risk of CVD and mortality, whereas clockwise rotation was associated with the highest risk of heart failure and non-CVD mortality. These results have implications on how to interpret QRS transition zone rotation when ECG was recorded. © 2017 The Authors

ECG-derived spatial QRS-T angle is associated with ICD implantation, mortality and heart failure admissions in patients with LV systolic dysfunction.

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Sarah Gleeson

Full Text Available Increased spatial QRS-T angle has been shown to predict appropriate implantable cardioverter defibrilIator (ICD therapy in patients with left ventricular systolic dysfunction (LVSD. We performed a retrospective cohort study in patients with left ventricular ejection fraction (LVEF 31-40% to assess the relationship between the spatial QRS-T angle and other advanced ECG (A-ECG as well as echocardiographic metadata, with all-cause mortality or ICD implantation for secondary prevention.534 patients ≤75 years of age with LVEF 31-40% were identified through an echocardiography reporting database. Digital 12-lead ECGs were retrospectively matched to 295 of these patients, for whom echocardiographic and A-ECG metadata were then generated. Data mining was applied to discover novel ECG and echocardiographic markers of risk. Machine learning was used to develop a model to predict possible outcomes.49 patients (17% had events, defined as either mortality (n = 16 or ICD implantation for secondary prevention (n = 33. 72 parameters (58 A-ECG, 14 echocardiographic were univariately different (p110° had an adjusted HR of 3.4 (95% CI 1.6 to 7.4 for secondary ICD implantation or all-cause death and adjusted HR of 4.1 (95% CI 1.2 to 13.9 for future heart failure admission. There was a loss of complexity between A-ECG and echocardiographic variables with an increasing degree of disease.Spatial QRS-T angle >110° was strongly associated with arrhythmic events and all-cause death. Deep analysis of global ECG and echocardiographic metadata revealed underlying relationships, which otherwise would not have been appreciated. Delivered at scale such techniques may prove useful in clinical decision making in the future.

[Arrhythmogenic right ventricular cardiomyopathy. Case report and a brief literature review].

Science.gov (United States)

Izurieta, Carlos; Curotto-Grasiosi, Jorge; Rocchinotti, Mónica; Torres, María J; Moranchel, Manuel; Cañas, Sebastián; Cardús, Marta E; Alasia, Diego; Cordero, Diego J; Angel, Adriana

2013-01-01

A 51-year-old man was admitted to this hospital because of palpitations and a feeling of dizziness for a period of 2h. The electrocardiogram revealed a regular wide-QRS complex tachycardia at a rate of 250 beats per minute, with superior axis and left bundle branch block morphology without hemodynamically decompensation, the patient was cardioverted to sinus rhythm after the administration of a loading and maintenance dose of amiodarone. The elechtrophysiological study showed the ventricular origin of the arrhythmia. In order to diagnose the etiology of the ventricular tachycardia we performed a coronary arteriography that showed normal epicardial vessels, thus ruling out coronary disease. Doppler echocardiography revealed systolic and diastolic functions of both left and right ventricles within normal parameters, and normal diameters as well. A cardiac magnetic resonance with late enhancement was done, showing structural abnormalities of the right ventricle wall with moderate impairment of the ejection fraction, and a mild dysfunction of the left ventricle. The diagnosis of arrhythmogenic right ventricular cardiomyopathy was performed as 2 major Task Force criteria were met. We implanted an automatic cardioverter defibrillator as a prophylactic measure. The patient was discharged without complications. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Ventricular Tachycardia in the Absence of Structural Heart Disease

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Luis R. P. Scott

2005-04-01

Full Text Available In up to 10% of patients who present with ventricular tachycardia (VT, obvious structural heart disease is not identified. In such patients, causes of ventricular arrhythmia include right ventricular outflow tract (RVOT VT, extrasystoles, idiopathic left ventricular tachycardia (ILVT, idiopathic propranolol-sensitive VT (IPVT, catecholaminergic polymorphic VT (CPVT, Brugada syndrome, and long QT syndrome (LQTS. RVOT VT, ILVT, and IPVT are referred to as idiopathic VT and generally do not have a familial basis. RVOT VT and ILVT are monomorphic, whereas IPVT may be monomorphic or polymorphic. The idiopathic VTs are classified by the ventricle of origin, the response to pharmacologic agents, catecholamine dependence, and the specific morphologic features of the arrhythmia. CPVT, Brugada syndrome, and LQTS are inherited ion channelopathies. CPVT may present as bidirectional VT, polymorphic VT, or catecholaminergic ventricular fibrillation. Syncope and sudden death in Brugada syndrome are usually due to polymorphic VT. The characteristic arrhythmia of LQTS is torsades de pointes. Overall, patients with idiopathic VT have a better prognosis than do patients with ventricular arrhythmias and structural heart disease. Initial treatment approach is pharmacologic and radiofrequency ablation is curative in most patients. However, radiofrequency ablation is not useful in the management of inherited ion channelopathies. Prognosis for patients with VT secondary to ion channelopathies is variable. High-risk patients (recurrent syncope and sudden cardiac death survivors with inherited ion channelopathies benefit from implantable cardioverter-defibrillator placement. This paper reviews the mechanism, clinical presentation, and management of VT in the absence of structural heart disease.

Pre-excitation pattern associated with accessory pathway related tachycardia: Case report

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Burazor Mirko

2010-01-01

Full Text Available Introduction. Pre-excitation is based on an accessory conduction pathway between the atrium and ventricle. The term Wolff- Parkinson-White (WPW syndrome is used for patients with the pre-excitation/WPW pattern associated with AP-related tachycardia. Case Outline. We present a 52-year-old man with severe palpitation, fatigue, lightheadedness and difficulty breathing. The initial ECG showed tachyarrhythmia with heart rate between 240 and 300/min. He was treated with antiarrhythmics (Digitalis, Verapamil, Lidocaine with no response. Then, the patient was treated with electrical cardioversion and was referred to our Clinic for further evaluation with the diagnosis: “Ventricular tachycardia”. During in-hospital stay, the previously undiagnosed WPW pattern had been seen. Additional diagnostic tests confirmed permanent pre-excitacion pattern (ECG Holter recording, exercises test. The patient was referred to an electrophysiologist for further evaluation. Mapping techniques provided an accurate assessment of the position of the accessory pathway which was left lateral. The elimination of the accessory pathway by radiofrequent catheter ablation is highly effective in termination and elimination of tacchyarrhythmias. Conclusion. Symptomatic, life-threatening arrhythmia, first considered as ventricular tachycardia, reflected atrial fibrillation with ventricular pre-excitation over an accessory pathway in a patient with previously undiagnosed WPW syndrome.

Contribution of body surface mapping to clinical outcome after surgical ablation of postinfarction ventricular tachycardia

NARCIS (Netherlands)

van Dessel, Pascal F.; van Hemel, Norbert M.; Groenewegen, Arne Sippens; de Bakker, Jacques M.; Linnebank, André C.; Defauw, Jo J.

2002-01-01

This article investigates the influence of body surface mapping on outcome of ventricular antiarrhythmic surgery. Preoperative mapping is advocated to optimize map-guided antiarrhythmic surgery of postinfarction ventricular tachycardia. We sequentially analyzed the results of catheter activation

A Prospective Study of Ripple Mapping the Post-Infarct Ventricular Scar to Guide Substrate Ablation for Ventricular Tachycardia.

Science.gov (United States)

Luther, Vishal; Linton, Nick W F; Jamil-Copley, Shahnaz; Koa-Wing, Michael; Lim, Phang Boon; Qureshi, Norman; Ng, Fu Siong; Hayat, Sajad; Whinnett, Zachary; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa

2016-06-01

Post-infarct ventricular tachycardia is associated with channels of surviving myocardium within scar characterized by fractionated and low-amplitude signals usually occurring late during sinus rhythm. Conventional automated algorithms for 3-dimensional electro-anatomic mapping cannot differentiate the delayed local signal of conduction within the scar from the initial far-field signal generated by surrounding healthy tissue. Ripple mapping displays every deflection of an electrogram, thereby providing fully informative activation sequences. We prospectively used CARTO-based ripple maps to identify conducting channels as a target for ablation. High-density bipolar left ventricular endocardial electrograms were collected using CARTO3v4 in sinus rhythm or ventricular pacing and reviewed for ripple mapping conducting channel identification. Fifteen consecutive patients (median age 68 years, left ventricular ejection fraction 30%) were studied (6 month preprocedural implantable cardioverter defibrillator therapies: median 19 ATP events [Q1-Q3=4-93] and 1 shock [Q1-Q3=0-3]). Scar (ripple mapping conducting channels were seen within each scar (length 60 mm; initial component 0.44 mV; delayed component 0.20 mV; conduction 55 cm/s). Ablation was performed along all identified ripple mapping conducting channels (median 18 lesions) and any presumed interconnected late-activating sites (median 6 lesions; Q1-Q3=2-12). The diastolic isthmus in ventricular tachycardia was mapped in 3 patients and colocated within the ripple mapping conducting channels identified. Ventricular tachycardia was noninducible in 85% of patients post ablation, and 71% remain free of ventricular tachycardia recurrence at 6-month median follow-up. Ripple mapping can be used to identify conduction channels within scar to guide functional substrate ablation. © 2016 American Heart Association, Inc.

A Case Report and Review of Postural Orthostatic Tachycardia Syndrome in Pregnancy

OpenAIRE

Lide, Brianna; Haeri, Sina

2015-01-01

Purpose - Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by an increased heart rate upon transition from supine to standing, and head-up tilt without orthostatic hypotension. Its etiology is multifactorial, and no clear cause has been identified. Common symptoms include light-headedness, blurred vision, weakness, cognitive difficulties, and fatigue and are often accompanied by palpitations, shortness of breath, syncope, or gastrointestinal ...

Unmappable ventricular tachycardia after an old myocardial infarction. Long-term results of substrate modification in patients with an implantable cardioverter defibrillator

OpenAIRE

Alzand, B. S. N.; Timmermans, C. C. M. M.; Wellens, H. J. J.; Dennert, R.; Philippens, S. A. M.; Portegijs, P. J. M.; Rodriguez, LM.

2011-01-01

Purpose The frequent occurrence of ventricular tachycardia can create a serious problem in patients with an implantable cardioverter defibrillator. We assessed the long-term efficacy of catheter-based substrate modification using the voltage mapping technique of infarct-related ventricular tachycardia and recurrent device therapy. Methods The study population consisted of 27 consecutive patients (age 68 ± 8 years, 25 men, mean left ventricular ejection fraction 31 ± 9%) with an old myocardial...

Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

Science.gov (United States)

Bassett, Elwin C; Kholmovski, Eugene G; Wilson, Brent D; DiBella, Edward V R; Dosdall, Derek J; Ranjan, Ravi; McGann, Christopher J; Kim, Daniel

2014-02-01

Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI

A review of postural orthostatic tachycardia syndrome.

LENUS (Irish Health Repository)

Carew, Sheila

2012-01-31

A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months. She is not taking any regular medications. Her supine blood pressure was 126\\/84 mmHg with a heart rate of 76 bpm, and her upright blood pressure was 122\\/80 mmHg with a heart rate of 114 bpm. A full system examination was otherwise normal. She had a 12-lead electrocardiogram performed which was unremarkable. She was referred for head-up tilt testing. She was symptomatic during the test and lost consciousness at 16 min. Figure 1 summarizes her blood pressure and heart rate response to tilting. A diagnosis of postural orthostatic tachycardia syndrome with overlapping vasovagal syncope was made.

Sequential biventricular pacing improves regional contractility, longitudinal function and dyssynchrony in patients with heart failure and prolonged QRS

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Ring Margareta

2010-04-01

Full Text Available Abstract Aims Biventricular pacing (BiP is an effective treatment in systolic heart failure (HF patients with prolonged QRS. However, approximately 35% of the patients receiving BiP are classified as non-responders. The aim of this study is to evaluate the acute effects of VV-optimization on systolic heart function. Methods Twenty-one HF patients aged 72 (46-88 years, QRS 154 (120-190 ms, were studied with echocardiography, Tissue Doppler Imaging (TDI and 3D-echo the first day after receiving a BiP device. TDI was performed; during simultaneous pacing (LV-lead pacing 4 ms before the RV-lead and during sequential pacing (LV 20 and 40 ms before RV and RV 20 and 40 ms before LV-lead pacing. Systolic heart function was studied by tissue tracking (TT for longitudinal function and systolic maximal velocity (SMV for regional contractility and signs of dyssynchrony assessed by time-delays standard deviation of aortic valve opening to SMV, AVO-SMV/SD and tissue synchronization imaging (TSI. Results The TT mean value preoperatively was 4,2 ± 1,5 and increased at simultaneous pacing to 5,0 ± 1,2 mm (p Conclusions VV-optimization in the acute phase improves systolic heart function more than simultaneous BiP pacing. Long-term effects should be evaluated in prospective randomized trials.

Histamine induces postprandian tachycardia through a direct effect on cardiac H2-receptors in pythons

DEFF Research Database (Denmark)

Jensen, Nini Skovgaard; Møller, Kate; Gesser, Hans

2009-01-01

The intrinsic heart rate of most vertebrates studied, including humans, is elevated during digestion, suggesting that a non-adrenergic-non-cholinergic factor contributes to the postprandial tachycardia. The regulating factor, however, remains elusive and difficult to identify. Pythons can ingest...... very large meals and digestion is associated with a marked rise in metabolism that is sustained for several days. The metabolic rise causes more than a doubling of heart rate and a four-fold rise in cardiac output. This makes the python an interesting model to investigate the postprandial tachycardia....... We measured blood pressure and heart rate in fasting Python regius, and at 24 and 48h after ingestion of a meal amounting to 25% of body weight. Digestion caused heart rate to increase from 25 to 56 min-1 while blood pressure was unchanged. The postprandial rise in heart rate was partially due...

Heart rate variability analysis in postural orthostatic tachycardia syndrome: a case report

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Raffaele Calabrò

2006-09-01

Full Text Available The authors present a case of 36 year old male patient with idiopathic postural orthostatic tachycardia syndrome (POTS diagnosed during head-up tilt testing. Power spectral analysis of heart rate variability (HRV during the tilt test revealed that the ratio of low and high frequency powers (LF/HF increased with the onset of orthostatic intolerance. This analysis confirmed in our patient a strong activation in sympathetic tone.

Electrocardiographic artefacts mimicking atrial tachycardia resulted in unnecessary diagnostic and therapeutic measures

OpenAIRE

Y-Hassan, Shams; Sylv?n, Christer

2013-01-01

Electrocardiographic (ECG) artefacts may closely simulate both supraventricular and ventricular tachycardias. We describe a case initially diagnosed as rapid atrial fibrillation, based on 12-lead surface ECG (especially the limb leads) and monitor tracing. The arrhythmia was resistant to beta blockers. Because of the at times apparently regular rhythm, an esophageal ECG recording was performed, and adenosine was administered. When the presumed atrial fibrillation terminated after sodium pento...

Catheter Ablation of a Complex Atrial Tachycardia after Surgical Repair of Tetralogy of Fallot Guided by Combined Noncontact and Contact Mapping

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Eitaro Fujii, MD

2010-01-01

Full Text Available A 34-year-old man with a surgically repaired Tetralogy of Fallot complained of palpitation, fatigue, and presyncope. A 12-lead ECG showed atrial tachycardia with a cycle length of 250 ms and a P wave morphology positive in leads II, III and aVF, and negative in lead V1. Although the EnSite system (version 6.OJ made use of noncontact mapping to delineate the counterclockwise reentry around the crista tenninalis, it was difficult to rule out the incisional atrial reentry because the location of the surgical incision was far from the multi-electrode array. Since the bipolar contact mapping of the EnSite system revealed the location of the atriotomy incision, entrainment mapping during the tachycardia demonstrated the critical reentry circuit around the crista terminalis. Radiofrequency ablation targeting the critical isthmus from the lower position of the crista terminalis to the posterior dense scar which was continuous with the inferior vena cava, and to the atriotomy scar, eliminated the tachycardia.

Molecular diagnostics of catecholaminergic polymorphic ventricular tachycardia using denaturing high-performance liquid chromatography and sequencing

NARCIS (Netherlands)

Postma, Alex V.; Bhuiyan, Zahurul A.; Bikker, Hennie

2006-01-01

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease characterized by adrenergic-induced arrhythmias in the form of bidirectional and PVT. CPVT is a distinct clinical entity associated with a high mortality rate of up to 50% by the age of 30 yr. Recently, the

P-Wave Amplitude and PR Changes in Patients With Inappropriate Sinus Tachycardia: Findings Supportive of a Central Mechanism.

Science.gov (United States)

Field, Michael E; Donateo, Paolo; Bottoni, Nicola; Iori, Matteo; Brignole, Michele; Kipp, Ryan T; Kopp, Douglas E; Leal, Miguel A; Eckhardt, Lee L; Wright, Jennifer M; Walsh, Kathleen E; Page, Richard L; Hamdan, Mohamed H

2018-04-19

The mechanism of inappropriate sinus tachycardia (IST) remains incompletely understood. We prospectively compared 3 patient groups: 11 patients with IST (IST Group), 9 control patients administered isoproterenol (Isuprel Group), and 15 patients with cristae terminalis atrial tachycardia (AT Group). P-wave amplitude in lead II and PR interval were measured at a lower and higher heart rate (HR1 and HR2, respectively). P-wave amplitude increased significantly with the increase in HR in the IST Group (0.16±0.07 mV at HR1=97±12 beats per minute versus 0.21±0.08 mV at HR2=135±21 beats per minute, P =0.001). The average increase in P-wave amplitude in the IST Group was similar to the Isuprel Group ( P =0.26). PR interval significantly shortened with the increases in HR in the IST Group (146±15 ms at HR1 versus 128±16 ms at HR2, P PR interval was noted in the Isuprel Group ( P =0.6). In contrast, patients in the atrial tachycardia Group experienced PR lengthening during atrial tachycardia when compared with baseline normal sinus rhythm (153±25 ms at HR1=78±17 beats per minute versus 179±29 ms at HR2=140±28 beats per minute, P PR shortening similar to what is seen in healthy controls following isoproterenol infusion. The increase in P-wave amplitude and absence of PR lengthening in IST support an extrinsic mechanism consistent with a state of sympatho-excitation with cephalic shift in sinus node activation and enhanced atrioventricular nodal conduction. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Postural tachycardia in hypermobile Ehlers-Danlos syndrome: A distinct subtype?

Science.gov (United States)

Miglis, Mitchell G; Schultz, Brittany; Muppidi, Srikanth

2017-12-01

It is not clear if patients with postural tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (hEDS) differ from patients with POTS due to other etiologies. We compared the results of autonomic testing and healthcare utilization in POTS patients with and without hEDS. Patients with POTS+hEDS (n=20) and POTS controls without hypermobility (n=20) were included in the study. All patients underwent autonomic testing, and the electronic medical records were reviewed to determine the number and types of medications patients were taking, as well as the number of outpatient, emergency department, and inpatient visits over the prior year. Patients with hEDS had twice as many outpatient visits (21 v. 10, p=0.012), were taking more prescription medications (8 vs. 5.5, p=0.030), and were more likely to see a pain physician (70% vs 25%, p=0.005). Autonomic testing demonstrated a slight reduction in heart rate variability and slightly lower blood pressures on tilt table testing in hEDS patients, however for most patients these variables remained within the range of normal. Orthostatic tachycardia on tilt table testing was greater in POTS controls (46bpm vs 39bpm, p=0.018). Abnormal QSweat responses were common in both groups (38% of POTS+hEDS and 36% of POTS controls). While autonomic testing results were not significantly different between groups, patients with POTS+hEDS took more medications and had greater markers of healthcare utilization, with chronic pain likely playing a prominent role. Copyright © 2017 Elsevier B.V. All rights reserved.

Autonomic control of heart rate during orthostasis and the importance of orthostatic-tachycardia in the snake Python molurus.

Science.gov (United States)

Armelin, Vinicius Araújo; da Silva Braga, Victor Hugo; Abe, Augusto Shinya; Rantin, Francisco Tadeu; Florindo, Luiz Henrique

2014-10-01

Orthostasis dramatically influences the hemodynamics of terrestrial vertebrates, especially large and elongated animals such as snakes. When these animals assume a vertical orientation, gravity tends to reduce venous return, cardiac filling, cardiac output and blood pressure to the anterior regions of the body. The hypotension triggers physiological responses, which generally include vasomotor adjustments and tachycardia to normalize blood pressure. While some studies have focused on understanding the regulation of these vasomotor adjustments in ectothermic vertebrates, little is known about regulation and the importance of heart rate in these animals during orthostasis. We acquired heart rate and carotid pulse pressure (P PC) in pythons in their horizontal position, and during 30 and 60° inclinations while the animals were either untreated (control) or upon muscarinic cholinoceptor blockade and a double autonomic blockade. Double autonomic blockade completely eradicated the orthostatic-tachycardia, and without this adjustment, the P PC reduction caused by the tilts became higher than that which was observed in untreated animals. On the other hand, post-inclinatory vasomotor adjustments appeared to be of negligible importance in counterbalancing the hemodynamic effects of gravity. Finally, calculations of cardiac autonomic tones at each position revealed that the orthostatic-tachycardia is almost completely elicited by a withdrawal of vagal drive.

Pulmonary damage following right ventricular outflow tachycardia ablation in a child: When electroanatomical mapping isn't good enough.

Science.gov (United States)

Bansal, Neha; Kobayashi, Daisuke; Karpawich, Peter P

2017-11-11

A 14-year-old female was referred for severe pulmonary valve insufficiency after undergoing radiofrequency ablation for a right ventricular outflow tract tachycardia that originated in the proximal pulmonary artery at 10 years of age. Clinical records indicated that ablation was guided solely by electrograms and electroanatomical mapping. Due to myocardial tissue extensions, mapping failed to identify the level of the pulmonary valve annulus, which resulted in delivery of energy on the valve proper and into the pulmonary artery. She developed severe pulmonary valve insufficiency and moderate proximal pulmonary artery stenosis necessitating intravascular stent placement 4 years later with an associated transcatheter valve. Although the nonfluoroscopic approach during ablation has gained wide acceptance for use in children, this report highlights the benefits of adjunctive imaging to identify the precise location of the pulmonary valve when ablation therapy is contemplated in the right ventricle outflow tract. © 2017 Wiley Periodicals, Inc.

Unmappable ventricular tachycardia after an old myocardial infarction. Long-term results of substrate modification in patients with an implantable cardioverter defibrillator.

Science.gov (United States)

Alzand, B S N; Timmermans, C C M M; Wellens, H J J; Dennert, R; Philippens, S A M; Portegijs, P J M; Rodriguez, L M

2011-08-01

The frequent occurrence of ventricular tachycardia can create a serious problem in patients with an implantable cardioverter defibrillator. We assessed the long-term efficacy of catheter-based substrate modification using the voltage mapping technique of infarct-related ventricular tachycardia and recurrent device therapy. The study population consisted of 27 consecutive patients (age 68 ± 8 years, 25 men, mean left ventricular ejection fraction 31 ± 9%) with an old myocardial infarction and multiple and/or hemodynamically not tolerated ventricular tachycardia necessitating repeated device therapy. A total of 31 substrate modification procedures were performed using the three-dimensional electroanatomical mapping system. Patients were followed up for a median of 23.5 (interquartile range 6.5-53.2) months before and 37.8 (interquartile range 11.7-71.8) months after ablation. Antiarrhythmic drugs were not changed after the procedure, and were stopped 6 to 9 months after the procedure in patients who did not show ventricular tachycardia recurrence. Median ventricular tachycardias were 1.6 (interquartile range 0.7-6.7) per month before and 0.2 (interquartile range 0.00-1.3) per month after ablation (P = 0.006). Nine ventricular fibrillation episodes were registered in seven patients before and two after ablation (P = 0.025). Median antitachycardia pacing decreased from 1.6 (interquartile range 0.01-5.5) per month before to 0.18 (interquartile range 0.00-1.6) per month after ablation (P = 0.069). Median number of shocks decreased from 0.19 (interquartile range 0.04-0.81) per month before to 0.00 (interquartile range 0.00-0.09) per month after ablation (P = 0.001). One patient had a transient ischemic attack during the procedure, and another developed pericarditis. Nine patients died during follow-up, eight patients due to heart failure and one patient during valve surgery. Catheter-based substrate modification using voltage mapping results in a long-lasting reduction

Benign joint hypermobility syndrome with postural orthostatic tachycardia syndrome and acrocyanosis

Directory of Open Access Journals (Sweden)

Navjyot Kaur

2017-01-01

Full Text Available Benign joint hypermobility syndrome (BJHS and postural orthostatic tachycardia syndrome (POTS are two common conditions which are frequently overlooked. While patients with BJHS are known to attend rheumatology, orthopedic, and medical outpatient departments for years with polyarthralgia; POTS is commonly misdiagnosed as anxiety neurosis or panic attack. Described first in 1940, POTS is one of the common causes of orthostatic symptoms in females. POTS is defined as orthostatic intolerance associated with tachycardia exceeding 120 beats/min (bpm or an increase in the heart rate (HR of 30 bpm from baseline within 10 min of changing the posture from a lying to standing position, in the absence of long-term chronic diseases and medications that affect the autonomic or vascular tone. Classified as primary and secondary, the underlying pathophysiological mechanism is assumed to be a failure of peripheral vascular resistance to increase sufficiently in response to orthostatic stress, and consequently, venous pooling occurs in the legs resulting in decreased venous return to the heart. This is compensated by an increase in HR and inotropy. We present a case of BJHS, who reported to us with recurrent episodes of syncope and presyncope and was diagnosed to have POTS secondary to his hypermobility syndrome. Although the tilt-table test is the gold standard for diagnosis of POTS, this case highlights the importance of bedside tests in evaluation of orthostatic symptoms and in diagnosis of relatively common but frequently overlooked syndrome.

vQRS Based on Hybrids of CNT with PMMA-POSS and PS-POSS Copolymers to Reach the Sub-PPM Detection of Ammonia and Formaldehyde at Room Temperature Despite Moisture

Directory of Open Access Journals (Sweden)

Abhishek Sachan

2017-07-01

Full Text Available Nanocomposite-based quantum resistive vapour sensors (vQRS have been developed from the assembly of hybrid copolymers of polyhedral oligomeric silsesquioxane (POSS and poly(methyl methacrylate (PMMA or poly(styrene (PS with carbon nanotubes (CNT. The originality of the resulting conducting architecture is expected to be responsible for the ability of the transducer to detect sub-ppm concentrations of ammonia and formaldehyde at room temperature despite the presence of humidity. In particular, the boosting effect of POSS is evidenced in CNT-based nanocomposite vQRS. The additive fabrication by spraying layer-by-layer provides (sLbL is an effective method to control the reproducibility of the transducers’ chemo-resistive responses. In dry atmosphere, the two types of sensors showed a high sensitivity towards both hazardous gases, as they were able to detect 300 ppb of formaldehyde and 500 ppb of ammonia with a sufficiently good signal to noise ratio (SNR > 10. They also exhibited a quick response times less than 5 s for both vapours and, even in the presence of 100 ppm of water, they were able to detect small amounts of gases (1.5 ppm of NH3 and 9 ppm of CH2O. The results suggest promising applications of POSS-based vQRS for air quality or volatolome monitoring.

Bivariable analysis of ventricular late potentials in high resolution ECG records

International Nuclear Information System (INIS)

Orosco, L; Laciar, E

2007-01-01

In this study the bivariable analysis for ventricular late potentials detection in high-resolution electrocardiographic records is proposed. The standard time-domain analysis and the application of the time-frequency technique to high-resolution ECG records are briefly described as well as their corresponding results. In the proposed technique the time-domain parameter, QRSD and the most significant time-frequency index, EN QRS are used like variables. A bivariable index is defined, that combines the previous parameters. The propose technique allows evaluating the risk of ventricular tachycardia in post-myocardial infarct patients. The results show that the used bivariable index allows discriminating between the patient's population with ventricular tachycardia and the subjects of the control group. Also, it was found that the bivariable technique obtains a good valuation as diagnostic test. It is concluded that comparatively, the valuation of the bivariable technique as diagnostic test is superior to that of the time-domain method and the time-frequency technique evaluated individually

Cardiovascular profile in postural orthostatic tachycardia syndrome and Ehlers-Danlos syndrome type III.

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Cheng, Jem L; Au, Jason S; Guzman, Juan C; Morillo, Carlos A; MacDonald, Maureen J

2017-04-01

The cardiovascular profile of postural orthostatic tachycardia syndrome + Ehlers-Danlos syndrome hypermobility type (POTS + EDSIII) has not been described, despite suggestions that it plays a role in orthostatic intolerance. We studied nine individuals diagnosed with POTS + EDSIII and found that the arterial stiffness and cardiac profiles of patients with POTS + EDSIII were comparable to those of age- and sex-matched controls, suggesting an alternate explanation for orthostatic intolerance.

Phrenic nerve protection via packing of gauze into the pericardial space during ablation of cristal atrial tachycardia in a child.

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Takahashi, Kazuhiro; Fuchigami, Tai; Nabeshima, Taisuke; Sashinami, Arata; Nakayashiro, Mami

2016-03-01

The success of catheter ablation of focal atrial tachycardia is limited by possible collateral damage to the phrenic nerve. Protection of the phrenic nerve is required. Here we present a case of a 9-year-old girl having a history of an unsuccessful catheter ablation of a focal atrial tachycardia near the crista terminalis (because of proximity of the phrenic nerve) who underwent a successful ablation by means of a novel technique for phrenic nerve protection: packing of gauze into the pericardial space. This method is a viable approach for patients with a failed endocardial ablation due to the proximity of the phrenic nerve.

Malignant ventricular tachycardia in acromegaly: a case report

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Zhe An

Full Text Available CONTEXT: In patients with acromegaly, cardiovascular complications are the main cause of death; sudden death has been associated with ventricular tachyarrhythmias. In other patients with life-threatening malignant ventricular tachyarrhythmias, surgical placement of an implantable cardioverter-defibrillator (ICD has proved highly effective in reducing sudden death rates. CASE REPORT: The present article reports the case of a 50-year-old male acromegalic patient who presented symptoms of syncope induced by ventricular tachycardia. An ICD was surgically implanted and a pituitary adenoma, which was responsible for the acromegaly, was completely removed in the same procedure. The surgery was successful and the ventricular arrhythmias were effectively terminated. During six months of follow-up, no documented arrhythmic episodes occurred. CONCLUSION: In patients with acromegaly, malignant ventricular tachyarrhythmia might be effectively controlled by implantation of an ICD and surgical removal of the pituitary adenoma.

"Heart rate-dependent" electrocardiographic diagnosis of left ventricular hypertrophy.

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Madias, John E

2013-05-01

A case is presented revealing the common phenomenon of heart rate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heart rate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. ©2012, The Author. Journal compilation ©2012 Wiley Periodicals, Inc.

Postural tachycardia syndrome and other forms of orthostatic intolerance in Ehlers-Danlos syndrome.

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Roma, Maria; Marden, Colleen L; De Wandele, Inge; Francomano, Clair A; Rowe, Peter C

2018-03-05

To review the association between orthostatic intolerance syndromes and both joint hypermobility and Ehlers-Danlos syndrome, and to propose reasons for identifying hereditary connective tissue disorders in those with orthostatic intolerance in the context of both clinical care and research. We searched the published peer-reviewed medical literature for papers reporting an association between joint hypermobility or Ehlers-Danlos syndrome and orthostatic intolerance. We identified 10 relevant papers. Although methodological variability between studies introduces some limitations, the published literature consistently identifies a significantly higher prevalence of orthostatic intolerance symptoms in patients with joint hypermobility or Ehlers-Danlos syndrome than in healthy controls, and a significantly higher prevalence of cardiovascular and autonomic abnormalities both at rest and during orthostatic challenge. Postural tachycardia syndrome is the most commonly recognized circulatory disorder. The severity of orthostatic symptoms in those with EDS correlates with impairments in quality of life. There is a strong association between several forms of cardiovascular dysfunction, most notably postural tachycardia syndrome, and joint hypermobility or Ehlers-Danlos syndrome. We propose that recognition of joint hypermobility and Ehlers-Danlos syndrome among those with orthostatic intolerance syndromes has the potential to improve clinical care and the validity of research findings. Copyright © 2018 Elsevier B.V. All rights reserved.

Unexplored relationship of sleep disturbances linked to suicidal ideation and behavior in postural orthostatic tachycardia syndrome

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Shafqat MN

2017-07-01

Full Text Available Muhammad Nabeel Shafqat,1 Muhammad Aadil,2 Maria Shoaib31Department of Medicine, University of Medical Sciences “Serafin Ruiz de Zarate” Villa Clara (UCMVC, Villa Clara, Cuba; 2Department of Psychiatry, Rush University Medical Center, Chicago, IL, USA; 3Department of Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, PakistanWe read with great interest the currently published article written by Pederson and Brook1 entitled “Sleep disturbance linked to suicidal ideation in postural orthostatic tachycardia syndrome”. Awareness of postural orthostatic tachycardia syndrome (POTS has increased in recent years. However, sleep disturbance has not been thoroughly investigated as a cause of increased suicidal risk in patients with POTS. We would like to applaud the authors on conducting this novel cross-sectional study to understand and highlight the potential relationship between sleep disturbances and increased risk of suicide in patients suffering from POTS.1View the original paper by Pederson and Brook.

Identification of a sudden cardiac death susceptibility locus at 2q24.2 through genome-wide association in European ancestry individuals.

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Dan E Arking

2011-06-01

Full Text Available Sudden cardiac death (SCD continues to be one of the leading causes of mortality worldwide, with an annual incidence estimated at 250,000-300,000 in the United States and with the vast majority occurring in the setting of coronary disease. We performed a genome-wide association meta-analysis in 1,283 SCD cases and >20,000 control individuals of European ancestry from 5 studies, with follow-up genotyping in up to 3,119 SCD cases and 11,146 controls from 11 European ancestry studies, and identify the BAZ2B locus as associated with SCD (P = 1.8×10(-10. The risk allele, while ancestral, has a frequency of ~1.4%, suggesting strong negative selection and increases risk for SCD by 1.92-fold per allele (95% CI 1.57-2.34. We also tested the role of 49 SNPs previously implicated in modulating electrocardiographic traits (QRS, QT, and RR intervals. Consistent with epidemiological studies showing increased risk of SCD with prolonged QRS/QT intervals, the interval-prolonging alleles are in aggregate associated with increased risk for SCD (P = 0.006.

The roles of the Q (q) wave in lead I and QRS frontal axis for diagnosing loss of left ventricular capture during cardiac resynchronization therapy.

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Cao, Yuan-Yuan; Su, Yan-Gang; Bai, Jin; Wang, Wei; Wang, Jing-Feng; Qin, Sheng-Mei; Ge, Jun-Bo

2015-01-01

Loss of left ventricular (LV) capture may lead to deterioration of heart failure in patients with cardiac resynchronization therapy (CRT). Recognition of loss of LV capture in time is important in clinical practice. A total of 422 electrocardiograms were acquired and analyzed from 53 CRT patients at 8 different pacing settings (LV only, right ventricle [RV] only, biventricular [BV] pacing with LV preactivation of 60, 40, 20, and 0 milliseconds and RV preactivation of 20 and 40 milliseconds). A modified Ammann algorithm by adding a third step-presence of Q (q, or QS) wave-to the original 2-step Ammann algorithm and a QRS axis shift method were devised to identify the loss of LV capture. The accuracy of modified Ammann algorithm was significantly higher than that of Ammann algorithm (78.9% vs. 69.1%, P capture. The LV preactivation, or simultaneous BV activation and LV lead positioned in nonposterior or noninferior wall can increase the diagnostic power of the modified Ammann algorithm and QRS axis shift method. © 2014 Wiley Periodicals, Inc.

New exome data question the pathogenicity of genetic variants previously associated with catecholaminergic polymorphic ventricular tachycardia

DEFF Research Database (Denmark)

Jabbari, Javad; Jabbari, Reza; Nielsen, Morten Wagner

2013-01-01

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal, rare hereditary disease with an estimated prevalence of 1:10 000. The genetic variants that cause CPVT are usually highly penetrant. To date, about 189 variants in 5 genes (RYR2, CASQ2, CALM1, TRND, and KCNJ2) have been...

THE CLINICAL-SIGNIFICANCE OF CORONARY ANATOMY IN POST-INFARCT PATIENTS WITH LATE SUSTAINED VENTRICULAR-TACHYCARDIA OR VENTRICULAR-FIBRILLATION

NARCIS (Netherlands)

WIESFELD, ACP; CRIJNS, HJGM; HILLEGE, HL; TUININGA, YS; LIE, KI

The role of ischaemia in post-infarct patients with ventricular tachyarrhythmias is not firmly established Using coronary angiography, 82 post-infarct patients with sustained ventricular tachycardia or fibrillation were subclassified into three groups. Fourteen patients (17%) had significant

Successful radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia in a patient with dextrocardia due to unilateral pulmonary agenesis: a case report

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Aksu T

2015-02-01

Full Text Available Tolga Aksu, Tumer Erdem Guler, Ebru Golcuk, Ismail Erden, Kazim Serhan Ozcan Department of Cardiology, Kocaeli Derince Education and Research Hospital, Derince, Kocaeli, Turkey Abstract: Radiofrequency catheter ablation of the slow pathway is considered to be the treatment of choice for patients with atrioventricular nodal reentrant tachycardia. We report a 34-year-old female with mirror image dextrocardia due to unilateral pulmonary agenesis who underwent successful slow pathway ablation for typical atrioventricular nodal reentrant tachycardia. Using contrast injection, cardiac anatomy was identified in a short time and successfully ablated. Keywords: dextrocardia, AVNRT, ablation, pulmonary agenesis

Hyperkalemia on ECG

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Bryson Hicks

2016-09-01

Full Text Available History of present illness: A 34-year-old diabetic female presented to the emergency department with chest pain status-post AICD firing. She described the pain as a “12 out of 10” which woke her from sleep at 0200, one hour prior to arrival. Vitals were unremarkable. She had no known history of renal failure. Due to frequent ED visits for chronic pain, patient had difficult vascular access and nursing was initially unable to obtain IV access. An abnormal rhythm was noted on the cardiac monitor, and ECG was ordered. Significant findings: Initial ECG shows tall, peaked T waves, most prominently in V3 and V4, as well as QRS widening. These findings are consistent with hyperkalemia, which was promptly treated. Follow-up ECG post-treatment shows narrowing of the QRS complexes and normalization of peaked T waves. Discussion: The etiology of hyperkalemia may be due to an acute insult such as crush injury, drug side effect, or in acute renal failure, but may also occur in the setting of a chronic insult such as chronic kidney disease.1 As potassium rises, several abnormalities can be identified on ECG. Initially the T waves become peaked and the QRS complexes widen.2,3 This can devolve into a wide complex rhythm, ventricular tachycardia, ventricular fibrillation, or asystole. Patients may also experience systemic symptoms such as weakness or paralysis.1 In this particular case, labs showed a potassium of 7.6-mmol/L after initial treatment (see repeat EKG. While the incidence of hyperkalemia in the general population is not defined, the incidence in hospitalized patients is 1.3-10%.4-8 Impaired kidney function is the most common risk factor found in 33-83% of affected patients.4,5,8,9 Treatment for hyperkalemia generally includes IV insulin and IV dextrose and nebulized albuterol for intracellular shift of potassium, IV furosemide and IV fluids for dilution and renal excretion of furosemide, and IV calcium for stabilization of cardiac membranes.2,3

Objective Sleep Assessments in Patients with Postural Tachycardia Syndrome using Overnight Polysomnograms

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Bagai, Kanika; Peltier, Amanda C.; Malow, Beth A.; Diedrich, André; Shibao, Cyndya A.; Black, Bonnie K.; Paranjape, Sachin Y.; Orozco, Carlos; Biaggioni, Italo; Robertson, David; Raj, Satish R.

2016-01-01

Study Objectives: Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness, and diminished quality of life. The study objective was to assess objective sleep quality in POTS patients using overnight polysomnography. Methods: We studied 16 patients with POTS and 15 healthy control subjects performing daytime autonomic functions tests and overnight polysomnography at the Vanderbilt Clinical Research Center. Results: There were no significant differences in the objective sleep parameters including sleep efficiency, sleep onset latency, wake time after sleep onset, REM latency, percentage of time spent in N1, N2, N3, and REM sleep, arousal index, apnea-hypopnea index, or periodic leg movement index in POTS patients as compared with healthy control subjects. There were significant negative correlations between sleep efficiency and the change in HR from supine to stand (rs = −0.527; p = 0.036) Conclusions: POTS patients do not have significant differences in objective sleep parameters as compared to control subjects based on overnight polysomnograms. Activation of the sympathetic nervous system may contribute significantly to the hyper arousal state and worsening of subjective estimates of sleep quality as previously reported in POTS patients. Citation: Bagai K, Peltier AC, Malow BA, Diedrich A, Shibao CA, Black BK, Paranjape SY, Orozco C, Biaggioni I, Robertson D, Raj SR. Objective sleep assessments in patients with postural tachycardia syndrome using overnight polysomnograms. J Clin Sleep Med 2016;12(5):727–733. PMID:26951415

Ondas J de Osborn en hipotermia: Presentación de un caso poco frecuente en el trópico Osborn waves in hypothermia: One rare case in the tropic

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Eduardo Ramírez

2009-08-01

Full Text Available En 1953, el Doctor John Osborn describió la onda J en el electrocardiograma. La hipotermia (temperatura corporal menor a 35 grados centígrados inicialmente se asocia a taquicardia sinusal, pero con temperaturas menores a 32,2 grados centígrados se inicia la bradicardia sinusal, asociada a prolongación progresiva del intervalo PR, el complejo QRS y el intervalo QTc. De otra parte, a temperaturas por debajo de 30 grados centígrados, 80% de los pacientes presenta ondas J o de Osborn, que consisten en una deflexión extra, al final del QRS, la cual se observa mejor en las derivaciones inferiores y laterales. Empeora a medida que la temperatura desciende y mejora en el momento en que al paciente se le incrementa su temperatura corporal. Este fenómeno no es raro en países con estaciones, pero en el trópico no es un hallazgo frecuente.Dr. John Osborn described J wave in the electrocardiogram 1953. Hypothermia (body temperature < 35°C is initially associated with sinus tachycardia, but with temperatures < 32.2°C, sinus bradycardia associated to progressive prolongation of PR interval, QRS complex and QTc interval, appears. Otherwise, at temperatures below 30°C, 80% patients present J or Osborn waves consisting of an extra deflection at the end of QRS, best depicted in inferior and lateral leads. They become more prominent as the temperature drops and gradually disappear with re-warming. This phenomenon is not rare in countries with 4 seasons but is not common in the tropics.

