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Sample records for premature ventricular beats

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Heart rate turbulence after ventricular premature beats in healthy Doberman pinschers and those with dilated cardiomyopathy.

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    Harris, J D; Little, C J L; Dennis, J M; Patteson, M W

    2017-10-01

    To describe the measurement of heart rate turbulence (HRT) after ventricular premature beats and compare HRT in healthy Doberman pinschers and those with dilated cardiomyopathy (DCM), with and without congestive heart failure (CHF). Sixty-five client-owned Dobermans: 20 healthy (NORMAL), 31 with preclinical DCM and 14 with DCM and CHF (DCM + CHF). A retrospective study of data retrieved from clinical records and ambulatory ECG (Holter) archives, including data collected previously for a large-scale prospective study of Dobermans with preclinical DCM. Holter data were reanalysed quantitatively, including conventional time-domain heart rate variability and the HRT parameters turbulence onset and turbulence slope. Heart rate turbulence could be measured in 58/65 dogs. Six Holter recordings had inadequate ventricular premature contractions (VPCs) and one exhibited VPCs too similar to sinus morphology. Heart rate turbulence parameter, turbulence onset, was significantly reduced in DCM dogs, whereas conventional heart rate variability measures were not. Heart rate variability and HRT markers were reduced in DCM + CHF dogs as expected. Heart rate turbulence can be measured from the majority of good quality standard canine 24-hour Holter recordings with >5 VPCs. Turbulence onset is significantly reduced in Dobermans with preclinical DCM which indicates vagal withdrawal early in the course of disease. Heart rate turbulence is a powerful prognostic indicator in human cardiac disease which can be measured from standard 24-hour ambulatory ECG (Holter) recordings using appropriate computer software. Further studies are warranted to assess whether HRT may be of prognostic value in dogs with preclinical DCM and in other canine cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Relationship between redistribution on exercise thallium-201 scintigraphy and repetitive ventricular premature beats in patients with recent myocardial infarction

    International Nuclear Information System (INIS)

    Tsuji, H.; Iwasaka, T.; Sugiura, T.; Shimada, T.; Nakamori, H.; Kimura, Y.; Inada, M.

    1991-01-01

    The relationship between myocardial ischemia detected by exercise thallium-201 scintigraphy and repetitive ventricular premature beats (VPBs) during ambulatory monitoring was evaluated in 57 patients with recent myocardial infarction. Multivariate analysis was performed to obtain the relatively important factor related to repetitive VPBs with the use of the following variables: age, redistribution, left ventricular ejection fraction, serum potassium and magnesium concentration, QRS score, left ventricular aneurysm, and the number of diseased vessels. Thirty-five patients had redistribution, but only three of them had repetitive VPBs during exercise testing. The average heart rate before 79% of 398 episodes of repetitive VPBs during ambulatory monitoring was in the range of 56 to 70/min. These data indicate that most of repetitive VPBs during ambulatory monitoring were not provoked by exercise-induced acute myocardial ischemia. However, redistribution was found to be an important factor associated with repetitive VPBs. The electrical abnormality relating to a substrate characterized by chronic reversible ischemia may explain the association between redistribution and repetitive VPBs

  4. Beat-to-beat left ventricular performance in atrial fibrillation: radionuclide assessment with the computerized nuclear probe

    International Nuclear Information System (INIS)

    Schneider, J.; Berger, H.J.; Sands, M.J.; Lachman, A.B.; Zaret, B.L.

    1983-01-01

    There is wide beat-to-beat variability in cycle length and left ventricular performance in patients with atrial fibrillation. In this study, left ventricular ejection fraction and relative left ventricular volumes were evaluated on a beat-to-beat basis with the computerized nuclear probe, an instrument with sufficiently high sensitivity to allow continuous evaluation of the radionuclide time-activity curve. Of 18 patients with atrial fibrillation, 5 had mitral stenosis, 6 had mitral regurgitation, and 7 had coronary artery disease. Fifty consecutive beats were analyzed in each patient. The mean left ventricular ejection fraction ranged from 17 to 51%. There was substantial beat-to-beat variation in cycle length and left ventricular ejection fraction in all patients, including those with marked left ventricular dysfunction. In 14 patients who also underwent multiple gated cardiac blood pool imaging, there was an excellent correlation between mean ejection fraction derived from the nuclear probe and gated ejection fraction obtained by gamma camera imaging (r . 0.90). Based on beat-to-beat analysis, left ventricular function was dependent on relative end-diastolic volume and multiple preceding cycle lengths, but not preceding end-systolic volumes. This study demonstrates that a single value for left ventricular ejection fraction does not adequately characterize left ventricular function in patients with atrial fibrillation. Furthermore, both the mean beat-to-beat and the gated ejection fraction may underestimate left ventricular performance at rest in such patients

  5. Bayesian Classification Models for Premature Ventricular Contraction Detection on ECG Traces.

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    Casas, Manuel M; Avitia, Roberto L; Gonzalez-Navarro, Felix F; Cardenas-Haro, Jose A; Reyna, Marco A

    2018-01-01

    According to the American Heart Association, in its latest commission about Ventricular Arrhythmias and Sudden Death 2006, the epidemiology of the ventricular arrhythmias ranges from a series of risk descriptors and clinical markers that go from ventricular premature complexes and nonsustained ventricular tachycardia to sudden cardiac death due to ventricular tachycardia in patients with or without clinical history. The premature ventricular complexes (PVCs) are known to be associated with malignant ventricular arrhythmias and sudden cardiac death (SCD) cases. Detecting this kind of arrhythmia has been crucial in clinical applications. The electrocardiogram (ECG) is a clinical test used to measure the heart electrical activity for inferences and diagnosis. Analyzing large ECG traces from several thousands of beats has brought the necessity to develop mathematical models that can automatically make assumptions about the heart condition. In this work, 80 different features from 108,653 ECG classified beats of the gold-standard MIT-BIH database were extracted in order to classify the Normal, PVC, and other kind of ECG beats. Three well-known Bayesian classification algorithms were trained and tested using these extracted features. Experimental results show that the F1 scores for each class were above 0.95, giving almost the perfect value for the PVC class. This gave us a promising path in the development of automated mechanisms for the detection of PVC complexes.

  6. LEFT-VENTRICULAR BEAT-TO-BEAT PERFORMANCE IN ATRIAL-FIBRILLATION - CONTRIBUTION OF FRANK-STARLING MECHANISM AFTER SHORT RATHER THAN LONG RR INTERVALS

    NARCIS (Netherlands)

    GOSSELINK, ATM; BLANKSMA, PK; CRIJNS, HJGM; VANGELDER, IC; DEKAM, PJ; HILLEGE, HL; NIEMEIJER, MG; LIE, KI; MEIJLER, FL

    1995-01-01

    Objectives. This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Background. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat

  7. Left ventricular beat-to-beat performance in atrial fibrillation: Contribution of Frank-Starling mechanism after short rather than long intervals

    NARCIS (Netherlands)

    Gosselink, A.T.M.; Blanksma, P.K.; Crijns, H.J.G.M.; Gelder, I.C. van; Kam, P.J. de; Hillege, H.L.; Niemeijer, M.G.; Lie, K.I.; Meijler, F.L.