Prophylactic implantable defibrillator in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia and no prior ventricular fibrillation or sustained ventricular tachycardia.

LENUS (Irish Health Repository)

Corrado, Domenico

2010-09-21

The role of implantable cardioverter-defibrillator (ICD) in patients with arrhythmogenic right ventricular cardiomyopathy\\/dysplasia and no prior ventricular fibrillation (VF) or sustained ventricular tachycardia is an unsolved issue.

Delayed Onset of Atrial Fibrillation and Ventricular Tachycardia after an Automobile Lightning Strike.

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Drigalla, Dorian; Essler, Shannon E; Stone, C Keith

2017-11-01

Lightning strike is a rare medical emergency. The primary cause of death in lightning strike victims is immediate cardiac arrest. The mortality rate from lightning exposure can be as high as 30%, with up to 70% of patients left with significant morbidity. An 86-year-old male was struck by lightning while driving his vehicle and crashed. On initial emergency medical services evaluation, he was asymptomatic with normal vital signs. During his transport, he lost consciousness several times and was found to be in atrial fibrillation with intermittent runs of ventricular tachycardia during the unconscious periods. In the emergency department, atrial fibrillation persisted and he experienced additional episodes of ventricular tachycardia. He was treated with i.v. amiodarone and admitted to cardiovascular intensive care unit, where he converted to a normal sinus rhythm on the amiodarone drip. He was discharged home without rhythm-control medications and did not have further episodes of dysrhythmias on follow-up visits. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Lightning strikes are one of the most common injuries suffered from natural phenomenon, and short-term mortality ordinarily depends on the cardiac effects. This case demonstrates that the cardiac effects can be multiple, delayed, and recurrent, which compels the emergency physician to be vigilant in the initial evaluation and ongoing observation of patients with lightning injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

Complete atrio-ventricular septal defect and Wolf-Parkinson-White syndrome

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Gudrun Björkhem

2006-09-01

Full Text Available A full term female infant was born after 41 weeks of gestation, with a birth weight of 3815g and normal Apgar scores (9-10-10. Immediately after birth tachycardia was noted. An electrocardiogram (ECG showed a heart rate of 300 beats per minute (bpm and narrow QRS complexes. The newborn was clinically stable. She was admitted to the neonatal intensive care unite and an intravenous line was inserted for treatment with Adenosine. While preparing for Adenosine infusion her heart rate spontaneously decreased. Her ECG at presentation with normal heart rate is shown in figure1a. On auscultation, a soft systolic murmur was heard.

A case of short-coupled premature ventricular beat-induced ventricular fibrillation with early repolarization in the inferolateral leads

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Hidekazu Kondo, MD

2015-02-01

Full Text Available This case report describes a 19-year-old man with early repolarization (ER in the inferolateral leads and a normal QT interval who survived a cardiac arrest that was likely related to polymorphic ventricular tachycardia (VT. Electrocardiograms (ECGs also showed unifocal premature ventricular beats (PVBs with a relatively narrow QRS duration. A Holter ECG documented occasional short-coupled PVBs following non-sustained VTs. Pharmacological stress testing was also performed to assess the effects of anti-arrhythmic drugs on ER (the J wave and PVBs. We performed successful radiofrequency catheter ablation to prevent the recurrence of ventricular fibrillation after cardioverter-defibrillator implantation.

Local activation time sampling density for atrial tachycardia contact mapping: how much is enough?

Science.gov (United States)

Williams, Steven E; Harrison, James L; Chubb, Henry; Whitaker, John; Kiedrowicz, Radek; Rinaldi, Christopher A; Cooklin, Michael; Wright, Matthew; Niederer, Steven; O'Neill, Mark D

2018-02-01

Local activation time (LAT) mapping forms the cornerstone of atrial tachycardia diagnosis. Although anatomic and positional accuracy of electroanatomic mapping (EAM) systems have been validated, the effect of electrode sampling density on LAT map reconstruction is not known. Here, we study the effect of chamber geometry and activation complexity on optimal LAT sampling density using a combined in silico and in vivo approach. In vivo 21 atrial tachycardia maps were studied in three groups: (1) focal activation, (2) macro-re-entry, and (3) localized re-entry. In silico activation was simulated on a 4×4cm atrial monolayer, sampled randomly at 0.25-10 points/cm2 and used to re-interpolate LAT maps. Activation patterns were studied in the geometrically simple porcine right atrium (RA) and complex human left atrium (LA). Activation complexity was introduced into the porcine RA by incomplete inter-caval linear ablation. In all cases, optimal sampling density was defined as the highest density resulting in minimal further error reduction in the re-interpolated maps. Optimal sampling densities for LA tachycardias were 0.67 ± 0.17 points/cm2 (focal activation), 1.05 ± 0.32 points/cm2 (macro-re-entry) and 1.23 ± 0.26 points/cm2 (localized re-entry), P = 0.0031. Increasing activation complexity was associated with increased optimal sampling density both in silico (focal activation 1.09 ± 0.14 points/cm2; re-entry 1.44 ± 0.49 points/cm2; spiral-wave 1.50 ± 0.34 points/cm2, P density (0.61 ± 0.22 points/cm2 vs. 1.0 ± 0.34 points/cm2, P = 0.0015). Optimal sampling densities can be identified to maximize diagnostic yield of LAT maps. Greater sampling density is required to correctly reveal complex activation and represent activation across complex geometries. Overall, the optimal sampling density for LAT map interpolation defined in this study was ∼1.0-1.5 points/cm2. Published on behalf of the European Society of

[Analysis of pacemaker ECGs].

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Israel, Carsten W; Ekosso-Ejangue, Lucy; Sheta, Mohamed-Karim

2015-09-01

The key to a successful analysis of a pacemaker electrocardiogram (ECG) is the application of the systematic approach used for any other ECG without a pacemaker: analysis of (1) basic rhythm and rate, (2) QRS axis, (3) PQ, QRS and QT intervals, (4) morphology of P waves, QRS, ST segments and T(U) waves and (5) the presence of arrhythmias. If only the most obvious abnormality of a pacemaker ECG is considered, wrong conclusions can easily be drawn. If a systematic approach is skipped it may be overlooked that e.g. atrial pacing is ineffective, the left ventricle is paced instead of the right ventricle, pacing competes with intrinsic conduction or that the atrioventricular (AV) conduction time is programmed too long. Apart from this analysis, a pacemaker ECG which is not clear should be checked for the presence of arrhythmias (e.g. atrial fibrillation, atrial flutter, junctional escape rhythm and endless loop tachycardia), pacemaker malfunction (e.g. atrial or ventricular undersensing or oversensing, atrial or ventricular loss of capture) and activity of specific pacing algorithms, such as automatic mode switching, rate adaptation, AV delay modifying algorithms, reaction to premature ventricular contractions (PVC), safety window pacing, hysteresis and noise mode. A systematic analysis of the pacemaker ECG almost always allows a probable diagnosis of arrhythmias and malfunctions to be made, which can be confirmed by pacemaker control and can often be corrected at the touch of the right button to the patient's benefit.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-01-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Medical image of the week: Wolff-Parkinson-White syndrome

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Van Hook C

2017-04-01

Full Text Available No abstract available. Article truncated at 150 words. A 38-year-old man developed sustained rapid heart rate while rock climbing. The patient reported that he had experienced rare bouts of self-limited palpitations in the past. Blood pressure on arrival to the emergency department was 112/ 65 mm Hg. The patient’s initial EKG demonstrated a regular, narrow complex supraventricular tachycardia, with a rate of 232 (Figure 1. Intravenous adenosine was administered with no change in his rate or rhythm. The patient then received amiodarone by intravenous bolus, with subsequent conversion to sinus rhythm (Figure 2. Wolff-Parkinson-White (WPW syndrome is a congenital cardiac condition present in approximately 0.15% of the general population. WPW is characterized by the abnormal presence of conduction tissue that creates an accessory atrioventricular pathway and thus potentiates reentrant tachycardia (1. The classic resting EKG findings in WPW are: a shortened PR interval (less than 0.12 seconds, an indistinct initial upslope of the QRS complex (known as the …

Electrical cardioversion

Science.gov (United States)

Sucu, Murat; Davutoglu, Vedat; Ozer, Orhan

2009-01-01

External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The succcess rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately performed. PMID:19448376

[Cardioversion for paroxysmal supraventricular tachycardia during lung surgery in a patient with concealed Wolff-Parkinson-White syndrome].

Science.gov (United States)

Sato, Yoshiharu; Nagata, Hirofumi; Inoda, Ayako; Miura, Hiroko; Watanabe, Yoko; Suzuki, Kenji

2014-10-01

We report a case of paroxysmal supraventricular tachycardia (PSVT) that occurred during video-assisted thoracoscopic (VATS) lobectomy in a patient with concealed Wolff-Parkinson-White (WPW) syndrome. A 59-year-old man with lung cancer was scheduled for VATS lobectomy under general anesthesia. After inserting a thoracic epidural catheter, general anesthesia was induced with intravenous administration of propofol. Anesthesia was maintained with inhalation of desfurane in an air/oxygen mixture and intravenous infusion of remifentanil. Recurrent PSVT occurred three times, and the last episode of PSVT continued for 50 minutes regardless of administration of antiarrhythmic drugs. Synchronized electric shock via adhesive electrode pads on the patient's chest successfully converted PSVT back to normal sinus rhythm. The remaining course and postoperative period were uneventful. An electrophysiological study performed after hospital discharge detected concealed WPW syndrome, which had contributed to the development of atrioventricular reciprocating tachycardia. Concealed WPW syndrome is a rare, but critical complication that could possibly cause lethal atrial tachyarrhythmias during the perioperative period. In the present case, cardioversion using adhesive electrode pads briefly terminated PSVT in a patient with concealed WPW syndrome.

Noninvasive predictors of perioperative atrial arrhythmias in patients with tetralogy of Fallot undergoing pulmonary valve replacement.

Science.gov (United States)

Cortez, Daniel; Barham, Waseem; Ruckdeschel, Emily; Sharma, Nandita; McCanta, Anthony C; von Alvensleben, Johannes; Sauer, William H; Collins, Kathryn K; Kay, Joseph; Patel, Sonali; Nguyen, Duy T

2017-08-01

Patients with tetralogy of Fallot (TOF) have increased risk of atrial arrhythmias. A measure of atrial dispersion, the P-wave vector magnitude (Pvm), can identify patients at risk for perioperative atrial flutter (AFL) or intra-atrial re-entrant tachycardia (IART) in a large TOF cohort. We performed a blinded, retrospective analysis of 158 TOF patients undergoing pulmonary valve replacement between 1997 and 2015. History of AFL/IART was documented using electrocardiogram, Holter monitor, exercise stress test, implanted cardiac device, and electrophysiology study. P-R intervals, Pvm, QRS duration, and QRS vector magnitude were assessed from resting sinus-rhythm 12-lead electrocardiograms and identification of those with AFL/IART was determined. Fourteen patients (8.9%) were found to have AFL/IART. Pvm, QRS duration, and QRS vector magnitude significantly differentiated those with AFL/IART from those without on univariate analysis: 0.09 ± 0.04 vs 0.18 ± 0.07 mV, 161.3 ± 21.9 vs 137.7 ± 31.4 ms, and 1.2 (interquartile range, 1.0-1.2) vs 1.6 mV (1.0-2.3), respectively (P < 0.05 for each). The Pvm had the highest area under the ROC curve (0.88) and was the only significant predictor on multivariate analysis, with odds ratio of 0.02 (95% confidence interval: 0.01-0.53). P-R duration, MRI volumes, and right-heart hemodynamics did not significantly differentiate those with vs those without AFL/IART. In TOF patients undergoing pulmonary valve replacement, Pvm has significant value in predicting those with perioperative AFL/IART. These clinical features may help further evaluate TOF patients at risk for perioperative atrial arrhythmias. Prospective studies are warranted. © 2017 Wiley Periodicals, Inc.

Risk factors and predictors of Torsade de pointes ventricular tachycardia in patients with left ventricular systolic dysfunction receiving Dofetilide

DEFF Research Database (Denmark)

Pedersen, Henriette Sloth; Elming, Hanne; Seibaek, Marie

2007-01-01

The purpose of this study was to identify risk factors of Torsade de pointes (TdP) ventricular tachycardia in patients medicated with a class III antiarrhythmic drug (dofetilide) and left ventricular systolic dysfunction with heart failure (HF) or recent myocardial infarction (MI). The 2 Danish...

Identifying an evidence-based model of therapy for the pre-hospital emergency management of supraventricular tachycardia

OpenAIRE

Smith, Gavin

2017-01-01

This thesis provides a comprehensive reporting of the work undertaken to identify evidence supporting pre-hospital management of supraventricular tachycardia (SVT), delivering an evidence base for paramedic treatment of these patients. The literature search identified absences in evidence supporting therapies used within existing clinical guidelines. The vagal manoeuvres, the simplest and least invasive therapy to employ in the stable patient, were insufficiently evidenced regarding technique...

Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest

Institute of Scientific and Technical Information of China (English)

Pablo; Salinas; Esteban; Lopez-de-Sa; Laura; Pena-Conde; Ana; Viana-Tejedor; Juan; Ramon; Rey-Blas; Eduardo; Armada; Jose; Luis; Lopez-Sendon

2015-01-01

AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34℃. TH was obtained with cool fluid infusion or a specific intravascular device. Twelvelead ECG before,during,and after TH,as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period,47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG,recorded at 25 mm/s and 10 mm/m V. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm,RR,PR,QT and corrected QT(QTc by Bazett formula,measured in lead v2) intervals,QRS duration,presence of Osborn’s J wave and U wave,as well as ST segment displacement and T wave amplitude in leads Ⅱ,v2 and v5.RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming(P < 0.0005,both). There was a nonsignificant prolongation of the PR interval during TH and a significant decrease with rewarming(P = 0.041). QRS duration significantly prolonged(P = 0.041) with TH and shortened back(P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms(P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms(P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia(19.1%),followed by severe bradycardia or paced rhythm(10.6%),accelerated nodal rhythm(8.5%) and atrial fibrillation(6.4%). No life threatening arrhythmias(sustained ventricular tachycardia,polymorphic ventricular tachycardia or ventricular fibrillation) occurred

Zero-fluoroscopy cryothermal ablation of atrioventricular nodal re-entry tachycardia guided by endovascular and endocardial catheter visualization using intracardiac echocardiography (Ice&ICE Trial).

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Luani, Blerim; Zrenner, Bernhard; Basho, Maksim; Genz, Conrad; Rauwolf, Thomas; Tanev, Ivan; Schmeisser, Alexander; Braun-Dullaeus, Rüdiger C

2018-01-01

Stochastic damage of the ionizing radiation to both patients and medical staff is a drawback of fluoroscopic guidance during catheter ablation of cardiac arrhythmias. Therefore, emerging zero-fluoroscopy catheter-guidance techniques are of great interest. We investigated, in a prospective pilot study, the feasibility and safety of the cryothermal (CA) slow-pathway ablation in patients with symptomatic atrioventricular-nodal-re-entry-tachycardia (AVNRT) using solely intracardiac echocardiography (ICE) for endovascular and endocardial catheter visualization. Twenty-five consecutive patients (mean age 55.6 ± 12.0 years, 17 female) with ECG-documentation or symptoms suggesting AVNRT underwent an electrophysiology study (EPS) in our laboratory utilizing ICE for catheter navigation. Supraventricular tachycardia was inducible in 23 (92%) patients; AVNRT was confirmed by appropriate stimulation maneuvers in 20 (80%) patients. All EPS in the AVNRT subgroup could be accomplished without need for fluoroscopy, relying solely on ICE-guidance. CA guided by anatomical location and slow-pathway potentials was successful in all patients, median cryo-mappings = 6 (IQR:3-10), median cryo-ablations = 2 (IQR:1-3). Fluoroscopy was used to facilitate the trans-septal puncture and localization of the ablation substrate in the remaining 3 patients (one focal atrial tachycardia and two atrioventricular-re-entry-tachycardias). Mean EPS duration in the AVNRT subgroup was 99.8 ± 39.6 minutes, ICE guided catheter placement 11.9 ± 5.8 minutes, time needed for diagnostic evaluation 27.1 ± 10.8 minutes, and cryo-application duration 26.3 ± 30.8 minutes. ICE-guided zero-fluoroscopy CA in AVNRT patients is feasible and safe. Real-time visualization of the true endovascular borders and cardiac structures allow for safe catheter navigation during the ICE-guided EPS and might be an alternative to visualization technologies using geometry reconstructions. © 2017 Wiley Periodicals, Inc.

Tachycardia-Induced Right Heart Failure and Severe Tricuspid Regurgitation That Improved with Medication.

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Yang, Young Ae; Yang, Dong Heon; Kim, Hong Nyun; Kwon, Sang Hoon; Jang, Se Young; Bae, Myung Hwan; Lee, Jang Hoon; Chae, Shung Chull

2015-12-01

Secondary tricuspid regurgitation (TR) primarily develops due to left heart failure or primary pulmonary diseases. Tricuspid annular dilation, which is commonly caused by right ventricular volume and pressure overload followed by right ventricle dilation, is believed to be the main mechanism underlying secondary TR. It is reported that once the tricuspid annulus is dilated, its size cannot spontaneously return to normal, and it may continue to dilate. These reports also suggest the use of an aggressive surgical approach for secondary TR. In the present report, we describe a case of tachycardia-induced severe TR that was completely resolved without the need for surgery.

[Fatal flecainide intoxication in a 17-year-old girl].

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Dokter, M; Talarico, G; Armbrust, S; Below, E; Bockholdt, B

2018-05-01

A 17-year-old girl was found vomiting and somnolent at home and was taken to a hospital. The girl initially presented with ventricular tachycardia with broad QRS complexes which was very difficult to control. During the course a subsequent cardiogenic shock developed and despite exhaustion of all therapeutic options the fatal outcome could not be averted. The medicolegal autopsy revealed no evidence of any form of violence but the signs of medical treatment. Furthermore, no pathology of internal organs was detected. The toxicological analyses revealed a lethal intoxication with flecainide as the cause of death. The investigations of the police indicated that the girl took flecainide in suicidal intention.

Therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia and the risk factors for postoperative recurrence.

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Li, Chunli; Jia, Libo; Wang, Zhenzhou; Niu, Ling; An, Xinjiang

2018-05-01

The present study investigated the therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia (SVT), and explored the risk factors for postoperative recurrence. A total of 312 patients with pediatric SVT were selected in the Affiliated Children's Hospital of Xuzhou Medical University from April, 2011 to March, 2017. All the patients were subjected to radiofrequency ablation, and clinical data were retrospectively analyzed. Tilt table test was performed before and after treatment, and heart rate, systolic and diastolic blood pressure before and after treatment were compared. Plasma levels of D-dimer (D-D), platelet α-granule membrane protein (GMP-140) and thrombin-antithrombin III complex (TAT) were detected by enzyme-linked immunosorbent assay before treatment, immediately after radiofrequency oblation, and at 1, 3 and 7 days after treatment. Treatment outcomes were compared between the atrioventricular reentrant tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) groups. Risk factors for postoperative recurrence were analyzed. Supine position heart rate after treatment was not significantly different from that before treatment (P>0.05), while the upright position heart rate was significantly increased after treatment (P0.05). No significant difference in radiofrequency ablation rate, recurrence rate and incidence of complications were found between the AVRT and AVNRT groups (P>0.05). After radiofrequency, the levels of D-D, GMP-140 and TAT ablation showed an upward trend, but decreased at day 7 to reach preoperative levels. Logistic regression analysis revealed that residual slow pathway (OR=6.718, P=0.005) and inaccurate targeting (OR=2.815, P=0.007) were independent risk factors for postoperative recurrence (Pradiofrequency ablation can damage the cardiac vagal nerve, resulting in an increase in the heart rate after ablation during the course of the tilt table test and changed hemagglutination state

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

Energy Technology Data Exchange (ETDEWEB)

El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-02-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE{sub 2}) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS{sub PE} and BRS{sub SNP}). Nicotine (100 μg/kg i.v.) reduced BRS{sub SNP} in OVX rats but not in proestrus or OVXE{sub 2} rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS{sub PE} was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS{sub SNP} interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS{sub SNP} attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E{sub 2} against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Four faces of baroreflex failure: hypertensive crisis, volatile hypertension, orthostatic tachycardia, and malignant vagotonia

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Ketch, Terry; Biaggioni, Italo; Robertson, RoseMarie; Robertson, David

2002-01-01

BACKGROUND: The baroreflex normally serves to buffer blood pressure against excessive rise or fall. Baroreflex failure occurs when afferent baroreceptive nerves or their central connections become impaired. In baroreflex failure, there is loss of buffering ability, and wide excursions of pressure and heart rate occur. Such excursions may derive from endogenous factors such as stress or drowsiness, which result in quite high and quite low pressures, respectively. They may also derive from exogenous factors such as drugs or environmental influences. METHODS AND RESULTS: Impairment of the baroreflex may produce an unusually broad spectrum of clinical presentations; with acute baroreflex failure, a hypertensive crisis is the most common presentation. Over succeeding days to weeks, or in the absence of an acute event, volatile hypertension with periods of hypotension occurs and may continue for many years, usually with some attenuation of pressor surges and greater prominence of depressor valleys during long-term follow-up. With incomplete loss of baroreflex afferents, a mild syndrome of orthostatic tachycardia or orthostatic intolerance may appear. Finally, if the baroreflex failure occurs without concomitant destruction of the parasympathetic efferent vagal fibers, a resting state may lead to malignant vagotonia with severe bradycardia and hypotension and episodes of sinus arrest. CONCLUSIONS: Although baroreflex failure is not the most common cause of the above conditions, correct differentiation from other cardiovascular disorders is important, because therapy of baroreflex failure requires specific strategies, which may lead to successful control.

New micro waveforms firstly recorded on electrocardiogram in human.

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Liu, Renguang; Chang, Qinghua; Chen, Juan

2015-10-01

In our study, not only the P-QRS-T waves but also the micro-wavelets before QRS complex (in P wave and PR segment) and after QRS complex (ST segment and upstroke of T wave) were first to be identified on surface electrocardiogram in human by the "new electrocardiogram" machine (model PHS-A10) according to conventional 12-lead electrocardiogram connection methods. By comparison to the conventional electrocardiogram in 100 cases of healthy individuals and several patients with arrhythmias, we have found that the wavelets before P wave theoretically reflected electrical activity of sinus node and the micro-wavelets before QRS complex may be related to atrioventricular conduction system (atrioventricular node, His bundle and bundle branch) potentials. Noninvasive atrioventricular node and His bundle potential tracing will contribute to differentiation of the origin of wide QRS and the location of the atrioventricular block. We also have found that the wavelets after QRS complex may be associated with phase 2 and 3 repolarization of ventricular action potential, which will further reveal ventricular repolarization changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

The incidence and characteristics of supraventricular tachycardia in left atrial isomerism: a high incidence of atrial fibrillation in young patients.

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Miyazaki, Aya; Sakaguchi, Heima; Ohuchi, Hideo; Yamamoto, Tetsuya; Igarashi, Takehiro; Negishi, Jun; Toyota, Naoki; Kagisaki, Koji; Yagihara, Toshikatsu; Yamada, Osamu

2013-06-20

In left atrial isomerism (LAI), both atria show left atrial morphology. Although bradyarrhythmias are frequent and highly complex in LAI patients, previous studies have reported a low incidence of supraventricular tachycardia (SVT). To evaluate the incidence and characteristics of SVT in LAI, we retrospectively evaluated the clinical characteristics of SVTs in 83 patients with LAI (age at last follow-up, 15.3±10.5 years). There were 27 SVTs in 19 patients (23%), including nine episodes of atrial fibrillation (AF) and eight non-reentrant SVTs. Sixteen of the 19 patients with SVT had histories of atriotomy, but the three patients with AF or non-reentrant tachycardia had no history of atriotomy. The rates of freedom from SVT were 66% and 59% at ages of 20 and 30 years, respectively; the corresponding rates for freedom from AF were 89% and 74%. In multivariate analysis, the predictors of SVT were age (OR, 1.14; 95% CI, 1.06-1.26; p=0.003) and sinus node dysfunction (SND) (OR, 3.88; 95% CI, 1.57-13.34; p=0.01). In patients with LAI, SVTs are common, and AF and non-reentrant SVTs are the major type of SVTs. The incidence of AF was high in young patients with LAI. The lack of anatomical barriers in the atria that allow the formation of macro-reentrant circuits may account for the higher incidence of AF and non-reentrant SVT than macro-reentrant tachycardia. Moreover, the increasing prevalence of SND with age should contribute to a higher incidence of SVT. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The role of the autonomic nervous system in the resting tachycardia of human hyperthyroidism.

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Maciel, B C; Gallo, L; Marin Neto, J A; Maciel, L M; Alves, M L; Paccola, G M; Iazigi, N

1987-02-01

The mechanisms that control resting heart rate in hyperthyroidism were evaluated in six patients before and after treatment with propylthiouracil. The patients were subjected to pharmacological blockade under resting conditions in two experimental sessions: first session, propranolol (0.2 mg/kg body weight); second session, atropine (0.04 mg/kg body weight) followed by propranolol (0.2 mg/kg body weight). All drugs were administered intravenously. Resting heart rate was significantly reduced from 100 +/- 6.5 beats/min to 72 +/- 2.5 beats/min (P less than 0.005) after clinical and laboratory control of the disease. After double blockade, intrinsic heart rate was reduced from 105 +/- 6.8 beats/min before treatment to 98 +/- 6.0 beats/min after treatment (P less than 0.025). The reduction in heart rate caused by propranolol was not significantly different before (-13 +/- 1.4 beats/min) and after (-9 +/- 1.0 beats/min) propylthiouracil. In contrast, atropine induced a higher elevation of heart rate after treatment (45 +/- 8.6 beats/min) than before treatment (26 +/- 4.0 beats/min). The present results suggest no appreciable participation of the sympathetic component of the autonomic nervous system in the tachycardia of hyperthyroidism, at least under the conditions of the present study. The small change observed in intrinsic heart rate, although significant, seems to indicate that this is not the most important mechanism involved in this tachycardia. Our results suggest that an important reduction in the efferent activity of the parasympathetic component participates in the mechanisms that modify resting heart rte in hyperthyroidism.

Successful radiofrequency catheter ablation assisted by the CartoSound® system for outflow tract origin nonsustained ventricular tachycardia in a patient with a severely deformed thorax

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Naoaki Onishi

2014-02-01

Full Text Available We report the case of a 72-year-old man with a nonsustained ventricular tachycardia and a history of palpitations. He had a severely deformed thorax since childhood due to spinal caries. An integrated computed tomography image of the outflow tract region from the CartoSound® system revealed the detailed anatomical information around the origin of the tachycardia and that the left anterior descending coronary artery was very close (<10 mm to the target site. We carefully ablated that site with a 3.5-mm cooled-tip catheter while confirming it in the sound view, and succeeded without any complications.

An Unusual Cause of Supraventricular Tachycardia: Acute Carbon Monoxide Poisoning

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Suat Zengin

2014-03-01

Full Text Available      Carbon monoxide (CO is a toxic gas produced by the incomplete combustion of carbon-containing compounds. Exposure to high concentrations of CO can be letha and is the most common cause of death from poisoning worldwide. Cardiac manifestations after exposure to CO, including myocardial ischemia, heart failure, and arrhythmias, have been reported. A 28-year-old a patient was admitted to our emergency department with altered consciousness as a consequence of acute domestic exposure to CO from a stove. His carboxyhemoglobin level was 39%. The oxygen treatment was started promptly, and therapeutic red cell exchange was performed. An electrocardiogram revealed supraventricular tachycardia (SVT, and an echocardiographic examination demonstrated normal cardiac functions. To the best of our knowledge, this study is the second to report a case of SVT attack due to acute CO intoxication. This paper discusses the management of this complication in patients poisoned with CO.

Isolated left ventricular non-compaction cardiomyopathy associated with polymorphous ventricular tachycardia mimicking torsades de pointes

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Oana Dickinson

2013-02-01

Full Text Available Left ventricular non-compaction (LVNC cardiomyopathy is a rare congenital disorder, classified by the American Heart Association as a primary genetic cardiomyopathy and characterized by multiple trabeculations within the left ventricle. LVNC cardiomyopathy has been associated with 3 major clinical manifestations: heart failure, atrial and ventricular arrhythmias and thromboembolic events, including stroke. In this case report, we describe a female patient with apparently isolated LVNC in whom pause-dependent polymorphic ventricular tachycardia suggesting torsades de pointes occurred in the presence of a normal QT interval.

Postural Orthostatic Tachycardia With Chronic Fatigue After HPV Vaccination as Part of the “Autoimmune/Auto-inflammatory Syndrome Induced by Adjuvants”

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Lucija Tomljenovic PhD

2014-03-01

Full Text Available We report the case of a 14-year-old girl who developed postural orthostatic tachycardia syndrome (POTS with chronic fatigue 2 months following Gardasil vaccination. The patient suffered from persistent headaches, dizziness, recurrent syncope, poor motor coordination, weakness, fatigue, myalgias, numbness, tachycardia, dyspnea, visual disturbances, phonophobia, cognitive impairment, insomnia, gastrointestinal disturbances, and a weight loss of 20 pounds. The psychiatric evaluation ruled out the possibility that her symptoms were psychogenic or related to anxiety disorders. Furthermore, the patient tested positive for ANA (1:1280, lupus anticoagulant, and antiphospholipid. On clinical examination she presented livedo reticularis and was diagnosed with Raynaud’s syndrome. This case fulfills the criteria for the autoimmune/auto-inflammatory syndrome induced by adjuvants (ASIA. Because human papillomavirus vaccination is universally recommended to teenagers and because POTS frequently results in long-term disabilities (as was the case in our patient, a thorough follow-up of patients who present with relevant complaints after vaccination is strongly recommended.

Radiofrequency ablation of fast ventricular tachycardia causing an ICD storm in an infant with hypertrophic cardiomyopathy.

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Ergul, Yakup; Ozyilmaz, Isa; Bilici, Meki; Ozturk, Erkut; Haydin, Sertaç; Guzeltas, Alper

2018-04-01

An implantable cardioverter defibrillator (ICD) storm involves very frequent arrhythmia episodes and ICD shocks, and it is associated with poor short-term and long-term prognosis. Radiofrequency catheter ablation can be used as an effective rescue treatment for patients with an ICD storm. To our knowledge, this is the first report of an infant with hypertrophic cardiomyopathy presenting with an ICD storm and undergoing successful radiofrequency catheter ablation salvage treatment for the fast left posterior fascicular ventricular tachycardia. © 2017 Wiley Periodicals, Inc.

Wolff-Parkinson-White syndrome: lessons learnt and lessons remaining.

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Benson, D Woodrow; Cohen, Mitchell I

2017-01-01

The Wolff-Parkinson-White pattern refers to the electrocardiographic appearance in sinus rhythm, wherein an accessory atrioventricular pathway abbreviates the P-R interval and causes a slurring of the QRS upslope - the "delta wave". It may be asymptomatic or it may be associated with orthodromic reciprocating tachycardia; however, rarely, even in children, it is associated with sudden death due to ventricular fibrillation resulting from a rapid response by the accessory pathway to atrial fibrillation, which itself seems to result from orthodromic reciprocating tachycardia. Historically, patients at risk for sudden death were characterised by the presence of symptoms and a shortest pre- excited R-R interval during induced atrial fibrillation Wolff-Parkinson-White pattern and availability of catheter ablation, there has been a need to identify risk among asymptomatic patients. Recent guidelines recommend invasive evaluation for such patients where pre-excitation clearly does not disappear during exercise testing. This strategy has a high negative predictive value only. The accuracy of this approach is under continued investigation, especially in light of other considerations: Patients having intermittent pre-excitation, once thought to be at minimal risk may not be, and the role of isoproterenol in risk assessment.

Comparative Clinical Profile of Postural Orthostatic Tachycardia Patients With and Without Joint Hypermobility Syndrome

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Blair P Grubb

2010-04-01

Full Text Available Background: Autonomic dysfunction is common in patients with the joint hypermobility syndrome (JHS. However, there is a paucity of reported data on clinical features of Postural orthostatic tachycardia syndrome (POTS in patients suffering from JHS.Methods: This retrospective study was approved by our local Institutional Review Board (IRB. Over a period of 10 years, 26 patients of POTS were identified for inclusion in this study. All these patients had features of Joint Hypermobility Syndrome (by Brighton criterion. A comparison group of 39 patients with other forms of POTS were also followed in the autonomic clinic during the same time. We present a descriptive report on the comparative clinical profile of the clinical features of Postural Orthostatic Tachycardia patients with and without Joint Hypermobility syndrome. The data is presented as a mean±SD and percentages wherever applicable.Results: Out of 65 patients, 26 patients (all females, 20 Caucasians had POTS and JHS. The mean age at presentation of POTS was 24±13 (range 10-53 years vs 41±12 (range 19-65 years, P=0.0001, Migraine was a common co morbidity 73 vs 29% p=0,001. In two patients POTS was precipitated by pregnancy, and in three by surgery, urinary tract infection and a viral syndrome respectively. The common clinical features were fatigue (58%, orthostatic palpitations (54%, presyncope (58%, and syncope (62%.Conclusion: Patients with POTS and JHS appear to become symptomatic at an earlier age compared to POTS patients without JHS. In addition patients with JHS had a greater incidence of migraine and syncope than their non JHS counterparts.

The value of adrenaline in the induction of supraventricular tachycardia in the electrophysiological laboratory.

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Cismaru, Gabriel; Rosu, Radu; Muresan, Lucian; Puiu, Mihai; Andronache, Marius; Hengan, Erika; Ispas, Daniel; Gusetu, Gabriel; Pop, Dana; Mircea, Petru Adrian; Zdrenghea, Dumitru

2014-11-01

The most commonly used drug for the facilitation of supraventricular tachycardia (SVT) induction in the electrophysiological (EP) laboratory is isoprenaline. Despite isoprenaline's apparent indispensability, availability has been problematic in some European countries. Alternative sympatomimethic drugs such as adrenaline have therefore been tried. However, no studies have determined the sensitivity and specificity of adrenaline for the induction of SVT. The objective of this study was to determine the sensitivity and specificity of adrenaline for the induction of SVT. Between February 2010 and July 2013, 336 patients underwent an EP study for prior documented SVT. In 66 patients, adrenaline was infused because tachycardia was not induced under basal conditions. This group was compared with 30 control subjects with no history of SVT. Programmed atrial stimulation was carried out during baseline state and repeated after an infusion of adrenaline (dose ranging from 0.05 mcg/kgc to 0.3 mcg/kgc). The endpoint was the induction of SVT. Among 66 patients with a history of SVT but no induction under basal conditions, adrenaline facilitated induction in 54 patients (82%, P Adrenaline was generally well tolerated, except for two patients (3.0%), where it had to be discontinued due to headache and high blood pressure or lumbar pain. Adrenaline infusion has a high sensitivity (82%) and specificity (100%) for the induction of SVT in patients with prior documented SVT. Therefore, it could serve as an acceptable alternative to isoprenaline, when the latter is not available. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

The electrocardiographic "triangular QRS-ST-T waveform" pattern in patients with ST-segment elevation myocardial infarction: Incidence, pathophysiology and clinical implications.

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Cipriani, Alberto; D'Amico, Gianpiero; Brunello, Giulia; Perazzolo Marra, Martina; Migliore, Federico; Cacciavillani, Luisa; Tarantini, Giuseppe; Bauce, Barbara; Iliceto, Sabino; Corrado, Domenico; Zorzi, Alessandro

A specific ECG pattern of presentation of ST-segment elevation acute myocardial infarction (STEMI), characterized by "triangular QRS-ST-T waveform" (TW), has been associated with poor in-hospital prognosis but longitudinal data on its incidence and clinical impact are lacking. We prospectively evaluated the incidence and prognostic meaning of the TW pattern in a cohort of consecutive STEMI patients. All STEMI patients who presented within 12h of symptoms onset and showed no complete bundle branch block or paced ventricular rhythm were included. The TW pattern was defined as a unique, giant wave (amplitude≥1mV) resulting from the fusion of the QRS complex, the ST-segment and the T-wave and showing a "triangular" morphology with a positive polarity in the leads exploring the ischemic region. Among 428 consecutive STEMI patients, 367 fulfilled the enrollment criteria. The TW pattern was identified in 5 of 367 patients (1.4%) on the admission ECG. This subset of STEMI patients with TW pattern significantly more often showed a left main coronary artery involvement (2/4, 50% vs 2/322, 0.6%; p<0.001), experienced ventricular fibrillation (5/5, 100% vs 35/362, 9.6% p<0.001), had cardiogenic shock (4/5, 80% vs. 14/362, 3.8%, p<0.001) and died during hospitalization (2/5, 40% vs 15/362, 4.1% p=0.02), compared with those with other ST-segment elevation ECG patterns. The TW pattern is an uncommon ECG finding, which reflects the presence of a large area of transmural myocardial ischemia and predicts cardiogenic shock accounting for high in-hospital mortality. When present, this ECG pattern should prompt aggressive therapeutic strategies, including mechanical support of circulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous total cavopulmonary connection and cardiac re-synchronisation therapy.

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Nakanishi, Keisuke; Kawasaki, Shiori; Amano, Atsushi

2017-08-01

We report the simultaneous use of cardiac re-synchronisation therapy and total cavopulmonary connection in a patient with dyssynchrony, wide QRS, and cardiac failure. To our knowledge, this simultaneous approach has not been reported previously. On follow-up, we noted that QRS width and brain natriuretic peptide levels improved. In addition, speckle tracking revealed improved synchronisation of ventricular wall motion.

Alterations in myocardial free fatty acid clearance precede mechanical abnormalities in canine tachycardia-induced heart failure.

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Freeman, G L; Colston, J T; Miller, D D

1994-01-01

The purpose of this study was to evaluate whether abnormalities of free fatty acid metabolism are present before the onset of overt mechanical dysfunction in dogs with tachycardia-induced heart failure. We studied six dogs chronically instrumented to allow assessment of left ventricular function in the pressure-volume plane. Free fatty acid clearance was assessed according to the washout rate of a free fatty acid analog, iodophenylpentadecanoic acid ([123I]PPA or IPPA). IPPA clearance was measured within 1 hour of the hemodynamic assessment. The animals were studied under baseline conditions and 11.7 +/- 3.6 days after ventricular pacing at a rate of 240 beats/min. Hemodynamic studies after pacing showed a nonsignificant increase in left ventricular end-diastolic pressure (11.7 +/- 4.7 to 17.4 +/- 6.5 mm Hg) and a nonsignificant decrease in the maximum derivative of pressure with respect to time (1836 +/- 164 vs 1688 +/- 422 mm Hg/sec). There was also no change in the time constant of left ventricular relaxation, which was 34.8 +/- 7.67 msec before and 35.3 +/- 7.3 msec after pacing. However, a significant prolongation in the clearance half-time of [123I]PPA, from 86.1 +/- 23.9 to 146.5 +/- 22.6 minutes (p < 0.01) was found. Thus abnormal lipid clearance appears before the onset of significant mechanical dysfunction in tachycardia-induced heart failure. This suggests that abnormal substrate metabolism may play an important role in the pathogenesis of this condition.

Management of supraventricular tachycardia using the Valsalva manoeuvre: a historical review and summary of published evidence.

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Smith, Gavin

2012-12-01

Use of the Valsalva manoeuvre (VM) as a first-line management tool for the reversion of supraventricular tachycardia (SVT) in both emergency medicine and prehospital emergency-care settings has presented challenges, requiring continuous examination and refinement to define both its appropriateness and effectiveness. This report details the evolution of knowledge related to SVT and the historical evolution and controversies associated with VM; it also highlights the ongoing development of an evidence-based model of practice for the management of SVT in the emergency medicine and prehospital emergency-care settings. A two-part review of the literature using electronic medical databases was conducted. Other relevant texts or articles unavailable within the electronic search were also identified. Part 1 of the search criteria identified the historical evolution of the pathophysiology of SVT, whereas part 2 identified the use of VM for the clinical management of SVT. Part 1 of the review identified a total of 38 articles with eight meeting the inclusion criteria, and part 2 of the review identified a total of 44 articles with 17 meeting the inclusion criteria. An evidence-based model of practice requires clarification. The differentiation of nodal re-entrant tachycardias may, with further research, lead to identification of the specificity of VM in reversion of SVT during the early stages of arrhythmia. There is a need for further prehospital and emergency department research to quantify an evidence-based approach to VM.

[Competitive sports and dilated cardiomyopathy: the case of a 32-year-old soccer player with ventricular tachycardia].