    1995-01-01

    This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat mechanical behavior and

  8. Beat-to-beat evaluation of left ventricular ejection in cardiac arrhythmias

    International Nuclear Information System (INIS)

    Itti, R.; Philippe, L.; Lorgeron, J.M.

    1982-01-01

    Conventional multi-gated cardiac blood pool studies suffer from two kinds of superimpositions: the spatial overlapping of various heart chambers and the temporal superimposition of a large number of cardiac cycles. The first problem can be partially solved by first pass techniques or by emission tomography. For the second one, which is specially critical arrhythmias, the single probe device (''nuclear stethoscope'') represents an original solution. Patients with normal cardiac rythm and patients presenting various kinds of cardiac rythm alterations were examined using a commercial ''nuclear stethoscope''. Some characteristic results achieved in these cases, were presented. For blood pool labeling, 20 mCi of 99mTc albumin was injected. The single probe detector was then positioned over the left ventricular area. The beat-to-beat left ventricular activity curve was then recorded for several minutes on paper in the same time as the E.C.G. signal. In cases with irregular cardiac rythm, the multigated techniques yield an average value of left ventricular ejection. Due to the relatively constant duration of systole, the superimposition of cycles may be valid during contration: differences mainly appear during diastole. But, as it could be demonstrated using the ''nuclear stethoscope'', individual cycles can show a large variability of ejection and average ejection fraction is only a very partial aspect of the real cardiac function

  9. Beat-to-beat assessment of left ventricular ejection in atrial fibrillation

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    Benjelloun, H; Brochier, M; Itti, R; Philippe, L; Lorgeron, J M

    1983-05-01

    Beat-to-beat left ventricular ejection was evaluated in a group of 20 patients with chronic atrial fibrillation using a computerized single probe detector. The reference group consisted of 10 patients with sinus rhythm. For each patient 30 successive cardiac cycles were analyzed and the relative variations of four parameters were assessed: R-R interval, diastolic and systolic time intervals, and ejection amplitude, corresponding to the left ventricular stroke volume. The mean variations were respectively 3.4%, 10.4%, 8.4%, and 11.8% in patients with sinus rhythm, and 21.9%, 37.9%, 10.6% and 30.5% in patients with artrial fibrillation. This demonstrates that changes in ejection are mainly related to the duration of the filling phase, with nearly constant systolic times. Correlations between R-R intervals and systolic ejection amplitudes were highly significant (P<0.001) in patients with atrial fibrillation in 85% of cases. This information complements the average ejection fraction obtained from multiple cycle superimposition.

  10. Beat-to-beat assessment of left ventricular ejection in atrial fibrillation

    International Nuclear Information System (INIS)

    Benjelloun, H.; Brochier, M.; Itti, R.; Philippe, L.; Lorgeron, J.M.

    1983-01-01

    Beat-to-beat left ventricular ejection was evaluated in a group of 20 patients with chronic atrial fibrillation using a computerized single probe detector. The reference group consisted of 10 patients with sinus rhythm. For each patient 30 successive cardiac cycles were analyzed and the relative variations of four parameters were assessed: R-R interval, diastolic and systolic time intervals, and ejection amplitude, corresponding to the left ventricular stroke volume. The mean variations were respectively 3.4%, 10.4%, 8.4%, and 11.8% in patients with sinus rhythm, and 21.9%, 37.9%, 10.6% and 30.5% in patients with artrial fibrillation. This demonstrates that changes in ejection are mainly related to the duration of the filling phase, with nearly constant systolic times. Correlations between R-R intervals and systolic ejection amplitudes were highly significant (P<0.001) in patients with atrial fibrillation in 85% of cases. This information complements the average ejection fraction obtained from multiple cycle superimposition. (orig.)

  11. Further insights into blood pressure induced premature beats: Transient depolarizations are associated with fast myocardial deformation upon pressure decline.

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    Haemers, Peter; Sutherland, George; Cikes, Maja; Jakus, Nina; Holemans, Patricia; Sipido, Karin R; Willems, Rik; Claus, Piet

    2015-11-01

    An acute increase in blood pressure is associated with the occurrence of premature ventricular complexes (PVCs). We aimed to study the timing of these PVCs with respect to afterload-induced changes in myocardial deformation in a controlled, preclinically relevant, novel closed-chest pig model. An acute left ventricular (LV) afterload challenge was induced by partial balloon inflation in the descending aorta, lasting 5-10 heartbeats (8 pigs; 396 inflations). Balloon inflation enhanced the reflected wave (augmentation index 30% ± 8% vs 59% ± 6%; P blood pressure by 35% ± 4%. This challenge resulted in a more abrupt LV pressure decline, which was delayed beyond ventricular repolarization (rate of pressure decline 0.16 ± 0.01 mm Hg/s vs 0.27 ± 0.04 mm Hg/ms; P pressure 1 ± 12 ms vs 36 ± 9 ms; P = .008), during which the velocity of myocardial shortening at the basal septum increased abruptly (ie, postsystolic shortening) (peak strain rate -0.6 ± 0.5 s(-1) vs -2.5 ± 0.8 s(-1); P pressure decline, with increased postsystolic shortening, and not at peak pressure, that PVCs occur (22% of inflations). These PVCs preferentially occurred at the basal and apical segments. In the same regions, monophasic action potentials demonstrated the appearance of delayed afterdepolarization-like transient depolarizations as origin of PVCs. An acute blood pressure increase results in a more abrupt LV pressure decline, which is delayed after ventricular repolarization. This has a profound effect on myocardial mechanics with enhanced postsystolic shortening. Coincidence with induced transient depolarizations and PVCs provides support for the mechanoelectrical origin of pressure-induced premature beats. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  12. Detection of premature ventricular contractions on a ventricular electrocardiogram for patients with left ventricular assist devices.

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    Park, Sung Min; Lee, Jin Hong; Choi, Seong Wook

    2014-12-01

    The ventricular electrocardiogram (v-ECG) was developed for long-term monitoring of heartbeats in patients with a left ventricular assist device (LVAD) and does not normally have the functionality necessary to detect additional heart irregularities that can progress to critical arrhythmias. Although the v-ECG has the benefits of physiological optimization and counterpulsation control, when abnormal heartbeats occur, the v-ECG does not show the distinct abnormal waveform that enables easy detection of an abnormal heartbeat among normal heartbeats on the conventional ECG. In this study, the v-ECGs of normal and abnormal heartbeats are compared with each other with respect to peak-to-peak voltage, area, and maximal slopes, and a new method to detect abnormal heartbeats is suggested. In a series of animal experiments with three porcine models (Yorkshire pigs weighing 30-40 kg), a v-ECG and conventional ECG were taken simultaneously during LVAD perfusion. Clinical experts found 104 abnormal heartbeats from the saved conventional ECG data and confirmed that the other 3159 heartbeats were normal. Almost all of the abnormal heartbeats were premature ventricular contractions (PVCs), and there was short-term tachycardia for 3 s. A personal computer was used to automatically detect abnormal heartbeats with the v-ECG according to the new method, and its results were compared with the clinicians' results. The new method found abnormal heartbeats with 90% accuracy, and less than 15% of the total PVCs were missed. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  13. Workup and management of patients with frequent premature ventricular contractions.

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    Giles, Katie; Green, Martin S

    2013-11-01

    Premature ventricular contractions (PVCs) are a frequently encountered entity in clinical cardiology. They rarely affect prognosis or management. However, they might produce bothersome symptoms and, in select individuals with a high PVC burden, they might contribute to left ventricular (LV) dysfunction. Workup of patients with very frequent PVCs consists of a thorough history and physical examination to screen for underlying cardiac disease and potential triggers. Routine investigations include a standard 12-lead electrocardiogram, as well as an echocardiogram. A Holter monitor should be performed in those with severe symptoms, a history of syncope, or a malignant family history. Exercise stress testing has a role in evaluating for ischemia and in the assessment of patients with exertional symptoms. More advanced testing is not warranted if these initial investigations are reassuring. Referral to an arrhythmia specialist should be considered in patients with LV dysfunction whose PVC burden exceeds 15%. Frequent ventricular ectopy represents a rare, but reversible cause of LV dysfunction and these patients should be further evaluated for possible catheter ablation. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  14. Dual-source CT coronary angiography in patients with premature heart-beats: initial experience

    International Nuclear Information System (INIS)

    Wang Yining; Zhang Zhuhua; Kong Lingyan; Song Lan; Mu Wenbin; Wang Yun; Jin Zhengyu

    2008-01-01

    Objective: To evaluate the feasibility of dual-source computed tomography (DSCT) coronary angiography in a population with premature heart-beats. Methods: Seventy patients with suspected coronary artery disease and premature heart-beats were routinely imaged on a DSCT scanner (Somatom Definition, Siemens AG, Germany). The images were reconstmcted before and after ECG editing. Two readers independently assessed image quality of all coronary segments using a four-point grading scale from excellent (1) to non-assessable (4). The results of the two groups were compared with a paired t-test, and a P value of less than 0.05 was considered significant. Results: The mean heart rate during examination ranged from 49 to 111 bpm[ mean(70.7±12.4) bpm]. Twenty-eight of 70 patients with relatively small variability of the heart rate [(41.0±18.4) bpm] got diagnostic image quality without ECG editing. In other 42 patients with larger variability of the heart rate [(71.4±28.7) bpm], the mean image quality scores were 2.09±1.27 and 1.50±0.79 before and after ECG editing, there was a significant difference (t= 13.764, P 2 =121.846, P<0.01). Finally, the diagnostic image accounted 98.0% (1014/1035) in all segments of 70 patients. Conclusion: DSCT can provide diagnostic images for patients with premature heart-beats. The image quality in patients with larger variability of the heart rate can be significantly improved through ECG editing. (authors)

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

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    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.

  16. HRV changes before and after radiofrequency ablation in patients with different origin of right ventricular outflow tract ventricular premature contraction

    Directory of Open Access Journals (Sweden)

    Yi-Ming Ma

    2017-04-01

    Full Text Available Objective: To observe the HRV changes before and after the radiofrequency current catheter ablationventricular premature beats originated from different site of right ventricular outflow tract. Methods: A total of 102 patients with frequent RVOT-VPC admitted to our hospital were accepted radiofrequency current catheter ablation (RF. According to the origin of RVOT-VPC, it was divided into 2 groups, one is from ventricular septum, and the other one is from free wall, and in each group, male and female are observed separately. Results: (1 HRV before RF ablation: 1 rMSSD in the female patients with RVOT-VPC from free wall was significantly lower than those from septum; 2 frequency domain index (W, LF were higher than normal range, and in male patients, LF/HF1. (2 HRV after RF ablation: 1 Significant changes were found in female patients with RVOT-VPC from septum, rMSSD, PNN50, HF and LF decreased; 2 In female patients with RVOT-VPC from free wall, rMSSD decreased; 3 In male patients, there were no significant HRV changes found before and after RF ablation. (3 Heart rate changes: 1 In female patients with RVOT-VPC from septum, heart rate decreased significantly [(76.47±9.47 bpm vs (69.29±14.59 bpm]. 2 No significant changes were found in male patients. Conclusion: In patients with RVOT-PVC sympathetic and vagus excitability increased, and after catheter ablation, in female patients with RVOT-PVC originated from septum, the HRV index relating to sympathetic and vagus excitability significantly decreased.

  17. Frequent premature ventricular contractions in an orbital spaceflight participant.

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    Jennings, Richard T; Stepanek, Jan P; Scott, Luis R; Voronkov, Yury I

    2010-06-01

    Commercial spaceflight participants on orbital flights typically are older than career astronauts and they often have medical conditions that have not been studied at high g or in microgravity. This is a case report of a 56-yr-old orbital spaceflight participant with essential tremor and frequent premature ventricular contractions that occurred at rates up to 7000 per day. Before training and spaceflight, he was required to complete extensive clinical investigations to demonstrate normal cardiac structures and the absence of cardiac pathology. The evaluation included signal averaged ECG, transthoracic stress echocardiography, exercise tolerance tests, electrophysiological studies, cardiac MRI, electron beam CT, Holter monitoring, and overnight oximetry. While no cardiac pathology was demonstrated, the Russian medical team required that the PVCs be treated prior to training and spaceflight. For the initial flight, a selective beta-1 receptor beta blocker was used and for the second a calcium channel blocker was used in combination with a nonselective beta blocker for tremor control. Analogue environment testing assured that this combination of medications was compatible. The spaceflight participant's PVCs were incompletely suppressed with a low-dose selective beta-1 blocker, but were well suppressed by a calcium channel blocker. He tolerated in-flight periodic use of a nonselective beta blocker in combination with a calcium channel blocker. In-flight ECG and blood pressure monitoring results were normal, and an ECG obtained midmission and on landing day showed successful PVC suppression. He did not have any cardiac difficulty with launch, on-orbit operations, entry, or recovery

  18. 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).

  19. Ventricular premature contraction in hypertrophic cardiomyopathy and essential hypertension with left ventricular hypertrophy

    International Nuclear Information System (INIS)

    Kobiki, Naoki

    1989-01-01

    In order to investigate the relationship of different morbid states of the hypertrophied myocardium to the appearance of ventricular premature contraction (VPC), we compared the VPC findings from Holter ECG with those of UCG and stress thallium-201 myocardial SPECT scintigraphy (stress scinti) in 31 patients with hypertrophic cardiomyopathy (HCM) and 20 with essential hypertension (HT). The HCM patients consisted of 21 with asymmetric hypertrophy (ASH), 3 with symmetric hypertrophy (SH), and 7 with apical hypertrophy (APH). We recognized positive findings on the stress scinti such as fixed perfusion defect (FD) or reversible perfusion defect (RD) in 11 patients (ASH 10, APH 1) out of 31 patients with HCM (35%). Positive findings were observed in only one patient out of 20 with HT (5%). We recognized a high grade VPC (grade 4a and 4b of Lown's criteria) in 8 of 11 scinti positive patients with HCM (ASH 7, APH 1)(73%), while high grade VPC appeared in 5 (all of them are ASH) out of 20 scinti negative patients with HCM (25%). Therefore, these findings suggest that high grade VPCs in HCM occur in relation to a myocardial perfusion defect. (author)

  20. Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta 2-adrenergic stimulation with terbutaline in healthy subjects

    DEFF Research Database (Denmark)

    Tveskov, C; Djurhuus, M S; Klitgaard, N A

    1994-01-01

    OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo or terbu......OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo......-potassium pump number. Urinary excretion of potassium and magnesium. ECG changes (T-wave and QTC interval) and the number of ventricular ectopic beats. MAIN RESULTS: Terbutaline produced an immediate decrease in serum potassium level from 4.17 (4.04 to 4.30) mmol/L to a nadir of 3.32 (3.06 to 3.58) mmol/L (p ... of sodium-potassium pumps. Furthermore, terbutaline induced changes in ECG with a highly significant lengthening of the QTc interval but with an unchanged number of ventricular ectopic beats in healthy subjects....