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Scharhag, J; Meyer, T; Görge, G; Kindermann, W

2003-01-24

A 32-year-old competitive soccer player presented with palpitations he had felt for 4 weeks during maximal activity (soccer training and match). The physical examination and an exercise electrocardiogram were carried out by his general practitioner up to 19 s at 350 W and a heart rate of 147/min without showing any abnormalities. All blood parameters revealed no signs of illness. During treadmill exercise at a heart rate of 181/min, a non-sustained ventricular tachycardia was induced. Echocardiography showed a dilated left ventricle with an enddiastolic diameter of 70 mm and low fractional shortening (28 %). Cardiac catheterization demonstrated a diminished left ventricular ejection fraction (38 %) and an enlarged enddiastolic volume (199 ml) without signs of coronary artery disease. Electrophysiologic testing induced a non-sustained ventricular tachycardia. The echocardiographic and angiographic results indicated a dilated cardiomyopathy. Competitive sports activities were stopped and treatment with a beta-blocker (metoprolol) and an ACE-antagonist (ramipril) was started. In young male and female athletes, the possibility of severe cardiac abnormalities have to be considered even in the presence of good physical fitness and performance. To reach a high sensitivity for diagnostic ergometry, the work-load must reach the maximal capacity of the cardio-pulmonary system. Differences in the exercise performance of athletes and untrained subjects have to be considered.

Catheter ablation of epicardial ventricular tachycardia

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Takumi Yamada, MD, PhD

2014-08-01

Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

Recurrent Pulseless Ventricular Tachycardia Induced by Commotio Cordis Treated with Therapeutic Hypothermia

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Sanghyun Lee

2015-11-01

Full Text Available The survival rate of commotio cordis is low, and there is often associated neurological disability if return of spontaneous circulation (ROSC can be achieved. We report a case of commotio cordis treated with therapeutic hypothermia (TH that demonstrated a favorable outcome. A 16-year-old female was transferred to our emergency department (ED for collapse after being struck in the chest with a dodgeball. She has no history of heart problems. She was brought to our ED with pulseless ventricular tachycardia (VT, and ROSC was achieved with defibrillation. She was comatose at our ED and was treated with TH at a target temperature of 33°C for 24 hours. After transfer to the intensive care unit, pulseless VT occurred, and defibrillation was performed twice. She recovered to baseline neurologic status with the exception of some memory difficulties.

Amitriptyline Cardiac Toxicity Treated with Hemoperfusion

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Nurdan Ünlü

2017-04-01

Full Text Available Tricyclic antidepressant intoxication is frequently encountered among children and adults due to widespread use of the drugs. Amitriptyline is among the major tricyclic antidepressants. It affects the cardiovascular, respiratory and central nervous system. In the treatment of amitriptyline intoxication, various treatments such as gastric lavage, activated charcoal, bicarbonate infusion, antiarrhythmic, and anticonvulsant drug usage were applied. Here, we reported a patient with severe amitriptyline intoxication who did not respond to these treatments but dramatically improved with hemoperfusion. A 33 year-old woman applied to the emergency service half an hour later ingesting 2000 mg of amitriptyline as a suicide attempt. On admission, her Glasgow coma scale (GCS was 10, blood pressure was 100/60 mmHg, heart rate was 160 beats/min. Wide QRS and ventricular tachycardia was seen in the Electrocardiography (ECG results. Having her GCS regressed to 7, she was intubated and admitted to intensive care unit after the initial treatments. Hemoperfusion was commenced within half an hour. While hemoperfusion was continuing, her ECG was seen to turn to sinus tachycardia. Her cardiovascular and neurological status returned to normal on the 2nd day and she was discharged from the intensive care unit on the 4th day. Besides hemoperfusion is not recommended due to high protein binding and large volume of distribution in classical treatment of amitriptyline overdose, current reports representing efficacy of hemoperfusion are also accumulating. After ingestion, tricyclic antidepressants are absorbed rapidly and reach to their effective concentration in the tissues, especially by the lung, the brain and the heart. Hence, hemoperfusion performed in early stage of ingestion is an effective treatment and in cases that do not respond to conventional therapies, it should be considered that this method can be used in the early period.

Value of the Electrocardiogram as a Predictor of Right Ventricular Dysfunction in Patients With Chronic Right Ventricular Volume Overload.

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Alonso, Pau; Andrés, Ana; Rueda, Joaquín; Buendía, Francisco; Igual, Begoña; Rodríguez, María; Osa, Ana; Arnau, Miguel A; Salvador, Antonio

2015-05-01

Pulmonary regurgitation is a common complication in patients with repaired tetralogy of Fallot or congenital pulmonary stenosis. Electrocardiographic variables have been correlated with parameters used to evaluate right ventricular function. We aimed to analyze the diagnostic value of the width and fragmentation of the electrocardiogram in the identification of patients with right ventricular dysfunction and/or dilation. We selected 107 consecutive patients diagnosed with severe pulmonary insufficiency after repair of pulmonary stenosis or tetralogy of Fallot. The tests included electrocardiography, echocardiography, and magnetic resonance. Each electrocardiogram was analyzed manually to measure QRS duration. We defined QRS fragmentation as the presence of low-voltage waves in the terminal portion of the QRS complex in at least 2 contiguous leads. We found a significant negative correlation between QRS width and right ventricular function, as well as a positive correlation with right ventricular volume. The receiver operating characteristic curve indicated a cut-off point for QRS width of 140ms, which showed good sensitivity for a diagnosis of right ventricular dilation (> 80%) and dysfunction (> 95%). In logistic regression models, a QRS duration > 140ms was found to be the only independent predictor of right ventricular dilation and dysfunction. Electrocardiography is a rapid, widely available, and reproducible tool. QRS width constitutes an independent predictor of the presence of right ventricular dilation and dysfunction. This study is the first to provide a cutoff value for QRS width to screen for right ventricle involvement. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Bilateral passive leg raising attenuates and delays tourniquet deflation-induced hypotension and tachycardia under spinal anaesthesia: a randomised controlled trial.

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Huang, Go-Shine; Wang, Chih-Chien; Hu, Mei-Hua; Cherng, Chen-Hwan; Lee, Meei-Shyuan; Tsai, Chien-Sung; Chan, Wei-Hung; Hsieh, Xhang-Xian; Lin, Leou-Chyr

2014-01-01

The pneumatic tourniquet is frequently used in total knee arthroplasty. Tourniquet deflation may result in hypotension and tachycardia caused by the rapid shift of blood volume back to the ischaemic limb and a decrease in cardiac preload. Passive leg raising (PLR) represents a 'self-volume challenge' that can result in an increase in preload. Such a PLR-induced increase in preload was hypothesised to attenuate the decrease in preload resulting from tourniquet deflation. To evaluate the effect of PLR on hypotension and tachycardia following tourniquet deflation. A randomised controlled trial. Single medical centre. Seventy patients who underwent unilateral total knee arthroplasty were randomised into two groups: tourniquet deflation with PLR (n = 35) or without PLR (control group, n = 35). Patients in both groups were administered a single dose of plain bupivacaine for spinal anaesthesia. The pneumatic tourniquet was inflated on the thigh and the surgery was performed. The study composed of four steps: for the PLR group, step 1 - inflation of the tourniquet while the patient was supine; step 2 - the patient's legs were raised to a 45° angle; step 3 - the tourniquet was deflated while the patient's legs were still raised; and step 4 - the legs were returned to the supine position. In the control group, the same perioperative procedure was used, but PLR was not conducted. The patients' blood pressure and heart rate were measured before, during and after tourniquet deflation. After tourniquet deflation, the magnitude of the changes in blood pressure and heart rate was less in the PLR group than that in the control group. In addition, the blood pressure nadir also occurred later in the PLR group than in the controls. Bilateral PLR is a simple, reversible manoeuvre that mimics rapid fluid loading. Bilateral PLR attenuates the severity of, and delays the time to, hypotension and tachycardia following deflation of a lower limb tourniquet. ClinicalTrials.gov number

What is the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome?

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Carew, Sheila

2012-01-31

AIMS: The aim of this study is to define the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome (POTS). METHODS AND RESULTS: This was a case-control study. Cases were identified retrospectively from a database of patients referred with orthostatic intolerance (OI). All met the diagnostic criteria for POTS. Controls were enrolled prospectively. All subjects underwent tilting to 70 degrees for 40 min if tolerated. Continuous monitoring was provided by a Finometer. Analysis of responses to tilting was performed on 28 cases and 28 controls. The mean age in the case group was 23.6 and in the control group was 26.2. The majority was female in both groups (cases = 4F:3M, controls = 2F:1M). All cases met the criteria for POTS within 7 min of orthostasis. No controls demonstrated a sustained tachycardia. The prevalence of vasovagal syncope (VVS) was 36% in cases vs. 7% in controls (P = 0.02) and 25% in the remaining patients (n = 233) on the OI database (P = 0.259). CONCLUSION: A 10 min tilt will diagnose POTS in the majority of patients. It will not, however, be sufficient to identify the overlap that exists between POTS and VVS. The optimal duration of tilt testing in patients suspected of POTS is 40 min.

A giant cardiac hydatid cyst presenting with chest pain and ventricular tachycardia in a pregnant woman undergoing cesarean section

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Mehmet Yaman

2016-09-01

Full Text Available Cyst hydatid disease is an infectious disease caused by development of the larval form of Echinococcus granulosus in humans. Cardiac involvement of this disease is a rare condition, and if present, it is most commonly located in the left ventricle. Interventricular septal involvement is observed only in 4% of these cases. Herein, we report a case of cyst hydatid located at interventricular septum causing chest pain and ventricular tachycardia during cesarean section.

Orthostatic intolerance and postural tachycardia syndrome as suspected adverse effects of vaccination against human papilloma virus

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Brinth, Louise S; Pors, Kirsten; Theibel, Ann C

2015-01-01

of postural orthostatic tachycardia syndrome (POTS) rested on finding a sustained heart rate increment of >30min(-1) (>40min(-1) in adolescents) or to levels >120min(-1) during orthostatic challenge. RESULTS: 35 women aged 23.3±7.1 years participated. Twenty-five had a high level of physical activity before...... vaccination and irregular periods were reported by all patients not on treatment with oral contraception. Serum bilirubin was below the lower detection limit in 17 patients. Twenty-one of the referred patients fulfilled the criteria for a diagnosis of POTS (60%, 95%CI 43-77%). All patients had orthostatic...

Human papillomavirus vaccines, complex regional pain syndrome, postural orthostatic tachycardia syndrome, and autonomic dysfunction - a review of the regulatory evidence from the European Medicines Agency

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Jefferson, Tom; Jørgensen, Lars

2017-01-01

Recent concerns about a possible association between exposure of young women to human papillomavirus (HPV) vaccines and two "dysautonomic syndromes" (a collection of signs and symptoms thought to be caused by autoimmunity) - complex regional pain syndrome (CRPS) and postural orthostatic tachycardia...

Catecholaminergic polymorphic ventricular tachycardia. An important diagnosis in children with syncope and normal heart

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Luiz Roberto Leite

2001-01-01

Full Text Available Syncope in children is primarily related to vagal hyperreactivity, but ventricular tachycardia (VT way rarely be seen. Catecholaminergic polymorphic VT is a rare entity that can occur in children without heart disease and with a normal QT interval, which may cause syncope and sudden cardiac death. In this report, we describe the clinical features, treatment, and clinical follow-up of three children with syncope associated with physical effort or emotion and cathecolaminergic polymorphic VT. Symptoms were controlled with beta-blockers, but one patient died suddenly in the fourth year of follow-up. Despite the rare occurrence, catecholaminergic polymorphic VT is an important cause of syncope and sudden death in children with no identified heart disease and normal QT interval.

Effect of Pregnancy on Postural Tachycardia Syndrome

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Kimpinski, Kurt; Iodice, Valeria; Sandroni, Paola; Low, Phillip A.

2010-01-01

OBJECTIVES: To compare the clinical presentation, autonomic dysfunction, and pregnancy outcomes in parous and nulliparous women with postural tachycardia syndrome (POTS) and in women with POTS before and after pregnancy. PATIENTS AND METHODS: This study consists of women who had at least 1 pregnancy during which time they met criteria for POTS between May 1993 and July 2009. All patients underwent standard autonomic testing. POTS was defined as a heart rate (HR) increase of greater than 30 beats/min on head-up tilt (HUT) with symptoms of orthostatic intolerance. Patients' charts were reviewed retrospectively to determine pregnancy outcomes. RESULTS: Clinical characteristics related to POTS did not differ between parous and nulliparous women except for disease duration (parous, 3.7±2.6; nulliparous, 2.1±2.2; Pchange in HR on HUT: parous, 42.6±12.0 beats/min; nulliparous, 41.3±10.6 beats/min; P=.39). Of 116 total pregnancies, adverse pregnancy outcomes were reported in 9% and maternal complications in 1%. No complication was related to POTS. There was a trend toward modest improvement in autonomic dysfunction before and after pregnancy (change in HR on HUT: before pregnancy, 38.1±22.7 beats/min; after pregnancy, 21.9±14.9 beats/min; P=.07). CONCLUSION: The long-term impact of pregnancy on POTS does not appear to be clinically important. However, there does appear to be a trend toward improvement in the short-term postpartum period. Adverse pregnancy events were similar to those seen in the general public and do not present a barrier to women with POTS who want to have children. PMID:20516426

Ventricular tachycardia in post-myocardial infarction patients. Results of surgical therapy.

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Viganò, M; Martinelli, L; Salerno, J A; Minzioni, G; Chimienti, M; Graffigna, A; Goggi, C; Klersy, C; Montemartini, C

1986-05-01

This report addresses the problems related to surgical treatment of post-infarction ventricular tachycardia (VT) and is based on a 5 year experience of 36 consecutive patients. In every case the arrhythmia was unresponsive to pharmacological therapy. All patients were operated on after the completion of a diagnostic protocol including preoperative endocardial, intra-operative epi-endocardial mapping, the latter performed automatically when possible. Surgical techniques were: classical Guiraudon's encircling endocardial ventriculotomy (EEV); partial EEV, endocardial resection (ER); cryoablation or a combination of these procedures. The in-hospital mortality (30 days) was 8.3% (3 patients). During the follow-up period (1-68 months), 3 patients (9%) died of cardiac but not VT related causes. Of the survivors, 92% are VT-free. We consider electrophysiologically guided surgery a safe and reliable method for the treatment of post-infarction VT and suggest its more extensive use. We stress the importance of automatic mapping in pleomorphic and non-sustained VT, and the necessity of tailoring the surgical technique to the characteristics of each case.

Amiodarone for the treatment and prevention of ventricular fibrillation and ventricular tachycardia

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Hugo Van Herendael

2010-06-01

Full Text Available Hugo Van Herendael, Paul DorianDivision of Cardiology, St. Michael’s Hospital, University of Toronto, Toronto, CanadaAbstract: Amiodarone has emerged as the leading antiarrhythmic therapy for termination and prevention of ventricular arrhythmia in different clinical settings because of its proven efficacy and safety. In patients with shock refractory out-of-hospital cardiac arrest and hemodynamically destabilizing ventricular arrhythmia, amiodarone is the most effective drug available to assist in resuscitation. Although the superiority of the transvenous implantable cardioverter defibrillator (ICD over amiodarone has been well established in the preventive treatment of patients at high risk of life-threatening ventricular arrhythmias, amiodarone (if used with a beta-blocker is the most effective antiarrhythmic drug to prevent ICD shocks and treat electrical storm. Both the pharmacokinetics and the electrophysiologic profile of amiodarone are complex, and its optimal and safe use requires careful patient surveillance with respect to potential adverse effects.Keywords: amiodarone, ventricular fibrillation, unstable ventricular tachycardia

Ten-year outcomes of monomorphic ventricular tachycardia catheter ablation in repaired tetralogy of Fallot.

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Laredo, Mikaël; Frank, Robert; Waintraub, Xavier; Gandjbakhch, Estelle; Iserin, Laurence; Hascoët, Sebastien; Himbert, Caroline; Gallais, Yves; Hidden-Lucet, Françoise; Duthoit, Guillaume

2017-05-01

Monomorphic ventricular tachycardia (MVT) is common in adults with repaired tetralogy of Fallot (TOF), and is associated with sudden cardiac death. Management of MVT is not defined, and results of catheter ablation (CA) are limited. To evaluate long-term outcomes of MVT CA in repaired TOF. Thirty-four patients (mean age 32±10.3 years; 59% male) with repaired TOF underwent CA for symptomatic MVT between 1990 and 2012 in our centre; direct-current ablation (DCA) was used in 6%, radiofrequency followed by DCA in 29% and radiofrequency alone in 65%. Right ventricular (RV) dysfunction was present in 35% and left ventricular (LV) dysfunction in 21%. Mean numbers of clinical and induced MVTs were 1 and 2, respectively. Mean VT rate was 225±95bpm. Ablation targeted a single site (range 1-2), which was RV outflow tract in 85%. Primary success, defined as ventricular tachycardia (VT) termination during CA and final non-inducibility, was obtained in 82%. Seven patients (21%) required redo ablation in the first 3 months (before 2004; DCA). No death related to CA occurred. Mean follow-up time was 9.5±5.2 years. Antiarrhythmic therapy was discontinued in 71%. There were two cases of sudden cardiac death and four VT recurrences. Freedom from death and arrhythmia recurrence was 94% at 5 years, 81% at 10 years and 70% at 20 years. Global survival was 91% at 20 years. Baseline LV ejection fraction<60% was significantly associated with ventricular arrhythmia recurrence (hazard ratio 16.4, 95% confidence interval 1.8-147; P=0.01). CA can safely address macroreentrant MVT in repaired TOF patients with an acceptable long-term rate of recurrence in this high-risk population. Anatomical classification of isthmuses with electroanatomical mapping provides reproducible endpoints for CA. Attention should be given to LV systolic function in risk assessment and selection of candidates for implantable cardioverter-defibrillator. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Ventricular tachycardia in ischemic cardiomyopathy; a combined endo-epicardial ablation as the first procedure versus a stepwise approach (EPILOGUE) - study protocol for a randomized controlled trial

NARCIS (Netherlands)

A.A. Hendriks (Astrid A.); M. Khan (M.); L. Geller (Laszlo); A. Kardos (Attila); L.J. de Vries (Lennart); S-C. Yap (Sing-Chien); S.A. Wijchers (Sip A.); D.A.M.J. Theuns (Dominic); T. Szili-Torok (Tamas)

2015-01-01

textabstractBackground: The role of epicardial substrate ablation of ventricular tachycardia (VT) as a first-line approach in patients with ischemic heart disease is not clearly defined. Epicardial ablation as a first-line option is standard for patients with nonischemic dilated cardiomyopathy and

Rare presentation of intralobar pulmonary sequestration associated with repeated episodes of ventricular tachycardia.

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Rao, D Sheshagiri; Barik, Ramachandra

2016-07-26

Arterial supply of an intralobar pulmonary sequestration (IPS) from the coronary circulation is extremely rare. A significant coronary steal does not occur because of dual or triple sources of blood supply to sequestrated lung tissue. We present a 60-year-old woman who presented to us with repeated episodes of monomorphic ventricular tachycardia (VT) in last 3 mo. Radio frequency ablation was ineffective. On evaluation, she had right lower lobe IPS with dual arterial blood supply, i.e., right pulmonary artery and the systemic arterial supply from the right coronary artery (RCA). Stress myocardial perfusion scan revealed significant inducible ischemia in the RCA territory. Coronary angiogram revealed critical stenosis of proximal RCA just after the origin of the systemic artery supplying IPS. The critical stenosis in the RCA was stented. At 12 mo follow-up, she had no further episodes of VT or angina.

Focal ablation for atrial tachycardia from the double-exit of the Marshall bundle inducing atrial fibrillation

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Jung Yeon Chin, MD

2017-08-01

Full Text Available Atrial fibrillation (AF from the ligament/vein of Marshall (LOM/VOM has previously been described. We report the case of a 23-year-old woman with an antiarrhythmic drug-resistant AF induced by two distinct atrial tachycardias (ATs. Focal ablation of these ATs from the double-exit of the Marshall bundle using a three-dimensional map eliminated AF triggering, even though pulmonary vein electrical isolation is the cornerstone for paroxysmal AF. Such mechanisms are important as triggering factors to plan ablation for paroxysmal AF. Focal ablation for triggering and inducing AF, originating from the double-exit of the Marshall bundle may be effective in eliminating AF in young patients.

Test Characteristics of Neck Fullness and Witnessed Neck Pulsations in the Diagnosis of Typical AV Nodal Reentrant Tachycardia

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Sakhuja, Rahul; Smith, Lisa M; Tseng, Zian H; Badhwar, Nitish; Lee, Byron K; Lee, Randall J; Scheinman, Melvin M; Olgin, Jeffrey E; Marcus, Gregory M

2011-01-01

Summary Background Claims in the medical literature suggest that neck fullness and witnessed neck pulsations are useful in the diagnosis of typical AV nodal reentrant tachycardia (AVNRT). Hypothesis Neck fullness and witnessed neck pulsations have a high positive predictive value in the diagnosis of typical AVNRT. Methods We performed a cross sectional study of consecutive patients with palpitations presenting to a single electrophysiology (EP) laboratory over a 1 year period. Each patient underwent a standard questionnaire regarding neck fullness and/or witnessed neck pulsations during their palpitations. The reference standard for diagnosis was determined by electrocardiogram and invasive EP studies. Results Comparing typical AVNRT to atrial fibrillation (AF) or atrial flutter (AFL) patients, the proportions with neck fullness and witnessed neck pulsations did not significantly differ: in the best case scenario (using the upper end of the 95% confidence interval [CI]), none of the positive or negative predictive values exceeded 79%. After restricting the population to those with supraventricular tachycardia other than AF or AFL (SVT), neck fullness again exhibited poor test characteristics; however, witnessed neck pulsations exhibited a specificity of 97% (95% CI 90–100%) and a positive predictive value of 83% (95% CI 52–98%). After adjustment for potential confounders, SVT patients with witnessed neck pulsations had a 7 fold greater odds of having typical AVNRT, p=0.029. Conclusions Although neither neck fullness nor witnessed neck pulsations are useful in distinguishing typical AVNRT from AF or AFL, witnessed neck pulsations are specific for the presence of typical AVNRT among those with SVT. PMID:19479968

Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome

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Elisabeth eLambert

2014-07-01

Full Text Available Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.

Left septal atrial tachycardia after open-heart surgery: relevance to surgical approach, anatomical and electrophysiological characteristics associated with catheter ablation, and procedural outcomes.

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Adachi, Toru; Yoshida, Kentaro; Takeyasu, Noriyuki; Masuda, Keita; Sekiguchi, Yukio; Sato, Akira; Tada, Hiroshi; Nogami, Akihiko; Aonuma, Kazutaka

2015-02-01

Septal atrial tachycardia (AT) can occur in patients without structural heart disease and in patients with previous catheter ablation of atrial fibrillation. We aimed to assess septal AT that occurs after open-heart surgery. This study comprised 20 consecutive patients undergoing catheter ablation of macroreentrant AT after open-heart surgery. Relevance to surgical approach, mechanisms, anatomic and electrophysiological characteristics, and outcomes were assessed. Septal AT was identified in 7 patients who had all undergone mitral valve surgery. All septal ATs were localized in the left atrial septum, whereas 10 of 13 nonseptal ATs originated from the right atrium. Patients with left septal AT had a thicker fossa ovalis (median, 4.0; 25th-75th percentile, 3.6-4.2 versus 2.3; 1.6-2.6 mm; P=0.006) and broader area of low voltage (open-heart surgery was characterized by a thicker septum, more scar burden in the septum, and repeated prolongations of the tachycardia cycle length during ablation. Such an arrhythmogenic substrate may interfere with transmural lesion formation by ablation and may account for higher likelihood of recurrence of left septal AT. © 2014 American Heart Association, Inc.

A Case Report and Review of Postural Orthostatic Tachycardia Syndrome in Pregnancy

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Brianna Lide

2015-04-01

Full Text Available Purpose - Postural orthostatic tachycardia syndrome (POTS is a form of orthostatic intolerance characterized by an increased heart rate upon transition from supine to standing, and head-up tilt without orthostatic hypotension. Its etiology is multifactorial, and no clear cause has been identified. Common symptoms include light-headedness, blurred vision, weakness, cognitive difficulties, and fatigue and are often accompanied by palpitations, shortness of breath, syncope, or gastrointestinal symptoms. Management includes volume expansion, physical counter maneuvers, and pharmacological agents such as fludrocortisone, midodrine, propranolol, and pyridostigmine. The course of POTS in pregnancy is variable and POTS has not been directly implicated in any adverse outcomes for the mother or fetus. Methods - Two cases of POTS in pregnancy are presented, along with a review of the literature for reports of POTS in pregnancy. Results - Along with our 2 cases, 10 other case reports were identified and included. Conclusion - The course of POTS in pregnancy is variable, and not directly linked to increase perinatal morbidity or mortality. Women can safely undergo regional anesthesia, and vaginal delivery with close monitoring of hemodynamic changes.

A Case Report and Review of Postural Orthostatic Tachycardia Syndrome in Pregnancy.

Science.gov (United States)

Lide, Brianna; Haeri, Sina

2015-04-01

Purpose Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by an increased heart rate upon transition from supine to standing, and head-up tilt without orthostatic hypotension. Its etiology is multifactorial, and no clear cause has been identified. Common symptoms include light-headedness, blurred vision, weakness, cognitive difficulties, and fatigue and are often accompanied by palpitations, shortness of breath, syncope, or gastrointestinal symptoms. Management includes volume expansion, physical counter maneuvers, and pharmacological agents such as fludrocortisone, midodrine, propranolol, and pyridostigmine. The course of POTS in pregnancy is variable and POTS has not been directly implicated in any adverse outcomes for the mother or fetus. Methods Two cases of POTS in pregnancy are presented, along with a review of the literature for reports of POTS in pregnancy. Results Along with our 2 cases, 10 other case reports were identified and included. Conclusion The course of POTS in pregnancy is variable, and not directly linked to increase perinatal morbidity or mortality. Women can safely undergo regional anesthesia, and vaginal delivery with close monitoring of hemodynamic changes.

Myocardial remodeling and bioelectric changes in tachycardia-induced heart failure in dogs

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Song, B.; Wang, B.N.; Chen, D.N.; Luo, Z.G. [Department of Cardiovascular Medicine, The First Affiliated Hospital, Anhui Medical University, HeFei, Anhui Province (China)

2013-09-06

In this study, electrical and structural remodeling of ventricles was examined in tachycardia-induced heart failure (HF). We studied two groups of weight-matched adult male mongrel dogs: a sham-operated control group (n=5) and a pacing group (n=5) that underwent ventricular pacing at 230 bpm for 3 weeks. Clinical symptoms of congestive HF were observed in both groups. Their hemodynamic parameters were determined and the severity of the HF was evaluated by M-mode echocardiography. Changes in heart morphology were observed by scanning electron and light microscopy. Ventricular action potential duration (APD), as well as the 50 and 90% APD were measured in both groups. All dogs exhibited clinical symptoms of congestive HF after rapid right ventricular pacing for 3 weeks. These data indicate that rapid, right ventricular pacing produces a useful experimental model of low-output HF in dogs, characterized by biventricular pump dysfunction, biventricular cardiac dilation, and non-ischemic impairment of left ventricular contractility. Electrical and structural myocardial remodeling play an essential role in congestive HF progression, and should thus be prevented.

Blocked Atrial Bi/Trigeminy In Utero Evolving in Supraventricular Tachycardia after Birth

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V. Martucci

2012-01-01

Full Text Available Transient episodes of fetal bradycardia (heart rate less than 110 bpm are usually benign and typically result from increased vagal stimulation in the fetus. Causes of sustained fetal bradycardia include sinus bradycardia, blocked atrial bigeminy/trigeminy, high-degree atrioventricular block, and long QT syndrome. We present the case of a 34-year-old Caucasian patient referred to our department for “blocked atrial bigeminy with pseudobradycardia” detected elsewhere at 33 weeks of gestation. A fetal echocardiography showed during all the examination a blocked atrial trigeminy with a mean fetal heart rate of 100 bpm. After birth three subsequent ECGs until day 3 showed no evidence of atrial extrasystoles, confirming the well-known frequent regression of this kind of fetal benign arrhythmia, but on day 11 recurrence of supraventricular trigeminy and development of episodes of paroxystic supraventricular tachycardia were observed. On the basis of this observation, we recommend that fetuses with complex atrial ectopic beats should be closely monitored before and after birth for evidence of new arrhythmias.

Cardiorespiratory adaptations induced by aerobic training in middle-aged men: the importance of a decrease in sympathetic stimulation for the contribution of dynamic exercise tachycardia

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Chacon-Mikahil M.P.T.

1998-01-01

Full Text Available We investigated the effects of aerobic training on the efferent autonomic control of heart rate (HR during dynamic exercise in middle-aged men, eight of whom underwent exercise training (T while the other seven continued their sedentary (S life style. The training was conducted over 10 months (three 1-h sessions/week on a field track at 70-85% of the peak HR. The contribution of sympathetic and parasympathetic exercise tachycardia was determined in terms of differences in the time constant effects on the HR response obtained using a discontinuous protocol (4-min tests at 25, 50, 100 and 125 watts on a cycle ergometer, and a continuous protocol (25 watts/min until exhaustion allowed the quantification of the parameters (anaerobic threshold, VO2 AT; peak O2 uptake, VO2 peak; power peak that reflect oxygen transport. The results obtained for the S and the T groups were: 1 a smaller resting HR in T (66 beats/min when compared to S (84 beats/min; 2 during exercise, a small increase in the fast tachycardia (D0-10 s related to vagal withdrawal (P<0.05, only at 25 watts was observed in T at all powers; at middle and higher powers a significant decrease (P<0.05 at 50, 100 and 125 watts in the slow tachycardia (D1-4 min related to a sympathetic-dependent mechanism was observed in T; 3 the VO2 AT (S = 1.06 and T = 1.33 l/min and VO2 peak (S = 1.97 and T = 2.47 l/min were higher in T (P<0.05. These results demonstrate that aerobic training can induce significant physiological adaptations in middle-aged men, mainly expressed as a decrease in the sympathetic effects on heart rate associated with an increase in oxygen transport during dynamic exercise.

[The complex origin of ventricular tachycardia after the total correction of tetralogy of Fallot].

Science.gov (United States)

Ressia, L; Graffigna, A; Salerno-Uriarte, J A; Viganò, M

1993-09-01

Two patients underwent surgical treatment of ventricular tachycardia after repair of tetralogy of Fallot. Both patients had right bundle branch block, moderate pulmonary valve incompetence and right ventricular dilatation, and were refractory to electrophysiologically guided drug therapy. Both patients underwent intraoperative epicardial mapping, which located the arrhythmogenic focus on the right ventricular outflow tract, on the border of the previous ventriculotomy. In one patient removal of the previous scar and endocardial cryoablation was successful in ablating the arrhythmia. In the other, the same procedure was only temporarily effective. VT recurred and was subsequently identified at the superior border of the closed ventricular septal defect. It was ablated by means of transcatheter radiofrequency. While VT from foci located on the right ventricular free wall can be easily detected and ablated, septal origin of VT requires extensive preoperative and intraoperative electrophysiological evaluation and may necessitate combined surgical and transcatheter procedures.

Neurocardiogenic Syncope and Supraventricular Tachycardia in Association with a Rare Congenital Aortic Valve Abnormality

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Yashwant Agrawal

2016-01-01

Full Text Available We report a case of a 26-year-old woman who presented with multiple episodes of syncope over a five-months period of time. Transthoracic echocardiogram had shown a normal functioning quadricuspid aortic valve (QAV which was also confirmed on a transesophageal echocardiogram. Computed tomographic angiography of heart and coronary arteries showed the QAV with equal size of all aortic cusps and normal coronary arteries. Intermittent chest pain and palpitations warranted an exercise stress test. The stress test revealed normal aerobic exertion, with achievement of 101% of maximal peak heart rate. However, during peak stress, we noted a drop in her blood pressure significantly resulting in dizziness. No arrhythmias were noted during the stress test. With recurrent syncope episodes and palpitations, Holter monitoring was done, revealing supraventricular tachycardia (SVT. We discuss current available literature and coassociations with QAV. New association of QAV with SVT needs further analysis.

[Long QT syndrome and polymorphic ventricular tachycardia due to hypopituitarism. Report of one case].

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García-Castro, José Miguel; García-Martín, Antonia; Guirao-Arrabal, Emilio; Carrillo-Alascio, Pedro Luis

2017-07-01

Symptoms of hypopituitarism are usually chronic and nonspecific, but rarely the disease can have acute and life threatening manifestations. We report a 53 years old female with a pituitary adenoma that was admitted to our hospital because of syncope. The electrocardiogram showed sinus bradycardia with a prolonged QT interval. Frequent runs of non-sustained polymorphic ventricular tachycardia were noted on telemetry. The patient had a history of severe acute headaches in the previous days and laboratory tests revealed severe secondary hypothyroidism, adrenal insufficiency and a decrease in pituitary hormones. A magnetic resonance imaging of the head showed changes in the size and contrast enhancement of the adenoma. A diagnosis of hypopituitarism secondary to pituitary apoplexy was made and treatment with hydrocortisone and, subsequently, levothyroxine was started. Hormonal disorders such as hypothyroidism, adrenal insufficiency or hypopituitarism should be considered as unusual causes for reversible cardiomyopathy, long QT syndrome and ventricular arrhythmias.

POSTURAL TACHYCARDIA IN CHILDREN AND ADOLESCENTS – WHAT IS ABNORMAL?

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Singer, Wolfgang; Sletten, David M.; Opfer-Gehrking, Tonette L.; Brands, Chad K.; Fischer, Philip R.; Low, Phillip A.

2011-01-01

Objectives To evaluate whether the use of adult heart rate (HR) criteria is appropriate for diagnosing Postural Tachycardia Syndrome (POTS) and orthostatic intolerance (OI) in children and adolescents and to establish normative data and diagnostic criteria for pediatric POTS and OI. Study design 106 normal controls between the ages 8 and 19 years (14.5±3.3 years) underwent standardized autonomic testing, including 5 minutes of 70 degree head-up tilt. The orthostatic HR increment and absolute orthostatic HR were assessed and retrospectively compared with 654 pediatric patients of similar age (15.5±2.3 years), who were referred to our Clinical Autonomic Laboratory with symptoms of OI. Results The HR increment was mildly higher in patients referred for POTS/OI but there was considerable overlap between patient and control group. 42% of normal controls had a HR increment of 30bpm or more. The 95th percentile for the orthostatic HR increment in normal controls was 42.9bpm. Absolute orthostatic HR showed a greater and more consistent difference between groups, although there was still considerable overlap. Conclusions The diagnostic criteria for OI/POTS in adults are inadequate for children and adolescents. Based on our normative data, new criteria are proposed for the diagnosis of OI and POTS in children and adolescents. PMID:21996154

A case of typical atrioventricular nodal (AVN) reentrant tachycardia confined to the compact AV node, showing a variety of rare electrophysiological findings, including eccentric AVN echoes

OpenAIRE

Tanaka, Kazushi; Shiotani, Shinji; Fukuda, Keisuke; Fujihara, Masahiko; Higashimori, Akihiro; Morioka, Nobuyuki; Yokoi, Yoshiaki; Fujimura, Osamu

2014-01-01

Herein, we report the case of a 49-year-old woman with typical atrioventricular nodal (AVN) reentrant tachycardia, confined to the compact atrioventricular node, showing numerous rare electrophysiological findings such as unique AVN reentrant echoes, double ventricular responses, latent retrograde dual AVN pathways, antegrade triple AVN pathways, and longitudinal dissociation within the lower final common pathway.

A case of typical atrioventricular nodal (AVN reentrant tachycardia confined to the compact AV node, showing a variety of rare electrophysiological findings, including eccentric AVN echoes

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Kazushi Tanaka, M.D., Ph.D.

2014-12-01

Full Text Available Herein, we report the case of a 49-year-old woman with typical atrioventricular nodal (AVN reentrant tachycardia, confined to the compact atrioventricular node, showing numerous rare electrophysiological findings such as unique AVN reentrant echoes, double ventricular responses, latent retrograde dual AVN pathways, antegrade triple AVN pathways, and longitudinal dissociation within the lower final common pathway.

Association between obesity and ECG variables in children and adolescents: A cross-sectional study.

Science.gov (United States)

Sun, Guo-Zhe; Li, Yang; Zhou, Xing-Hu; Guo, Xiao-Fan; Zhang, Xin-Gang; Zheng, Li-Qiang; Li, Yuan; Jiao, Yun-DI; Sun, Ying-Xian

2013-12-01

Obesity exhibits a wide variety of electrocardiogram (ECG) abnormalities in adults, which often lead to cardiovascular events. However, there is currently no evidence of an association between obesity and ECG variables in children and adolescents. The present study aimed to explore the associations between obesity and ECG intervals and axes in children and adolescents. A cross-sectional observational study of 5,556 students aged 5-18 years was performed. Anthropometric data, blood pressure and standard 12-lead ECGs were collected for each participant. ECG variables were measured manually based on the temporal alignment of simultaneous 12 leads using a CV200 ECG Work Station. Overweight and obese groups demonstrated significantly longer PR intervals, wider QRS durations and leftward shifts of frontal P-wave, QRS and T-wave axes, while the obese group also demonstrated significantly higher heart rates, compared with normal weight groups within normotensive or hypertensive subjects (Pobesity was also associated with longer PR intervals, wider QRS duration and a leftward shift of frontal ECG axes compared with normal waist circumference (WC) within normotensive or hypertensive subjects (Paffecting the ECG variables. Furthermore, the ECG variables, including PR interval, QRS duration and frontal P-wave, QRS and T-wave axes, were significantly linearly correlated with body mass index, WC and waist-to-height ratio adjusted for age, gender, ethnicity and blood pressure. However, there was no significant association between obesity and the corrected QT interval (P>0.05). The results of the current study indicate that in children and adolescents, general and abdominal obesity is associated with longer PR intervals, wider QRS duration and a leftward shift of frontal P-wave, QRS and T-wave axes, independent of age, gender, ethnicity and blood pressure.

Electroconvulsive therapy-induced Wolff-Parkinson-White syndrome: a case report.

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Enomoto, Shingo; Yoshino, Aihide; Takase, Bonpei; Kuwahara, Tatsuro; Tatsuzawa, Yasutaka; Nomura, Soichiro

2013-01-01

Wolff-Parkinson-White (WPW) syndrome is characterized by premature ventricular excitation due to the presence of an abnormal accessory pathway. Electrocardiography (ECG) of patients with WPW syndrome portrays a short PR interval and a wide QRS interval with a delta wave. Herein, we report the case of a patient with schizophrenia who developed a wide QRS interval with a delta wave immediately following electroconvulsive therapy (ECT). Initially, the delta wave disappeared within 2 days after ECT. However, the duration of the delta wave increased exponentially to 4 months when ECT was repeated. Although the patient's cardiocirculatory dynamics remained normal, we continued to monitor her ECG until the delta wave disappeared because WPW syndrome can lead to serious arrhythmia. Copyright © 2013 Elsevier Inc. All rights reserved.

Ventricular Tachycardia Detected by Implantable Loop Recorder in a Child with Recurrent Syncope

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İsa Özyılmaz

2014-06-01

Full Text Available In this article, we present a 10-year-old boy who was admitted to the hospital with recurrent syncope. There was no remarkable finding in patient’s physical examination, family history, and the diagnostic 12-lead electrocardiogram (ECG, chest x-ray, ECG Holter monitoring, event recording, echocardiography, coronary computed tomography (CT angiography, Ajmaline test for the diagnosis of Brugada syndrome, brain magnetic resonance imaging, and sleep/wake electroencephalogram. We started beta-blocker therapy because the patient had exercise-induced syncope. An Implantable loop recorder (ILR was inserted to the patient. Three years later, polymorphic ventricular tachycardia called torsades de pointes was detected by the ILR during syncope occurred with exercise. The patient had been taking high-dose betablocker treatment, an implantable cardioverter defibrillator was implanted into the patient. ILR can play an important role in the diagnosis of life-threatening arrhythmia in children with unexplained syncope. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 123-5

Management of Arrhythmias in Athletes: Atrial Fibrillation, Premature Ventricular Contractions, and Ventricular Tachycardia.

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Lai, Ernest; Chung, Eugene H

2017-10-09

Management of atrial fibrillation, premature ventricular contractions, and ventricular tachycardia without underlying cardiac disease or arrhythmogenic conditions differs in athletes from the general population. Athletes tend to be younger, healthier individuals with few comorbidities. Therapies that work well in the general population may not be appropriate or preferable for athletes. Management strategies include deconditioning, pharmacologic therapy, such as rate control with β-blockers or non-dihydropyridine calcium channel blockers and rhythm control with class I or class III antiarrhythmic drugs, and catheter ablation. Deconditioning is not preferred by athletes because of lost playing time. Pharmacologic therapy is well tolerated among most individuals, but is not as favorable in athletes. Rate control medications can reduce performance and β-blockers, in particular, are prohibited in many sports. Antiarrhythmic drugs are preferred over rate control with athletes, but many, especially younger athletes, may not like the idea of long-term medical therapy. Catheter ablation has been proven to be safe and efficacious, may eliminate the need for long-term medical therapy, and is supported by the major societies (AHA, ACC, ESC).

Possible genetic implications in the response to cardiac resynchronisation therapy in a patient affected by heart failure

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Natalia Pezzali

2011-06-01

Full Text Available This report presents a case of a patient with idiopathic dilated cardiomyopathy and severe left ventricular systolic dysfunction who underwent cardiac resynchronisation therapy (CRT. During the follow-up a progressive increase in left ventricular ejection fraction was observed, as well as clinical improvement. No cardiovascular events occurred during the follow-up, except for appropriate Implantable Cardioverter Defibrillator (ICD bursts for fast ventricular tachycardia. Genotyping for adrenoceptor gene polymorphisms detected that the patient was Glu27Glu homozygous carrier. There’s a large interindividual variability in response to CRT. Despite attempts to identify factors having an impact on this therapy, only QRS duration is accepted according to guidelines. Beta-adrenoceptors polymorphisms, modulating sympathetic drive in heart failure and left ventricular remodelling, may have a role in identifying patients with a better response to CRT, in order to target and individualise the patients’ treatment.

Radiofrequency Ablation of an Atrial Tachycardia Emanating From the Non-coronary Aortic Cusp Guided by an Electroanatomic Navigation System

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Agustin Bortone

2010-02-01

Full Text Available We report on an atrial tachycardia (AT, emanating from the non-coronary (NC aortic cusp, ablated with the aid of an electro-anatomical navigation system. In this setting, the electrocardiographic, electrophysiologic (EP, anatomical, and ablative considerations are discussed.Although NC aortic cusp focal ATs are an uncommon EP finding, their ablation is effective and safe, especially from an atrio-ventricular (AV conductive point of view. This origin of AT must be invoked and systematically disclosed when a peri-AV nodal AT origin is suspected, in order to avoid a potentially harmful energy application at the vicinity of the AV conductive tissue.

3H-digoxin distribution in the nervous system in ventricular tachycardia

International Nuclear Information System (INIS)

Frazer, G.; Binnion, P.

1981-01-01

The distribution of 3H-digoxin has been measured in a large number of tissues from the central, autonomic, and peripheral nervous system after the induction of ventricular tachycardia by infusing digoxin into anesthetized dogs. In most parts of the nervous system the tissue digoxin concentration was close to that in the cerebrospinal fluid. Digoxin accumulation in the choroid plexus probably represented a labeling of adenosine triphosphatase. There was a markedly higher concentration of digoxin in the neurohypophysis than in the adenohypophysis, and the very high levels in the neurohypophysis are hard to explain. There may be a relationship between the pituitary and the hypothalamic digoxin levels, although the concentration in the latter was unimpressive. The fornix showed a modest increase in 3H-digoxin concentration and may play a role, as its efferent discharge goes to the hypothalamus. The high concentration of digoxin in the area postrema suggests that this central nervous system structure is responsible, at least in part, for producing digoxin-induced cardiac arrhythmias. It may act as a sensing organ sensitive to blood digoxin concentration. Either it is the only central nervous structure implicated, or it is involved together with the fornix-hypothalamus-hypophysis pathways. Further proof is given for the importance of the autonomic nervous system in cardiac arrhythmias by the high digoxin levels in the superior cervical sympathetic ganglion and adrenal medulla

T wave alternans threshold late after repair of tetralogy of Fallot

Science.gov (United States)

Cheung, Michael M H.; Weintraub, Robert G.; Cohen, Richard J.; Karl, Tom R.; Wilkinson, James L.; Davis, Andrew M.

2002-01-01

INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) is a marker of increased risk for malignant ventricular arrhythmia. There is a significant risk of arrhythmia and sudden death after repair of congenital heart disease. The aim of this study was to determine the prevalence and characteristics of TWA after repair of tetralogy of Fallot (TOF). METHODS AND RESULTS: TWA was evaluated during bicycle exercise in 49 subjects who had consecutively undergone transatrial-transpulmonary repair. Median values for age, age at repair, and follow-up duration were 14.9 years (11.5-20.8), 1.6 years (0.2-4.9), and 11.6 years (9.4-17.2), respectively. All patients were in New York Heart Association functional class I and were asymptomatic. Median QRS duration was 120 msec (80-150). Sustained TWA was detected in 7 (23%) of 31 subjects with adequate tests. In these 7 subjects, median onset heart rate (HR) was 120 (98-155). Median HR threshold as a percentage of predicted maximum HR (220 - age) was 58% (48-77). Sustained TWA prevalence was not significantly different compared with normal subjects (7/31 vs 9/83; P = 0.1). Onset HR in the TOF group was significantly lower [mean (SD) of 122 (20) vs 139 (12), P < 0.05]. In the TOF group with sustained TWA, the TWA occurred in 4 of 7 at <60% predicted maximum HR versus 1 of 9 normal subjects (P < 0.05); 3 of 7 had onset HR <120 versus 0 of 9 normal subjects (P < 0.03). There was no significant difference in age, gender, transannular patch use, restrictive right ventricular physiology, QRS duration, QTc, QT/QRS dispersion, or nonsustained ventricular tachycardia in subjects with or those without sustained TWA. CONCLUSION: The onset HR for sustained TWA is significantly lower after repair of TOF. Further study is required to determine whether this represents an increased risk for arrhythmia in this patient group.

Electron states in quantum rings with structural distortions under axial or in-plane magnetic fields

International Nuclear Information System (INIS)

Planelles, J; Rajadell, F; Climente, J I

2007-01-01

A comprehensive study of anisotropic quantum rings, QRs, subject to axial and in-plane magnetic field, both aligned and transverse to the anisotropy direction, is carried out. Elliptical QRs for a wide range of eccentricity values and also perfectly circular QRs including one or more barriers disturbing the QR current are considered. These models mimic anisotropic geometry deformations and mass diffusion occurring in the QR fabrication process. Symmetry considerations and simplified analytical models supply physical insight into the obtained numerical results. Our study demonstrates that, except for unusual extremely large eccentricities, QR geometry deformations only appreciably influence a few low-lying states, while the effect of barriers disturbing the QR current is stronger and affects all studied states to a similar extent. We also show that the response of the electron states to in-plane magnetic fields provides accurate information on the structural anisotropy

Isolated persistent left-sided superior vena cava, giant coronary sinus, atrial tachycardia and heart failure in a child

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Nagaraja Moorthy

2013-09-01

Full Text Available Persistence of a left-sided superior vena cava (PLSVC with absent right superior vena cava (isolated PLSVC is a very rare venous malformation and commonly associated with congenital heart disease or alterations of the cardiac situs. We describe an unusual case of a young boy presenting with persistent atrial tachycardia and congestive heart failure. He was detected to have unexplained grossly dilated right atrium, right ventricle with systolic dysfunction and a giant coronary sinus (CS. The dilated CS closely mimicked a pseudo cor-triatriatum on echocardiography. Contrast echocardiography from both arms revealed opacification of the CS before the right atrium. Bilateral upper limb venography confirmed the presence of absent right SVC and isolated persistent left SVC draining into the giant coronary sinus.

Development of porcine model of chronic tachycardia-induced cardiomyopathy.

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Paslawska, Urszula; Gajek, Jacek; Kiczak, Liliana; Noszczyk-Nowak, Agnieszka; Skrzypczak, Piotr; Bania, Jacek; Tomaszek, Alicja; Zacharski, Maciej; Sambor, Izabela; Dziegiel, Piotr; Zysko, Dorota; Banasiak, Waldemar; Jankowska, Ewa A; Ponikowski, Piotr

2011-11-17

There are few experimental models of heart failure (HF) in large animals, despite structural and functional similarities to human myocardium. We have developed a porcine model of chronic tachycardia-induced cardiomyopathy. Homogenous siblings of White Large breed swine (n=6) underwent continuous right ventricular (RV) pacing at 170 bpm; 2 subjects served as controls. In the course of RV pacing, animals developed a clinical picture of HF and were presented for euthanasia at subsequent stages: mild, moderate and end-stage HF. Left ventricle (LV) sections were analyzed histologically and relative ANP, BNP, phospholamban and sarcoplasmic reticulum calcium ATPase 2a transcript levels in LV were quantified by real time RT-PCR. In the course of RV pacing, animals demonstrated reduced exercise capacity (time of running until being dyspnoeic: 6.6 ± 0.5 vs. 2.4 ± 1.4 min), LV dilatation (LVEDD: 4.9 ± 0.4 vs. 6.7 ± 0.4 cm), impaired LV systolic function (LVEF: 69 ± 8 vs. 32 ± 7 %), (all baseline vs. before euthanasia, all p<0.001). LV tissues from animals with moderate and end-stage HF demonstrated local foci of interstitial fibrosis, congestion, cardiomyocyte hypertrophy and atrophy, which was not detected in controls and mild HF animals. The up-regulation of ANP and BNP and a reduction in a ratio of sarcoplasmic reticulum calcium ATPase 2a and phospholamban in failing myocardium were observed as compared to controls. In pigs, chronic RV pacing at relatively low rate can be used as an experimental model of HF, as it results in a gradual deterioration of exercise tolerance accompanied by myocardial remodeling confirmed at subcellular level. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

QT prolongation and sudden cardiac death risk in hypertrophic cardiomyopathy.

Science.gov (United States)

Patel, Salma I; Ackerman, Michael J; Shamoun, Fadi E; Geske, Jeffrey B; Ommen, Steve R; Love, William T; Cha, Stephen S; Bos, Johan M; Lester, Steven J

2018-03-07

Risk assessment for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains complex. The goal of this study was to assess electrocardiogram (ECG)-derived risk factors on SCD in a large HCM population Methods: Retrospective review of adults with HCM evaluated at Mayo Clinic, Rochester, MN from 1 December 2002 to 31 December 2012 was performed. Data inclusive of ECG and 24-hour ambulatory Holter monitor were assessed. SCD events were documented by ventricular fibrillation (VF) noted on implantable cardioverter defibrillator (ICD), or appropriate VT or VF-terminating ICD shock. Overall, 1615 patients (mean age 53.7 ± 15.2 years; 943 males, 58.4%) were assessed, with mean follow-up 2.46 years and 110 SCD events. Via logistic regression (n = 820), the odds of SCD increased with increasing number of conventional risk factors. With one risk factor the OR was 4.88 (p  450 to this logistic regression model had OR 1.722 (p = .04, CI 1.01-2.937) to predict SCD. QTc ≥ 450 was a significant predictor for death (HR 1.88, p = .021, CI 1.10-3.20). There was no correlation between sinus bradycardia, sinus tachycardia, first degree AV block, atrial fibrillation, left bundle branch block, right bundle branch block, premature atrial complexes, premature ventricular complexes, supraventricular tachycardia, PR interval, QRS interval and SCD. Prolonged QTc was a risk factor for SCD and death even when controlling for typical risk factors.

Spatiotemporal Characteristics of QRS Complexes Enable the Diagnosis of Brugada Syndrome Regardless of the Appearance of a Type 1 ECG.

Science.gov (United States)

Guillem, Maria S; Climent, Andreu M; Millet, José; Berne, Paola; Ramos, Rafael; Brugada, Josep; Brugada, Ramon

2016-05-01

The diagnosis of Brugada syndrome based on the ECG is hampered by the dynamic nature of its ECG manifestations. Brugada syndrome patients are only 25% likely to present a type 1 ECG. The objective of this study is to provide an ECG diagnostic criterion for Brugada syndrome patients that can be applied consistently even in the absence of a type 1 ECG. We recorded 67-lead body surface potential maps from 94 Brugada syndrome patients and 82 controls (including right bundle branch block patients and healthy individuals). The spatial propagation direction during the last r' wave and the slope at the end of the QRS complex were measured and compared between patients groups. Receiver-operating characteristic curves were constructed for half of the database to identify optimal cutoff values; sensitivity and specificity for these cutoff values were measured in the other half of the database. A spontaneous type 1 ECG was present in only 30% of BrS patients. An orientation in the sagittal plane ECG recordings can enable a robust identification of BrS even without the presence of a type 1 ECG. © 2016 Wiley Periodicals, Inc.

Development of heart failure is independent of K+ channel-interacting protein 2 expression

DEFF Research Database (Denmark)

Speerschneider, Tobias; Grubb, Søren; Metoska, Artina

2013-01-01

of the transient outward K(+) current (Ito). We aim to investigate the possible significance of a changed KChIP2 expression on the development of HF and proarrhythmia. Transverse aortic constrictions (TAC) and sham operations were performed in wild-type (WT) and KChIP2(-/-) mice. Echocardiography was performed......(-/-) mice. Ventricular protein expression of KChIP2 was reduced by 70% after 10 weeks TAC in WT mice. The amplitudes of the J and T waves were enlarged in KChIP2(-/-) control mice. Ventricular effective refractory period, RR, QRS and QT intervals were longer in mice with HF compared to sham-operated mice...... of either genotype. Pacing-induced ventricular tachycardia (VT) was observed in 5/10 sham-operated WT mice compared with 2/10 HF WT mice with HF. Interestingly, and contrary to previously published data, sham-operated KChIP2(-/-) mice were resistant to pacing-induced VT resulting in only 1/10 inducible mice...

ZP123 increases gap junctional conductance and prevents reentrant ventricular tachycardia during myocardial ischemia in open chest dogs

DEFF Research Database (Denmark)

Xing, Dezhi; Kjølbye, Anne Louise; Nielsen, Morten S

2003-01-01

INTRODUCTION: The aim of this study was to determine if the stable antiarrhythmic peptide (AAP) analogue ZP123 increases gap junctional intercellular conductance and prevents reentrant ventricular tachycardia (VT) during coronary artery occlusion. METHODS AND RESULTS: Voltage clamp experiments...... demonstrated that 10 nM ZP123 improved gap junctional intercellular conductance by 69% +/- 20% in pairs of guinea pig ventricular myocytes. VT was induced by programmed stimulation in alpha-chloralose anaesthetized open chest dogs 1 to 4 hours after coronary artery occlusion. Three-dimensional activation...... AAP analogue ZP123 increased gap junctional intercellular conductance and specifically prevented the induction of reentrant VT during ischemia in a broad dose range without proarrhythmic or hemodynamic side effects. ZP123 is a promising candidate for use in preventing ischemia-induced VT....

Atrial flutter with spontaneous 1:1 atrioventricular conduction in adults: an uncommon but frequently missed cause for syncope/presyncope.

Science.gov (United States)

Turitto, Gioia; Akhrass, Philippe; Leonardi, Marino; Saponieri, Cesare; Sette, Antonella; El-Sherif, Nabil

2009-01-01

To compare patients with atrial flutter (AFl) and 1:1 atrioventricular conduction (AVC) with patients with AFl and higher AVC. The characteristics of 19 patients with AFl and 1:1 AVC (group A) were compared with those of 116 consecutive patients with AFl and 2:1 AVC or higher degree AV block (group B). Age, gender, and left ventricular function were similar in the two groups. In group A versus group B, more patients had no structural heart disease (42% vs 17%, P AVC or vice versa was associated with small but definite changes in AFl CL, which showed larger variations in response to sympathetic stimulation. In group A patients who were studied off drugs, the atrial-His interval was not different from group B, but maximal atrial pacing rate with 1:1 AVC was faster. In group A, five patients were misdiagnosed as ventricular tachyarrhythmias, and three with a defibrillator received inappropriate shocks. Four patients had ablation of AVC and six had ablation of AFl circuit. The main difference between groups A and B may be an inherent capacity of the AV node for faster conduction, especially in response to increased sympathetic tone. The latter affects not only AVC but also the AFl CL. One should be aware of the different presentations of AFl with 1:1 AVC to avoid misdiagnosis/mismanagement and to consider the diagnosis in patients with narrow or wide QRS tachycardia and rates above 220/min.

An intelligent telecardiology system using a wearable and wireless ECG to detect atrial fibrillation.

Science.gov (United States)

Lin, Chin-Teng; Chang, Kuan-Cheng; Lin, Chun-Ling; Chiang, Chia-Cheng; Lu, Shao-Wei; Chang, Shih-Sheng; Lin, Bor-Shyh; Liang, Hsin-Yueh; Chen, Ray-Jade; Lee, Yuan-Teh; Ko, Li-Wei

2010-05-01

This study presents a novel wireless, ambulatory, real-time, and autoalarm intelligent telecardiology system to improve healthcare for cardiovascular disease, which is one of the most prevalent and costly health problems in the world. This system consists of a lightweight and power-saving wireless ECG device equipped with a built-in automatic warning expert system. This device is connected to a mobile and ubiquitous real-time display platform. The acquired ECG signals are instantaneously transmitted to mobile devices, such as netbooks or mobile phones through Bluetooth, and then, processed by the expert system. An alert signal is sent to the remote database server, which can be accessed by an Internet browser, once an abnormal ECG is detected. The current version of the expert system can identify five types of abnormal cardiac rhythms in real-time, including sinus tachycardia, sinus bradycardia, wide QRS complex, atrial fibrillation (AF), and cardiac asystole, which is very important for both the subjects who are being monitored and the healthcare personnel tracking cardiac-rhythm disorders. The proposed system also activates an emergency medical alarm system when problems occur. Clinical testing reveals that the proposed system is approximately 94% accurate, with high sensitivity, specificity, and positive prediction rates for ten normal subjects and 20 AF patients. We believe that in the future a business-card-like ECG device, accompanied with a mobile phone, can make universal cardiac protection service possible.

The role of surgery in the treatment of post-infarction ventricular tachycardia. A 5 year experience.

Science.gov (United States)

Martinelli, L; Goggi, C; Graffigna, A; Salerno, J A; Chimienti, M; Klersy, C; Viganò, M

1987-01-01

The purpose of this report is to present a 5 year experience in electrophysiologically guided surgical treatment of post-infarction ventricular tachycardia (VT) in a consecutive series of 39 patients. In every case the arrhythmia was not responsive to pluripharmacological therapy. The diagnostic steps included preoperative endocardial, intraoperative epi- and endocardial mapping, automatically carried out when possible. Surgical techniques were: classic Guiraudon's encircling endocardial ventriculotomy (EEV), partial EEV, endocardial resection (ER), cryoablation or combined procedures. The hospital mortality was of 4 patients (10%). During the follow-up period (1-68 mo), 4 patients (11%) died of cardiac non-VT related causes. Among the survivors, 90% are in sinus rhythm. The authors consider electrophysiologically guided surgery a safe and reliable method for the treatment of post-infarction VT and suggest more extensive indications. They stress the importance of automatic mapping in pleomorphic and non-sustained VT, and the necessity of tailoring the surgical technique to the characteristics of each case.

Ventricular Tachycardia from a Central Line Fracture Fragment Embolus: A Rare Complication of a Commonly Used Procedure—A Case Report and Review of the Relevant Literature

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Saptarshi Biswas

2015-01-01

Full Text Available A 22-year-old male admitted with multiple gunshot wounds (GSW had central line placed initially for hemodynamic monitoring and later for long term antibiotics and total parenteral nutrition (TPN. On postoperative day 4 he presented with bouts of nonsustained ventricular tachycardia; the cause was unknown initially and later attributed to a catheter fragment accidentally severed and lodged in the right heart. Percutaneous retrieval technique was used to successfully extract the catheter fragment and complete recovery was achieved.

Sleep disturbances and autonomic dysfunction in patients with postural orthostatic tachycardia syndrome

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Julia eMallien

2014-07-01

Full Text Available Many patients with Postural Tachycardia Syndrome (PoTS suffer from fatigue, daytime sleepiness and sleeping disturbances. The objective of this study was to compare subjective and objective sleep quality of PoTS patients with a group of healthy controls. All Patients completed a Pittsburgh Sleep Quality Index questionnaire and the Epworth Sleepiness Scale. The patients sleep architecture, heart rate and heart rate variability measurements were taken during one night at the sleep laboratorium. All Data was collected at the Sleep Unit, at Helios Klinikum Wuppertal. 38 patients diagnosed with PoTS were compared to 31 healthy controls, matched in age and gender. Patients with PoTS reached significantly higher scores in sleep questionnaires, which means that they were more sleepy and had a lower sleep qualitiy. Polysomnography showed a significantly higher proportion of stage 2 sleep. The results of heart rate variability analysis in different sleep stages confirmed changes in autonomic activity in both groups. PoTS patients, however, showed a diminished variability of the LF band, HF band and LF/HF ratio in different sleep stages. It can therefore be gathererd that PoTS could be considered as potential differential diagnosis for sleep disturbances since PoTS patients had a subjective diminished sleep quality, reached higher levels of daytime sleepiness and showed a higher proportion of stage 2 sleep. PoTS patients showed furthermore a reduction of LF/HF ratio variability in different sleep stages.

Acute Purulent Tuberculosis Pericarditis with Cardiac Tamponade: a Case Report.

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F. Z. Benaich

2015-12-01

Full Text Available Tuberculosis is a disease caused by Mycobacterium tuberculosis. Pulmonary localization is the most frequent. However, pericardial including extra- pulmonary disease, can cause fatal complications. A 37 years old man , without pathological history , who consults for emergency mid-thoracic pain associated with dyspnea, preceded by 10 days before a febrile syndrome with night sweats. Clinical examination showed patient in poor general condition, dyspneic and tachycardia. Cardiovascular examination showed spontaneous jugular veins and painful hepatomegaly, auscultation showed muted heart sounds without pericardial friction and breathless. Chest radiography showed cardiomegaly with symmetric edge straightness, electrocardiogram showed sinus tachycardia at 125bpm, microvoltage and electric alternating QRS complexes. A diffuse ST elevation ascending .Diagnosis of tamponade is suspected, transthoracic echocardiography showed abundance circumferential pericardial effusion measuring 40mm, with prolonged collapse of the right atrium and right ventricle , paradoxical septum , and significant changes in the flow inspiration. Pericardiocentesis ultrasound-guided has allowed a gradual evacuation of 2 liters of a cloudy yellow pericardial fluid, slightly viscous. Direct examination revealed the presence of 14 400 white cells, 99 % are neutrophils with gram-negative bacilli. Research bacillus by PCR and culture in the middle of LOWENSTEIN, later returned negative. Biologically, it is an important infectious syndrome. Taking into account the epidemiological profile of the country, diagnosis tuberculous primary infection tamponade was certain. quadruple anti- tuberculous treatment associated to corticosteroid therapy is instituted, The outcome was good, the patient was asymptomatic, with complete remission, echocardiography control finds no signs suggesting chronic constrictive pericarditis.

Association of temporary complete AV block and junctional ectopic tachycardia after surgery for congenital heart disease

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Paech, Christian; Dähnert, Ingo; Kostelka, Martin; Mende, Meinhardt; Gebauer, Roman

2015-01-01

Junctional ectopic tachycardia (JET) is a postoperative complication with a mortality rate of up to 14% after surgery for congenital heart disease. This study evaluated the risk factors of JET and explored the association of postoperative temporary third degree atrioventricular (AV) block and the occurrence of JET. Data were collected retrospectively from 1158 patients who underwent surgery for congenital heart disease. The overall incidence of JET was 2.8%. Temporary third degree AV block occurred in 1.6% of cases. Permanent third degree AV block requiring pacemaker implantation occurred in 1% of cases. In all, 56% of patients with JET had temporary AV block (P < 0.001), whereas no case of postoperative JET was reported in patients with permanent AV block (P = 0.56). temporary third degree AV block did not suffer from JET. A correlation between temporary third degree AV block and postoperative JET could be observed. The risk factors identified for JET include younger age groups at the time of surgery, longer aortic cross clamping time and surgical procedures in proximity to the AV node

Genome wide analysis of drug-induced torsades de pointes: lack of common variants with large effect sizes

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Behr, Elijah R.; Ritchie, Marylyn D.; Tanaka, Toshihiro; Kääb, Stefan; Crawford, Dana C.; Nicoletti, Paola; Floratos, Aris; Sinner, Moritz F.; Kannankeril, Prince J.; Wilde, Arthur A. M.; Bezzina, Connie R.; Schulze-Bahr, Eric; Zumhagen, Sven; Guicheney, Pascale; Bishopric, Nanette H.; Marshall, Vanessa; Shakir, Saad; Dalageorgou, Chrysoula; Bevan, Steve; Jamshidi, Yalda; Bastiaenen, Rachel; Myerburg, Robert J.; Schott, Jean-Jacques; Camm, A. John; Steinbeck, Gerhard; Norris, Kris; Altman, Russ B.; Tatonetti, Nicholas P.; Jeffery, Steve; Kubo, Michiaki; Nakamura, Yusuke; Shen, Yufeng; George, Alfred L.; Roden, Dan M.

2013-01-01

Marked prolongation of the QT interval on the electrocardiogram associated with the polymorphic ventricular tachycardia Torsades de Pointes is a serious adverse event during treatment with antiarrhythmic drugs and other culprit medications, and is a common cause for drug relabeling and withdrawal.

Source-Sink Mismatch Causing Functional Conduction Block in Re-Entrant Ventricular Tachycardia.

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Ciaccio, Edward J; Coromilas, James; Wit, Andrew L; Peters, Nicholas S; Garan, Hasan

2018-01-01

Ventricular tachycardia (VT) caused by a re-entrant circuit is a life-threatening arrhythmia that at present cannot always be treated adequately. A realistic model of re-entry would be helpful to accurately guide catheter ablation for interruption of the circuit. In this review, models of electrical activation wavefront propagation during onset and maintenance of re-entrant VT are discussed. In particular, the relationship between activation mapping and maps of transition in infarct border zone thickness, which results in source-sink mismatch, is considered in detail and supplemented with additional data. Based on source-sink mismatch, the re-entry isthmus can be modeled from its boundary properties. Isthmus boundary segments with large transitions in infarct border zone thickness have large source-sink mismatch, and functional block forms there during VT. These alternate with segments having lesser thickness change and therefore lesser source-sink mismatch, which act as gaps, or entrance and exit points, to the isthmus during VT. Besides post-infarction substrates, the source-sink model is likely applicable to other types of volumetric changes in the myocardial conducting medium, such as when there is presence of fibrosis or dissociation of muscle fibers. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Genetic variants in post myocardial infarction patients presenting with electrical storm of unstable ventricular tachycardia.

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Rangaraju, Advithi; Krishnan, Shuba; Aparna, G; Sankaran, Satish; Mannan, Ashraf U; Rao, B Hygriv

2018-01-30

Electrical storm (ES) is a life threatening clinical situation. Though a few clinical pointers exist, the occurrence of ES in a patient with remote myocardial infarction (MI) is generally unpredictable. Genetic markers for this entity have not been studied. In the present study, we carried out genetic screening in patients with remote myocardial infarction presenting with ES by next generation sequencing and identified 25 rare variants in 19 genes predominantly in RYR2, SCN5A, KCNJ11, KCNE1 and KCNH2, CACNA1B, CACNA1C, CACNA1D and desmosomal genes - DSP and DSG2 that could potentially be implicated in electrical storm. These genes have been previously reported to be associated with inherited syndromes of Sudden Cardiac Death. The present study suggests that the genetic architecture in patients with remote MI and ES of unstable ventricular tachycardia may be similar to that of Ion channelopathies. Identification of these variants may identify post MI patients who are predisposed to develop electrical storm and help in risk stratification. Copyright © 2018 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

Bundle branch block after ablation for Wolff-Parkinson-White syndrome.

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Fuenmayor A, Abdel J; Rodríguez S, Yenny A

2013-09-20

Bundle branch block (BBB) is a difficult diagnosis in the Wolff-Parkinson-White syndrome (WPW). We investigated the clinical implications of BBB that appears after performing an accessory pathway (AP) ablation. We studied 199 patients with WPW who were submitted to AP ablation. Thirty (15%) exhibited BBB after the ablation. Twenty-two patients had right BBB and 8 had left BBB. Thirteen patients had right-sided AP and 17 had left-sided AP. They were compared with 82 similar patients without BBB after the AP ablation. Among the patients with BBB, 86.66% showed delays in the middle part of the QRS in the ECG recorded before ablation vs. 18.29% of the patients without BBB (p<0.05) (sensitivity 86%, specificity 81%, positive predictive value 67% and negative predictive value 93%). Forty-four percent of the patients with BBB had BBB morphology during orthodromic tachycardia vs. 10% of the patients without BBB (p<0.05) (sensitivity 44%, specificity 89%, positive predictive value 57% and negative predictive value 82%). No relationship was found between AP location and the site of the BBB. Ejection fraction was normal before (0.61 ± 0.03) and upon completion of follow-up (0.61 ± 0.07). BBB disappeared in 95.3% of the patients. Delays in the middle portion of the QRS may predict BBB after AP ablation. BBB after performing AP ablation is frequent, transient, benign, and not related to either the ablation lesion location or progression to structural heart disease. BBB after AP ablation may be related to cardiac memory. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The value of the 12-lead electrocardiogram in localizing the scar in non-ischaemic cardiomyopathy.

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Oloriz, Teresa; Wellens, Hein J J; Santagostino, Giulia; Trevisi, Nicola; Silberbauer, John; Peretto, Giovanni; Maccabelli, Giuseppe; Della Bella, Paolo

2016-12-01

Patients with non-ischaemic cardiomyopathy (NICM) and ventricular tachycardia can be categorized as anteroseptal (AS) or inferolateral (IL) scar sub-types based on imaging and voltage mapping studies. The aim of this study was to correlate the baseline electrocardiogram (ECG) with endo-epicardial voltage maps created during ablation procedures and identify the ECG characteristics that may help to distinguish the scar as AS or IL. We assessed 108 baseline ECGs; 72 patients fulfilled criteria for dilated cardiomyopathy whereas 36 showed minimal structural abnormalities. Based on the unipolar low-voltage distribution, the scar pattern was classified as predominantly AS (n = 59) or IL (n = 49). Three ECG criteria (PR interval 230 ms or QRS > 170 ms or an r ≤ 0.3 mV in V3 having 92 and 81% of sensitivity and specificity, respectively, in predicting AS scar pattern. A significant negative correlation was found between the extension of the endocardial unipolar low voltage area and left ventricular EF (r s = -0.719, P < 0.001). The extent of endocardial AS unipolar low voltage was correlated with PR interval and QRS duration (r s = 0.583 and r s = 0.680, P < 0.001, respectively) and the IL epicardial unipolar low voltage with the mean voltage of the limb leads (r s = -0.639, P < 0.001). Baseline ECG features are well correlated with the distribution of unipolar voltage abnormalities in NICM and may help to predict the location of scar in this population. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Risk factors for postural tachycardia syndrome in children and adolescents.

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Jing Lin

Full Text Available BACKGROUND: Postural tachycardia syndrome (POTS is prevalent in children and adolescents and has a great impact on health. But its risk factors have not been fully understood. This study aimed to explore possible risk factors for children and adolescents with POTS. METHODS AND FINDINGS: 600 children and adolescents (test group aged 7-18 (11.9 ± 3.0 years old, 259 males and 341 females, were recruited for identifying its risk factors. Another 197 subjects aged from 7 to 18 (11.3 ± 2.3 years old were enrolled in the validation group. Heart rate (HR and blood pressure (BP were monitored during upright test. Risk factors were analyzed and sensitivity and specificity for predicting POTS were tested via receiver operating characteristic curve. Among 600 subjects, 41 were confirmed with POTS patients (6.8% based on clinical manifestation and upright test. The results showed a significant difference in daily water intake, the daily sleeping hours, supine HR, HR increment and maximum HR during upright test between POTS and the unaffected children (P<0.05. Likelihood of POTS would increase by 1.583 times if supine HR was increased by 10 beats/min (95%CI 1.184 to 2.116, P<0.01, by 3.877 times if a child's water intake was less than 800 ml/day (95%CI 1.937 to 7.760, P<0.001, or by 5.905 times (95%CI 2.972 to 11.733, P<0.001 if sleeping hours were less than 8 hours/day. Supine HR, daily water intake and sleeping hours showed the capability of predicting POTS in children and adolescents with an AUC of 83.9% (95% CI: 78.6%-89.1%, sensitivity of 80.5% and specificity of 75%. Furthermore, in validation group, predictive sensitivity and specificity were 73.3% and 72.5%. CONCLUSION: Faster supine HR, less water intake and shorter sleeping hours were identified as risk factors for POTS.

Brugada-Phenocopy Induced by Propafenone Overdose and Successful Treatment: A Case Report

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Mehmet Emre Arı

2017-10-01

Full Text Available Background: Brugada syndrome is an inherited arrhythmogenic disease that may cause sudden cardiac death due to ventricular fibrillation in young adults. Brugada syndrome caused by propafenone intoxication has been noted rarely in the literature. We report a rare case, Brugada phenocopy due to propafenone intoxication and its treatment. Case Report: A 15-year-old girl having a seizure was brought to the emergency room. She took 1.5 g propafenone (Rythmol, Abbott, Chicago, IL, USA for suicidal intention. She had metabolic acidosis. Long QRS interval and ST elevation in leads V1 through V3 were seen on electrocardiography. After bicarbonate infusion for 4 hours, haemodynamic and neurologic findings were recovered, and all electrocardiography abnormalities disappeared. The Brugada-like electrocardiography pattern was not recognized in her surface and 24-hour Holter electrocardiography at follow-up. Ajmaline challenge test was negative 2 weeks later. Conclusion: Absence of symptoms and documented ventricular tachycardia, negative challenge test, and a negative family history demonstrated that the Brugada phenocopy was a transient finding in this case and related to propafenone intoxication

100-fold but not 50-fold dystrophin overexpression aggravates electrocardiographic defects in the mdx model of Duchenne muscular dystrophy

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Yongping Yue

2016-01-01

Full Text Available Dystrophin gene replacement holds the promise of treating Duchenne muscular dystrophy. Supraphysiological expression is a concern for all gene therapy studies. In the case of Duchenne muscular dystrophy, Chamberlain and colleagues found that 50-fold overexpression did not cause deleterious side effect in skeletal muscle. To determine whether excessive dystrophin expression in the heart is safe, we studied two lines of transgenic mdx mice that selectively expressed a therapeutic minidystrophin gene in the heart at 50-fold and 100-fold of the normal levels. In the line with 50-fold overexpression, minidystrophin showed sarcolemmal localization and electrocardiogram abnormalities were corrected. However, in the line with 100-fold overexpression, we not only detected sarcolemmal minidystrophin expression but also observed accumulation of minidystrophin vesicles in the sarcoplasm. Excessive minidystrophin expression did not correct tachycardia, a characteristic feature of Duchenne muscular dystrophy. Importantly, several electrocardiogram parameters (QT interval, QRS duration and the cardiomyopathy index became worse than that of mdx mice. Our data suggests that the mouse heart can tolerate 50-fold minidystrophin overexpression, but 100-fold overexpression leads to cardiac toxicity.

Contemporary Tools and Techniques for Substrate Ablation of Ventricular Tachycardia in Structural Heart Disease.

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Hutchinson, Mathew D; Garza, Hyon-He K

2018-02-24

As we have witnessed in other arenas of catheter-based therapeutics, ventricular tachycardia (VT) ablation has become increasingly anatomical in its execution. Multi-modality imaging provides anatomical detail in substrate characterization, which is often complex in nonischemic cardiomyopathy patients. Patients with intramural, intraseptal, and epicardial substrates provide challenges in delivering effective ablation to the critical arrhythmia substrate due to the depth of origin or the presence of adjacent critical structures. Novel ablation techniques such as simultaneous unipolar or bipolar ablation can be useful to achieve greater lesion depth, though at the expense of increasing collateral damage. Disruptive technologies like stereotactic radioablation may provide a tailored approach to these complex patients while minimizing procedural risk. Substrate ablation is a cornerstone of the contemporary VT ablation procedure, and recent data suggest that it is as effective and more efficient that conventional activation guided ablation. A number of specific targets and techniques for substrate ablation have been described, and all have shown a fairly high success in achieving their acute procedural endpoint. Substrate ablation also provides a novel and reproducible procedural endpoint, which may add predictive value for VT recurrence beyond conventional programmed stimulation. Extrapolation of outcome data to nonischemic phenotypes requires caution given both the variability in substrate nonischemic distribution and the underrepresentation of these patients in previous trials.

Composition and conductance distributions of single GeSi quantum rings studied by conductive atomic force microscopy combined with selective chemical etching.

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Lv, Y; Cui, J; Jiang, Z M; Yang, X J

2013-02-15

Atomic force microscopy imaging combined with selective chemical etching is employed to quantitatively investigate three-dimensional (3D) composition distributions of single GeSi quantum rings (QRs). In addition, the 3D quantitative composition distributions and the corresponding conductance distributions are simultaneously obtained on the same single GeSi QRs by conductive atomic force microscopy combined with selective chemical etching, allowing us to investigate the correlations between the conductance and composition distributions of single QRs. The results show that the QRs' central holes have higher Ge content, but exhibit lower conductance, indicating that the QRs' conductance distribution is not consistent with their composition distribution. By comparing the topography, composition and conductance profiles of the same single QRs before and after different etching processes, it is found that the conductance distributions of GeSi QRs do not vary with the change of composition distribution. Instead, the QRs' conductance distributions are found to be consistent with their topographic shapes, which can be supposed to be due to the shape determined electronic structures.

Response of the ECG to short-term diuresis in patients with heart failure.

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Madias, John E; Song, Jessica; White, C Michael; Kalus, James S; Kluger, Jeffrey

2005-07-01

Increase in the amplitude of electrocardiogram (ECG) QRS complexes has been observed in patients treated for heart failure (HF), but the underlying mechanism has not been delineated. Also, correlation of augmentation of the QRS potentials with loss of weight has been noted in patients recovering from anasarca of varying etiology, or after hemodialysis. We assessed the effect of diuresis-based fluid loss in patients treated for HF on the amplitude of ECG QRS complexes. This is a cohort study based on ECG and other data from a previously published investigation of patients with HF conducted at a university affiliated hospital, which used new measurements and analysis, performed by a totally blinded investigator based at another institution. Twenty-one patients (10 men) aged 70.5+/-12.7 years, 13 with ischemic, and 8 with nonischemic cardiomyopathy, were admitted to the hospital for management of exacerbated HF and were observed for 48 hours. The patients received diuresis, and had routine laboratory testing, documentation of the net fluid lost, and recording of ECGs prior to the initiation of therapy and at 24 and 48 hours. Percent change (%Delta) over the course of observation in the sums of the amplitude of QRS complexes from 12 leads (SigmaQRS12), 6-limb leads (SigmaQRS6), and leads 1+2 (SigmaQRS2) in mm of standard ECGs were correlated with net fluid loss corrected for admission weight in mL/kg. Fluid loss amounted to 3204.9+/-1399.5 mL in the course of 40+/-23 hours of diuresis. SigmaQRS12 was 160.9+/-42.3 mm before and 170.0+/-50.7 mm after diuresis (P=0. 024). Percent change in SigmaQRS12, SigmaQRS6, and SigmaQRS2 correlated well with the net fluid loss (r=-0.70, -0.82, -0.61, and P=0.002, 0.0005, 0.001) correspondingly. Changes in sums of the amplitude of QRS complexes of the standard ECG correlates well with net fluid loss in response to short-term diuresis in patients with HF. Change in the SigmaQRS12, SigmaQRS6, and SigmaQRS2 from ECGs before and after

Cognitive function, health-related quality of life and symptoms of depression and anxiety sensitivity are impaired in patients with the postural orthostatic tachycardia syndrome (POTS

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Jake W Anderson

2014-06-01

Full Text Available The Postural Orthostatic Tachycardia Syndrome (POTS is a condition in which heart rate increases abnormally when the individual assumes an upright position. In addition to the marked tachycardia, presyncope and syncope, patients with POTS often complain of light-headedness, fatigue and difficulty in concentrating. The present study assessed individuals with POTS for psychiatric comorbidity, anxiety sensitivity and health related quality of life and examined general cognitive ability. Data was obtained from patients with POTS (n=15, 12 female, aged 30±3 years and age matched healthy subjects (n=30, 21 female, aged 32±2 years. Patients with POTS commonly presented with symptoms of depression, elevated anxiety and increased anxiety sensitivity, particularly with regards to cardiac symptoms, and had a poorer health related quality of life in both the physical and mental health domains. While patients with POTS performed worse in tests of current intellectual functioning (verbal and non-verbal IQ and in measures of focused attention (digits forward and short term memory (digits back, test results were influenced largely by years of education and the underlying level of depression and anxiety. Acute changes in cognitive performance in response to head up tilt were evident in the POTS patients. From results obtained, it was concluded that participants with POTS have an increased prevalence of depression and higher levels of anxiety. These underlying symptoms impact on cognition in patients with POTS, particularly in the cognitive domains of attention and short-term memory. Our results indicate that psychological interventions may aid in recovery and facilitate uptake and adherence of other treatment modalities in patients with POTS.

Functional Na(V)1.8 Channels in Intracardiac Neurons The Link Between SCN10A and Cardiac Electrophysiology

NARCIS (Netherlands)

Verkerk, Arie O.; Remme, Carol Ann; Schumacher, Cees A.; Scicluna, Brendon P.; Wolswinkel, Rianne; de Jonge, Berend; Bezzina, Connie R.; Veldkamp, Marieke W.

2012-01-01

Rationale: The SCN10A gene encodes the neuronal sodium channel isoform Na(V)1.8. Several recent genome-wide association studies have linked SCN10A to PR interval and QRS duration, strongly suggesting an as-yet unknown role for Na(V)1.8 in cardiac electrophysiology. Objective: To demonstrate the

Ventricular arrhythmias and sudden cardiac arrest in Takotsubo cardiomyopathy: Incidence, predictive factors, and clinical implications.