  1. Beat-to-beat ECG restitution: A review and proposal for a new biomarker to assess cardiac stress and ventricular tachyarrhythmia vulnerability.

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    Fossa, Anthony A

    2017-09-01

    Cardiac restitution is the ability of the heart to recover from one beat to the next. Ventricular arrhythmia vulnerability can occur when the heart does not properly adjust to sudden changes in rate or in hemodynamics leading to excessive temporal and/or spatial heterogeneity in conduction or repolarization. Restitution has historically been used to study, by invasive means, the dynamics of the relationship between action potential duration (APD) and diastolic interval (DI) in sedated subjects using various pacing protocols. Even though the analogous measures of APD and DI can be obtained using the surface ECG to acquire the respective QT and TQ intervals for ECG restitution, this methodology has not been widely adopted for a number of reasons. Recent development of more advanced software algorithms enables ECG intervals to be measured accurately, on a continuous beat-to-beat basis, in an automated manner, and under highly dynamic conditions (i.e., ambulatory or exercise) providing information beyond that available in the typical resting state. Current breakthroughs in ECG technology will allow ECG restitution measures to become a practical approach for providing quantitative measures of the risks for ventricular arrhythmias as well as cardiac stress in general. In addition to a review of the underlying principles and caveats of ECG restitution, a new approach toward an advancement of more integrated restitution biomarkers is proposed. © 2017 Wiley Periodicals, Inc.

  2. Cardiac arrhythmia with premature ventricular contractures induced by interferon beta in a patient with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Igor Sobol

    2015-03-01

    Full Text Available Multiple sclerosis (MS is an immune-mediated inflammatory and neurodegenerative disease of the central nervous system. Interferon (IFN beta is an active ingredient of five out of twelve disease modifying treatments approved for MS. We report a case of IFN-beta-induced cardiac arrhythmia with premature ventricular contractures in a patient recently diagnosed with MS.

  3. Dictionary-based monitoring of premature ventricular contractions: An ultra-low-cost point-of-care service.

    Science.gov (United States)

    Bollepalli, S Chandra; Challa, S Sastry; Anumandla, Laxminarayana; Jana, Soumya

    2018-04-25

    While cardiovascular diseases (CVDs) are prevalent across economic strata, the economically disadvantaged population is disproportionately affected due to the high cost of traditional CVD management, involving consultations, testing and monitoring at medical facilities. Accordingly, developing an ultra-low-cost alternative, affordable even to groups at the bottom of the economic pyramid, has emerged as a societal imperative. Against this backdrop, we propose an inexpensive yet accurate home-based electrocardiogram (ECG) monitoring service. Specifically, we seek to provide point-of-care monitoring of premature ventricular contractions (PVCs), high frequency of which could indicate the onset of potentially fatal arrhythmia. Note that the first-generation telecardiology system acquires the ECG, transmits it to a professional diagnostic center without processing, and nearly achieves the diagnostic accuracy of a bedside setup. In the process, such a system incurs high bandwidth cost and requires the physicians to process the entire record for diagnosis. To reduce cost, current telecardiology systems compress data before transmitting. However, the burden on physicians remains undiminished. In this context, we develop a dictionary-based algorithm that reduces not only the overall bandwidth requirement, but also the physicians workload by localizing anomalous beats. Specifically, we detect anomalous beats with high sensitivity and only those beats are then transmitted. In fact, we further compress those beats using class-specific dictionaries subject to suitable reconstruction/diagnostic fidelity. Finally, using Monte Carlo cross validation on MIT/BIH arrhythmia database, we evaluate the performance of the proposed system. In particular, with a sensitivity target of at most one undetected PVC in one hundred beats, and a percentage root mean squared difference less than 9% (a clinically acceptable level of fidelity), we achieved about 99.15% reduction in bandwidth cost

  4. [Experimental studies on the diffusion of excitation on the right ventricular surface in the dog, during normal and stimulated beats].

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    Arisi, G; Macchi, E; Baruffi, S; Musso, E; Spaggiari, S; Stilli, D; Taccardi, B

    1982-01-01

    Previous work on the spread of excitation on the dog's ventricular surface enabled us to locate up to 30 breakthrough points (BKTPs) where excitation reaches the ventricular surface. In particular the equipotential contour maps enabled us to detect 3 to 5 BKTPs on the anterior right ventricular surface, near the a-v groove when a large part of ventricular surface was still at rest. With a view to investigating the mechanism underlying the early excitation of these basal regions, we stimulated the heart at several right ventricular BKTPs and in other points located at a distance from the BKTPs. The instantaneous equipotential maps showed that after stimulation most right ventricular BKTPs remained in the same position as observed the normal beats. The early appearance of epicardial wavefronts in the basal region and generally in other areas of the right ventricle was attributed to the rapid propagation of excitation waves through the Purkinje network, probably associated to a short transmural crossing time, due to a local thinness of the ventricular wall.

  5. Inclusion of extremes of prematurity in ventricular index centile charts.

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    Boyle, M; Shim, R; Gnanasekaran, R; Tarrant, A; Ryan, S; Foran, A; McCallion, N

    2015-06-01

    To assess the relationship between ventricular index (VI) measurements and postmenstrual age in preterm infants and to generate centile charts and normal ranges for frontal horn ratio (FHR) for a large contemporary cohort of preterm infants. A retrospective cohort study of 253 infants with birth gestation less than 32 weeks admitted between January 2009 and December 2011 to a tertiary NICU in Ireland. A total of 816 cranial ultrasounds were reviewed. Data collected were grouped according to postmenstrual age at the time of scan from 23 weeks to 45 weeks. Median values for VI show a general trend to increase with gestation. FHR did not significantly change with postmenstrual age at scan with a median value of 0.31. There is a slight increase in VI as gestation at the time of scans increases. These results provide the basis for updated centile charts which we propose for current practice.