Science.gov (United States)

Jesel, Laurence; Berthon, Charlotte; Messas, Nathan; Lim, Han S; Girardey, Mélanie; Marzak, Halim; Marchandot, Benjamin; Trinh, Annie; Ohlmann, Patrick; Morel, Olivier

2018-04-06

Takotsubo cardiomyopathy (TTC) is a stress-related transient cardiomyopathy. Life-threatening arrhythmias (LTA) can occur and worsen prognosis. The purpose of this study was to assess the incidence and outcome of LTA in TTC, as well as its predictive factors and clinical implications. We studied 214 consecutive cases of TTC over 8 years. The study cohort was divided into 2 groups: those with LTA (LTA group) and those without (non-LTA group). LTA was defined as ventricular tachycardia, ventricular fibrillation, or cardiac arrest. LTA occurred in 10.7% of patients mainly in the first 24 hours of hospitalization: ventricular tachycardia (n = 2), ventricular fibrillation (n = 11), cardiac arrest (n = 10: 5 asystole, 3 complete heart block, and 2 sinoatrial block). LTA were associated with lower left ventricular ejection fraction (LVEF) and a high rate of conduction disturbances. In-hospital (39.1% vs 8.9%; P 105 ms were independent predictors of LTA. In cases where a device was implanted, conduction disturbances persisted after the index event despite complete recovery of LVEF. There was no ventricular arrhythmia recurrence during follow-up. LTA occur early in patients presenting with TTC and is associated with significantly worse short- and long-term prognosis. Left ventricular impairment and QRS duration >105 ms are independent predictors of LTA. Ventricular arrhythmias occurred in the acute phase without further recurrence recorded in hospital survivors, whereas severe conduction disorders persisted during long-term follow-up. These findings may have implications on the choice of device therapy for this specific patient subgroup. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

What is brain fog? An evaluation of the symptom in postural tachycardia syndrome.

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Ross, Amanda J; Medow, Marvin S; Rowe, Peter C; Stewart, Julian M

2013-12-01

Adolescents with postural tachycardia syndrome (POTS) often experience ill-defined cognitive impairment referred to by patients as "brain fog." The objective of this study was to evaluate the symptom of brain fog as a means of gaining further insight into its etiology and potential palliative interventions. Eligible subjects who reported having been diagnosed with POTS were recruited from social media web sites. Subjects were asked to complete a 38-item questionnaire designed for this study, and the Wood mental fatigue inventory (WMFI). Responses were received from 138 subjects with POTS (88 % female), ranging in age from 14 to 29 years; 132 subjects reported brain fog. WMFI scores correlated with brain fog frequency and severity (P fog were "forgetful," "cloudy," and "difficulty focusing, thinking and communicating." The most frequently reported brain fog triggers were fatigue (91 %), lack of sleep (90 %), prolonged standing (87 %), dehydration (86 %), and feeling faint (85 %). Although aggravated by upright posture, brain fog was reported to persist after assuming a recumbent posture. The most frequently reported interventions for the treatment of brain fog were intravenous saline (77 %), stimulant medications (67 %), salt tablets (54 %), intra-muscular vitamin B-12 injections (48 %), and midodrine (45 %). Descriptors for "brain fog" are most consistent with it being a cognitive complaint. Factors other than upright posture may play a role in the persistence of this symptom. Subjects reported a number of therapeutic interventions for brain fog not typically used in the treatment of POTS that may warrant further investigation.

Stable gastric pentadecapeptide BPC 157 and bupivacaine.

Science.gov (United States)

Zivanovic-Posilovic, Gordana; Balenovic, Diana; Barisic, Ivan; Strinic, Dean; Stambolija, Vasilije; Udovicic, Mario; Uzun, Sandra; Drmic, Domagoj; Vlainic, Josipa; Bencic, Martina Lovric; Sindic, Aleksandra; Seiwerth, Sven; Sikiric, Predrag

2016-12-15

Bupivacaine toxicity following accidental overdose still lacks therapeutic solution. However, there are major arguments for testing BPC 157 against bupivacaine toxicity in vivo in rats, in particular, and then finally, in vitro. These are: the lack of any known BPC 157 toxicity, a lifesaving effect via the mitigation of arrhythmias in rats underwent hyperkalemia or digitalis toxicity, the elimination of hyperkalemia and arrhythmias in rats underwent succinylcholine toxicity and finally, the reduction of potassium-induced depolarization in vitro (in HEK293 cells) in severe hyperkalemia. Most importantly, BPC 157 successfully prevents and counteracts bupivacaine cardiotoxicity; BPC 157 is effective even against the worst outcomes such as a severely prolonged QRS complex. Here, rats injected with bupivacaine (100mg/kg IP) exhibited bradycardia, AV-block, ventricular ectopies, ventricular tachycardia, T-wave elevation and asystole. All of the fatalities had developed T-wave elevation, high-degree AV-block, respiratory arrest and asystole. These were largely counteracted by BPC 157 administration (50µg/kg, 10µg/kg, 10ng/kg, or 10pg/kg IP) given 30min before or 1min after the bupivacaine injection. When BPC 157 was given 6min after bupivacaine administration, and after the development of prolonged QRS intervals (20ms), the fatal outcome was markedly postponed. Additionally, the effect of bupivacaine on cell membrane depolarization was explored by measuring membrane voltages (Vm) in HEK293 cells. Bupivacaine (1mM) alone caused depolarization of the cells, while in combination with BPC 157 (1µm), the bupivacaine-induced depolarization was inhibited. Together, these findings suggest that the stable gastric pentadecapeptide BPC 157 should be a potential antidote for bupivacaine cardiotoxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

Propafenone Overdose-induced Arrhythmia and Subsequent Correction After Administration of Sodium Bicarbonate

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Patrick Bruss, MD

2018-04-01

Full Text Available History of present illness: 71-year old woman presented to the emergency department with near-syncope, chest pain, and shortness of breath. She has a history of hypertension, congestive heart failure and an “irregular heartbeat.” She cannot remember what medications she takes. She recently saw her cardiologist and had some of her medications adjusted, but she can’t remember what specific changes were made. An electrocardiogram was performed, one ampule of sodium bicarbonate was administered and a repeat ECG obtained; patient felt improvement of her symptoms after administration of sodium bicarbonate. Significant findings: The first ECG in this case showed sinus tachycardia with a widened QRS (black arrow, a rightward axis, prolonged corrected QT interval (QTc, and terminal R wave in AVR (white arrow. There are several potential causes for these ECG findings, but put together with the patient’s history, we were suspicious of sodium channel blockers being the most likely cause. The second ECG, after sodium bicarbonate was administered, demonstrated a normal QRS (black arrow and no rightward axis deviation, reduction of the QTC and resolution of the terminal R wave (white arrow. We later learned that the patient’s cardiologist recently increased her propafenone dose. Discussion: Propafenone is a class 1C anti-arrhythmic that slows influx of sodium ions into the cells. It slows the rate of increase of the action potential thereby prolonging conduction and refractoriness in all areas of the myocardium.1 The mortality from acute Class 1C toxicity has been reported as high as 22.5%.1 The degree of propafenone toxicity is directly correlated to the QRS interval,1 so monitoring said interval is very helpful in determining resolution of the drug’s cardiotoxic effects. The electrocardiac effect of tricyclic antidepressants (TCAs is a well-known and often tested finding. These effects include prolongation of the QRS and QTc, right axis deviation

Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy.

Science.gov (United States)

Lv, Yi; Cui, Jian; Jiang, Zuimin M; Yang, Xinju

2012-11-29

The nanoscale electrical properties of individual self-assembled GeSi quantum rings (QRs) were studied by scanning probe microscopy-based techniques. The surface potential distributions of individual GeSi QRs are obtained by scanning Kelvin microscopy (SKM). Ring-shaped work function distributions are observed, presenting that the QRs' rim has a larger work function than the QRs' central hole. By combining the SKM results with those obtained by conductive atomic force microscopy and scanning capacitance microscopy, the correlations between the surface potential, conductance, and carrier density distributions are revealed, and a possible interpretation for the QRs' conductance distributions is suggested.

A robust physiology-based source separation method for QRS detection in low amplitude fetal ECG recordings

International Nuclear Information System (INIS)

Vullings, R; Bergmans, J W M; Peters, C H L; Hermans, M J M; Wijn, P F F; Oei, S G

2010-01-01

The use of the non-invasively obtained fetal electrocardiogram (ECG) in fetal monitoring is complicated by the low signal-to-noise ratio (SNR) of ECG signals. Even after removal of the predominant interference (i.e. the maternal ECG), the SNR is generally too low for medical diagnostics, and hence additional signal processing is still required. To this end, several methods for exploiting the spatial correlation of multi-channel fetal ECG recordings from the maternal abdomen have been proposed in the literature, of which principal component analysis (PCA) and independent component analysis (ICA) are the most prominent. Both PCA and ICA, however, suffer from the drawback that they are blind source separation (BSS) techniques and as such suboptimum in that they do not consider a priori knowledge on the abdominal electrode configuration and fetal heart activity. In this paper we propose a source separation technique that is based on the physiology of the fetal heart and on the knowledge of the electrode configuration. This technique operates by calculating the spatial fetal vectorcardiogram (VCG) and approximating the VCG for several overlayed heartbeats by an ellipse. By subsequently projecting the VCG onto the long axis of this ellipse, a source signal of the fetal ECG can be obtained. To evaluate the developed technique, its performance is compared to that of both PCA and ICA and to that of augmented versions of these techniques (aPCA and aICA; PCA and ICA applied on preprocessed signals) in generating a fetal ECG source signal with enhanced SNR that can be used to detect fetal QRS complexes. The evaluation shows that the developed source separation technique performs slightly better than aPCA and aICA and outperforms PCA and ICA and has the main advantage that, with respect to aPCA/PCA and aICA/ICA, it performs more robustly. This advantage renders it favorable for employment in automated, real-time fetal monitoring applications

Changes in parasympathetic system in medulla oblongata in male pigs in the course of tachycardia-induced cardiomyopathy.

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Tomaszek, Alicja; Kiczak, Liliana; Bania, Jacek; Krupa, Paweł; Pasławska, Urszula; Zacharski, Maciej; Janiszewski, Adrian; Stefaniak, Tadeusz; Zyśko, Dorota; Ardehali, Hossein; Jankowska, Ewa A; Ponikowski, Piotr

2013-10-01

Autonomic imbalance constituting a fundamental feature of heart failure (HF) has been assessed mainly at the periphery. Changes in the functioning of autonomic centers in the brain remain unclear. We investigated the molecular elements of parasympathetic system, i.e. α7 nicotinic acetylcholine receptor (α7nAChR) and enzymes metabolizing acetylcholine (acetylcholinesterase, AChE, choline acetyltransferase, ChAT) in medulla oblongata (MO) of male pigs with chronic tachycardia-induced cardiomyopathy. The mRNA levels of AChE, ChAT, α7nAChR and X-box binding protein 1 (spliced form, XBP1s) in MO were analyzed using qPCR, AChE and ChAT activities using spectrophotometry, proteasome activity using fluorometry, and the protein level of α7nAChR using Western blotting. The development of systolic HF was accompanied by an increase in circulating catecholamines, a decrease in the AChE and α7nAChR mRNA in MO, an increase in AChE activity (all pmedulla oblongata during the progression of systolic non-ischemic heart failure in male pigs, indicating a functional link between MO and heart in HF. Copyright © 2013 Elsevier B.V. All rights reserved.

Prevention of disease progression by cardiac resynchronization therapy in patients with asymptomatic or mildly symptomatic left ventricular dysfunction: insights from the European cohort of the REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) trial

DEFF Research Database (Denmark)

Daubert, Claude; Gold, Michael R; Abraham, William T

2009-01-01

were decreased in this patient population in New York Heart Association functional classes I or II. These observations suggest that CRT prevents the progression of disease in patients with asymptomatic or mildly symptomatic LV dysfunction. (REsynchronization reVErses Remodeling in Systolic Left v......OBJECTIVES: The aim of this study was to determine the long-term effects of cardiac resynchronization therapy (CRT) in the European cohort of patients enrolled in the REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) trial. BACKGROUND: Previous data suggest...... that CRT slows disease progression and improves the outcomes of asymptomatic or mildly symptomatic patients with left ventricular (LV) dysfunction and a wide QRS complex. METHODS: We randomly assigned 262 recipients of CRT pacemakers or defibrillators, with QRS > or =120 ms and LV ejection fraction...

Postural Tachycardia Syndrome and Vasovagal Syncope: A Hidden Case of Obstructive Cardiomyopathy without Severe Septal Hypertrophy.

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Mayuga, Kenneth A; Ho, Natalie; Shields, Robert W; Cremer, Paul; Rodriguez, L Leonardo

2018-01-01

A 36-year-old female with symptoms of orthostatic intolerance and syncope was diagnosed with vasovagal syncope on a tilt table test and with postural tachycardia syndrome (POTS) after a repeat tilt table test. However, an echocardiogram at our institution revealed obstructive cardiomyopathy without severe septal hypertrophy, with a striking increase in left ventricular outflow tract gradient from 7 mmHg at rest to 75 mmHg during Valsalva, with a septal thickness of only 1.3 cm. Cardiac MRI showed an apically displaced multiheaded posteromedial papillary muscle with suggestion of aberrant chordal attachments to the anterior mitral leaflet contributing to systolic anterior motion of the mitral valve. She underwent surgery with reorientation of the posterior medial papillary muscle head, resection of the tethering secondary chordae to the A1 segment of the mitral valve, chordal shortening and tacking of the chordae to the A1 and A2 segments of the mitral valve, and gentle septal myectomy. After surgery, she had significant improvement in her prior symptoms. To our knowledge, this is the first reported case of obstructive cardiomyopathy without severe septal hypertrophy with abnormalities in papillary muscle and chordal attachment, in a patient diagnosed with vasovagal syncope and POTS.

Postural Tachycardia Syndrome and Vasovagal Syncope: A Hidden Case of Obstructive Cardiomyopathy without Severe Septal Hypertrophy

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Kenneth A. Mayuga

2018-01-01

Full Text Available A 36-year-old female with symptoms of orthostatic intolerance and syncope was diagnosed with vasovagal syncope on a tilt table test and with postural tachycardia syndrome (POTS after a repeat tilt table test. However, an echocardiogram at our institution revealed obstructive cardiomyopathy without severe septal hypertrophy, with a striking increase in left ventricular outflow tract gradient from 7 mmHg at rest to 75 mmHg during Valsalva, with a septal thickness of only 1.3 cm. Cardiac MRI showed an apically displaced multiheaded posteromedial papillary muscle with suggestion of aberrant chordal attachments to the anterior mitral leaflet contributing to systolic anterior motion of the mitral valve. She underwent surgery with reorientation of the posterior medial papillary muscle head, resection of the tethering secondary chordae to the A1 segment of the mitral valve, chordal shortening and tacking of the chordae to the A1 and A2 segments of the mitral valve, and gentle septal myectomy. After surgery, she had significant improvement in her prior symptoms. To our knowledge, this is the first reported case of obstructive cardiomyopathy without severe septal hypertrophy with abnormalities in papillary muscle and chordal attachment, in a patient diagnosed with vasovagal syncope and POTS.

Quantifying the determinants of decremental response in critical ventricular tachycardia substrate.

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Beheshti, Mohammadali; Nayyar, Sachin; Magtibay, Karl; Massé, Stéphane; Porta-Sanchez, Andreu; Haldar, Shouvik; Bhaskaran, Abhishek; Vigmond, Edward; Nanthakumar, Kumaraswamy

2018-05-28

Decremental response evoked with extrastimulation (DEEP) is a useful tool for determining diastolic return path of ventricular tachycardia (VT). Though a targeted VT ablation is feasible with this approach, determinants of DEEP response have not been studied OBJECTIVES: To elucidate the effects of clinically relevant factors, specifically, the proximity of the stimulation site to the arrhythmogenic scar, stimulation wave direction, number of channels open in the scar, size of the scar and number of extra stimuli on decrement and entropy of DEEP potentials. In a 3-dimensional bi-domain simulation of human ventricular tissue (TNNP cell model), an irregular subendocardial myopathic region was generated. An irregular channel of healthy tissue with five potential entry branches was shaped into the myopathic region. A bipolar electrogram was derived from two electrodes positioned in the centre of the myopathic region. Evoked delays between far-field and local Electrogram (EGM) following an extrastimulus (S1-S2, 500-350 ms) were measured as the stimulation site, channel branches, and inexcitable tissue size were altered. Stimulation adjacent to the inexcitable tissue from the side opposite to the point-of-entry produces longest DEEP delay. The DEEP delay shortens when the stimulation point is farther away from the scar, and it decreases maximally when stimulation is done from a site beside a conduction barrier. Entropy increases with S2 when stimulation site is from farther away. An unprotected channel structure with multiple side-branch openings had shorter DEEP delay compared to a protected channel structure with a paucity of additional side-branch openings and a point-of-entry on the side opposite to the pacing source. Addition of a second shorter extrastimulus did not universally lead to higher DEEP delay CONCLUSIONS: Location and direction of the wavefront in relation to scar entry and size of scar determine the degree of evoked response while the number of

Dobutamine stress echocardiography related sustained ventricular tachycardia in a patient with ischaemic cardiomyopathy

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Amrit S Lota

2014-01-01

Full Text Available A 66 year-old Asian man; with a complex history of ischaemic heart disease presented with cardiac and troponin negative chest pain. His ECG showed sinus bradycardia with old left bundle branch block. The transthoracic echocardiography showed severely impaired left ventricular systolic function (EF 30-35%. The patient had had coronary artery bypass grafting at age of 42 years and remained asymptomatic until age of 56 years when he presented with incessant ventricular tachycardia requiring amiodarone, lidocaine and electrical cardioversion. Coronary angiography at that time showed occluded vein grafts to the circumflex and diagonal arteries. The right coronary artery (RCA was small and received collaterals from the left system. A myocardial perfusion scan showed extensive inferolateral infarction but no evidence for reversible ischaemia. An implantable cardiac defibrillator (ICD was thus inserted. Over the following years, the patient underwent multiple PCI procedures with rotational atherectomy to the native LAD and associated vein graft, but subsequently developed in-stent restenosis. He also had PCI to the native RCA. He declined a minimally invasive grafting of the left internal mammary artery (LIMA to the LAD and re-implantation of a new ICD after ex-plantation of the original one due to sepsis. His coronary artery disease remained stable following a recent admission with Troponin positive event which was confirmed by a repeat angiogram, therefore, had up-titrated anti-anginal medications. A low dose beta-blockade was discontinued due to documented sinus pauses up to 3 seconds. Following the recent admission, a joint cardiology-cardiothoracic meeting discussion recommended a stress echocardiogram with highdose dobutamine to guide towards considering re-do bypass grafting.

Genome wide analysis of drug-induced torsades de pointes: lack of common variants with large effect sizes.

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Elijah R Behr

Full Text Available Marked prolongation of the QT interval on the electrocardiogram associated with the polymorphic ventricular tachycardia Torsades de Pointes is a serious adverse event during treatment with antiarrhythmic drugs and other culprit medications, and is a common cause for drug relabeling and withdrawal. Although clinical risk factors have been identified, the syndrome remains unpredictable in an individual patient. Here we used genome-wide association analysis to search for common predisposing genetic variants. Cases of drug-induced Torsades de Pointes (diTdP, treatment tolerant controls, and general population controls were ascertained across multiple sites using common definitions, and genotyped on the Illumina 610k or 1M-Duo BeadChips. Principal Components Analysis was used to select 216 Northwestern European diTdP cases and 771 ancestry-matched controls, including treatment-tolerant and general population subjects. With these sample sizes, there is 80% power to detect a variant at genome-wide significance with minor allele frequency of 10% and conferring an odds ratio of ≥2.7. Tests of association were carried out for each single nucleotide polymorphism (SNP by logistic regression adjusting for gender and population structure. No SNP reached genome wide-significance; the variant with the lowest P value was rs2276314, a non-synonymous coding variant in C18orf21 (p  =  3×10(-7, odds ratio = 2, 95% confidence intervals: 1.5-2.6. The haplotype formed by rs2276314 and a second SNP, rs767531, was significantly more frequent in controls than cases (p  =  3×10(-9. Expanding the number of controls and a gene-based analysis did not yield significant associations. This study argues that common genomic variants do not contribute importantly to risk for drug-induced Torsades de Pointes across multiple drugs.

Asymptomatic Wolff-Parkinson-White Syndrome: Incidental EKG

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Samer Assaf

2017-07-01

Full Text Available History of present illness: A 38-year-old male presents to the emergency department for a minor trauma evaluation after falling off a bicycle at a moderate rate of speed. The patient was not wearing a helmet when he hit his head with unknown loss of consciousness. Focused assessment with sonography for trauma (FAST exam and head computed tomography (CT were negative. Routine electrocardiogram (ECG showed sinus rhythm with pre-excitation indicative of Wolff-Parkinson-White Syndrome (WPW. The patient confirmed a previous diagnosis of WPW, but had not previously followed up with a cardiologist. Significant findings: The ECG shows slurred up-stroking of the QRS complexes characteristic of a delta wave. The PR interval is normal; however, the QT interval is greater than 110ms. Discussion: Wolff-Parkinson-White Syndrome (WPW is a frequently encountered macro-reentrant arrhythmia characterized by a shortened PR interval less than 120ms, prolonged QRS greater than 120ms with an up-stroking QRS complex (delta wave, and occasional ST abnormalities.1 The incidence is reported to be 0.9%-3% of the general population and most diagnoses are made on routine EKGs.2,3 WPW is thought to be caused by abnormalities of conduction through the accessory pathway, also known as the Bundle of Kent, causing premature excitation of the ventricles. The complications from WPW are supraventricular tachycardia, atrial arrhythmias, and ventricular fibrillation leading to sudden cardiac death.3 Approximately 40-50% of patients who die from sudden cardiac arrest associated with WPW were previously asymptomatic.4 Unfortunately, it is agreed that approximately 50% of patients with WPW are asymptomatic and unaware of their diagnosis.5 The definitive treatment for WPW is radiofrequency catheter ablation (RFCA. However, it comes with a low risk of complications including arrhythmias and death.6 For asymptomatic WPW, children are at the highest risk for ventricular arrhythmias while

Optimizing implantable cardioverter-defibrillator treatment of rapid ventricular tachycardia: antitachycardia pacing therapy during charging.

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Schoels, Wolfgang; Steinhaus, David; Johnson, W Ben; O'hara, Gilles; Schwab, Joerg O; Jenniskens, Inge; Degroot, Paul J; Tang, Feng; Helmling, Erhard

2007-07-01

Previous studies in implantable cardioverter-defibrillator (ICD) patients demonstrated the efficacy and safety of antitachycardia pacing (ATP) for rapid ventricular tachycardias (VT). To prevent shock delay in case of ATP failure, a new feature (ATP during charging) was developed to deliver ATP for rapid VT while charging for shock. The purpose of this study was to determine the efficacy and safety of this new feature. In a prospective, nonrandomized trial, patients with standard ICD indication received an EnTrust ICD. VT and ventricular fibrillation (VF) episodes were reviewed for appropriate detection, ATP success, rhythm acceleration, and related symptoms. In 421 implanted patients, 116 VF episodes occurred in 37 patients. Eighty-four (72%) episodes received ATP during or before charging. ATP prevented a shock in 58 (69%) of 84 episodes in 15 patients. ATP stopped significantly more monomorphic (77%) than polymorphic VTs (44%, P = .05). Five (6%) episodes accelerated after ATP but were terminated by the backup shock(s). No symptoms were related to ATP during charging. In four patients, 38 charges were saved by delivering ATP before charging. Of 98 induced VF episodes, 28% were successfully terminated by ATP versus 69% for spontaneous episodes (P <.01). Most VTs detected in the VF zone can be painlessly terminated by ATP delivered during charging, with a low risk of acceleration or symptoms. ATP before charging allows delivery of two ATP attempts before shock in the same time that would otherwise be required to deliver only one ATP plus a shock. It also offers potential battery energy savings.

Noninvasive imaging of three-dimensional cardiac activation sequence during pacing and ventricular tachycardia.

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Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; He, Bin

2011-08-01

Imaging cardiac excitation within ventricular myocardium is important in the treatment of cardiac arrhythmias and might help improve our understanding of arrhythmia mechanisms. This study sought to rigorously assess the imaging performance of a 3-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of 3D intracardiac mapping from up to 216 intramural sites during paced rhythm and norepinephrine (NE)-induced ventricular tachycardia (VT) in the rabbit heart. Body surface potentials and intramural bipolar electrical recordings were simultaneously measured in a closed-chest condition in 13 healthy rabbits. Single-site pacing and dual-site pacing were performed from ventricular walls and septum. VTs and premature ventricular complexes (PVCs) were induced by intravenous NE. Computed tomography images were obtained to construct geometry models. The noninvasively imaged activation sequence correlated well with invasively measured counterpart, with a correlation coefficient of 0.72 ± 0.04, and a relative error of 0.30 ± 0.02 averaged over 520 paced beats as well as 73 NE-induced PVCs and VT beats. All PVCs and VT beats initiated in the subendocardium by a nonreentrant mechanism. The averaged distance from the imaged site of initial activation to the pacing site or site of arrhythmias determined from intracardiac mapping was ∼5 mm. For dual-site pacing, the double origins were identified when they were located at contralateral sides of ventricles or at the lateral wall and the apex. 3DCEI can noninvasively delineate important features of focal or multifocal ventricular excitation. It offers the potential to aid in localizing the origins and imaging activation sequences of ventricular arrhythmias, and to provide noninvasive assessment of the underlying arrhythmia mechanisms. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrophysiological markers predicting impeding AV-block during ablation of atrioventricular nodal reentry tachycardia.

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Fragakis, Nikolaos; Krexi, Lydia; Kyriakou, Panagiota; Sotiriadou, Melani; Lazaridis, Charalambos; Karamanolis, Athanasios; Dalampyras, Panagiotis; Tsakiroglou, Stelios; Skeberis, Vassilios; Tsalikakis, Dimitrios; Vassilikos, Vassilios

2018-01-01

Radiofrequency (RF) ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is occasionally complicated with atrioventricular block (AVB) often predicted by junctional beats (JB) with loss of ventriculo-atrial (VA) conduction. We analyzed retrospectively 153 patients undergoing ablation of SP for typical AVNRT. Patients were divided into two age groups: 127 ≤ 70 years and 26 > 70 years. We analyzed the interval between the atrial electrogram in the His-bundle position and the distal ablation catheter [A(H)-A(RFd)] and between the distal ablation catheter and the proximal coronary sinus catheter [A(RFd)-A(CS)] before RF applications with and without JB. We evaluated if these intervals can be used as predictors of JB incidence and also of JB with loss of VA conduction. We also assessed if age influences the risk of loss of VA conduction. The A(H)-A(RFd) and A(RFd)-A(CS) intervals were significantly shorter in RF applications causing JB than those without JB (33 ± 11 ms vs 39 ± 9 ms, P JB with VA block than those with VA conduction (29 ± 11 ms vs 35 ± 11 ms, P  70 years had shorter intervals (36 ± 11 ms vs 29 ± 8 ms, P  =  0.012, 17 ± 8 ms vs 13 ± 7 ms, P  =  0.027, respectively), while VA block was more common in this age group. The A(H)-A(RFd) and A(RFd)-A(CS) intervals can be used as markers for predicting JB occurrence as well as impending AVB. JB with loss of VA conduction occur more often in older patients possibly due to a higher position of SP. © 2017 Wiley Periodicals, Inc.

Distinctive Left Ventricular Activations Associated With ECG Pattern in Heart Failure Patients.

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Derval, Nicolas; Duchateau, Josselin; Mahida, Saagar; Eschalier, Romain; Sacher, Frederic; Lumens, Joost; Cochet, Hubert; Denis, Arnaud; Pillois, Xavier; Yamashita, Seigo; Komatsu, Yuki; Ploux, Sylvain; Amraoui, Sana; Zemmoura, Adlane; Ritter, Philippe; Hocini, Mélèze; Haissaguerre, Michel; Jaïs, Pierre; Bordachar, Pierre

2017-06-01

In contrast to patients with left bundle branch block (LBBB), heart failure patients with narrow QRS and nonspecific intraventricular conduction delay (NICD) display a relatively limited response to cardiac resynchronization therapy. We sought to compare left ventricular (LV) activation patterns in heart failure patients with narrow QRS and NICD to patients with LBBB using high-density electroanatomic activation maps. Fifty-two heart failure patients (narrow QRS [n=18], LBBB [n=11], NICD [n=23]) underwent 3-dimensional electroanatomic mapping with a high density of mapping points (387±349 LV). Adjunctive scar imaging was available in 37 (71%) patients and was analyzed in relation to activation maps. LBBB patients typically demonstrated (1) a single LV breakthrough at the septum (38±15 ms post-QRS onset); (2) prolonged right-to-left transseptal activation with absence of direct LV Purkinje activity; (3) homogeneous propagation within the LV cavity; and (4) latest activation at the basal lateral LV. In comparison, both NICD and narrow QRS patients demonstrated (1) multiple LV breakthroughs along the posterior or anterior fascicles: narrow QRS versus LBBB, 5±2 versus 1±1; P =0.0004; NICD versus LBBB, 4±2 versus 1±1; P =0.001); (2) evidence of early/pre-QRS LV electrograms with Purkinje potentials; (3) rapid propagation in narrow QRS patients and more heterogeneous propagation in NICD patients; and (4) presence of limited areas of late activation associated with LV scar with high interindividual heterogeneity. In contrast to LBBB patients, narrow QRS and NICD patients are characterized by distinct mechanisms of LV activation, which may predict poor response to cardiac resynchronization therapy. © 2017 American Heart Association, Inc.

Power-line Interference Removal from ECG in Case of Power-line Frequency Variations

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Todor Stoyanov

2008-10-01

Full Text Available The original version of the most successful approach for power-line (PL interference removal from ECG, called subtraction procedure, is based on linear segment detection in the signal and hardware synchronised analogue-to-digital conversion to cope with the PL frequency variations. However, this is not feasible for battery supplied devices and some computer-aided ECG systems. Recent improvements of the procedure apply software measurement of the frequency variations that allow a re-sampling of the contaminated signal with the rated PL frequency followed by interference removal and back re-sampling for restoration of the original time intervals. This study deals with a more accurate software frequency measurement and introduces a notch filtration as alternative to the procedure when no linear segments are encountered for long time, e.g. in cases of ventricular fibrillation or tachycardia. The result obtained with large PL frequency variations demonstrate very small errors, usually in the range of ± 20 μV for the subtraction procedure and ± 60 μV for the notch filtration, the last values strongly depending on the frequency contents of the QRS complexes.

Cardiac pacing in heart failure patients with left bundle branch block: impact of pacing site for optimizing left ventricular resynchronization.

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Pappone, C; Rosanio, S; Oreto, G; Tocchi, M; Gulletta, S; Salvati, A; Dicandia, C; Santinelli, V; Mazzone, P; Veglia, F; Ding, J; Sallusti, L; Spinelli, J; Vicedomini, G

2000-07-01

Acute left ventricular pacing has been associated with hemodynamic improvement in patients with congestive heart failure and wide QRS complex. We hypothesized that pacing two left ventricular sites simultaneously would produce faster activation and better systolic function than single-site pacing. We selected 14 heart failure patients (NYHA functional class III or IV) in normal sinus rhythm with left bundle branch block and QRS > 150 ms. An 8F dual micromanometer catheter was placed in the aorta for measuring +dP/dt (mmHg/s), aortic pulse pressure (mmHg), and end-diastolic pressure (mmHg). Pacing leads were positioned via coronary veins at the posterior base and lateral wall. Patients were acutely paced VDD at the posterior base, lateral wall, and both sites (dual-site) with 5 atrioventricular delays (from 8 ms to PR -30 ms). Pacing sequences were executed in randomized order using a custom external computer (FlexStim, Guidant CRM). Dual-site pacing increased peak +dP/dt significantly more than posterior base and lateral wall pacing. Dual-site and posterior base pacing raised aortic pulse pressure significantly more than lateral wall pacing. Dual-site pacing shortened QRS duration by 22 %, whereas posterior base and lateral wall pacing increased it by 2 and 12%, respectively (p = 0.006). In heart failure patients with left bundle branch block, dual-site pacing improves systolic function more than single-site stimulation. Improved ventricular activation synchrony, expressed by paced QRS narrowing, may account for the additional benefit of dual- vs single-site pacing in enhancing contractility. This novel approach deserves consideration for future heart failure pacing studies.

Thoracic Epidural Anesthesia Can Be Effective for the Short-Term Management of Ventricular Tachycardia Storm.

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Do, Duc H; Bradfield, Jason; Ajijola, Olujimi A; Vaseghi, Marmar; Le, John; Rahman, Siamak; Mahajan, Aman; Nogami, Akihiko; Boyle, Noel G; Shivkumar, Kalyanam

2017-10-27

Novel therapies aimed at modulating the autonomic nervous system, including thoracic epidural anesthesia (TEA), have been shown in small case series to be beneficial in treating medically refractory ventricular tachycardia (VT) storm. However, it is not clear when these options should be considered. We reviewed a multicenter experience with TEA in the management of VT storm to determine its optimal therapeutic use. Data for 11 patients in whom TEA was instituted for VT storm between July 2005 and March 2016 were reviewed to determine the clinical characteristics, outcomes, and role in management. The clinical presentation was incessant VT in 7 (64%), with polymorphic VT in 3 (27%) and monomorphic VT in 8 (73%). The underlying conditions were nonischemic cardiomyopathy in 5 (45%), ischemic cardiomyopathy in 3 (27%), and hypertrophic cardiomyopathy, Brugada syndrome, and cardiac lipoma in 1 (9%) each. Five (45%) had a complete and 1 (9%) had a partial response to TEA; 4 of the complete responders had incessant VT. All 4 patients with a documented response to deep sedation demonstrated a complete response to TEA. More than half of the patients with VT storm in our series responded to TEA. TEA may be effective and should be considered as a therapeutic option in patients with VT storm, especially incessant VT, who are refractory to initial management. Improvement in VT burden with deep sedation may suggest that sympathoexcitation plays a key role in perpetuating VT and predict a positive response to TEA. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the rabbit heart.

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Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; He, Bin

2011-01-01

Ventricular arrhythmias represent one of leading causes for sudden cardiac death, a significant problem in public health. Noninvasive imaging of cardiac electric activities associated with ventricular arrhythmias plays an important role in better our understanding of the mechanisms and optimizing the treatment options. The present study aims to rigorously validate a novel three-dimensional (3-D) cardiac electrical imaging (3-DCEI) technique with the aid of 3-D intra-cardiac mapping during paced rhythm and ventricular tachycardia (VT) in the rabbit heart. Body surface potentials and intramural bipolar electrical recordings were simultaneously measured in a closed-chest condition in thirteen healthy rabbits. Single-site pacing and dual-site pacing were performed from ventricular walls and septum. VTs and premature ventricular complexes (PVCs) were induced by intravenous norepinephrine (NE). The non-invasively imaged activation sequence correlated well with invasively measured counterparts, with a correlation coefficient of 0.72 and a relative error of 0.30 averaged over all paced beats and NE-induced PVCs and VT beats. The averaged distance from imaged site of initial activation to measured site determined from intra-cardiac mapping was ∼5mm. These promising results suggest that 3-DCEI is feasible to non-invasively localize the origins and image activation sequence of focal ventricular arrhythmias.

Electronic and optical properties of HEMT heterostructures with δ-Si doped GaAs/AlGaAs quantum rings — quantum well system

Science.gov (United States)

Sibirmovsky, Y. D.; Vasil'evskii, I. S.; Vinichenko, A. N.; Zhigunov, D. M.; Eremin, I. S.; Kolentsova, O. S.; Safonov, D. A.; Kargin, N. I.

2017-11-01

Samples of δ-Si doped AlGaAs/GaAs/AlGaAs HEMT heterostructures with GaAs quantum rings (QRs) on top of the quantum well (QW) were grown by molecular beam epitaxy and their properties were compared to the reference samples without QRs. The thickness of the QW was 6 - 10 nm for the samples with QRs and 20 nm for the reference samples. Photoluminescence measurements at low temperatures for all samples show at least two distinct lines in addition to the bulk GaAs line. The Hall effect and low temperature magnetotransport measurements at 4 - 320 K show that conductivity with and without illumination decreases significantly with QRs introduction, however the relative photoconductivity increases. Samples with 6 nm QW are insulating, which could be caused by the strong localization of the charge carriers in the QRs.

Large size self-assembled quantum rings: quantum size effect and modulation on the surface diffusion.

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Tong, Cunzhu; Yoon, Soon Fatt; Wang, Lijun

2012-09-24

We demonstrate experimentally the submicron size self-assembled (SA) GaAs quantum rings (QRs) by quantum size effect (QSE). An ultrathin In0.1 Ga0.9As layer with different thickness is deposited on the GaAs to modulate the surface nucleus diffusion barrier, and then the SA QRs are grown. It is found that the density of QRs is affected significantly by the thickness of inserted In0.1 Ga0.9As, and the diffusion barrier modulation reflects mainly on the first five monolayer . The physical mechanism behind is discussed. The further analysis shows that about 160 meV decrease in diffusion barrier can be achieved, which allows the SA QRs with density of as low as one QR per 6 μm2. Finally, the QRs with diameters of 438 nm and outer diameters of 736 nm are fabricated using QSE.

[Supraventricular tachycardia in utero. Apropos of a personal case, review of the literature].

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Pelletier, P; Delarue, T; Souplet, J P; Foissey, A; Oudry, B; Lefrançois, C

1983-01-01

After describing a case of early hydrops fetalis in a fetus demonstrating supraventricular tachycardia (TSVF) the authors review the literature: First they note the increase in the number of cases of TSVF published in the last few years, thanks to better means of monitoring pregnancies and to the place taken by TSVF among the different other troubles of fetal heart rhythm than can occur. The second section enumerates and analyses the pathological associations and the complications that have been observed in cases of TSVF that have been indexed. All have a poor prognosis: as far as those cases where there are faults in the rhythm which are associated with or alternate with TSVF, congestive heart failure occurs in 50% of cases, and organic heart pathological conditions in 20% of cases. 19.1% die. The third section analyses the means available for diagnosis and prognosis and the value of these means. Diagnosis rests on screening by clinical observation (careful auscultation in every pregnancy, observation of the raised height of the uterine fundus and a lessening in active fetal movements) and by monitoring. Only the ECG can confirm the diagnosis. Congestive heart failure is diagnosed by using ultrasound. A cardiac malformation should be searched for thoroughly by ultrasound. Monitoring in labour has no use as a prognostic indicator. Only repeated measurements of pH can demonstrate fetal distress in labour. The last section is concerned with management: digitalisation is strongly to be recommended before the fetus is mature. Propranolol should be reserved for resistant and severe cases: when there is no congestive heart failure a wait and see policy under strict observation can be followed. If there is congestive heart failure, caesarean section must be carried out. After delivery resuscitation with vagal stimulation is often sufficient, but when it is not digitalisation can be used and very rarely electric cardioversion is needed. Relapses are frequent and treatment

Imaging cardiac activation sequence during ventricular tachycardia in a canine model of nonischemic heart failure.

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Han, Chengzong; Pogwizd, Steven M; Yu, Long; Zhou, Zhaoye; Killingsworth, Cheryl R; He, Bin

2015-01-15

Noninvasive cardiac activation imaging of ventricular tachycardia (VT) is important in the clinical diagnosis and treatment of arrhythmias in heart failure (HF) patients. This study investigated the ability of the three-dimensional cardiac electrical imaging (3DCEI) technique for characterizing the activation patterns of spontaneously occurring and norepinephrine (NE)-induced VTs in a newly developed arrhythmogenic canine model of nonischemic HF. HF was induced by aortic insufficiency followed by aortic constriction in three canines. Up to 128 body-surface ECGs were measured simultaneously with bipolar recordings from up to 232 intramural sites in a closed-chest condition. Data analysis was performed on the spontaneously occurring VTs (n=4) and the NE-induced nonsustained VTs (n=8) in HF canines. Both spontaneously occurring and NE-induced nonsustained VTs initiated by a focal mechanism primarily from the subendocardium, but occasionally from the subepicardium of left ventricle. Most focal initiation sites were located at apex, right ventricular outflow tract, and left lateral wall. The NE-induced VTs were longer, more rapid, and had more focal sites than the spontaneously occurring VTs. Good correlation was obtained between imaged activation sequence and direct measurements (averaged correlation coefficient of ∼0.70 over 135 VT beats). The reconstructed initiation sites were ∼10 mm from measured initiation sites, suggesting good localization in such a large animal model with cardiac size similar to a human. Both spontaneously occurring and NE-induced nonsustained VTs had focal initiation in this canine model of nonischemic HF. 3DCEI is feasible to image the activation sequence and help define arrhythmia mechanism of nonischemic HF-associated VTs. Copyright © 2015 the American Physiological Society.

Periodic Two-Dimensional GaAs and InGaAs Quantum Rings Grown on GaAs (001) by Droplet Epitaxy.

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Tung, Kar Hoo Patrick; Huang, Jian; Danner, Aaron

2016-06-01

Growth of ordered GaAs and InGaAs quantum rings (QRs) in a patterned SiO2 nanohole template by molecular beam epitaxy (MBE) using droplet epitaxy (DE) process is demonstrated. DE is an MBE growth technique used to fabricate quantum nanostructures of high crystal quality by supplying group III and group V elements in separate phases. In this work, ordered QRs grown on an ordered nanohole template are compared to self-assembled QRs grown with the same DE technique without the nanohole template. This study allows us to understand and compare the surface kinetics of Ga and InGa droplets when a template is present. It is found that template-grown GaAs QRs form clustered rings which can be attributed to low mobility of Ga droplets resulting in multiple nucleation sites for QR formation when As is supplied. However, the case of template-grown InGaAs QRs only one ring is formed per nanohole; no clustering is observed. The outer QR diameter is a close match to the nanohole template diameter. This can be attributed to more mobile InGa droplets, which coalesce from an Ostwald ripening to form a single large droplet before As is supplied. Thus, well-patterned InGaAs QRs are demonstrated and the kinetics of their growth are better understood which could potentially lead to improvements in the future devices that require the unique properties of patterned QRs.