  6. In utero premature closure of the ductus arteriosus presenting as isolated right ventricular hypertrophy.

    Science.gov (United States)

    Long, Webb E; Wilson, Allen D; Srinivasan, Shardha; Seeger, Kimberly J; Maginot, Kathleen R

    2009-10-01

    The etiology of isolated right ventricular hypertrophy (RVH) is distinct from other forms of hypertrophic cardiomyopathy. RVH is typically seen in the setting of pulmonary valve stenosis or Tetralogy of Fallot. A rare cause of isolated RVH is premature closure of the patent ductus arteriosus (PDA) in utero that results in pulmonary hypertension. This can have a range of outcomes, from spontaneous resolution to fetal demise. This case report describes a term infant who presented with respiratory distress and striking isolated RVH, pulmonary hypertension, and no PDA. She was treated conservatively with supplemental oxygen. The patient was gradually weaned off oxygen over the course of two weeks and follow-up echocardiography showed resolution of her RVH and pulmonary hypertension by 14 weeks of age. The presentation and course of this patient with severe isolated RVH is consistent with spontaneous premature closure of the ductus arteriosus in utero.

  7. Fatigue as Presenting Symptom and a High Burden of Premature Ventricular Contractions Are Independently Associated With Increased Ventricular Wall Stress in Patients With Normal Left Ventricular Function.

    Science.gov (United States)

    van Huls van Taxis, Carine F B; Piers, Sebastiaan R D; de Riva Silva, Marta; Dekkers, Olaf M; Pijnappels, Daniël A; Schalij, Martin J; Wijnmaalen, Adrianus P; Zeppenfeld, Katja

    2015-12-01

    High idiopathic premature ventricular contractions (PVC) burden has been associated with PVC-induced cardiomyopathy. Patients may be symptomatic before left ventricular (LV) dysfunction develops. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and circumferential end-systolic wall stress (cESS) on echocardiography are markers for increased ventricular wall stress. This study aimed to evaluate the relation between presenting symptoms, PVC burden, and increased ventricular wall stress in patients with frequent PVCs and preserved LV function. Eighty-three patients (41 men; 49±15 years) with idiopathic PVCs and normal LV function referred for PVC ablation were included. Type of symptoms (palpitations, fatigue, and [near-]syncope), PVC burden on 24-hour Holter, NT-proBNP levels, and cESS on echocardiography were assessed before and 3 months after ablation. Sustained successful ablation was defined as ≥80% PVC burden reduction during follow-up. Patients were symptomatic for 24 months (Q1-Q3, 16-60); 73% reported palpitations, 47% fatigue, and 30% (near-)syncope. Baseline PVC burden was 23±13%, median NT-proBNP 92 pg/mL (Q1-Q3 50-156), and cESS 143±35 kdyne/cm(2). Fatigue was associated with higher baseline NT-proBNP and cESS (PFatigue was independently associated with a significantly larger reduction in NT-proBNP. In patients with nonsuccessful ablation, NT-proBNP and cESS remained unchanged. In patients with frequent PVCs and preserved LV function, fatigue was associated with higher baseline NT-proBNP and cESS, and with a significantly larger reduction in NT-proBNP after sustained successful ablation. These findings support a link between fatigue and PVC-induced increased ventricular wall stress, despite preserved LV function. © 2015 American Heart Association, Inc.

  8. A new intracavitary probe for detecting the site of origin of ectopic ventricular beats during one cardiac cycle.

    Science.gov (United States)

    Taccardi, B; Arisi, G; Macchi, E; Baruffi, S; Spaggiari, S

    1987-01-01

    An olive-shaped probe (25 X 12 mm) with 41 evenly distributed recording electrodes on its surface was introduced into the left ventricles of seven open-chest dogs via the left atrium. In two other dogs a cylindrical probe (40 X 3 mm) was used. Electrical stimuli were delivered at 66 endocardial, midwall, or epicardial sites in the left and right ventricular walls and the septum. Mechanical stimuli were also applied at various epicardial sites. On-line mapping of equipotential contour lines on the surface of the probe invariably revealed a clear-cut potential minimum on the electrode that faced the pacing site. Time of appearance of potential minimum was 3 to 5 msec after endocardial stimuli, 10 to 25 msec for midwall and epicardial pacing, and 30 msec or more for right ventricular stimulation. Simultaneous stimulation at two sites 1.2 cm apart gave rise to two separate minima on the maps. "Pseudoisochrones" derived from electrograms recorded by the new probe were slightly less accurate in indicating the site of origin of extrasystoles. We conclude that equipotential and "isochrone" contour maps recorded from an array of semidirect electrodes, regularly distributed on the surface of an intraventricular probe, provide information on the site of origin (location and intramural depth) of ectopic paced beats in a normal dog heart.

  9. Recruitment pattern of sympathetic muscle neurons during premature ventricular contractions in heart failure patients and controls.

    Science.gov (United States)

    Maslov, Petra Zubin; Breskovic, Toni; Brewer, Danielle N; Shoemaker, J Kevin; Dujic, Zeljko

    2012-12-01

    Premature ventricular contractions (PVC) elicit larger bursts of multiunit muscle sympathetic nerve activity (MSNA), reflecting the ability to increase postganglionic axonal recruitment. We tested the hypothesis that chronic heart failure (CHF) limits the ability to recruit postganglionic sympathetic neurons as a response to PVC due to the excessive sympathetic activation in these patients. Sympathetic neurograms of sufficient signal-to-noise ratio were obtained from six CHF patients and from six similarly aged control individuals. Action potentials (APs) were extracted from the multiunit sympathetic neurograms during sinus rhythm bursts and during the post-PVC bursts. These APs were classified on the basis of the frequency per second, the content per burst, and the peak-to-peak amplitude, which formed the basis of binning the APs into active clusters. Compared with controls, CHF had higher APs per burst and higher number of active clusters per sinus rhythm burst (P < 0.05). Compared with sinus rhythm bursts, both groups increased AP frequency and the number of active clusters in the post-PVC burst (P < 0.05). However, compared with controls, the increase in burst integral, AP frequency, and APs per burst during the post-PVC burst was less in CHF patients. Nonetheless, the PVC-induced increase in active clusters per burst was similar between the groups. Thus, these CHF patients retained the ability to recruit larger APs but had a diminished ability to increase overall AP content.

  10. Premature ventricular contraction detection combining deep neural networks and rules inference.

    Science.gov (United States)

    Zhou, Fei-Yan; Jin, Lin-Peng; Dong, Jun

    2017-06-01

    Premature ventricular contraction (PVC), which is a common form of cardiac arrhythmia caused by ectopic heartbeat, can lead to life-threatening cardiac conditions. Computer-aided PVC detection is of considerable importance in medical centers or outpatient ECG rooms. In this paper, we proposed a new approach that combined deep neural networks and rules inference for PVC detection. The detection performance and generalization were studied using publicly available databases: the MIT-BIH arrhythmia database (MIT-BIH-AR) and the Chinese Cardiovascular Disease Database (CCDD). The PVC detection accuracy on the MIT-BIH-AR database was 99.41%, with a sensitivity and specificity of 97.59% and 99.54%, respectively, which were better than the results from other existing methods. To test the generalization capability, the detection performance was also evaluated on the CCDD. The effectiveness of the proposed method was confirmed by the accuracy (98.03%), sensitivity (96.42%) and specificity (98.06%) with the dataset over 140,000 ECG recordings of the CCDD. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Evaluation of left ventricular function by nuclear stethoscope

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, T [National Cardiovascular Center, Suita, Osaka (Japan)

    1981-03-01

    The Nuclear Stethoscope (N.S.) is a unique cardiac probe system that provides a precise, rapid, noninvasive method to directly quantify ventricular functions at the bedside or actual beat-to-beat or composite beat basis. The accuracy and validity of N.S. were studied in 42 patients with cardiac diseases in comparison with camera-computer EF. The N.S. EF was well correlated with camera-computer EF (r = 0.82). In this study, clinical application of N.S. was as follows. 1. Beat-to-beat left ventricular volume response for evaluation of arrythmia (atrial fibrillation, premature ventricular conduction, bigemy et al.) 2. exercise study by handgrip and ergometer. EF is an extremely sensitive indicator to discriminate coronary arteries diseases from normal subjects.