A wavelet-based ECG delineation algorithm for 32-bit integer online processing.

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Di Marco, Luigi Y; Chiari, Lorenzo

2011-04-03

Since the first well-known electrocardiogram (ECG) delineator based on Wavelet Transform (WT) presented by Li et al. in 1995, a significant research effort has been devoted to the exploitation of this promising method. Its ability to reliably delineate the major waveform components (mono- or bi-phasic P wave, QRS, and mono- or bi-phasic T wave) would make it a suitable candidate for efficient online processing of ambulatory ECG signals. Unfortunately, previous implementations of this method adopt non-linear operators such as root mean square (RMS) or floating point algebra, which are computationally demanding. This paper presents a 32-bit integer, linear algebra advanced approach to online QRS detection and P-QRS-T waves delineation of a single lead ECG signal, based on WT. The QRS detector performance was validated on the MIT-BIH Arrhythmia Database (sensitivity Se = 99.77%, positive predictive value P+ = 99.86%, on 109010 annotated beats) and on the European ST-T Database (Se = 99.81%, P+ = 99.56%, on 788050 annotated beats). The ECG delineator was validated on the QT Database, showing a mean error between manual and automatic annotation below 1.5 samples for all fiducial points: P-onset, P-peak, P-offset, QRS-onset, QRS-offset, T-peak, T-offset, and a mean standard deviation comparable to other established methods. The proposed algorithm exhibits reliable QRS detection as well as accurate ECG delineation, in spite of a simple structure built on integer linear algebra.

Plasma C-type natriuretic peptide as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome.

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Jing Lin

Full Text Available POTS is a global public-health disease, but predictor for therapeutic response to metoprolol in children with POTS is lacking. This study was designed to investigate predictive value of plasma C-type natriuretic peptide (CNP in the therapeutic efficacy of metoprolol on postural tachycardia syndrome (POTS in children. Totally 34 children with POTS and 27 healthy children were included in the study. The head-up test or head-up tilt test was used to check heart rate and blood pressure from supine to upright in subjects. A double antibody (competitive sandwich immunoluminometric assay was used to detect plasma CNP. Metoprolol was used to treat children with POTS. The difference in plasma concentrations of CNP between responders and non-responders was compared. An ROC curve was used to analyze plasma CNP to predict efficacy of metoprolol on POTS in children. Plasma CNP in children with POTS was significantly higher than that of healthy children [(51.9 ± 31.4 vs. (25.1 ± 19.1 pg/ml, P 32.55 pg/ml yielded a sensitivity of 95.8% and specificity of 70% in predicting therapeutic efficacy of metoprolol on POTS children. Plasma CNP might serve as a useful predictor for the therapeutic efficacy of metoprolol on POTS in children.

Scar Homogenization Versus Limited-Substrate Ablation in Patients With Nonischemic Cardiomyopathy and Ventricular Tachycardia.

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Gökoğlan, Yalçın; Mohanty, Sanghamitra; Gianni, Carola; Santangeli, Pasquale; Trivedi, Chintan; Güneş, Mahmut F; Bai, Rong; Al-Ahmad, Amin; Gallinghouse, G Joseph; Horton, Rodney; Hranitzky, Patrick M; Sanchez, Javier E; Beheiry, Salwa; Hongo, Richard; Lakkireddy, Dhanunjaya; Reddy, Madhu; Schweikert, Robert A; Dello Russo, Antonio; Casella, Michela; Tondo, Claudio; Burkhardt, J David; Themistoclakis, Sakis; Di Biase, Luigi; Natale, Andrea

2016-11-01

Scar homogenization improves long-term ventricular arrhythmia-free survival compared with standard limited-substrate ablation in patients with post-infarction ventricular tachycardia (VT). Whether such benefit extends to patients with nonischemic cardiomyopathy and scar-related VT is unclear. The aim of this study was to assess the long-term efficacy of an endoepicardial scar homogenization approach compared with standard ablation in this population. Consecutive patients with dilated nonischemic cardiomyopathy (n = 93), scar-related VTs, and evidence of low-voltage regions on the basis of pre-defined criteria on electroanatomic mapping (i.e., bipolar voltage homogenization and standard ablation, respectively (p = 0.01). During a mean follow-up period of 14 ± 2 months, single-procedure success rates were 63.9% after scar homogenization and 38.6% after standard ablation (p = 0.031). After multivariate analysis, scar homogenization and left ventricular ejection fraction were predictors of long-term success. During follow-up, the rehospitalization rate was significantly lower in the scar homogenization group (p = 0.035). In patients with dilated nonischemic cardiomyopathy, scar-related VT, and evidence of low-voltage regions on electroanatomic mapping, endoepicardial homogenization of the scar significantly increased freedom from any recurrent ventricular arrhythmia compared with a standard limited-substrate ablation. However, the success rate with this approach appeared to be lower than previously reported with ischemic cardiomyopathy, presumably because of the septal and midmyocardial distribution of the scar in some patients. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Impact of Heat Stress on Electrocardiographic Changes in New Zealand White Rabbits

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Kour, Juneet

2013-04-01

Full Text Available A study was conducted on twelve clinically normal and healthy New Zealand White rabbits of both sexes, weighing between 2-3 kg, and aged between 1-3 years to observe the normal electrocardiogram and its changes during heat stress. The normal electrocardiogram and changes during heat stress were evaluated for the three bipolar standard limb leads (I, II and III and three unipolar augmented limb leads (aVR, aVL and aVF. ECG recordings were made in sternal recumbency using a multi channel electrocardiograph . The normal heart rate with a mean of 204±7 beats/min was recorded. The mean amplitude observed was 0.05±0.002 mV for P wave; 0.19±0.008 mV for QRS; 0.14±0.007 mV for T wave. The mean duration observed was 0.03±0.002 sec for P wave; 0.06±0.002 sec for PR interval; 0.05±0.003 sec for QRS complex; 0.13±0.004 sec for QT interval; 0.07±0.002 sec for T wave. During heat stress tachycardia was observed with progressive rise in temperature along with ventricular fibrillation, ventricular extra-systole and atrial fibrillation. At 43°C, ventricular fibrillation was observed in Lead II, III, aVL and aVF. At 45°C, ventricular extra-systole was recorded in Lead III, aVL and aVF. At 45°C (30 mins more exposure, ventricular extra-systole in Lead I and ventricular fibrillation in Lead III was observed. At 47°C, ventricular fibrillation was seen in Lead II, III, aVR, aVL and aVF. At 47°C (30 mins more exposure, atrial fibrillation in all the leads were observed. The mean cardiac axis recorded was 90°±0.065 without significant alterations throughout the study.

Electrocardiographic Changes in Certain Cardiovascular Physiological and Pathological Settings. Impact on Coronary Artery Bypass Grafting

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Dimitar Simov

2016-03-01

Full Text Available Review on electrocardiographic changes provoked by aging, diagnostic tests, cardiac surgery, hemodialysis, diabetes, etc., is the objective of the current material. Several electrocardiographic (ECG parameters that are well known risk markers of arrhythmias, incidental heart failure and sudden cardiac death (SCD are discussed: QRS amplitude, QRS morphology, QRS duration, QRS alternans, T-wave amplitude, T-wave morphology, T-wave alternans, negative T-waves, 3D-spatial angle between maximal QRS and T vectors of the vectorcardiographic loops, ST-segment elevation, QT-interval dispersion, and heart rate. All reviewed parameters are compared with the results on the ECG-alterations, induced by coronary artery bypass grafting (CABG surgery. Two parameters showed an improvement in the patients' condition: QRS-T angle and cardiac autonomic innervation while two others (T-wave alternans and heart rate indicated deterioration. We tend to assume that the deterioration in this early post-operative period is an effect of the post-surgery trauma. We speculate that this effect will fade away in a period of a month and more after surgery, and we intend to conduct such a research in the future. The analysis of ECG's changes will help to better assess the impact of the CABG surgery.

Orthostatic Intolerance and Postural Orthostatic Tachycardia Syndrome in Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome, Hypermobility Type: Neurovegetative Dysregulation or Autonomic Failure?

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Claudia Celletti

2017-01-01

Full Text Available Background. Joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type (JHS/EDS-HT, is a hereditary connective tissue disorder mainly characterized by generalized joint hypermobility, skin texture abnormalities, and visceral and vascular dysfunctions, also comprising symptoms of autonomic dysfunction. This study aims to further evaluate cardiovascular autonomic involvement in JHS/EDS-HT by a battery of functional tests. Methods. The response to cardiovascular reflex tests comprising deep breathing, Valsalva maneuver, 30/15 ratio, handgrip test, and head-up tilt test was studied in 35 JHS/EDS-HT adults. Heart rate and blood pressure variability was also investigated by spectral analysis in comparison to age and sex healthy matched group. Results. Valsalva ratio was normal in all patients, but 37.2% of them were not able to finish the test. At tilt, 48.6% patients showed postural orthostatic tachycardia, 31.4% orthostatic intolerance, 20% normal results. Only one patient had orthostatic hypotension. Spectral analysis showed significant higher baroreflex sensitivity values at rest compared to controls. Conclusions. This study confirms the abnormal cardiovascular autonomic profile in adults with JHS/EDS-HT and found the higher baroreflex sensitivity as a potential disease marker and clue for future research.

Orthostatic Intolerance and Postural Orthostatic Tachycardia Syndrome in Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome, Hypermobility Type: Neurovegetative Dysregulation or Autonomic Failure?

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Celletti, Claudia; Camerota, Filippo; Castori, Marco; Censi, Federica; Gioffrè, Laura; Calcagnini, Giovanni; Strano, Stefano

2017-01-01

Background . Joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type (JHS/EDS-HT), is a hereditary connective tissue disorder mainly characterized by generalized joint hypermobility, skin texture abnormalities, and visceral and vascular dysfunctions, also comprising symptoms of autonomic dysfunction. This study aims to further evaluate cardiovascular autonomic involvement in JHS/EDS-HT by a battery of functional tests. Methods . The response to cardiovascular reflex tests comprising deep breathing, Valsalva maneuver, 30/15 ratio, handgrip test, and head-up tilt test was studied in 35 JHS/EDS-HT adults. Heart rate and blood pressure variability was also investigated by spectral analysis in comparison to age and sex healthy matched group. Results . Valsalva ratio was normal in all patients, but 37.2% of them were not able to finish the test. At tilt, 48.6% patients showed postural orthostatic tachycardia, 31.4% orthostatic intolerance, 20% normal results. Only one patient had orthostatic hypotension. Spectral analysis showed significant higher baroreflex sensitivity values at rest compared to controls. Conclusions. This study confirms the abnormal cardiovascular autonomic profile in adults with JHS/EDS-HT and found the higher baroreflex sensitivity as a potential disease marker and clue for future research.

A Case of Atrial Tachycardia Circulating around a Left Atrial Roof Scar with Diabetes Mellitus and Renal Failure on Hemodialysis

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Naoko Hijioka

2016-01-01

Full Text Available Introduction. Little is known about the effects of volume change by hemodialysis (HD and mechanical stress caused by an anatomical structure being in contact with the left atrium on the progression of atrial remodeling. We experienced a case of atrial tachycardia (AT in a patient who had left atrial (LA scarring at the LA roof and a low-voltage area with slow conduction around the LA scar as components of AT circuit. Here, we present the conceivable hypothesis of the LA scar and the low-voltage area formation. Our concept can be useful in developing a strategy for ablation in a patient with chronic renal failure (CRF on HD. Case Report. A 65-year-old man with CRF on HD was referred for AT ablation. Three-dimensional electroanatomical mapping revealed that the AT conducted around an LA scar in a counterclockwise fashion. There was a slow conduction area at the superior side of the LA scar, where the AT was terminated during the ablation. Computed tomography indicated a close relationship between the LA and the anatomical structures (ascending aorta and pulmonary artery. Conclusion. Volume change by HD and close contact of anatomical structures to the LA can promote atrial remodeling, resulting in AT occurrence.

Type A Wolff-Parkinson-White Syndrome Generating an Antidromic Atrioventricular (AV Reentrant Tachycardia (AVRT and an Orthodromic AVRT with a Long RP Interval Initiated only after Incomplete Impairment of an AV Accessory Pathway

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Kazushi Tanaka, MD PhD

2011-01-01

Full Text Available We report on a case of a 23-year-old male with Wolff-Parkinson-White syndrome. At baseline, constant right atrial pacing induced antidromic atrioventricular reentrant tachycardia (AVRT, whereas constant right ventricular (RV pacing only revealed a normal His-Purkinje system. Mapping below the mitral annulus during sinus rhythm revealed fusion of atrial and ventricular potentials at multiple lateral sites. After unsuccessful ablation at these sites, constant RV pacing induced a long RP interval, orthodromic AVRT with the earliest atrial site being located at an anterior aspect, where successful ablation was later achieved. These phenomena may indicate an unexpected arrhythmogenic effect of initial ablations.

Outcome of slow pathway modulation for atrioventricular nodal reentrant tachycardia with 50 versus 30 watts-more power, more effect?

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Dechering, Dirk G; Schleberger, Ruben; Greiser, Eva; Dickow, Jannis; Koebe, Julia; Frommeyer, Gerrit; Willems, Stephan; Eckardt, Lars; Hoffmann, Boris A; Wasmer, Kristina

2018-03-19

Slow pathway modulation is the treatment of choice in patients with atrioventricular nodal reentrant tachycardia (AVNRT). No comparative data on ablation strategies exist. Therefore, we sought to compare two common ablation approaches. We analyzed prospective ablation databases of two high-volume tertiary centers (> 1000 ablations/year) using either 30 or 50 W for slow pathway modulation from 2012 to 2013. We analyzed procedural characteristics as well as short- and long-term outcomes. Mean follow-up was 36 ± 9 months. Six hundred thirty-four patients (50 W center: n = 342, 30 W center: n = 292) were ablated. Slow pathway modulation was successful in 99% in both groups (p = ns). Periprocedural AV block occurred in nine patients (2.6%) in the 50 W and five patients (1.7%) in the 30 W group (p = 0.59), respectively. We documented no permanent higher-degree AV block. The number of RF lesions and seconds of RF delivery was significantly less in the 50 W group (p = 0.04 for number of lesions; p modulation are highly effective and safe. Significantly, fewer RF duration was necessary to modulate the slow pathway with higher power output (50 W). Our subgroup analysis suggests that males and females might benefit most from different modulation approaches.

Mechanical circulatory treatment of advanced heart failure

DEFF Research Database (Denmark)

Rujic, Dragana; Sundbøll, Jens; Tofig, Bawer Jalal

2016-01-01

The paroxysmal supraventricular tachycardias (SVT) are commonly encountered arrhythmias and include atrioventricular nodal re-entrant tachycardia, atrioventricular reciprocating tachycardia, and focal atrial tachycardia. These tachycardias share several clinical features as well as similar manage...

Postural orthostatic tachycardia is not a useful diagnostic marker for chronic fatigue syndrome.

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Roerink, M E; Lenders, J W M; Schmits, I C; Pistorius, A M A; Smit, J W; Knoop, H; van der Meer, J W M

2017-02-01

Postural orthostatic tachycardia syndrome (POTS) is considered a diagnostic marker for chronic fatigue syndrome (CFS). The aims of this study were to (i) compare POTS prevalence in a CFS cohort with fatigued patients not meeting CFS criteria, and (ii) assess activity, impairment and response to cognitive behavioural therapy (CBT) in CFS patients with POTS (POTS-CFS) and without POTS (non-POTS-CFS). Prospective cohort study at the Radboud University Medical Centre in the Netherlands. Between June 2013 and December 2014, 863 consecutive patients with persistent fatigue were screened. Patients underwent an active standing test, filled out questionnaires and wore an activity-sensing device for a period of 12 days. A total of 419 patients with CFS and 341 non-CFS fatigued patients were included in the study. POTS prevalence in adult patients with CFS was 5.7% vs. 6.9% in non-CFS adults (P = 0.54). In adolescents, prevalence rates were 18.2% and 17.4%, respectively (P = 0.93). Adult patients with POTS-CFS were younger (30 ± 12 vs. 40 ± 13 years, P = 0.001) and had a higher supine heart rate (71 ± 11 vs. 65 ± 9 beats per min, P = 0.009) compared with non-POTS-CFS patients. Severity and activity patterns did not differ between groups. In patients with CFS, criteria for Systemic Exertion Intolerance Disease (SEID) were met in 76% of adults and 67% of adolescents. In these patients with CFS fulfilling the SEID criteria, the prevalence of POTS was not different from that in the overall CFS population. POTS-CFS adolescents had less clinically significant improvement after CBT than non-POTS-CFS adolescents (58% vs. 88%, P = 0.017). In adults with CFS, the prevalence of POTS was low, was not different from the rate in non-CFS fatigued patients and was not related to disease severity or treatment outcome. In POTS-CFS adolescents, CBT was less successful than in non-POTS-CFS patients. The evaluation of POTS appears to be of limited value for the diagnosis of CFS. © 2016 The

Relation between electrocardiographic and enzymatic methods of estimating acute myocardial infarct size.

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Hindman, N; Grande, P; Harrell, F E; Anderson, C; Harrison, D; Ideker, R E; Selvester, R H; Wagner, G S

1986-07-01

The extent of initial acute myocardial infarction (AMI) and subsequent patient prognosis were studied using 2 independent indicators of AMI size. Two inexpensive, readily available techniques, the complete Selvester QRS score from the standard 12-lead electrocardiogram and the peak value of the isoenzyme MB of creatine kinase (CK-MB), were evaluated in 125 patients with initial AMI. The overall correlation between peak CK-MB and QRS score was fair (0.57), with marked difference according to anterior (0.72) or inferior (0.35) location. The prognostic capabilities of each measurement varied. Peak CK-MB provided significant information concerning hospital morbidity or early mortality (within 30 days) for both anterior (chi 2 = 9.83) and inferior (chi 2 = 7.68) AMI locations; however, the QRS score was significant only for anterior AMI (chi 2 = 9.50). For total 24-month mortality, the QRS score alone provided the most information (chi 2 = 10.0, p = 0.0016), which was not improved with the addition of CK-MB (chi 2 = 0.07, p = 0.79). This study shows a good relation between these 2 independent estimates of AMI size for patients with anterior AMI location. Both QRS and CK-MB results are significantly related to early morbidity and mortality; however, only the QRS score is related to total 24-month prognosis.

NeutrAvidin Functionalization of CdSe/CdS Quantum Nanorods and Quantification of Biotin Binding Sites using Biotin-4-Fluorescein Fluorescence Quenching.

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Lippert, Lisa G; Hallock, Jeffrey T; Dadosh, Tali; Diroll, Benjamin T; Murray, Christopher B; Goldman, Yale E

2016-03-16

We developed methods to solubilize, coat, and functionalize with NeutrAvidin elongated semiconductor nanocrystals (quantum nanorods, QRs) for use in single molecule polarized fluorescence microscopy. Three different ligands were compared with regard to efficacy for attaching NeutrAvidin using the "zero-length cross-linker" 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC). Biotin-4-fluorescene (B4F), a fluorophore that is quenched when bound to avidin proteins, was used to quantify biotin binding activity of the NeutrAvidin coated QRs and biotin binding activity of commercially available streptavidin coated quantum dots (QDs). All three coating methods produced QRs with NeutrAvidin coating density comparable to the streptavidin coating density of the commercially available quantum dots (QDs) in the B4F assay. One type of QD available from the supplier (ITK QDs) exhibited ∼5-fold higher streptavidin surface density compared to our QRs, whereas the other type of QD (PEG QDs) had 5-fold lower density. The number of streptavidins per QD increased from ∼7 streptavidin tetramers for the smallest QDs emitting fluorescence at 525 nm (QD525) to ∼20 tetramers for larger, longer wavelength QDs (QD655, QD705, and QD800). QRs coated with NeutrAvidin using mercaptoundecanoicacid (MUA) and QDs coated with streptavidin bound to biotinylated cytoplasmic dynein in single molecule TIRF microscopy assays, whereas Poly(maleic anhydride-alt-1-ocatdecene) (PMAOD) or glutathione (GSH) QRs did not bind cytoplasmic dynein. The coating methods require optimization of conditions and concentrations to balance between substantial NeutrAvidin binding vs tendency of QRs to aggregate and degrade over time.

Shape-engineered epitaxial InGaAs quantum rods for laser applications

International Nuclear Information System (INIS)

Li, L. H.; Ridha, P.; Chauvin, N.; Fiore, A.; Patriarche, G.

2008-01-01

We apply artificial shape engineering of epitaxial semiconductor nanostructures to demonstrate InGaAs quantum rods (QRs), nanocandles, and quantum dots-in-rods on a GaAs substrate. The evolution of the QRs from a zero-dimensional to one-dimensional confinement is evidenced by systematically measuring the photoluminescence and photoluminescence decay as a function of the rod length. Lasers based on a three-stack QR active region are demonstrated at room temperature, validating the applicability of the QRs in the real devices

Clinical characteristics of a novel subgroup of chronic fatigue syndrome patients with postural orthostatic tachycardia syndrome.

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Lewis, I; Pairman, J; Spickett, G; Newton, J L

2013-05-01

A significant proportion of patients with chronic fatigue syndrome (CFS) also have postural orthostatic tachycardia syndrome (POTS). We aimed to characterize these patients and differentiate them from CFS patients without POTS in terms of clinical and autonomic features. A total of 179 patients with CFS (1994 Centers for Disease Control and Prevention criteria) attending one of the largest Department of Health-funded CFS clinical services were included in this study. Outcome measures were as follows: (i) symptom assessment tools including the fatigue impact scale, Chalder fatigue scale, Epworth sleepiness scale (ESS), orthostatic grading scale (OGS) and hospital anxiety and depression scale (HADS-A and -D, respectively), (ii) autonomic function analysis including heart rate variability and (iii) haemodynamic responses including left ventricular ejection time and systolic blood pressure drop upon standing. CFS patients with POTS (13%, n = 24) were younger (29 ± 12 vs. 42 ± 13 years, P fatigued (Chalder fatigue scale, 8 ± 4 vs. 10 ± 2, P = 0.002), less depressed (HADS-D, 6 ± 4 vs. 9 ± 4, P = 0.01) and had reduced daytime hypersomnolence (ESS, 7 ± 6 vs. 10 ± 5, P = 0.02), compared with patients without POTS. In addition, they exhibited greater orthostatic intolerance (OGS, 11 ± 5; P < 0.0001) and autonomic dysfunction. A combined clinical assessment tool of ESS ≤9 and OGS ≥9 identifies accurately CFS patients with POTS with 100% positive and negative predictive values. The presence of POTS marks a distinct clinical group of CFS patents, with phenotypic features differentiating them from those without POTS. A combination of validated clinical assessment tools can determine which CFS patients have POTS with a high degree of accuracy, and thus potentially identify those who require further investigation and consideration for therapy to control heart rate. © 2013 The Association for the Publication of the Journal of Internal Medicine.

Outcomes of ventricular tachycardia ablation in patients with structural heart disease: The impact of electrical storm.

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Bashar Aldhoon

Full Text Available To investigate predictors of long-term outcomes after catheter ablation (CA for ventricular tachycardia (VT and the impact of electrical storm (ES prior to index ablation procedures.We studied consecutive patients with structural heart disease and VT (n = 328; age: 63±12 years; 88% males; 72% ischaemic cardiomyopathy; LVEF: 32±12% who had undergone CA. According to presenting arrhythmia at baseline, they were divided into ES (n = 93, 28% and non-ES groups. Clinical predictors of all-cause mortality were investigated and a clinically useful risk score (SCORE was constructed.During a median follow-up of 927 days (IQR: 564-1626, 67% vs. 60% of patients (p = 0.05 experienced VT recurrence in the ES vs. the non-ES group, respectively; and 41% vs. 32% patients died (p = 0.02, respectively. Five factors were independently associated with mortality: age >70 years (hazard ratio (HR: 1.6, 95% confidence interval (CI: 1.1-2.4, p = 0.01, NYHA class ≥3 (HR: 1.9, 95% CI: 1.2-2.9, p = 0.005, a serum creatinine level >1.3 mg/dL (HR: 1.6, 95% CI: 1.1-2.3, p = 0.02, LVEF ≤25% (HR: 2.4, 95% CI: 1.6-3.5, p = 0.00004, and amiodarone therapy (HR: 1.5, 95% CI: 1.0-2.2, p = 0.03. A risk SCORE ranging from 0-4 (1 point for either high-risk age, NYHA, creatinine, or LVEF correlated with mortality. ES during index ablation independently predicted mortality only in patients with a SCORE ≤1.Advanced LV dysfunction, older age, higher NYHA class, renal dysfunction, and amiodarone therapy, but not ES, were predictors of poor outcomes after CA for VT in the total population. However, ES did predict mortality in a low-risk sub-group of patients.

Absorption enhancement in type-II coupled quantum rings due to existence of quasi-bound states

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Hsieh, Chi-Ti; Lin, Shih-Yen; Chang, Shu-Wei

2018-02-01

The absorption of type-II nanostructures is often weaker than type-I counterpart due to spatially separated electrons and holes. We model the bound-to-continuum absorption of type-II quantum rings (QRs) using a multiband source-radiation approach using the retarded Green function in the cylindrical coordinate system. The selection rules due to the circular symmetry for allowed transitions of absorption are utilized. The bound-tocontinuum absorptions of type-II GaSb coupled and uncoupled QRs embedded in GaAs matrix are compared here. The GaSb QRs act as energy barriers for electrons but potential wells for holes. For the coupled QR structure, the region sandwiched between two QRs forms a potential reservoir of quasi-bound electrons. Electrons in these states, though look like bound ones, would ultimately tunnel out of the reservoir through barriers. Multiband perfectly-matched layers are introduced to model the tunneling of quasi-bound states into open space. Resonance peaks are observed on the absorption spectra of type-II coupled QRs due to the formation of quasi-bound states in conduction bands, but no resonance exist in the uncoupled QR. The tunneling time of these metastable states can be extracted from the resonance and is in the order of ten femtoseconds. Absorption of coupled QRs is significantly enhanced as compared to that of uncoupled ones in certain spectral windows of interest. These features may improve the performance of photon detectors and photovoltaic devices based on type-II semiconductor nanostructures.

Universal algorithm for diagnosis of biventricular capture in patients with cardiac resynchronization therapy.

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Jastrzebski, Marek; Kukla, Piotr; Fijorek, Kamil; Czarnecka, Danuta

2014-08-01

An accurate and universal method for diagnosis of biventricular (BiV) capture using a standard 12-lead electrocardiogram (ECG) would be useful for assessment of cardiac resynchronization therapy (CRT) patients. Our objective was to develop and validate such an ECG method for BiV capture diagnosis that would be independent of pacing lead positions-a major confounder that significantly influences the morphologies of paced QRS complexes. On the basis of an evaluation of 789 ECGs of 443 patients with heart failure and various right ventricular (RV) and left ventricular (LV) lead positions, the following algorithm was constructed and validated. BiV capture was diagnosed if the QRS in lead I was predominantly negative and either V1 QRS was predominantly positive or V6 QRS was of negative onset and predominantly negative (step 1), or if QRS complex duration was capture. The algorithm showed good accuracy (93%), sensitivity (97%), and specificity (90%) for detection of loss of LV capture. The performance of the algorithm did not differ among apical, midseptal, and outflow tract RV lead positions and various LV lead positions. LV capture leaves diagnostic hallmarks in the fused BiV QRS related to different vectors of depolarization and more rapid depolarization of the ventricles. An accurate two-step ECG algorithm for BiV capture diagnosis was developed and validated. This algorithm is universally applicable to all CRT patients, regardless of the positions of the pacing leads. ©2014 Wiley Periodicals, Inc.

Association of Age, Sex, Body Size and Ethnicity with Electrocardiographic Values in Community-based Older Asian Adults.

Science.gov (United States)

Tan, Eugene S J; Yap, Jonathan; Xu, Chang Fen; Feng, Liang; Nyunt, Shwe Zin; Santhanakrishnan, Rajalakshmi; Chan, Michelle M Y; Seow, Swee Chong; Ching, Chi Keong; Yeo, Khung Keong; Richards, A Mark; Ng, Tze Pin; Lim, Toon Wei; Lam, Carolyn S P

2016-07-01

Existing electrocardiographic (ECG) reference values were derived in middle-aged Caucasian adults. We aimed to assess the association of age, sex, body size and ethnicity on ECG parameters in a multi-ethnic Asian population. Resting 12-lead ECG and anthropometric measurements were performed in a community-based cohort of 3777 older Asians (age 64.7±9.1 years, 1467 men, 88.8% Chinese, 7.7% Malay, 3.5% Indian, body mass index [BMI] 24.0±3.9kg/m(2)). Men had longer PR interval, wider QRS, shorter QTc interval and taller SV3. In both sexes, older age was associated with longer PR interval, wider QRS, larger R aVL and more leftward QRS axis, while higher BMI was associated with longer PR interval, wider QRS, larger RaVL and more negative QRS axis. There were significant inter-ethnic differences in QRS duration among men, as well as in PR and QTc intervals among women (all adjusted p<0.05). Findings were similar in a healthy subset of 1158 adults (age 61.2±9.1 years, 365 men) without cardiovascular risk factors. These first community-based ECG data in multi-ethnic older Asians highlight the independent effects of age, sex, body size and ethnicity on ECG parameters. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Impacts of Coulomb Interactions on the Magnetic Responses of Excitonic Complexes in Single Semiconductor Nanostructures

Directory of Open Access Journals (Sweden)

Fu Ying-Jhe

2010-01-01

Full Text Available Abstract We report on the diamagnetic responses of different exciton complexes in single InAs/GaAs self-assembled quantum dots (QDs and quantum rings (QRs. For QDs, the imbalanced magnetic responses of inter-particle Coulomb interactions play a crucial role in the diamagnetic shifts of excitons (X, biexcitons (XX, and positive trions (X−. For negative trions (X− in QDs, anomalous magnetic responses are observed, which cannot be described by the conventional quadratic energy shift with the magnetic field. The anomalous behavior is attributed to the apparent change in the electron wave function extent after photon emission due to the strong Coulomb attraction by the hole in its initial state. In QRs, the diamagnetic responses of X and XX also show different behaviors. Unlike QDs, the diamagnetic shift of XX in QRs is considerably larger than that of X. The inherent structural asymmetry combined with the inter-particle Coulomb interactions makes the wave function distribution of XX very different from that of X in QRs. Our results suggest that the phase coherence of XX in QRs may survive from the wave function localization due to the structural asymmetry or imperfections.

Compound heterozygosity for mutations (W156X and R225W) in SCN5A associated with severe cardiac conduction disturbances and degenerative changes in the conduction system

NARCIS (Netherlands)

Bezzina, Connie R.; Rook, Martin B.; Groenewegen, W. Antoinette; Herfst, Lucas J.; van der Wal, Allard C.; Lam, Jan; Jongsma, Habo J.; Wilde, Arthur A. M.; Mannens, Marcel M. A. M.

2003-01-01

Cardiac conduction defects associate with mutations in SCN5A, the gene encoding the cardiac Na+ channel. In the present study, we characterized a family in which the proband was born in severe distress with irregular wide complex tachycardia. His older sister died at 1 year of age from severe

UNUSUALLY WIDE BINARIES: ARE THEY WIDE OR UNUSUAL?

International Nuclear Information System (INIS)

Kraus, Adam L.; Hillenbrand, Lynne A.

2009-01-01

We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3''-30'' (500-5000 AU) among all of the known members with masses of 2.5-0.012 M sun . The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at ∼ sun . We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses ∼ sun appear to be 'unusually wide'.

Wolff-Parkinson-White (WPW) syndrome: the detection of delta wave in an electrocardiogram (ECG).

Science.gov (United States)

Mahamat, Hassan Adam; Jacquir, Sabir; Khalil, Cliff; Laurent, Gabriel; Binczak, Stephane

2016-08-01

The delta wave remains an important indicator to diagnose the WPW syndrome. In this paper, a new method of detection of delta wave in an ECG signal is proposed. Firstly, using the continuous wavelet transform, the P wave, the QRS complex and the T wave are detected, then their durations are computed after determination of the boundary location (onsets and offsets of the P, QRS and T waves). Secondly, the PR duration, the QRS duration and the upstroke of the QRS complex are used to determine the presence or absence of the delta wave. This algorithm has been tested on the Physionel database (ptbdb) in order to evaluate its robustness. It has been applied to clinical signals from patients affected by WPW syndrome. This method can provide assistance to practitioners in order to detect the WPW syndrome.

Paroxysmal supraventricular tachycardia and Wolff-Parkinson-White syndrome in ankylosing spondylitis: a large cohort observation study and literature review.

Science.gov (United States)

Ho, Huei-Huang; Yeh, San-Jou; Tsai, Wen-Pin; Wang, Chin-Man; Chen, Ji Yih

2012-12-01

To investigate the associations of paroxysmal supraventricular tachycardia (PSVT) and Wolff-Parkinson-White (WPW) syndrome with ankylosing spondylitis (AS). We conducted a retrospective cohort study by reviewing the medical records of 1503 consecutive AS patients diagnosed at a tertiary medical center. The clinical and electrocardiographic (ECG) characteristics of 641 AS patients having 12-lead ECG available were further analyzed in a precise manner. Among the 641 AS patients with 12-lead ECG available for detecting cardiac abnormalities, 14 were identified as having PSVT, including 3 with WPW syndrome and 1 having a WPW (ventricular preexcitation) ECG pattern. A higher proportion of AS patients presented with PSVT (21.8/1000) compared with a general population-based study (2.25/1000). Also, AS patients demonstrated a higher prevalence of WPW syndrome or WPW pattern (6.24/1000) than found in general population-based studies (0.9 to 1.5/1000). Ankylosing spondylitis patients with PSVT or WPW syndrome had significantly higher rates of peripheral arthritis (78.6%; P = 0.002), acute anterior uveitis (64.3%; P = 0.003), bamboo spine (64.3%; P = 0.001), and other cardiovascular disorders (85.7%; P syndrome. Detailed ECG and electrophysiological examinations are required for early detection of PSVT and WPW syndrome for prompt resolution of potentially life-threatening complications in all AS patients, especially those presenting with the symptoms of palpitation, dizziness, dyspnea, or syncope. Copyright © 2012 Elsevier Inc. All rights reserved.

52 Genetic Loci Influencing Myocardial Mass

DEFF Research Database (Denmark)

van der Harst, Pim; van Setten, Jessica; Verweij, Niek

2016-01-01

BACKGROUND: Myocardial mass is a key determinant of cardiac muscle function and hypertrophy. Myocardial depolarization leading to cardiac muscle contraction is reflected by the amplitude and duration of the QRS complex on the electrocardiogram (ECG). Abnormal QRS amplitude or duration reflect cha...

Engineering of quality requirements as perceived by near-shore development centers' architects in eastern Europe: the hole in the whole.

NARCIS (Netherlands)

Daneva, Maia; Marczak, Sabrina; Herrmann, Andrea; Torchiano, M.

2014-01-01

Context: To software architects (SAs), the quality requirements (QRs) to a software system are key to designing the software architecture. However, understanding SAs' roles in the QRs engineering activities only recently became a topic in empirical requirements engineering research and very little

Dynamics and rate-dependence of the spatial angle between ventricular depolarization and repolarization wave fronts during exercise ECG.

Science.gov (United States)

Kenttä, Tuomas; Karsikas, Mari; Kiviniemi, Antti; Tulppo, Mikko; Seppänen, Tapio; Huikuri, Heikki V

2010-07-01

QRS/T angle and the cosine of the angle between QRS and T-wave vectors (TCRT), measured from standard 12-lead electrocardiogram (ECG), have been used in risk stratification of patients. This study assessed the possible rate dependence of these variables during exercise ECG in healthy subjects. Forty healthy volunteers, 20 men and 20 women, aged 34.6 +/- 3.4, underwent an exercise ECG testing. Twelve-lead ECG was recorded from each test subject and the spatial QRS/T angle and TCRT were automatically analyzed in a beat-to-beat manner with custom-made software. The individual TCRT/RR and QRST/RR patterns were fitted with seven different regression models, including a linear model and six nonlinear models. TCRT and QRS/T angle showed a significant rate dependence, with decreased values at higher heart rates (HR). In individual subjects, the second-degree polynomic model was the best regression model for TCRT/RR and QRST/RR slopes. It provided the best fit for both exercise and recovery. The overall TCRT/RR and QRST/RR slopes were similar between men and women during exercise and recovery. However, women had predominantly higher TCRT and QRS/T values. With respect to time, the dynamics of TCRT differed significantly between men and women; with a steeper exercise slope in women (women, -0.04/min vs -0.02/min in men, P exercise. The individual patterns of TCRT and QRS/T angle are affected by HR and gender. Delayed rate adaptation creates hysteresis in the TCRT/RR slopes.

Paediatrics Electrocardiography

African Journals Online (AJOL)

Prof Ezechukwu

2011-11-28

Nov 28, 2011 ... Right axis deviation- Tetralogy of Fallot, pulmonary atresia, transposition of the great arteries (TGA). Superior axis deviation- Atrioventricular septal defect, tricuspid atresia. QRS Complex. The QRS complex represents ventricular depolarization and the normal duration 0.10 seconds or less. It is meas-.

Epitaxial growth of quantum rods with high aspect ratio and compositional contrast

International Nuclear Information System (INIS)

Li, L. H.; Patriarche, G.; Fiore, A.

2008-01-01

The epitaxial growth of quantum rods (QRs) on GaAs was investigated. It was found that GaAs thickness in the GaAs/InAs superlattice used for QR formation plays a key role in improving the QR structural properties. Increasing the GaAs thickness results in both an increased In compositional contrast between the QRs and surrounding layer, and an increased QR length. QRs with an aspect ratio of up to 10 were obtained, representing quasiquantum wires in a GaAs matrix. Due to modified confinement and strain potential, such nanostructure is promising for controlling gain polarization

Fast nonclinical ventricular tachycardia inducible after ablation in patients with structural heart disease: Definition and clinical implications.

Science.gov (United States)

Watanabe, Masaya; de Riva, Marta; Piers, Sebastiaan R D; Dekkers, Olaf M; Ebert, Micaela; Venlet, Jeroen; Trines, Serge A; Schalij, Martin J; Pijnappels, Daniël A; Zeppenfeld, Katja

2018-01-08

Noninducibility of ventricular tachycardia (VT) with an equal or longer cycle length (CL) than that of the clinical VT is considered the minimum ablation endpoint in patients with structural heart disease. Because their clinical relevance remains unclear, fast nonclinical VTs are often not targeted. However, an accepted definition for fast VT is lacking. The shortest possible CL of a monomorphic reentrant VT is determined by the ventricular refractory period (VRP). The purpose of this study was to propose a patient-specific definition for fast VT based on the individual VRP (fVT VRP ) and assess the prognostic significance of persistent inducibility after ablation of fVT VRP for VT recurrence. Of 191 patients with previous myocardial infarction or with nonischemic cardiomyopathy undergoing VT ablation, 70 (age 63 ± 13 years; 64% ischemic) remained inducible for a nonclinical VT and composed the study population. FVT VRP was defined as any VT with CL ≤VRP 400 + 30 ms. Patients were followed for VT recurrence. After ablation, 30 patients (43%) remained inducible exclusively for fVT VRP and 40 (57%) for any slower VT. Patients with only fVT VRP had 3-year VT-free survival of 64% (95% confidence interval [CI] 46%-82%) compared to 27% (95% CI 14%-48%) for patients with any slower remaining VT (P = .013). Inducibility of only fVT VRP was independently associated with lower VT recurrence (hazard ratio 0.38; 95% CI 0.19-0.86; P = .019). Among 36 patients inducible for any fVT VRP , only 1 had recurrence with fVT VRP . In patients with structural heart disease, inducibility of exclusively fVT VRP after ablation is associated with low VT recurrence. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Mechanisms underlying reflux symptoms and dysphagia in patients with joint hypermobility syndrome, with and without postural tachycardia syndrome.

Science.gov (United States)

Fikree, A; Aziz, Q; Sifrim, D

2017-06-01

The joint hypermobility syndrome (JHS) is a common non-inflammatory connective tissue disorder which frequently co-exists with postural tachycardia syndrome (PoTS), a form of orthostatic intolerance. Gastrointestinal symptoms and dysmotility have been reported in PoTS. Dysphagia and reflux are common symptoms in JHS, yet no studies have examined the physiological mechanism for these, subdivided by PoTS status. Thirty patients (28 female, ages: 18-62) with JHS and symptoms of reflux (n=28) ± dysphagia (n=25), underwent high-resolution manometry and 24 hour pH-impedance monitoring after questionnaire-based symptom assessment. Esophageal physiology parameters were examined in JHS, subdivided by PoTS status. Fifty-three percent of JHS patients with reflux symptoms had pathological acid reflux, 21% had reflux hypersensitivity, and 25% had functional heartburn. Acid exposure was more likely to be increased in the recumbent than upright position (64% vs 43%). The prevalence of hypotensive lower esophageal sphincter (33%) and hiatus hernia (33%) was low. Forty percent of patients with dysphagia had minor disorders of motility, 60% had functional dysphagia. Eighteen (60%) patients had coexistent PoTS-they had significantly higher dysphagia (21 vs 11.5, P=.04) and reflux scores (24.5 vs 16.5, P=.05), and double the prevalence of pathological acid reflux (64% vs 36%, P=.1) and esophageal dysmotility (50% vs 25%, P=.2) though this was not significant. A large proportion of JHS patients with esophageal symptoms have true reflux-related symptoms or mild esophageal hypomotility, and this is more likely if they have PoTS. © 2017 John Wiley & Sons Ltd.