  12. Evaluation of left ventricular function by nuclear stethoscope

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko

    1981-01-01

    The Nuclear Stethoscope (N.S.) is a unique cardiac probe system that provides a precise, rapid, noninvasive method to directly quantify ventricular functions at the bedside or actual beat-to-beat or composite beat basis. The accuracy and validity of N.S. were studied in 42 patients with cardiac diseases in comparison with camera-computer EF. The N.S. EF was well correlated with camera-computer EF (r = 0.82). In this study, clinical application of N.S. was as follows. 1. Beat-to-beat left ventricular volume response for evaluation of arrythmia (atrial fibrillation, premature ventricular conduction, bigemy et al.) 2. exercise study by handgrip and ergometer. EF is an extremely sensitive indicator to discriminate coronary arteries diseases from normal subjects. (author)

  13. Predictive Value of Beat-to-Beat QT Variability Index across the Continuum of Left Ventricular Dysfunction: Competing Risks of Non-cardiac or Cardiovascular Death, and Sudden or Non-Sudden Cardiac Death

    Science.gov (United States)

    Tereshchenko, Larisa G.; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D.; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-01-01

    Background The goal of this study was to determine the predictive value of beat-to-beat QT variability in heart failure (HF) patients across the continuum of left ventricular dysfunction. Methods and Results Beat-to-beat QT variability index (QTVI), heart rate variance (LogHRV), normalized QT variance (QTVN), and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca (MUSIC) HF study (mean age 63.1±11.7; males 70.6%; LVEF >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance (IDEAL) database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death [hazard ratio (HR) 1.67(95%CI 1.14-2.47), P=0.009] and in particular with non-sudden cardiac death [HR 2.91(1.69-5.01), P<0.001]. Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular [HR 1.57(1.04-2.35), P=0.031], and non-sudden cardiac death in multivariate competing risk model [HR 2.58(1.13-3.78), P=0.001]. No interaction between QTVI and LVEF was found. QTVI predicted neither non-cardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability (HRV) rather than increased QT variability was the reason for increased QTVI in this study. Conclusions Increased QTVI due to depressed HRV predicts cardiovascular mortality and non-sudden cardiac death, but neither SCD nor excracardiac mortality in HF across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from HF patients at risk. PMID:22730411

  14. The effect of the physical activity on polymorphic premature ventricular complexes in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Márcio G. Kiuchi

    2017-06-01

    Full Text Available Background: Polymorphic premature ventricular complexes (PVCs are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Endurance exercise training clearly lowers sympathetic activity in sympatho-excitatory disease states and may be tolerated by patients with chronic kidney disease (CKD. Methods: We assessed 40 CKD patients with hypertension with polymorphic PVCs. Patients underwent a complete medical history and physical examination. We evaluated the effectiveness of β blocker only or β blocker + exercise during 12 months of follow-up regarding the changes of the numbers of PVCs and mean heart rate (HR by 24-hour-Holter. Results: We observed in the β blocker group a significant decrease in the number of polymorphic PVCs from baseline 36,515 ± 3,518 to 3, 6, 9 and 12 months of follow-up, 28,314 ± 2,938, 23,709 ± 1,846, 22,564 ± 1,673, and 22,725 ± 1,415, respectively (P < 0.001. In the β blocker + exercise group a significant decrease in the number of polymorphic PVCs also occurred from baseline 36,091 ± 3,327 to 3, 6, 9 and 12 months of follow-up, 29,252 ± 3,211, 20,948 ± 2,386, 14,238 ± 3,338, and 6,225 ± 2,319, respectively (P < 0.001. Comparisons between the two groups at the same time point showed differences from the sixth month onwards: the 6th (Δ = −2,761, P = 0.045, 9th (Δ = −8,325, P < 0.001 and 12th (Δ = −16,500, P < 0.001 months. There was an improvement during the 12 months of follow-up vs. baseline, after the β blocker or β blocker + exercise in mean 24-hour HR Holter monitoring, creatinine values, eGFR, and ACR. Conclusion: Polymorphic PVCs may be modifiable by physical activity in CKD patients with hypertension without structural heart disease.

  15. Treatment of premature infants with pulmonary hypertension and right ventricular dysfunction with milrinone: a case series.

    Science.gov (United States)

    James, A T; Bee, C; Corcoran, J D; McNamara, P J; Franklin, O; El-Khuffash, A F

    2015-04-01

    Milrinone has been proposed as an effective treatment for pulmonary hypertension (PH) and right ventricular (RV) dysfunction. We aimed to determine the effect of milrinone therapy on clinical and echocardiography parameters of PH in preterm infants with elevated pulmonary pressures. A retrospective case review was conducted on infants milrinone for the treatment of PH and reduced RV function. Echocardiographic data were collected before and after treatment with milrinone, and serial clinical parameters were recorded over a 72h  period. Seven infants met the inclusion criteria with a median gestation and birth weight of 27.3 weeks and 1140 g, respectively. Four infants had a diagnosis of pulmonary hypoplasia with PH, and three infants were recipients in twin-to-twin transfusion syndrome who also developed PH. Nitric oxide was used in six infants before commencement of milrinone. Milrinone was commenced at a dose of 0.33 μg kg(-1) min(-1) to 0.5 μg kg(-1) min(-1) and continued for a median duration of 70 h. Use of milrinone was associated with a fall in oxygenation index and inhaled nitric oxide dose. Following an initial fall in blood pressure over the first 6 h, there was an increase in blood pressure over the subsequent 72 h. Echocardiographic data demonstrated an increase in indicators of myocardial performance and PH. One infant died before discharge. This case series suggests that milrinone may be a useful therapy for premature infants with echocardiography findings of PH and/or RH dysfunction. This data support the need for a randomised control trial to confirm its efficacy.

  16. Clinical implications of hypothermic ventricular fibrillation versus beating-heart technique during cardiopulmonary bypass for pulmonary valve replacement in patients with repaired tetralogy of Fallot.