Conductive atomic force microscopy studies on the transformation of GeSi quantum dots to quantum rings.

Science.gov (United States)

Zhang, S L; Xue, F; Wu, R; Cui, J; Jiang, Z M; Yang, X J

2009-04-01

Conductive atomic force microscopy has been employed to study the topography and conductance distribution of individual GeSi quantum dots (QDs) and quantum rings (QRs) during the transformation from QDs to QRs by depositing an Si capping layer on QDs. The current distribution changes significantly with the topographic transformation during the Si capping process. Without the capping layer, the QDs are dome-shaped and the conductance is higher at the ring region between the center and boundary than that at the center. After capping with 0.32 nm Si, the shape of the QDs changes to pyramidal and the current is higher at both the center and the arris. When the Si capping layer increases to 2 nm, QRs are formed and the current of individual QRs is higher at the rim than that at the central hole. By comparing the composition distributions obtained by scanning Auger microscopy and atomic force microscopy combined with selective chemical etching, the origin of the current distribution change is discussed.

Cardiac conductive disturbance in patients with polycystic ovary syndrome.

Science.gov (United States)

Huang, Jen-Hung; Tsai, Jen-Chen; Hsu, Ming-I; Chen, Yi-Jen

2010-12-01

Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality of reproductive-aged women and increases the risk of cardiovascular disease. However, the effects of PCOS on electrocardiograms (ECGs) are not fully elucidated. The aim of this study was to evaluate the characteristics of ECGs in patients with PCOS. This study included 24 patients with PCOS and 12 patients without PCOS. The heart rate, PR interval, QRS duration, Sokolow-Lyon voltage (SV1 + RV5/6), Cornell voltage (RaVL + SV3), QT interval and QTc interval were measured in 12-lead ECGs. The QRS duration was wider in patients with PCOS than those without PCOS (91 ± 8 vs. 81 ± 10 ms, p heart rate, PR interval, Sokolow-Lyon voltage, product of the QRS duration times Cornell voltage combination, QT interval, QTc interval, QT dispersion and QTc dispersion were similar between the two groups. PCOS is associated with a widening QRS duration, which may contribute to its increased cardiovascular risks.

Epidemiology of Arrhythmias in Children

Directory of Open Access Journals (Sweden)

R Prem Sekar

2008-05-01

Full Text Available Unlike the adult population, arrhythmias occur less commonly in childhood. Only 5% of the emergency hospital admissions in the paediatric population is attributed to symptomatic arrhythmias. Majority of these tend to be accessory pathway mediated supraventricular tachyarrhythmias such as Wolff-Parkinson-White (WPW syndrome, permanent junctional reciprocating tachycardia (PJRT and Mahaim tachycardia. The non accessory pathway mediated supraventricular tachyarrhythmias commonly seen in children are junctional ectopic tachycardia (JET and automatic ectopic atrial tachycardia (AET and occur mostly in the post operative period after intracardiac repair for a structural heart defect. Ventricular tachycardia (VT although uncommon, occurs in the paediatric age group in association with hypertrophic cardiomyopathy (HCM, long QT syndrome (LQTS and Brugada syndrome. Occasionally, VT can also present symptomatically as incessant idiopathic infant ventricular tachycardia, right ventricular outflow tract tachycardia, benign VT, catecholaminic VT, idiopathic left ventricular tachycardia and in post cardiac surgical patients.

Isointegral analysis of body surface maps for the assessment of location and size of myocardial infarction

International Nuclear Information System (INIS)

Tonooka, I.; Kubota, I.; Watanabe, Y.; Tsuiki, K.; Yasui, S.

1983-01-01

To estimate the location and size of myocardial infarction (MI), an isointegral mapping technique was adopted from among various body surface electrocardiographic mapping techniques. QRS isointegral and departure maps were made in 35 patients with MI. These patients were separated into 3 groups, based on the location of MI: anterior, inferior, and anterior plus inferior. The severity and location of MI were estimated by thallium-201 myocardial perfusion imaging and the degree of scintigraphic defect was represented by a defect score. The extent of MI was expected to be reflected on the QRS isointegral maps as a distribution of negative QRS complex time-integral values. However, the extent and the location of MI were hardly detectable by the original maps. A departure mapping technique was then devised to observe the distribution of departure index on the body surface. Particular attention was given to the area where the departure index was less than -2, and this area was expected to reflect the location and size of specific abnormality of isointegral map due to MI. There were strong correlations between departure area and defect score in the anterior and inferior MI cases (r . 0.88 and r . 0.79, respectively). However, patients with anterior MI plus inferior MI showed no such correlation. Q-wave mapping was compared with QRS isointegral mapping, and QRS isointegral mapping was found to be more accurate in the estimation of the location and size of MI than Q wave mapping. Thus, QRS isointegral mapping, especially departure mapping, is more useful and convenient for detecting the location and size of MI than methods such as isopotential and Q wave mapping

Sleep Detriments Associated With Quick Returns in Rotating Shift Work: A Diary Study.

Science.gov (United States)

Vedaa, Øystein; Mørland, Erik; Larsen, Marit; Harris, Anette; Erevik, Eilin; Sivertsen, Børge; Bjorvatn, Bjørn; Waage, Siri; Pallesen, Ståle

2017-06-01

We aimed to compared sleep characteristics associated with quick returns (QRs, sleep diary (94.0% female, mean age 47.7 years). A multilevel fixed effects model was used to examine the sleep in QRs compared with two consecutive night shifts, two consecutive evening shifts, and two consecutive day shifts, respectively. None of the other shift transitions studied encumbered as many detriments as QRs, which included short sleep duration (5.6 hours), slightly prolonged sleep onset latency, more abrupt ending of main sleep period, increased sleepiness, and higher level of perceived stress on the following shift. The study emphasizes the need for sufficient time for rest and recuperation between shifts.

New approach for T-wave peak detection and T-wave end location in 12-lead paced ECG signals based on a mathematical model.

Science.gov (United States)

Madeiro, João P V; Nicolson, William B; Cortez, Paulo C; Marques, João A L; Vázquez-Seisdedos, Carlos R; Elangovan, Narmadha; Ng, G Andre; Schlindwein, Fernando S

2013-08-01

This paper presents an innovative approach for T-wave peak detection and subsequent T-wave end location in 12-lead paced ECG signals based on a mathematical model of a skewed Gaussian function. Following the stage of QRS segmentation, we establish search windows using a number of the earliest intervals between each QRS offset and subsequent QRS onset. Then, we compute a template based on a Gaussian-function, modified by a mathematical procedure to insert asymmetry, which models the T-wave. Cross-correlation and an approach based on the computation of Trapezium's area are used to locate, respectively, the peak and end point of each T-wave throughout the whole raw ECG signal. For evaluating purposes, we used a database of high resolution 12-lead paced ECG signals, recorded from patients with ischaemic cardiomyopathy (ICM) in the University Hospitals of Leicester NHS Trust, UK, and the well-known QT database. The average T-wave detection rates, sensitivity and positive predictivity, were both equal to 99.12%, for the first database, and, respectively, equal to 99.32% and 99.47%, for QT database. The average time errors computed for T-wave peak and T-wave end locations were, respectively, -0.38±7.12 ms and -3.70±15.46 ms, for the first database, and 1.40±8.99 ms and 2.83±15.27 ms, for QT database. The results demonstrate the accuracy, consistency and robustness of the proposed method for a wide variety of T-wave morphologies studied. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Right precordial-directed electrocardiographical markers identify arrhythmogenic right ventricular cardiomyopathy in the absence of conventional depolarization or repolarization abnormalities.

Science.gov (United States)

Cortez, Daniel; Svensson, Anneli; Carlson, Jonas; Graw, Sharon; Sharma, Nandita; Brun, Francesca; Spezzacatene, Anita; Mestroni, Luisa; Platonov, Pyotr G

2017-10-13

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) carries a risk of sudden death. We aimed to assess whether vectorcardiographic (VCG) parameters directed toward the right heart and a measured angle of the S-wave would help differentiate ARVD/C with otherwise normal electrocardiograms from controls. Task Force 2010 definite ARVD/C criteria were met for all patients. Those who did not fulfill Task Force depolarization or repolarization criteria (-ECG) were compared with age and gender-matched control subjects. Electrocardiogram measures of a 3-dimentional spatial QRS-T angle, a right-precordial-directed orthogonal QRS-T (RPD) angle, a root mean square of the right sided depolarizing forces (RtRMS-QRS), QRS duration (QRSd) and the corrected QT interval (QTc), and a measured angle including the upslope and downslope of the S-wave (S-wave angle) were assessed. Definite ARVD/C was present in 155 patients by 2010 Task Force criteria (41.7 ± 17.6 years, 65.2% male). -ECG ARVD/C patients (66 patients) were compared to 66 control patients (41.7 ± 17.6 years, 65.2% male). All parameters tested except the QRSd and QTc significantly differentiated -ECG ARVD/C from control patients (p right-sided VCG or measured angle markers better than the spatial QRS-T angle, the QRSd or QTc, in the absence of Taskforce ECG criteria.

Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy.

Science.gov (United States)

Lanjewar, Swapnil S; Chhabra, Lovely; Chaubey, Vinod K; Joshi, Saurabh; Kulkarni, Ganesh; Kothagundla, Chandrasekhar; Kaul, Sudesh; Spodick, David H

2013-01-01

The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration. We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups. There was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy. The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.

15 CFR 734.4 - De minimis U.S. content.

Science.gov (United States)

2010-01-01

... State, Directorate of Defense Trade Controls, except when the QRS11-00100-100/101 version of the sensor... standby instrument systems of the type described in ECCN 7A994 on the Commerce Control List (Supplement No... Sensors; (ii) Commercial automatic flight control systems when the systems integrate QRS11-00050-443/569...

Taquicardia ventricular del tracto de salida del ventrículo derecho durante el embarazo Right ventricular outflow tachycardia during pregnancy

Directory of Open Access Journals (Sweden)

Ariel K. Saad

2012-06-01

Full Text Available Durante el embarazo aumentan el metabolismo basal, el consumo de O2, la frecuencia cardíaca, el volumen sistólico, el volumen minuto y la volemia y disminuyen la tensión arterial y la resistencia periférica. Diferentes estudios han demostrado que durante este período la posibilidad de que ocurra una arritmia cardíaca o se produzca la exacerbación de una arritmia preexistente es mayor. No obstante, en su enorme mayoría carecen de importancia pronóstica tanto para la madre como para el feto. La taquicardia ventricular del tracto de salida del ventrículo derecho es una arritmia poco frecuente y su aparición se ha correlacionado con el aumento del tono adrenérgico. Se presentan los casos de dos pacientes que mostraron en el curso de la gestación reiterados episodios de taquicardia ventricular del tracto de salida del ventrículo derecho. Se analiza la asociación del embarazo con la ocurrencia de trastornos del ritmo cardíaco.During pregnancy, there is an increase in metabolism, oxygen consumption, heart rate, stroke volume, cardiac output, blood volume and a decrease in blood pressure and peripheral resistance. Studies have shown that during this period the occurrence of cardiac arrhythmias is not uncommon. Fortunately, malignant arrhythmias are rare. Herein we report two young patients who presented with symptomatic right ventricular outflow tachycardia during pregnancy that required antiarrhythmic therapy. Possible pathophysiologic mechanisms are discussed.

Ventricular fibrillation development following atrial fibrillation after the ingestion of sildenaphil in a patient with Wolff-Parkinson-White syndrome.

Science.gov (United States)

Inci, Sinan; Izgu, Ibrahim; Aktas, Halil; Dogan, Pinar; Dogan, Ali

2015-08-01

Complications in the accessory pathway in Wolff-Parkinson-White (WPW) syndrome could cause different clinical conditions by inducing different arrhythmias. Atrial fibrillation (AF) is one of these arrhythmias and is important as it causes life-threatening arrhythmias. It is known that some drugs, underlying cardiac diseases, and the number of accessory pathways, cause a predisposition to this condition. In the current report, we presented a patient with WPW who was admitted to the emergency department with AF, wide QRS and a rapid ventricular response that progressed to ventricular fibrillation.

Subtraction electrocardiography: Detection of ischemia-induced ST displacement without the need to identify the J point.

Science.gov (United States)

Ter Haar, C Cato; Man, Sum-Che; Maan, Arie C; Schalij, Martin J; Swenne, Cees A

2016-01-01

When triaging a patient with acute chest pain at first medical contact, an electrocardiogram (ECG) is routinely made and inspected for signs of myocardial ischemia. The guidelines recommend comparison of the acute and an earlier-made ECG, when available. No concrete recommendations for this comparison exist, neither is known how to handle J-point identification difficulties. Here we present a J-point independent method for such a comparison. After conversion to vectorcardiograms, baseline and acute ischemic ECGs after 3minutes of balloon occlusion during elective PCI were compared in 81 patients of the STAFF III ECG database. Baseline vectorcardiograms were subtracted from ischemic vectorcardiograms using either the QRS onsets or the J points as synchronization instants, yielding vector magnitude difference signals, ΔH. Output variables for the J-point synchronized differences were ΔH at the actual J point and at 20, 40, 60 and 80ms thereafter. Output variables for the onset-QRS synchronized differences were the ΔH at 80, 100, 120, 140 and 160ms after onset QRS. Finally, linear regressions of all combinations of ΔHJ+… versus ΔHQRS+… were made, and the best combination was identified. The highest correlation, 0.93 (pJ point and 160ms after the onset of the QRS complex. With a ΔH ischemia threshold of 0.05mV, 66/81 (J-point synchronized differences) and 68/81 (onset-QRS synchronized differences) subjects were above the ischemia threshold, corresponding to sensitivities of 81% and 84%, respectively. Our current study opens an alternative way to detect cardiac ischemia without the need for human expertise for determination of the J point by measuring the difference vector magnitude at 160ms after the onset of the QRS complex. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy

Directory of Open Access Journals (Sweden)

Lanjewar SS

2013-11-01

Full Text Available Swapnil S Lanjewar,1 Lovely Chhabra,1 Vinod K Chaubey,1 Saurabh Joshi,1 Ganesh Kulkarni,1 Chandrasekhar Kothagundla,1 Sudesh Kaul,1 David H Spodick21Department of Internal Medicine, 2Department of Cardiovascular Medicine, Saint Vincent Hospital, University of Massachusetts Medical School, Worcester, MA, USABackground: The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration.Methods: We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1 were computed and compared between the two subgroups.Results: There was no statistically significant difference in qualitative lung function (FEV1 between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy.Conclusion: The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.Keywords: emphysema, electrocardiogram, left ventricular hypertrophy, chronic

Atomic-scale structure and formation of self-assembled In(Ga)As quantum rings

NARCIS (Netherlands)

Offermans, P.; Koenraad, P.M.; Wolter, J.H.; Granados, D.; Garcia, J.M.; Fomin, V.; Gladilin, V.N.; Devreese, J.T.

2006-01-01

The authors present an at.-scale anal. of the In distribution of self-assembled (In,Ga)As quantum rings (QRs), which are formed from InAs quantum dots by capping with a thin layer of GaAs and subsequent annealing. The size and shape of QRs as obsd. by cross-sectional scanning tunneling microscopy

Atomic-scale structure of self-assembled In(Ga)As quantum rings in GaAs

NARCIS (Netherlands)

Offermans, P.; Koenraad, P.M.; Wolter, J.H.; Granados, D.; Garcia, J.M.; Fomin, V.; Gladilin, V.N.; Devreese, J.T.

2005-01-01

We present an atomic-scale analysis of the indium distribution of self-assembled In(Ga)As quantum rings (QRs) which are formed from InAs quantum dots by capping with a thin layer of GaAs and subsequent annealing. We find that the size and shape of QRs as observed by cross-sectional scanning

A novel method for the detection of R-peaks in ECG based on K-Nearest Neighbors and Particle Swarm Optimization

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He, Runnan; Wang, Kuanquan; Li, Qince; Yuan, Yongfeng; Zhao, Na; Liu, Yang; Zhang, Henggui

2017-12-01

Cardiovascular diseases are associated with high morbidity and mortality. However, it is still a challenge to diagnose them accurately and efficiently. Electrocardiogram (ECG), a bioelectrical signal of the heart, provides crucial information about the dynamical functions of the heart, playing an important role in cardiac diagnosis. As the QRS complex in ECG is associated with ventricular depolarization, therefore, accurate QRS detection is vital for interpreting ECG features. In this paper, we proposed a real-time, accurate, and effective algorithm for QRS detection. In the algorithm, a proposed preprocessor with a band-pass filter was first applied to remove baseline wander and power-line interference from the signal. After denoising, a method combining K-Nearest Neighbor (KNN) and Particle Swarm Optimization (PSO) was used for accurate QRS detection in ECGs with different morphologies. The proposed algorithm was tested and validated using 48 ECG records from MIT-BIH arrhythmia database (MITDB), achieved a high averaged detection accuracy, sensitivity and positive predictivity of 99.43, 99.69, and 99.72%, respectively, indicating a notable improvement to extant algorithms as reported in literatures.

Extraction of the fetal ECG in noninvasive recordings by signal decompositions

International Nuclear Information System (INIS)

Christov, I; Simova, I; Abächerli, R

2014-01-01

No signal processing technique has been able to reliably deliver an undistorted fetal electrocardiographic (fECG) signal from electrodes placed on the maternal abdomen because of the low signal-to-noise ratio of the fECG recorded from the maternal body surface. As a result, this led to increased rates of Caesarean deliveries of healthy infants. In an attempt to solve the problem, Physionet/Computing in Cardiology announced the 2013 Challenge: noninvasive fetal ECG. We are suggesting a method for cancellation of the maternal ECG consisting of: maternal QRS detection, heart rate dependant P-QRS-T interval selection, location of the fiducial points inside this interval for best matching by cross correlation, superimposition of the intervals, calculation of the mean signal of the P-QRS-T interval, and sequential subtraction of the mean signal from the whole fECG recording. Three signal decomposition methods were further applied in order to enhance the fetal QRSs (fQRS): principal component analysis, root-mean-square and Hotelling’s T-squared. A combined lead of all decompositions was synthesized and fQRS detection was performed on it. The current research differs from the Challenge in that it uses three signal decomposition methods to enhance the fECG. The new results for 97 recordings of test set B are: 305.657 for Event 4: Fetal heart rate (FHR) and 23.062 for Event 5: Fetal RR interval (FRR). (paper)

Diastolic Pressure Difference to Classify Pulmonary Hypertension in the Assessment of Heart Transplant Candidates.

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Wright, Stephen P; Moayedi, Yasbanoo; Foroutan, Farid; Agarwal, Suhail; Paradero, Geraldine; Alba, Ana C; Baumwol, Jay; Mak, Susanna

2017-09-01

The diastolic pressure difference (DPD) is recommended to differentiate between isolated postcapillary and combined pre-/postcapillary pulmonary hypertension (Cpc-PH) in left heart disease (PH-LHD). However, in usual practice, negative DPD values are commonly calculated, potentially related to the use of mean pulmonary artery wedge pressure (PAWP). We used the ECG to gate late-diastolic PAWP measurements. We examined the method's impact on calculated DPD, PH-LHD subclassification, hemodynamic profiles, and mortality. We studied patients with advanced heart failure undergoing right heart catheterization to assess cardiac transplantation candidacy (N=141). Pressure tracings were analyzed offline over 8 to 10 beat intervals. Diastolic pulmonary artery pressure and mean PAWP were measured to calculate the DPD as per usual practice (diastolic pulmonary artery pressure-mean PAWP). Within the same intervals, PAWP was measured gated to the ECG QRS complex to calculate the QRS-gated DPD (diastolic pulmonary artery pressure-QRS-gated PAWP). Outcomes occurring within 1 year were collected retrospectively from chart review. Overall, 72 of 141 cases demonstrated PH-LHD. Within PH-LHD, the QRS-gated DPD yielded higher calculated DPD values (3 [-1 to 6] versus 0 [-4 to 3] mm Hg; P pulmonary hypertension ( P pulmonary hypertension. The QRS-gated DPD reclassifies a subset of PH-LHD patients from isolated postcapillary pulmonary hypertension to Cpc-PH, which is characterized by an adverse hemodynamic profile. © 2017 American Heart Association, Inc.

Fetal beat detection in abdominal ECG recordings: global and time adaptive approaches

International Nuclear Information System (INIS)

Rodrigues, Rui

2014-01-01

We present a method for location of fetal QRS in maternal abdominal ECG recordings. This method’s initial, global approach was proposed in the context of the 2013 PhysioNet/Computing in Cardiology Challenge where it was tested on the 447 four channel one-minute recordings. The first step is filtering to eliminate baseline wander and high frequency noise. Upon detection, maternal QRS is removed on each channel using a filter applied to the other three channels. Next we locate fetal QRS on each channel and select the channel with the best set of detections. The method was awarded the third-best score in the Challenge event 1 with 278.755 (beats/minute) and the fourth-best score on event 2 with 28.201 ms. The 5 min long recordings of the Abdominal and Direct Fetal ECG Database were used to further test the method. This database contains five recordings obtained from women in labor. Results in these longer recordings were not satisfactory. This appears to be particularly the case in recordings with a more clearly non-stationary nature. In a new approach to our method, some changes are introduced. Two features are updated over time: the filter used to eliminate maternal QRS and the channel used to detect fetal beats. These changes significantly improved the QRS detection performance on longer recordings, but the scores on the 1 minute Challenge recordings were degraded. (paper)

Do implantable cardioverter defibrillators improve survival in patients with severe left ventricular systolic dysfunction after coronary artery bypass graft surgery?

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Fazal, Iftikhar A; Bates, Matthew G D; Matthews, Iain G; Turley, Andrew J

2011-06-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether implantable cardioverter defibrillators (ICD) improve survival in patients with severe left ventricular systolic dysfunction (LVSD) after coronary artery bypass graft (CABG) surgery. ICDs are designed to terminate potentially fatal cardiac tachyarrhythmias. A right ventricular lead is mandatory for detection, pacing and defibrillation capabilities. Dual chamber ICDs have an additional right atrial lead and are used for patients with conventional atrioventricular pacing indications. More sophisticated, biventricular devices exist to provide cardiac resynchronisation therapy (CRT) in addition to defibrillation (CRT-D). ICDs have been extensively investigated in patients with LVSD post myocardial infarction and in patients with non-ischaemic cardiomyopathy for both secondary prevention (history of ventricular arrhythmias) and primary prevention (deemed high risk for ventricular arrhythmias). This best evidence topic aims to review the evidence and its applicability to patients post CABG. Nine hundred and sixteen papers were identified using the search method outlined. Eight randomised controlled trials, two meta-analyses, and one non-randomised trial, in addition to international guidelines presented the best evidence to answer the clinical question. The current evidence base and guidelines suggest that ICDs should be considered for all patients with LVSD [ejection fraction (EF) ≤30-40%] receiving optimal pharmacological management, who are ≥40 days post MI [four weeks for National Institute for Health and Clinical Excellence (NICE)] and in New York Heart Association (NYHA) class I-III. UK NICE guidelines require in addition; non-sustained ventricular tachycardia (NSVT) on a Holter monitor and inducible ventricular tachycardia at electrophysiological study for EF between 30 and 35%; or a QRS >120 ms if EF <30%. The North American guidelines

Role of high-resolution image integration to visualize left phrenic nerve and coronary arteries during epicardial ventricular tachycardia ablation.

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Yamashita, Seigo; Sacher, Frédéric; Mahida, Saagar; Berte, Benjamin; Lim, Han S; Komatsu, Yuki; Amraoui, Sana; Denis, Arnaud; Derval, Nicolas; Laurent, François; Montaudon, Michel; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre; Cochet, Hubert

2015-04-01

Epicardial ventricular tachycardia (VT) ablation is associated with risks of coronary artery (CA) and phrenic nerve (PN) injury. We investigated the role of multidetector computed tomography in visualizing CA and PN during VT ablation. Ninety-five consecutive patients (86 men; age, 57 ± 15) with VT underwent cardiac multidetector computed tomography. The PN detection rate and anatomic variability were analyzed. In 49 patients undergoing epicardial mapping, real-time multidetector computed tomographic integration was used to display CAs/PN locations in 3-dimensional mapping systems. Elimination of local abnormal ventricular activities (LAVAs) was used as ablation end point. The distribution of CAs/PN with respect to LAVA was analyzed and compared between VT etiologies. Multidetector computed tomography detected PN in 81 patients (85%). Epicardial LAVAs were observed in 44 of 49 patients (15 ischemic cardiomyopathy, 15 nonischemic cardiomyopathy, and 14 arrhythmogenic right ventricular cardiomyopathy) with a mean of 35 ± 37 LAVA points/patient. LAVAs were located within 1 cm from CAs and PN in 35 (80%) and 18 (37%) patients, respectively. The prevalence of LAVA adjacent to CAs was higher in nonischemic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy than in ischemic cardiomyopathy (100% versus 86% versus 53%; P < 0.01). The prevalence of LAVAs adjacent to PN was higher in nonischemic cardiomyopathy than in ischemic cardiomyopathy (93% versus 27%; P < 0.001). Epicardial ablation was performed in 37 patients (76%). Epicardial LAVAs could not be eliminated because of the proximity to CAs or PN in 8 patients (18%). The epicardial electrophysiological VT substrate is often close to CAs and PN in patients with nonischemic cardiomyopathy. High-resolution image integration is potentially useful to minimize risks of PN and CA injury during epicardial VT ablation. © 2015 American Heart Association, Inc.

Pharmacological treatment of cardiac glycoside poisoning

OpenAIRE

Roberts, Darren M.; Gallapatthy, Gamini; Dunuwille, Asunga; Chan, Betty S.

2015-01-01

Cardiac glycosides are an important cause of poisoning, reflecting their widespread clinical usage and presence in natural sources. Poisoning can manifest as varying degrees of toxicity. Predominant clinical features include gastrointestinal signs, bradycardia and heart block. Death occurs from ventricular fibrillation or tachycardia. A wide range of treatments have been used, the more common including activated charcoal, atropine, ??adrenoceptor agonists, temporary pacing, anti?digoxin Fab a...

Toward magnetic resonance-guided electroanatomical voltage mapping for catheter ablation of scar-related ventricular tachycardia: a comparison of registration methods.

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Tao, Qian; Milles, Julien; VAN Huls VAN Taxis, Carine; Lamb, Hildo J; Reiber, Johan H C; Zeppenfeld, Katja; VAN DER Geest, Rob J

2012-01-01

Integration of preprocedural delayed enhanced magnetic resonance imaging (DE-MRI) with electroanatomical voltage mapping (EAVM) may provide additional high-resolution substrate information for catheter ablation of scar-related ventricular tachycardias (VT). Accurate and fast image integration of DE-MRI with EAVM is desirable for MR-guided ablation. Twenty-six VT patients with large transmural scar underwent catheter ablation and preprocedural DE-MRI. With different registration models and EAVM input, 3 image integration methods were evaluated and compared to the commercial registration module CartoMerge. The performance was evaluated both in terms of distance measure that describes surface matching, and correlation measure that describes actual scar correspondence. Compared to CartoMerge, the method that uses the translation-and-rotation model and high-density EAVM input resulted in a registration error of 4.32±0.69 mm as compared to 4.84 ± 1.07 (P <0.05); the method that uses the translation model and high-density EAVM input resulted in a registration error of 4.60 ± 0.65 mm (P = NS); and the method that uses the translation model and a single anatomical landmark input resulted in a registration error of 6.58 ± 1.63 mm (P < 0.05). No significant difference in scar correlation was observed between all 3 methods and CartoMerge (P = NS). During VT ablation procedures, accurate integration of EAVM and DE-MRI can be achieved using a translation registration model and a single anatomical landmark. This model allows for image integration in minimal mapping time and is likely to reduce fluoroscopy time and increase procedure efficacy. © 2011 Wiley Periodicals, Inc.

Antiarrhythmic Effects of Dantrolene in Patients with Catecholaminergic Polymorphic Ventricular Tachycardia and Replication of the Responses Using iPSC Models.

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Kirsi Penttinen

Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a highly malignant inherited arrhythmogenic disorder. Type 1 CPVT (CPVT1 is caused by cardiac ryanodine receptor (RyR2 gene mutations resulting in abnormal calcium release from sarcoplasmic reticulum. Dantrolene, an inhibitor of sarcoplasmic Ca(2+ release, has been shown to rescue this abnormal Ca(2+ release in vitro. We assessed the antiarrhythmic efficacy of dantrolene in six patients carrying various RyR2 mutations causing CPVT. The patients underwent exercise stress test before and after dantrolene infusion. Dantrolene reduced the number of premature ventricular complexes (PVCs on average by 74% (range 33-97 in four patients with N-terminal or central mutations in the cytosolic region of the RyR2 protein, while dantrolene had no effect in two patients with mutations in or near the transmembrane domain. Induced pluripotent stem cells (iPSCs were generated from all the patients and differentiated into spontaneously beating cardiomyocytes (CMs. The antiarrhythmic effect of dantrolene was studied in CMs after adrenaline stimulation by Ca(2+ imaging. In iPSC derived CMs with RyR2 mutations in the N-terminal or central region, dantrolene suppressed the Ca(2+ cycling abnormalities in 80% (range 65-97 of cells while with mutations in or near the transmembrane domain only in 23 or 32% of cells. In conclusion, we demonstrate that dantrolene given intravenously shows antiarrhythmic effects in a portion of CPVT1 patients and that iPSC derived CM models replicate these individual drug responses. These findings illustrate the potential of iPSC models to individualize drug therapy of inherited diseases.Trial Registration: EudraCT Clinical Trial Registry 2012-005292-14.

Geometric patterns of time-delay plots from different cardiac rhythms and arrhythmias using short-term EKG signals.

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Borracci, Raúl A; Montoya Pulvet, José D; Ingino, Carlos A; Fitz Maurice, Mario; Hirschon Prado, Alfredo; Dominé, Enrique

2017-12-27

To date, no systematic work has been intended to describe spatio-temporal patterns of cardiac rhythms using only short series of RR intervals, to facilitate visual or computerized-aided identification of EKG motifs for use in clinical practice. The aim of this study was to detect and classify eye-catching geometric patterns of Poincaré time-delay plots from different types of cardiac rhythms and arrhythmias using short-term EKG signals. Approximately 150-300 representative, consecutive beats were retrieved from 24-h Holter registers of 100 patients with different heart rhythms. Two-dimensional Poincaré charts were created, and the resulting geometric patterns were transformed into representative familiar eye-catching drawings to interpret different arrhythmias. Poincaré plot representation of RR interval data revealed a wide variety of visual patterns: (i) comet-shaped for sinus rhythm; (ii) torpedo-shaped for sinus bradycardia; (iii) cigarette-shaped for sinus tachycardia; (iv) butterfly-shaped for sinus tachycardia and isolated atrial premature complexes; (v) arrow-shaped for isolated premature complexes and inappropriate sinus tachycardia; (vi) inverted fan-shaped for sinus rhythm with frequent atrial premature complexes; (vii) tornado-shaped for atrial flutter and atrial tachycardia; and (viii) fan-shaped for atrial fibrillation. Modified Poincaré plots with smoothed lines connecting successive points could accurately classify different types of arrhythmias based on short RR interval sequence variability. Characteristic emergent patterns can be visually identified and eventually could be distinguished by an automatic classification system able to discern between arrhythmias. This work provides an alternative method to interpret time-delay plots obtained from short-term EKG signal recordings. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Multi-channel non-invasive fetal electrocardiography detection using wavelet decomposition

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Almeida, Javier; Ruano, Josué; Corredor, Germán.; Romo-Bucheli, David; Navarro-Vargas, José Ricardo; Romero, Eduardo

2017-11-01

Non-invasive fetal electrocardiography (fECG) has attracted the medical community because of the importance of fetal monitoring. However, its implementation in clinical practice is challenging: the fetal signal has a low Signal- to-Noise-Ratio and several signal sources are present in the maternal abdominal electrocardiography (AECG). This paper presents a novel method to detect the fetal signal from a multi-channel maternal AECG. The method begins by applying filters and signal detrending the AECG signals. Afterwards, the maternal QRS complexes are identified and subtracted. The residual signals are used to detect the fetal QRS complex. Intervals of these signals are analyzed by using a wavelet decomposition. The resulting representation feds a previously trained Random Forest (RF) classifier that identifies signal intervals associated to fetal QRS complex. The method was evaluated on a public available dataset: the Physionet2013 challenge. A set of 50 maternal AECG records were used to train the RF classifier. The evaluation was carried out in signals intervals extracted from additional 25 maternal AECG. The proposed method yielded an 83:77% accuracy in the fetal QRS complex classification task.

ECG abnormalities in patients with chronic kidney disease

International Nuclear Information System (INIS)

Shafi, S.; Saleem, M.; Anjum, R.; Abdullah, W.; Shafi, T.

2017-01-01

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease. Electrocardiographic (ECG) abnormalities are common in CKD patients. However, there is variation in literature regarding frequency of ECG abnormalities in CKD patients and limited information in local population. Methods: The study design was cross-sectional in nature. All patients between ages of 20-80 years with CKD not previously on renal replacement therapy who were admitted to nephrology ward at a tertiary care facility over a 6-month period were included. All patients underwent 12 lead electrocardiograms (ECG). ECG abnormalities were defined based on accepted standard criteria. Results: Total number of patients included in the study was 124. Mean age of all patients was 49.9+-13.8 years, 106 (84.8%) had hypertension, 84 (70%) had diabetes mellitus, and 35 (29.9%) had known cardiovascular disease. Mean serum creatinine was 7.2+-3.4 mg/dl, mean eGFR was 10.6+-9.2 ml/min/1.73 m/sup 2/. Overall 78.4% of all CKD patients have one or more ECG abnormality. Left ventricular hypertrophy (40%), Q waves (27.2%), ST segment elevation or depression (23.4%), prolonged QRS duration (19.2%), tachycardia (17.6%) and left and right atrial enlargement (17.6%) were the most common abnormalities. Conclusion: ECG abnormalities are common in hospitalized CKD patients in local population. All hospitalized CKD patients should undergo ECG to screen for cardiovascular disease. (author)

Value of local electrogram characteristics predicting successful catheter ablation of left-versus right-sided accessory atrioventricular pathways by radiofrequency current.

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Lin, J L; Schie, J T; Tseng, C D; Chen, W J; Cheng, T F; Tsou, S S; Chen, J J; Tseng, Y Z; Lien, W P

1995-01-01

Despite similar guidance by local electrogram criteria, catheter ablation of right-sided accessory atrioventricular (AV) pathways by radiofrequency current has been less effective than that of left-sided ones. In order to elucidate the possible diversities in local electrosignal criteria, we systematically analyzed the morphological and timing characteristics of 215 bipolar local electrograms from catheter ablation sites of 65 left-sided accessory AV pathways and of 356 from those of 37 right-sided ones in 92 consecutive patients with Wolff-Parkinson-White syndrome or AV reentrant tachycardia incorporating concealed accessory AV pathways. After stepwise multivariate analysis, we selected the presence of a possible accessory pathway potential, local ventricular activation preceding QRS complex for 20 ms or more during ventricular insertion mapping, and the local retrograde ventriculoatrial (VA) continuity, local retrograde VA interval right-sided targets only) during atrial insertion mapping, as independent local electrogram predictors for successful ablation of left- and right-sided accessory AV pathways. Combination of all local electrogram predictors could have moderate chance of success (80 and 51%) for the ventricular and atrial insertion ablation of left-sided accessory AV pathways, but only low probability of success (40% in ventricular insertion ablation) or very low sensitivity (12.5% in atrial insertion ablation) for right-sided ones. In conclusion, with the present approach, successful catheter ablation of right-sided accessory AV pathways, compared to left-sided ones, still necessitate a breakthrough in the precision mapping and the efficiency of energy delivery.

Ventricular arrhythmias in the absence of structural heart disease.

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Prystowsky, Eric N; Padanilam, Benzy J; Joshi, Sandeep; Fogel, Richard I

2012-05-15

Ventricular arrhythmia (VA) in structurally normal hearts can be broadly considered under non-life-threatening monomorphic and life-threatening polymorphic rhythms. Monomorphic VA is classified on the basis of site of origin in the heart, and the most common areas are the ventricular outflow tracts and left ventricular fascicles. The morphology of the QRS complexes on electrocardiogram is an excellent tool to identify the site of origin of the rhythm. Although these arrhythmias are common and generally carry an excellent prognosis, rare sudden death events have been reported. Very frequent ventricular ectopy may also result in a cardiomyopathy in a minority of patients. Suppression of VA may be achieved using calcium-channel blockers, beta-adrenergic blockers, and class I or III antiarrhythmic drugs. Radiofrequency ablation has emerged as an excellent option to eliminate these arrhythmias, although certain foci including aortic cusps and epicardium may be technically challenging. Polymorphic ventricular tachycardia (VT) is rare and generally occurs in patients with genetic ion channel disorders including long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT, and short QT syndrome. Unlike monomorphic VT, these arrhythmic syndromes are associated with sudden death. While the cardiac gross morphology is normal, suggesting a structurally normal heart, abnormalities exist at the molecular level and predispose them to arrhythmias. Another fascinating area, idiopathic ventricular fibrillation and early repolarization syndrome, are undergoing research for a genetic basis. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Malignant progressive tumor cell clone exhibits significant up-regulation of cofilin-2 and 27-kDa modified form of cofilin-1 compared to regressive clone.

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Kuramitsu, Yasuhiro; Wang, Yufeng; Okada, Futoshi; Baron, Byron; Tokuda, Kazuhiro; Kitagawa, Takao; Akada, Junko; Nakamura, Kazuyuki

2013-09-01

QR-32 is a regressive murine fibrosarcoma cell clone which cannot grow when they are transplanted in mice; QRsP-11 is a progressive malignant tumor cell clone derived from QR-32 which shows strong tumorigenicity. A recent study showed there to be differentially expressed up-regulated and down-regulated proteins in these cells, which were identified by proteomic differential display analyses by using two-dimensional gel electrophoresis and mass spectrometry. Cofilins are small proteins of less than 20 kDa. Their function is the regulation of actin assembly. Cofilin-1 is a small ubiquitous protein, and regulates actin dynamics by means of binding to actin filaments. Cofilin-1 plays roles in cell migration, proliferation and phagocytosis. Cofilin-2 is also a small protein, but it is mainly expressed in skeletal and cardiac muscles. There are many reports showing the positive correlation between the level of cofilin-1 and cancer progression. We have also reported an increased expression of cofilin-1 in pancreatic cancer tissues compared to adjacent paired normal tissues. On the other hand, cofilin-2 was significantly less expressed in pancreatic cancer tissues. Therefore, the present study investigated the comparison of the levels of cofilin-1 and cofilin-2 in regressive QR-32 and progressive QRsP-11cells by western blotting. Cofilin-2 was significantly up-regulated in QRsP-11 compared to QR-32 cells (p<0.001). On the other hand, the difference of the intensities of the bands of cofilin-1 (18 kDa) in QR-32 and QRsP-11 was not significant. However, bands of 27 kDa showed a quite different intensity between QR-32 and QRsP-11, with much higher intensities in QRsP-11 compared to QR-32 (p<0.001). These results suggested that the 27-kDa protein recognized by the antibody against cofilin-1 is a possible biomarker for progressive tumor cells.

Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the canine heart.

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Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; He, Bin

2012-01-01

Single-beat imaging of myocardial activation promises to aid in both cardiovascular research and clinical medicine. In the present study we validate a three-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of simultaneous 3D intracardiac mapping to assess its capability to localize endocardial and epicardial initiation sites and image global activation sequences during pacing and ventricular tachycardia (VT) in the canine heart. Body surface potentials were measured simultaneously with bipolar electrical recordings in a closed-chest condition in healthy canines. Computed tomography images were obtained after the mapping study to construct realistic geometry models. Data analysis was performed on paced rhythms and VTs induced by norepinephrine (NE). The noninvasively reconstructed activation sequence was in good agreement with the simultaneous measurements from 3D cardiac mapping with a correlation coefficient of 0.74 ± 0.06, a relative error of 0.29 ± 0.05, and a root mean square error of 9 ± 3 ms averaged over 460 paced beats and 96 ectopic beats including premature ventricular complexes, couplets, and nonsustained monomorphic VTs and polymorphic VTs. Endocardial and epicardial origins of paced beats were successfully predicted in 72% and 86% of cases, respectively, during left ventricular pacing. The NE-induced ectopic beats initiated in the subendocardium by a focal mechanism. Sites of initial activation were estimated to be ∼7 mm from the measured initiation sites for both the paced beats and ectopic beats. For the polymorphic VTs, beat-to-beat dynamic shifts of initiation site and activation pattern were characterized by the reconstruction. The present results suggest that 3DCEI can noninvasively image the 3D activation sequence and localize the origin of activation of paced beats and NE-induced VTs in the canine heart with good accuracy. This 3DCEI technique offers the potential to aid interventional therapeutic procedures for

Noninvasive Diagnosis of Coronary Artery Disease Using 12-Lead High-Frequency Electrocardiograms

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Schlegel, Todd T.; Arenare, Brian

2006-01-01

A noninvasive, sensitive method of diagnosing certain pathological conditions of the human heart involves computational processing of digitized electrocardiographic (ECG) signals acquired from a patient at all 12 conventional ECG electrode positions. In the processing, attention is focused on low-amplitude, high-frequency components of those portions of the ECG signals known in the art as QRS complexes. The unique contribution of this method lies in the utilization of signal features and combinations of signal features from various combinations of electrode positions, not reported previously, that have been found to be helpful in diagnosing coronary artery disease and such related pathological conditions as myocardial ischemia, myocardial infarction, and congestive heart failure. The electronic hardware and software used to acquire the QRS complexes and perform some preliminary analyses of their high-frequency components were summarized in Real-Time, High-Frequency QRS Electrocardiograph (MSC- 23154), NASA Tech Briefs, Vol. 27, No. 7 (July 2003), pp. 26-28. To recapitulate, signals from standard electrocardiograph electrodes are preamplified, then digitized at a sampling rate of 1,000 Hz, then analyzed by the software that detects R waves and QRS complexes and analyzes them from several perspectives. The software includes provisions for averaging signals over multiple beats and for special-purpose nonrecursive digital filters with specific low- and high-frequency cutoffs. These filters, applied to the averaged signal, effect a band-pass operation in the frequency range from 150 to 250 Hz. The output of the bandpass filter is the desired high-frequency QRS signal. Further processing is then performed in real time to obtain the beat-to-beat root mean square (RMS) voltage amplitude of the filtered signal, certain variations of the RMS voltage, and such standard measures as the heart rate and R-R interval at any given time. A key signal feature analyzed in the present

Fetal movement detection based on QRS amplitude variations in abdominal ECG recordings.