    Science.gov (United States)

    Lee, Ji-Hyun; Lee, Ji-Eun; Shin, Jungho; Song, In-Kyung; Kim, Hee-Soo; Kim, Chong-Sung; Kim, Woong-Han; Kim, Jin-Tae

    2017-09-01

    This study aimed to compare the effects of hypothermic ventricular fibrillation and beating-heart techniques during cardiopulmonary bypass (CPB) on postoperative outcomes after simple pulmonary valve replacement in patients with repaired tetralogy of Fallot (TOF). We retrospectively reviewed the data of 47 patients with repaired tetralogy of Fallot at a single institution, who received pulmonary valve replacement under the ventricular fibrillation or beating-heart technique without cardioplegic cardiac arrest during CPB between January 2005 and April 2015. The patients were divided into fibrillation (n = 32) and beating-heart (n = 15) groups. On comparing these groups, the fibrillation group had a larger sinotubular junction (27.1 ± 4.6 vs 22.1 ± 2.4 mm), had a longer operation duration (396 ± 108 vs 345 ± 57 min), required more postoperative transfusions (2.1 ± 2.6 vs 5.0 ± 6.3 units) and had a higher vasoactive-inotropic score at intensive care unit admission (8.0 vs 10, all P tetralogy of Fallot. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  17. Successful catheter ablation of ventricular premature complexes from the right atrial side of the atrioventricular septum with good contact force.

    Science.gov (United States)

    Arai, Marina; Fukamizu, Seiji; Kawamura, Iwanari; Miyazawa, Satoshi; Hojo, Rintaro; Sakurada, Harumizu; Hiraoka, Masayasu

    2018-04-01

    The acquisition of good contact force for radiofrequency catheter ablation of ventricular premature complexes (VPCs) originating from the basal septum of the left ventricle (LV) is often difficult. We describe a case of VPCs originating from the basal septum of the LV, which were successfully eliminated by applying radiofrequency at the right atrium (RA) side of the atrioventricular septum (AVS) without causing any significant impairment of atrioventricular conduction because the ablation catheter could obtain better contact force through the RA approach. Moreover, intracardiac echocardiography (ICE) and RA angiography effectively demonstrated the AVS.

  18. REPEATED TREATMENTS WITH DOXORUBICIN CAUSES ELECTROCARDIOGRAM (ECG) CHANGES AND INCREASED VENTRICULAR PREMATURE BEATS IN WISTAR-KYOTO (WKY) RATS

    Science.gov (United States)

    Doxorubicin (DOX) is a widely used anthracycline anti-neoplastic drug used to treat tumors. However it has been implicated in irreversible cardiac toxicity via the generation of a proxidant semiquinone free radical, which often results in cardiomyopathy and changes in the ECG. Ac...

  19. Symbolic transfer entropy-based premature signal analysis

    International Nuclear Information System (INIS)

    Wang Jun; Yu Zheng-Feng

    2012-01-01

    In this paper, we use symbolic transfer entropy to study the coupling strength between premature signals. Numerical experiments show that three types of signal couplings are in the same direction. Among them, normal signal coupling is the strongest, followed by that of premature ventricular contractions, and that of atrial premature beats is the weakest. The T test shows that the entropies of the three signals are distinct. Symbolic transfer entropy requires less data, can distinguish the three types of signals and has very good computational efficiency. (interdisciplinary physics and related areas of science and technology)

  20. Repair of double-chambered right ventricle using right ventricular outflow chamber ventriculotomy via left intercostal thoracotomy under beating heart in two dogs

    Directory of Open Access Journals (Sweden)

    Keiichi Sato

    2014-05-01

    Full Text Available Double-chambered right ventricle was diagnosed in two dogs, one of them a pup and the other full grown. Both dogs underwent surgery using the novel approach of right ventricular outflow chamber ventriculotomy via left intercostal thoracotomy with moderate hypothermia and moderate pump flow cardiopulmonary bypass under beating heart. No major complication occurred during and after the operation. On continuous wave Doppler echocardiography, the pressure gradient across the stenosis in the right ventricle decreased from 130 mmHg pre-operatively to 40 mmHg post-operatively at 1 year 5 months in the adult dog, and from 209 mmHg pre-operatively to 47 mmHg post-operatively at 1 year in the pup. Both dogs are active without clinical signs.

  1. Premature Ventricular Contraction Coupling Interval Variability Destabilizes Cardiac Neuronal and Electrophysiological Control: Insights from Simultaneous Cardio-Neural Mapping

    Science.gov (United States)

    Hamon, David; Rajendran, Pradeep S.; Chui, Ray W.; Ajijola, Olujimi A.; Irie, Tadanobu; Talebi, Ramin; Salavatian, Siamak; Vaseghi, Marmar; Bradfield, Jason S.; Armour, J. Andrew; Ardell, Jeffrey L.; Shivkumar, Kalyanam

    2017-01-01

    Background Variability in premature ventricular contraction (PVC) coupling interval (CI) increases the risk of cardiomyopathy and sudden death. The autonomic nervous system regulates cardiac electrical and mechanical indices, and its dysregulation plays an important role in cardiac disease pathogenesis. The impact of PVCs on the intrinsic cardiac nervous system (ICNS), a neural network on the heart, remains unknown. The objective was to determine the effect of PVCs and CI on ICNS function in generating cardiac neuronal and electrical instability using a novel cardio-neural mapping approach. Methods and Results In a porcine model (n=8) neuronal activity was recorded from a ventricular ganglion using a microelectrode array, and cardiac electrophysiological mapping was performed. Neurons were functionally classified based on their response to afferent and efferent cardiovascular stimuli, with neurons that responded to both defined as convergent (local reflex processors). Dynamic changes in neuronal activity were then evaluated in response to right ventricular outflow tract PVCs with fixed short, fixed long, and variable CI. PVC delivery elicited a greater neuronal response than all other stimuli (P<0.001). Compared to fixed short and long CI, PVCs with variable CI had a greater impact on neuronal response (P<0.05 versus short CI), particularly on convergent neurons (P<0.05), as well as neurons receiving sympathetic (P<0.05) and parasympathetic input (P<0.05). The greatest cardiac electrical instability was also observed following variable (short) CI PVCs. Conclusions Variable CI PVCs affect critical populations of ICNS neurons and alter cardiac repolarization. These changes may be critical for arrhythmogenesis and remodeling leading to cardiomyopathy. PMID:28408652

  2. Premature Ventricular Contraction Coupling Interval Variability Destabilizes Cardiac Neuronal and Electrophysiological Control: Insights From Simultaneous Cardioneural Mapping.