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Rooijakkers, M J; de Lau, H; Rabotti, C; Oei, S G; Bergmans, J W M; Mischi, M

2014-01-01

Evaluation of fetal motility can give insight in fetal health, as a strong decrease can be seen as a precursor to fetal death. Typically, the assessment of fetal health by fetal movement detection relies on the maternal perception of fetal activity. The percentage of detected movements is strongly subject dependent and with undivided attention of the mother varies between 37% to 88%. Various methods to assist in fetal movement detection exist based on a wide spectrum of measurement techniques. However, these are typically unsuitable for ambulatory or long-term observation. In this paper, a novel method for fetal motion detection is presented based on amplitude and shape changes in the abdominally recorded fetal ECG. The proposed method has a sensitivity and specificity of 0.67 and 0.90, respectively, outperforming alternative fetal ECG-based methods from the literature.

Characteristics of the reindeer electrocardiogram

Directory of Open Access Journals (Sweden)

Jouni Timisjärvi

1982-05-01

Full Text Available The electrocardiogram (ECG provides reliable information about heart rate, initiation of heart beat and also, to some degree, indirect evidence on the functional state of the heart muscle. A wide range of such information is readily obtainable from conventional scalar leads, even if the records are limited to a single plane. The present investigation deals with the normal reindeer ECG in the frontal plane. The technique used is the scalar recording technique based on the Einthovenian postulates. The P wave was positive in leads II, III and aVF, negative in lead aVL and variable in leads I and aVR. The direction of the P vector was 60 to 120°. The QRS complex was variable. The most common forms of QRS complex were R and rS in leads I and aVR; R, Rs and rS in lead aVL and Qr or qR in other leads. The most common direction of the QRS vector was 240 to 300°. The T wave was variable. The duration of various intervals and deflection depended on heart rate.Elektrokardiogram på ren.Abstract in Swedish / Sammandrag: Elektrokardiogramet (EKG ger tillförlitliga uppgifter om hjärtfrekvens, retledning och, indirekt, delvis även om hjärtmuskelns funktionell tillstånd. Största delen av denna information fås med normal skalar koppling även om registrering sker i ett plan. I detta arbete har renens normala EKG i frontalplanet undersökts. Kopplingarna har baserats på Einthovs postulat. P-vågen var riktad uppåt i koppling II, III och aVF, nedåt i koppling aVL och den varierade i koppling I och aVR. P-vektorns riktning var 60 - 120°. QRS-komplexet varierade. De vanligaste formerna var R och rS i koppling I och aVR; R, Rs och rS i koppling aVL och Qr eller qR i andra kopplingar. Vanligen var QRS-vektorns riktning 240 - 300°. T-vågen varierade. Awikelserna och intervallernas längd var beroende av hiärtfrekvenssen.Poron sydänsähkökäyrän ominaisuuksia.Abstract in Finnish / Yhteenveto: Sydänsähkökäyrästä saadaan luotettavaa tietoa syd

Learning electrocardiogram on YouTube: how useful is it?

Science.gov (United States)

Akgun, Taylan; Karabay, Can Yucel; Kocabay, Gonenc; Kalayci, Arzu; Oduncu, Vecih; Guler, Ahmet; Pala, Selcuk; Kirma, Cevat

2014-01-01

YouTube has become a useful resource for knowledge and is widely used by medical students as an e-learning source. The purpose of this study was to assess the videos relating electrocardiogram (ECG) on YouTube. YouTube was searched on May 28, 2013 for the search terms "AF ecg" for atrial fibrillation, "AVNRT" for atrioventricular nodal reentrant tachycardia, "AVRT" for atrioventricular reentrant tachycardia, "AV block or heart block" for atrioventricular block, "LBBB, RBBB" for bundle branch block, "left anterior fascicular block or left posterior fascicular block" for fascicular blocks, "VT ecg" for ventricular tachycardia, "long QT" and "Brugada ecg". Non-English language, unrelated and non-educational videos were excluded. Remaining videos were assessed for usefulness, source and characteristics. Usefulness was assessed with using a checklist developed by the authors. One hundred nineteen videos were included in the analysis. Sources of the videos were as follows: individuals n=70, 58.8%, universities/hospitals n=10, 8.4% and medical organizations n=3, 2.5%, health ads n=10 8.4%, health websites n=26, 21.8%. Fifty-six (47.1%) videos were classified as very useful and 16 (13.4%) videos were misleading. 90% of the videos uploaded by universities/hospitals were grouped as very useful videos, the same ratio was 45% for the individual uploads. There were statistically significant differences in ECG diagnosis among the groups (for very useful, useful and misleading, pYouTube has a substantial amount of videos on ECG with a wide diversity from useful to misleading content. The lack of quality content relating to ECG on YouTube necessitates that videos should be selected with utmost care. © 2013 Elsevier Inc. All rights reserved.

Wide-Gap Chalcopyrites

CERN Document Server

Siebentritt, Susanne

2006-01-01

Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

Evaluation of Cardiovascular Morbidity in Nigerian Women after 3 ...

African Journals Online (AJOL)

There was statistically significant prolongation of the PR and QRS intervals at the 12 month visit; mean PR interval (seconds) pre-insertion 0.153± 0.003, and at 12 months 0.173±0.006 (P=0.019), mean QRS interval (seconds) pre-insertion 0.056±0.003 and at 12 months 0.074±0.002 (P=0.005). After 3 years of Norplant use, ...

Severe iatrogenic bradycardia related to the combined use of beta-blocking agents and sodium channel blockers

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Kawabata M

2015-02-01

treatments, such as intravenous administration of atropine or adrenergic agonist and temporary pacing. Bradycardia did not recur during follow-up (median, 687 days. Conclusion: Although wide QRS ventricular tachyarrhythmia is a better known proarrhythmic effect of Na channel blockers, life-threatening bradycardia may also occur in combination with beta-blockers in the elderly, even months after the start of medication, and at plasma concentrations that do not prolong QRS width. Keywords: proarrhythmia, elderly, QRS duration

Co-administration of Apelin and T4 Protects Inotropic and Chronotropic Changes Occurring in Hypothyroid Rats

Energy Technology Data Exchange (ETDEWEB)

Akhondali, Zahra; Badavi, Mohammad; Dianat, Mahin, E-mail: dianat@ajums.ac.ir; Faraji, Farzaneh [Physiology Research Center and Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz (Iran, Islamic Republic of)

2015-09-15

One of the most important thyroid hormone targets is the cardiovascular system. Hemodynamic changes, such as decreased resting heart rate (HR), myocardial contractility, and cardiac output, and increased diastolic pressure and systemic vascular resistance, have been observed in hypothyroid patients. Moreover, in these patients, ECG changes include sinus bradycardia and low voltage complexes (P waves or QRS complexes). This study aimed at evaluating the prophylactic effect of apelin on HR changes and QRS voltage that occur in propylthiouracil (PTU)-induced hypothyroid rats. In this study, 48 adult male Wistar rats weighing 170-235g were randomly divided into 6 groups: Control group (normal saline ip injection + tap water gavage); P group (PTU 0.05%, in drinking water); A group (apelin 200 µg.kg{sup -1}.day{sup -1}, ip); PA group [co-administration of PTU and apelin]; PT group [co-administration of PTU + T4 (0.2 mg/g per day, gavage)]; and PAT group (co-administration of PTU, apelin and T4). All experiments were performed for 28 consecutive days, and then the animals were anesthetized with an ip injection of ketamine (80 mg/kg) and xylazine (12 mg/kg). Lead II electrocardiogram was recorded to calculate HR and QRS voltage. Heart rate and QRS voltage increased more significantly in the hypothyroid group that consumed both apelin and T4 (201 ± 4 beat/min, 0.71 ± 0.02 mv vs. hypothyroid 145 ± 9 beat/min, 0.563 ± 0.015 mv; respectively). The co-administration of apelin and T4 showed a protective effect on QRS voltage and HR in PTU‑induced hypothyroid rats.

Co-administration of Apelin and T4 Protects Inotropic and Chronotropic Changes Occurring in Hypothyroid Rats

Directory of Open Access Journals (Sweden)

Zahra Akhondali

2015-01-01

Full Text Available Abstract Background: One of the most important thyroid hormone targets is the cardiovascular system. Hemodynamic changes, such as decreased resting heart rate (HR, myocardial contractility, and cardiac output, and increased diastolic pressure and systemic vascular resistance, have been observed in hypothyroid patients. Moreover, in these patients, ECG changes include sinus bradycardia and low voltage complexes (P waves or QRS complexes. Objective: This study aimed at evaluating the prophylactic effect of apelin on HR changes and QRS voltage that occur in propylthiouracil (PTU-induced hypothyroid rats. Method: In this study, 48 adult male Wistar rats weighing 170-235g were randomly divided into 6 groups: Control group (normal saline ip injection + tap water gavage; P group (PTU 0.05%, in drinking water; A group (apelin 200 µg.kg-1.day-1, ip; PA group [co-administration of PTU and apelin]; PT group [co-administration of PTU + T4 (0.2 mg/g per day, gavage]; and PAT group (co-administration of PTU, apelin and T4. All experiments were performed for 28 consecutive days, and then the animals were anesthetized with an ip injection of ketamine (80 mg/kg and xylazine (12 mg/kg. Lead II electrocardiogram was recorded to calculate HR and QRS voltage. Results: Heart rate and QRS voltage increased more significantly in the hypothyroid group that consumed both apelin and T4 (201 ± 4 beat/min, 0.71 ± 0.02 mv vs. hypothyroid 145 ± 9 beat/min, 0.563 ± 0.015 mv; respectively. Conclusion: The co-administration of apelin and T4 showed a protective effect on QRS voltage and HR in PTU‑induced hypothyroid rats.

Electrocardiographic Characterization of Cardiac Hypertrophy in Mice that Overexpress the ErbB2 Receptor Tyrosine Kinase

DEFF Research Database (Denmark)

Sysa-Shah, Polina; Sørensen, Lars L; Abraham, M Roselle

2015-01-01

, the ECG recordings of ErbB2(tg) mice were characterized by higher P- and R-wave amplitudes, broader QRS complexes, inverted T waves, and ST interval depression. Pearson's correlation matrix analysis of combined WT and ErbB2(tg) data revealed significant correlation between heart weight and the ECG...... parameters of QT interval (corrected for heart rate), QRS interval, ST height, R amplitude, P amplitude, and PR interval. In addition, the left ventricular posterior wall thickness as determined by echocardiography correlated with ECG-determined ST height, R amplitude, QRS interval; echocardiographic left...... ventricular mass correlated with ECG-determined ST height and PR interval. In summary, we have determined phenotypic ECG criteria to differentiate ErbB2(tg) from WT genotypes in 98.8% of mice. This inexpensive and time-efficient ECG-based phenotypic method might be applied to differentiate between genotypes...

Thyroid storm in a patient with Wolff-Parkinson-White syndrome.

Science.gov (United States)

Naqvi, Syed Yaseen; Luebbert, Jeffrey J; Rosen, Stephen G

2015-12-15

A 44-year-old woman with no medical history presented to the emergency department with a 2 h history of sudden onset chest pressure, palpitations, diaphoresis and shortness of breath. She reported a 90-pound unintentional weight loss, increased appetite, irritability, night sweats and palpitations for 2 months. Physical examination revealed a heart rate (HR) of 269 bpm and a blood pressure of 116/94 mm Hg. Her ECG revealed a wide-complex tachycardia with right bundle branch morphology and an HR of 265 bpm. Intravenous adenosine was administered with resolution of the arrhythmia and symptoms. Her subsequent ECG revealed sinus tachycardia with δ waves, which was consistent with Wolff-Parkinson-White (WPW) syndrome. Laboratory findings confirmed thyroid storm and treatment began with intravenous hydrocortisone, methimazole, metoprolol, amiodarone and iodine drops. Graves' disease was confirmed based on the presence of serum thyroid-stimulating hormone receptor antibody. The patient underwent successful WPW accessory tract ablation 6 weeks after initial presentation. 2015 BMJ Publishing Group Ltd.

Potenciais tardios ao eletrocardiograma de alta resolução no domínio do tempo em portadores de insuficiência cardíaca de diferentes etiologias Time domain analysis of the signal averaged electrocardiogram to detect late potentials in heart failure patients with different etiologies

Directory of Open Access Journals (Sweden)

Ernani de Sousa Grell

2006-09-01

included 215 males (74.65% and 73 females (25.35% between the ages of 16 and 70 (mean 51.5, standard deviation 11.24. The heart failure etiologies were: hypertensive heart disease (78 patients, 27.1%; idiopathic dilated cardiomyopathy (73 patients, 25.4%; ischemic cardiomyopathy (65 patients, 22.6%; Chagas disease (42 patients, 14.6%; alcoholic cardiomyopathy (9 patients, 3.1%; peripartum cardiomyopathy (6 patients, 2.1%; valvular heart disease (2 patients, 4.2% and viral myocarditis (3 patients, 1.04%. The variables included the duration of the standard QRS complex, duration of the filtered QRS complex, duration of the signal below 40µV and the root mean square of the last 40ms which were analyzed in regard to age, gender, etiology and mortality as well as the findings of the 12-lead electrocardiogram at rest, echocardiogram and ambulatory electrocardiogram. The statistical analysis tests used were: the Fisher exact probability test, Student’s t-test, Mann Whitney test, variance analysis, Log-Hank and the Kaplan-Meyer method. RESULTS: Late potentials were diagnosed in 90 patients (31.3% and there was no association with the etiologies. The presence of this condition is associated with: a lower maximum oxygen uptake during the ergospirometry (p=0.001; sustained and non-sustained ventricular tachycardia during Holter monitoring (p=0.001, sudden death and mortality (p<0.05. Patients that did not present late potentials had a higher overlife rate. CONCLUSION: The presence of late potentials was not associated with the etiologies and proved to be an indication of a worse prognosis.

?Spice? (Synthetic Marijuana) Induced Acute Myocardial Infarction: A Case Series

OpenAIRE

Ul Haq, E.; Shafiq, A.; Khan, A. A.; Awan, A. A.; Ezad, S.; Minteer, W. J.; Omar, B.

2017-01-01

Marijuana is the most widely abused “recreational” substance in the United States, with highest prevalence in young adults. It is reported to cause ischemic strokes, hepatitis, anxiety, and psychosis. Although it is associated with dose dependent tachycardia and can lead to coronary vasospasm, it has not been directly related to acute myocardial infarction (AMI). Marijuana induced coronary vasospasm can result in endothelial denudation at the site of a vulnerable atherosclerotic plaque in res...

WOLFF–PARKINSON–WHITE SYNDROME IN CHILDREN: CLINICAL COURSE, DIAGNOSTICS, TREATMENT

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T.K. Kruchina

2011-01-01

Full Text Available Wolff–Parkinson–White (WPW syndrome — is the most common cause of tachycardia in children. The clinical significance of WPW udden cardiac death. Data are presented on the principles of diagnosis of various types of WPW syndrome and characteristics of various types of tachycardia occurring in this disease. At present there is a radical method of treatment of the WPW syndrome — radiofrequency ablation of atrioventricular additional connections. Antiarhythmic therapy remains relevant in arresting attacks of tachycardia, as well as in the treatment of young children who have the age limits for radiofrequency ablation. The principles of choice of treatment and relief of the attack algorithm tachycardia syndrome WPW are described. Key words: Wolff–Parkinson–White syndrome, paroxysmal atrioventricular reciprocal tachycardia, children. (Pediatric Pharmacology. — 2011; 8 (5: 49–53.

Prediction and prognosis of ventricular tachycardia recurrence after catheter ablation with remote magnetic navigation for electrical storm in patients with ischemic cardiomyopathy.

Science.gov (United States)

Jin, Qi; Jacobsen, Peter Karl; Pehrson, Steen; Chen, Xu

2017-11-01

Ventricular tachycardia (VT) recurrence after catheter ablation for electrical storm is commonly seen in patients with ischemic cardiomyopathy (ICM). We hypothesized that VT recurrence can be predicted and be related to the all-cause death after VT storm ablation guided by remote magnetic navigation (RMN) in patients with ICM. A total of 54 ICM patients (87% male; mean age, 65 ± 7.1 years) presenting with VT storm undergoing acute ablation using RMN were enrolled. Acute complete ablation success was defined as noninducibility of any sustained monomorphic VT at the end of the procedure. Early VT recurrence was defined as the occurrence of sustained VT within 1 month after the first ablation. After a mean follow-up of 17.1 months, 27 patients (50%) had freedom from VT recurrence. Sustained VT recurred in 12 patients (22%) within 1 month following the first ablation. In univariate analysis, VT recurrence was associated with incomplete procedural success (hazard ratio [HR]: 6.25, 95% confidence interval [CI]: 1.20-32.47, P = 0.029), lack of amiodarone usage before ablation (HR: 4.71, 95% CI: 1.12-19.7, P = 0.034), and a longer procedural time (HR: 1.023, 95% CI: 1.00-1.05, P = 0.05). The mortality of patients with early VT recurrence was higher than that of patients without recurrence (P storm guided by RMN is the strongest predictor of VT recurrence. ICM patients who have early recurrences after VT storm ablation are at high risk of all-cause death. © 2017 Wiley Periodicals, Inc.

A Design of Wide Band and Wide Beam Cavity-Backed Slot Antenna Array with Slant Polarization

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Huiying Qi

2016-01-01

Full Text Available Design of antenna array under the limitation of restricted size is a challenging problem. Cavity-backed slot antenna is widely used because of its advantages of small size, wide band, and wide beam. In this paper, a design of wide band and wide beam cavity-backed slot antenna array with the slant polarization is proposed. To obtain wide band and wide beam with limited size, the inverted microstrip-fed cavity-backed slot antenna (IMF-CBSA is adopted as the element of 1 × 4 antenna array. The slant polarized antennas and their feeding networks are adopted because of their simple structures. The performance of the proposed antenna array is verified by the simulations and experiments. The measured VSWR < 2 bandwidth is 55% at the center frequency 21.8 GHz, and the gain is larger than 12.2 dB. Experimental results demonstrate that the proposed design achieves wide band and beam with the size of 68 mm × 56 mm × 14.5 mm.

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

Science.gov (United States)

Dijkman, B; Wellens, H J

2000-10-01

Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PRtachycardia); (2) programming settings (atrial fibrillation/atrial flutter with ventricular rate above the SVT limit); and (3) algorithm limitations (atrial tachycardia with ventricular rate around the shortest programmable SVT limit and SVT redetection following VT therapy). Programming measures improved detection ability in 13 of 59 of inappropriately detected arrhythmias. Dual chamber detection algorithms evaluated in a subset of diagnostically difficult arrhythmias allow safe detection of double tachycardias but require further extension and programmability to

High-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxer dogs Eletrocardiografia de alta resolução no diagnóstico da cardiomiopatia arritmogênica do ventrículo direito em cães da raça Boxer

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Evandro Zacché Pereira

2013-06-01

Full Text Available To evaluate the reliability of high-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers, 20 dogs with no structural cardiac alterations at echocardiographic examination were grouped on the basis of frequency of ventricular arrhythmias, evaluated by 24-hour ambulatory ECG, and undergoing a high-resolution electrocardiography. High frequency QRS duration, duration of terminal QRS complex less than 40µV (LAS40 and root mean square voltage of the terminal 40 milliseconds of the QRS complex (RMS40 were measured. Differences in high-resolution ECG variables were not observed between groups. Therefore, the results of this investigation suggest that high-resolution electrocardiography is not a useful method for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers without detectable myocardial alterations or systolic dysfunction.Com o objetivo de avaliar a importância da eletrocardiografia de alta resolução no diagnóstico da cardiomiopatia arritmogênica do ventrículo direito do Boxer, 20 cães sem evidências de doença cardíaca estrutural à avaliação ecodopplercardiográfica foram agrupados de acordo com a frequência de arritmias ventriculares, avaliadas pela eletrocardiografia ambulatorial de 24 horas, e submetidos ao exame eletrocardiográfico de alta resolução. Duração do complexo QRS filtrado, duração dos sinais de baixa amplitude (menor que 40µV dos últimos 40 milissegundos do complexo QRS e raiz quadrada média da voltagem ao quadrado dos últimos 40 milissegundos do complexo QRS (RMS40 foram as variáveis avaliadas. Não foram observadas diferenças significativas entre os grupos em relação às variáveis estudadas. Sendo assim, os resultados do presente estudo sugerem que a eletrocardiografia de alta resolução não é uma ferramenta útil no auxílio diagnóstico da cardiomiopatia arritmogênica do ventrículo direito dos cães da raça Boxer

Advanced ECG in 2016: is there more than just a tracing?

Science.gov (United States)

Reichlin, Tobias; Abächerli, Roger; Twerenbold, Raphael; Kühne, Michael; Schaer, Beat; Müller, Christian; Sticherling, Christian; Osswald, Stefan

2016-01-01

The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is critical for evidence-based management of patients with most cardiovascular conditions, including patients with acute myocardial infarction, suspected chronic cardiac ischaemia, cardiac arrhythmias, heart failure and implantable cardiac devices. In contrast to many other techniques in cardiology, the ECG is simple, small, mobile, universally available and cheap, and therefore particularly attractive. Standard ECG interpretation mainly relies on direct visual assessment. The progress in biomedical computing and signal processing, and the available computational power offer fascinating new options for ECG analysis relevant to all fields of cardiology. Several digital ECG markers and advanced ECG technologies have shown promise in preliminary studies. This article reviews promising novel surface ECG technologies in three different fields. (1) For the detection of myocardial ischaemia and infarction, QRS morphology feature analysis, the analysis of high frequency QRS components (HF-QRS) and methods using vectorcardiography as well as ECG imaging are discussed. (2) For the identification and management of patients with cardiac arrhythmias, methods of advanced P-wave analysis are discussed and the concept of ECG imaging for noninvasive localisation of cardiac arrhythmias is presented. (3) For risk stratification of sudden cardiac death and the selection of patients for medical device therapy, several novel markers including an automated QRS-score for scar quantification, the QRS-T angle or the T-wave peak-to-end-interval are discussed. Despite the existing preliminary data, none of the advanced ECG markers and technologies has yet accomplished the transition into clinical practice. Further refinement of these technologies and broader validation in large unselected patient cohorts are the critical next step needed to facilitate translation of advanced ECG technologies

Generalization of the Wide-Sense Markov Concept to a Widely Linear Processing

International Nuclear Information System (INIS)

Espinosa-Pulido, Juan Antonio; Navarro-Moreno, Jesús; Fernández-Alcalá, Rosa María; Ruiz-Molina, Juan Carlos; Oya-Lechuga, Antonia; Ruiz-Fuentes, Nuria

2014-01-01

In this paper we show that the classical definition and the associated characterizations of wide-sense Markov (WSM) signals are not valid for improper complex signals. For that, we propose an extension of the concept of WSM to a widely linear (WL) setting and the study of new characterizations. Specifically, we introduce a new class of signals, called widely linear Markov (WLM) signals, and we analyze some of their properties based either on second-order properties or on state-space models from a WL processing standpoint. The study is performed in both the forwards and backwards directions of time. Thus, we provide two forwards and backwards Markovian representations for WLM signals. Finally, different estimation recursive algorithms are obtained for these models

Postural Tachycardia Syndrome

Science.gov (United States)

... Youth Network of America, Inc. 1301 Greengate Court Waldorf MD Waldorf, MD 20601 info@dynainc.org http://www.dynainc. ... Youth Network of America, Inc. 1301 Greengate Court Waldorf MD Waldorf, MD 20601 info@dynainc.org http:// ...

Automatic ECG analysis using principal component analysis and wavelet transformation

OpenAIRE

Khawaja, Antoun

2007-01-01

The main objective of this book is to analyse and detect small changes in ECG waves and complexes that indicate cardiac diseases and disorders. Detecting predisposition to Torsade de Points (TDP) by analysing the beat-to-beat variability in T wave morphology is the main core of this work. The second main topic is detecting small changes in QRS complex and predicting future QRS complexes of patients. Moreover, the last main topic is clustering similar ECG components in different groups.

A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion - Adding QRS amplitude of V2 improves the model.

Science.gov (United States)

Driver, Brian E; Khalil, Ayesha; Henry, Timothy; Kazmi, Faraz; Adil, Amina; Smith, Stephen W

Precordial normal variant ST elevation (NV-STE), previously often called "early repolarization," may be difficult to differentiate from subtle ischemic STE due to left anterior descending (LAD) occlusion. We previously derived and validated a logistic regression formula that was far superior to STE alone for differentiating the two entities on the ECG. The tool uses R-wave amplitude in lead V4 (RAV4), ST elevation at 60 ms after the J-point in lead V3 (STE60V3) and the computerized Bazett-corrected QT interval (QTc-B). The 3-variable formula is: 1.196 x STE60V3 + 0.059 × QTc-B - 0.326 × RAV4 with a value ≥23.4 likely to be acute myocardial infarction (AMI). Adding QRS voltage in V2 (QRSV2) would improve the accuracy of the formula. 355 consecutive cases of proven LAD occlusion were reviewed, and those that were obvious ST elevation myocardial infarction were excluded. Exclusion was based on one straight or convex ST segment in V2-V6, 1 millimeter of summed inferior ST depression, any anterior ST depression, Q-waves, "terminal QRS distortion," or any ST elevation >5 mm. The NV-STE group comprised emergency department patients with chest pain who ruled out for AMI by serial troponins, had a cardiologist ECG read of "NV-STE," and had at least 1 mm of STE in V2 and V3. R-wave amplitude in lead V4 (RAV4), ST elevation at 60 ms after the J-point in lead V3 (STE60V3) and the computerized Bazett-corrected QT interval (QTc-B) had previously been measured in all ECGs; physicians blinded to outcome then measured QRSV2 in all ECGs. A 4-variable formula was derived to more accurately classify LAD occlusion vs. NV-STE and optimize area under the curve (AUC) and compared with the previous 3-variable formula. There were 143 subtle LAD occlusions and 171 NV-STE. A low QRSV2 added diagnostic utility. The derived 4-variable formula is: 0.052*QTc-B - 0.151*QRSV2 - 0.268*RV4 + 1.062*STE60V3. The 3-variable formula had an AUC of 0.9538 vs. 0.9686 for the 4-variable formula (p = 0

Unit 148 - World Wide Web Basics

OpenAIRE

148, CC in GIScience; Yeung, Albert K.

2000-01-01

This unit explains the characteristics and the working principles of the World Wide Web as the most important protocol of the Internet. Topics covered in this unit include characteristics of the World Wide Web; using the World Wide Web for the dissemination of information on the Internet; and using the World Wide Web for the retrieval of information from the Internet.

World Wide Web voted most wonderful wonder by web-wide world

CERN Multimedia

2007-01-01

The results are in, and the winner is...the World Wide Web! An online survey conducted by the CNN news group ranks the World Wide Web-invented at CERN--as the most wonderful of the seven modern wonders of the world. (See Bulletin No. 49/2006.) There is currently no speculation about whether they would have had the same results had they distributed the survey by post. The World Wide Web won with a whopping 50 per cent of the votes (3,665 votes). The runner up was CERN again, with 16 per cent of voters (1130 votes) casting the ballot in favour of the CERN particle accelerator. Stepping into place behind CERN and CERN is 'None of the Above' with 8 per cent of the votes (611 votes), followed by the development of Dubai (7%), the bionic arm (7%), China's Three Gorges Damn (5%), The Channel Tunnel (4%), and France's Millau viaduct (3%). Thanks to everyone from CERN who voted. You can view the results on http://edition.cnn.com/SPECIALS/2006/modern.wonders/

Reliability and Reproducibility of Advanced ECG Parameters in Month-to-Month and Year-to-Year Recordings in Healthy Subjects

Science.gov (United States)

Starc, Vito; Abughazaleh, Ahmed S.; Schlegel, Todd T.

2014-01-01

Advanced resting ECG parameters such the spatial mean QRS-T angle and the QT variability index (QTVI) have important diagnostic and prognostic utility, but their reliability and reproducibility (R&R) are not well characterized. We hypothesized that the spatial QRS-T angle would have relatively higher R&R than parameters such as QTVI that are more responsive to transient changes in the autonomic nervous system. The R&R of several conventional and advanced ECG para-meters were studied via intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) in: (1) 15 supine healthy subjects from month-to-month; (2) 27 supine healthy subjects from year-to-year; and (3) 25 subjects after transition from the supine to the seated posture. As hypothesized, for the spatial mean QRS-T angle and many conventional ECG parameters, ICCs we-re higher, and CVs lower than QTVI, suggesting that the former parameters are more reliable and reproducible.

Independent component analysis-based artefact reduction: application to the electrocardiogram for improved magnetic resonance imaging triggering

International Nuclear Information System (INIS)

Oster, Julien; Pietquin, Olivier; Felblinger, Jacques; Abächerli, Roger; Kraemer, Michel

2009-01-01

Electrocardiogram (ECG) is required during magnetic resonance (MR) examination for monitoring patients under anaesthesia or with heart diseases and for synchronizing image acquisition with heart activity (triggering). Accurate and fast QRS detection is therefore desirable, but this task is complicated by artefacts related to the complex MR environment (high magnetic field, radio-frequency pulses and fast switching magnetic gradients). Specific signal processing has been proposed, whether using specific MR QRS detectors or ECG denoising methods. Most state-of-the-art techniques use a connection to the MR system for achieving their task, which is a major drawback since access to the MR system is often restricted. This paper introduces a new method for on-line ECG signal enhancement, called ICARE, which takes advantage of using multi-lead ECG and does not require any connection to the MR system. It is based on independent component analysis (ICA) and applied in real time. This algorithm yields accurate QRS detection for efficient triggering

Spectral analysis of epicardial 60-lead electrograms in dogs with 4-week-old myocardial infarction.

Science.gov (United States)

Hosoya, Y; Ikeda, K; Komatsu, T; Yamaki, M; Kubota, I

2001-01-01

There were few studies on the spectral analysis of multiple-lead epicardial electrograms in chronic myocardial infarction. Spectral analysis of multi-lead epicardial electrograms was performed in 6 sham-operated dogs (N group) and 8 dogs with 4-week-old myocardial infarction (MI group). Four weeks after the ligation of left anterior descending coronary artery, fast Fourier transform was performed on 60-lead epicardial electrograms, and then inverse transform was performed on 5 frequency ranges from 0 to 250 Hz. From the QRS onset to QRS offset, the time integration of unsigned value of reconstructed waveform was calculated and displayed as AQRS maps. On 0-25 Hz AQRS map, there was no significant difference between the 2 groups. In the frequency ranges of 25-250 Hz, MI group had significantly smaller AQRS values than N group solely in the infarct zone. It was shown that high frequency potentials (25-250 Hz) within QRS complex were reduced in the infarct zone.

Prognostic importance of left ventricular mechanical dyssynchrony in heart failure with preserved ejection fraction

DEFF Research Database (Denmark)

Biering-Sørensen, Tor; Shah, Sanjiv J; Anand, Inder

2017-01-01

AIMS: Left ventricular mechanical dyssynchrony has been described in heart failure with preserved ejection fraction (HFpEF), but its prognostic significance is not known. METHODS AND RESULTS: Of 3445 patients with HFpEF enrolled in the Treatment of Preserved Cardiac Function Heart Failure...... models assessed the association of dyssynchrony with the composite outcome of cardiovascular death or heart failure hospitalization. Mean age was 70 ± 10 years, LVEF was 60 ± 8%, and QRS duration was 101 ± 27 ms. Worse dyssynchrony, reflected in SD T2P LS, was associated with wider QRS, prior myocardial...... with the composite outcome in unadjusted analysis [hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.07; P = 0.021, per 10 ms increase], but not after adjusting for clinical characteristics, or after further adjustment for LVEF, AF, NYHA class, stroke, heart rate, creatinine, haematocrit, and QRS duration...

A Correction Formula for the St Segment of the Ac-coupled Electrocardiogram

DEFF Research Database (Denmark)

Schmid, Ramun; Isaksen, Jonas; Leber, Remo

2016-01-01

Background: Many ECG devices apply an analog or an equivalent digital first order high-pass filter as part of the ECG acquisition chain. This type of filter is known to not only reduce baseline wandering but also change the ECG signal itself. Particularly, the ST-segment of ECGs with unipolar QRS...... complexes can be changed considerably. To a certain degree, it is possible to restore the original ECG and therefore the correct ST-segment by inverse filtering. However, this process requires the availability of a digital representation of the filtered ECG signal which is not always the case. We present...... an alternative approach that can estimate the true ST-values based on only three standard ECG parameters and the high-pass filter's time constant. Methods: Based on the high-pass filter's time constant T [s], the QRS integral A [Vs], the QRS width W [s] and the RR-interval RR [s], we derived the following...

Elevated T-wave alternans predicts nonsustained ventricular tachycardia in association with percutaneous coronary intervention in ST-segment elevation myocardial infarction (STEMI) patients.

Science.gov (United States)

Verrier, Richard L; Nearing, Bruce D; Ghanem, Raja N; Olson, Rachel E; Garberich, Ross F; Katsiyiannis, William T; Gornick, Charles C; Tang, Chuen Y; Henry, Timothy D

2013-06-01

Successful reperfusion with primary percutaneous coronary intervention (PCI) can paradoxically elicit temporary vulnerability to ventricular arrhythmia. We examined whether T-wave alternans (TWA) level is correlated with nonsustained ventricular tachycardia (NSVT) incidence in association with PCI in patients with acute ST-segment elevation myocardial infarction (STEMI). We analyzed continuous 24-hour ambulatory electrocardiograms in 48 STEMI patients during and after successful primary PCI, achieving Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow. TWA was measured using modified moving average method. Maximum TWA was elevated in patients with (N = 22) compared to without (N = 26) NSVT (75.1 ± 6.3 vs 49.9 ± 3.6 μV, P < 0.005) during the 22-hour monitoring period. TWA ≥ 60μV predicted NSVT with sensitivity of 77%; specificity, 73%; positive predictive value, 71%; and negative predictive value, 79%. Area under receiver operator characteristic curve (AUC) was 0.87 for maximum TWA in predicting NSVT. By comparison, ST-segment levels did not differ in patients with versus without NSVT and were not predictive (AUC = 0.52). TWA was elevated prior to PCI and remained elevated at 30 minutes after balloon inflation despite restoration of TIMI grade 3 flow in all patients, declining by 22 hours (P < 0.05). Maximum ST-segment levels decreased from before PCI to 30 minutes after balloon inflation. TWA is regionally specific, with higher values prior to PCI in precordial lead V5 than in V1 for left coronary lesions. TWA may be useful in identifying individuals at heightened risk for arrhythmia in association with primary PCI and can potentially signal time-dependent changes in arrhythmia vulnerability. © 2013 Wiley Periodicals, Inc.

O etanercepte induz QRS de baixa tensão e disfunção autonômica em camundongos com doença de Chagas experimental

Directory of Open Access Journals (Sweden)

Héctor Rodríguez-Angulo

2013-09-01

Full Text Available FUNDAMENTO: A doença de Chagas é uma doença parasitária tropical causada pelo protozoário flagelado Trypanosoma cruzi. A cardiomiopatia chagásica é caracterizada por distúrbios na regulação autonômica e na condução do potencial de ação nas fases aguda e crônica da infecção. Embora o fator de necrose tumoral alfa (TNF-α tenha sido associadoà cardiomiopatia em modelos experimentais e em pacientes com doença de Chagas, outros relatos sugerem que o TNF-α pode exercer ações antiparasitárias durante a fase aguda da infecção. OBJETIVOS: Este estudo teve como objetivo determinar os efeitos de um blocker TNF-α solúvel, o etanercepte, em parâmetros eletrocardiográficos na fase aguda da infecção experimental com Trypanosoma cruzi. MÉTODOS: Foram feitos eletrocardiogramas em camundongos infectados não tratados e camundongos infectados que foram tratados com etanercepte 7 dias após a infecção. Os parâmetros de variabilidade onda do eletrocardiograma e frequência cardíaca foram determinados utilizando o Chart para Windows. RESULTADOS: O tratamento com etanercepte resultou em uma baixa tensão do complexo QRS e uma redução da variabilidade da frequência cardíaca em comparação com a ausência de tratamento. No entanto, os camundongos tratados apresentaram um atraso na queda da curva de sobrevivência durante a fase aguda. CONCLUSÃO: Os resultados deste estudo sugerem que, embora o tratamento com etanercepte promova a sobrevivência em camundongos infectados com uma linhagem virulenta de T. cruzi, o bloqueio do TNF-α gera um complexo de baixa tensão e disfunção autonômica durante a fase aguda da infecção. Esses resultados indicam que a mortalidade durante a fase aguda pode ser atribuída a uma resposta inflamatória sistêmica, em vez da disfunção cardíaca.

The role of electrocardiography in evaluation of severity of chronic obstructive pulmonary disease in daily clinical practice.

Science.gov (United States)

Aktürk, Faruk; Bıyık, İsmail; Kocaş, Cüneyt; Ertürk, Mehmet; Yalçın, Ahmet Arif; Savaş, Ayfer Utku; Kuzer, Firuzan Pınar; Uzun, Fatih; Yıldırım, Aydın; Uslu, Nevzat; Çuhadaroğlu, Çağlar

2013-01-01

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of chronic morbidity and mortality. Bronchial obstruction and increased pulmonary vascular resistance impairs right atrial functions. In this study, we aimed to investigate the effect of bronchial obstruction on p wave axis in patients with COPD and usefulness of electrocardiography (ECG) in the evaluation of the severity of COPD. Ninety five patients (64 male and 31 female) included to the study. Patients were in sinus rhythm, with normal ejection fraction and heart chamber sizes. Their respiratory function tests and 12 lead electrocardiograms were obtained at same day. Correlations with severity of COPD and ECG findings including p wave axis, p wave duration, QRS axis, QRS duration were studied. The mean age was 58 ± 12 years. Their mean p wave axis was 62 ± 18 degrees. In this study, p wave axis has demonstrated significant positive correlations with stages of COPD and QRS axis but significant negative correlations with FEV1, FEF, BMI and QRS duration. P wave axis increases with increasing stages of COPD. Verticalization of the frontal p wave axis may be an early finding of worsening of COPD before occurrences of other ECG changes of hypertrophy and enlargement of right heart chambers such as p pulmonale. Verticalization of the frontal p wave axis reflecting right atrial electrical activity and right heart strain may be a useful parameter for quick estimation of the severity of COPD in an out-patient cared.

Radiofrequency catheter ablation for electrical storm in a patient with dilated cardiomyopathy.

Science.gov (United States)

Kolettis, Theofilos M; Naka, Katerina K; Katsouras, Christos S

2005-01-01

We report a case of successful radiofrequency catheter ablation in a patient with dilated cardiomyopathy, who presented with multiple, haemodynamically poorly tolerated episodes of monomorphic ventricular tachycardia, resistant to antiarrhythmic drug treatment. The ablation procedure consisted of focal ablation of three mapped left ventricular sites, using pace and activation mapping. Additional linear ablation lesions were created across these sites. After the procedure, the patient remained free of tachycardia episodes and seven days post-ablation he underwent implantation of a cardioverter-defibrillator. During a twelve-month follow-up period, the patient has remained free of monomorphic ventricular tachycardia episodes. Radiofrequency catheter ablation is feasible in electrical storm, using conventional mapping techniques, even in haemodynamically unstable tachycardias.

World-wide environmental problems

International Nuclear Information System (INIS)

Wohlers, H.C.

1975-01-01

Man and the physical and natural resources necessary to support him in a civilized society are on a collision course. It is simple to say that man cannot continue to grow in number at an ever-increasing rate without a destructive effect upon the environment. Positive scientific proof for this impending calamity is not now available, yet many indications--sometimes physical and sometimes natural--point toward major world-wide environmental troubles in the near future. A number of environmental problems are described, particularly as they relate to the total world system. A computer model simulating future world-wide environmental trends from 1900 to 2100 A.D. is evaluated and suggested as a major tool for data-gathering purposes to determine the extent of world-wide environmental problems. It is suggested that scientists take an active role in the study of the environment, particularly in relation to man's future on earth

Magnitude, direction and location of the resultant dipole moment of the pig heart.

Science.gov (United States)

Hodgkin, B C; Nelson, C V; Angelakos, E T

1976-04-01

Vectorcardiograms were obtained from 50 young domestic pigs using the Nelson lead system. Compensation for body size and shape is achieved and the resultant dipole moment magnitude reflects heart size. A strong relationship was found between heart size and maximum magnitude. Dipole moment magnitude increased as four pigs increased from five to ten weeks of age. The dipole moment during QRS is considered in light of known pig heart excitation pattern. Dipole locations during QRS, calculated by computer solution of the Gabor-Nelson equations, were in agreement with heart location and excitation data.