    Science.gov (United States)

    Hamon, David; Rajendran, Pradeep S; Chui, Ray W; Ajijola, Olujimi A; Irie, Tadanobu; Talebi, Ramin; Salavatian, Siamak; Vaseghi, Marmar; Bradfield, Jason S; Armour, J Andrew; Ardell, Jeffrey L; Shivkumar, Kalyanam

    2017-04-01

    Variability in premature ventricular contraction (PVC) coupling interval (CI) increases the risk of cardiomyopathy and sudden death. The autonomic nervous system regulates cardiac electrical and mechanical indices, and its dysregulation plays an important role in cardiac disease pathogenesis. The impact of PVCs on the intrinsic cardiac nervous system, a neural network on the heart, remains unknown. The objective was to determine the effect of PVCs and CI on intrinsic cardiac nervous system function in generating cardiac neuronal and electric instability using a novel cardioneural mapping approach. In a porcine model (n=8), neuronal activity was recorded from a ventricular ganglion using a microelectrode array, and cardiac electrophysiological mapping was performed. Neurons were functionally classified based on their response to afferent and efferent cardiovascular stimuli, with neurons that responded to both defined as convergent (local reflex processors). Dynamic changes in neuronal activity were then evaluated in response to right ventricular outflow tract PVCs with fixed short, fixed long, and variable CI. PVC delivery elicited a greater neuronal response than all other stimuli ( P <0.001). Compared with fixed short and long CI, PVCs with variable CI had a greater impact on neuronal response ( P <0.05 versus short CI), particularly on convergent neurons ( P <0.05), as well as neurons receiving sympathetic ( P <0.05) and parasympathetic input ( P <0.05). The greatest cardiac electric instability was also observed after variable (short) CI PVCs. Variable CI PVCs affect critical populations of intrinsic cardiac nervous system neurons and alter cardiac repolarization. These changes may be critical for arrhythmogenesis and remodeling, leading to cardiomyopathy. © 2017 American Heart Association, Inc.

  3. [Assessment of the right ventricular function in healthy volunteers with one beat full-volume real-time three-dimensional echocardiography].

    Science.gov (United States)

    Zhu, Wei-hong; Zhang, Jin; Tong, Kai; Zhi, Guang; He, Kun-lun

    2012-08-01

    To determine the normal value of right ventricle using one beat full-volume real-time three-dimensional echocardiography (RT-3DE) and assess the feasibility of this technique. One beat full volume images were acquired at the apical 4 chamber view in 129 healthy volunteers. The right and left ventricular volumes were examined with the eSie LVA and RVA. The subjects were divided into 2 gender groups (male and female) and 3 age groups (20 - 39 years old, 40 - 59 years old, 60 years old and above). Adequate data were obtained in 129 subjects. The RV-EDV was (92.4 ± 21.3) ml, RV-ESV (34.6 ± 9.2) ml, RV-SV (57.8 ± 13.9) ml, RV-EF (62.5 ± 5.0) ml. EDV, ESV, and EF were significant different while SV was similar between RV and LV (all P Right ventricle function can be measured noninvasively by RT-3DE with high feasibility. This novel method contributes to the detailed study of right heart function in various cardiovascular diseases.

  4. Idiopathic premature ventricular contractions and ventricular tachycardias originating from the vicinity of tricuspid annulus: Results of radiofrequency catheter ablation in thirty-five patients

    Directory of Open Access Journals (Sweden)

    Yue-Chun Li

    2012-07-01

    Full Text Available Abstract Background In recent years, catheter ablation has increasingly been used for ablation of idiopathic premature ventricular complexes (PVCs or ventricular tachycardias (IVTs. However, the mapping and catheter ablation of the arrhythmias originating from the vicinity of tricuspid annulus (TA may not be fully understood. This study aimed to investigate electrophysiologic characteristics and effects of radiofrequency catheter ablation (RFCA for patients with symptomatic PVCs and IVTs originating from the vicinity of TA. Methods Characteristics of body surface electrocardiogram (ECG and electrophysiologic recordings were analyzed in 35 patients with symptomatic PVCs/ IVTs originating from the vicinity of TA. RFCA was performed using pace mapping and activation mapping. Results Among the 35 patients with PVCs/IVTs arising from the vicinity of TA, complete elimination of PVCs/IVTs could be achieved by RFCA in 32 patients (success rate 91.43% during a median follow-up period of 21 months. PVCs/IVTs originating from the vicinity of TA had distinctive ECG characteristics that were useful for identifying the precise origin. An rS pattern was recorded in lead V1 in 93.1% of patients with PVCs/IVTs from the free wall of TA, vs 16.7% of patients with PVCs/IVTs from the septal TA, whereas a QS pattern in lead V1 occurred in 83.3% of patients with PVCs/IVTs from the septal TA vs 6.9% of patients with PVCs from the free wall of the TA. The precordial R wave transition occurred by lead V3 or earlier in all patients with PVCs/IVTs originating from the septal portion of the TA, as compared to transition beyond V3 in all patients with PVCs/IVTs from the free wall of the TA. Conclusions RFCA is an effective curative therapy for symptomatic PVCs/IVTs originating from the vicinity of TA. There are specific characteristics in ECG and the ablation site could be located by ECG analysis.

  5. Increased Ventricular Premature Contraction Frequency During REM Sleep in Patients with Coronary Artery Disease and Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Mari A. Watanabe

    2008-11-01

    Full Text Available Background Patients with obstructive sleep apnea are reported to have a peak of sudden cardiac death at night, in contrast to patients without apnea whose peak is in the morning. We hypothesized that ventricular premature contraction (VPC frequency would correlate with measures of apnea and sympathetic activity.Methods Electrocardiograms from a sleep study of 125 patients with coronary artery disease were evaluated. Patients were categorized by apnea-hypopnea index (AHI into Moderate (AHI 15 apnea groups. Sleep stages studied were Wake, S1, S2, S34, and rapid eye movement (REM. Parameters of a potent autonomically-based risk predictor for sudden cardiac death called heart rate turbulence were calculated.Results There were 74 Moderate and 51 Severe obstructive sleep apnea patients. VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, p<.005 and by AHI (F=8.7, p<.005. In Severe apnea patients, VPC frequency was higher in REM than in Wake (p=.011. In contrast, patients with Moderate apnea had fewer VPCs and exhibited no sleep stage dependence (p=.19. Oxygen desaturation duration per apnea episode correlated positively with AHI (r2=.71, p<.0001, and was longer in REM than in non-REM (p<.0001. The heart rate turbulence parameter TS correlated negatively with oxygen desaturation duration in REM (r2=.06, p=.014.Conclusions Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one reason for increased nocturnal death in apneic patients.

  6. Factors influencing left ventricular hypertrophy in children and adolescents with or without family history of premature myocardial infarction

    Directory of Open Access Journals (Sweden)

    Seyyed Mohsen Hosseini

    2014-01-01

    Result : The results showed that among the studied variables, gender, age, body mass index, and blood pressure were associated with the left ventricular hypertrophy. Conclusion: Considering the results and previous studies in this field, it was observed that left ventricular hypertrophy exists at early ages, which is very dangerous and can lead to heart diseases at early ages. Factors such as being overweight, having high blood pressure, and being male cause left ventricular hypertrophy and lead to undiagnosable heart diseases.

  7. Premature Ventricular Contractions (PVCs)

    Science.gov (United States)

    ... adrenaline in the body that may be caused by caffeine, tobacco, exercise or anxiety Injury to the heart muscle from coronary artery disease, congenital heart disease, high blood pressure or heart failure Risk factors The following can ...

  8. β1-Adrenoceptor blocker aggravated ventricular arrhythmia.

    Science.gov (United States)

    Wang, Yan; Patel, Dimpi; Wang, Dao Wu; Yan, Jiang Tao; Hsia, Henry H; Liu, Hao; Zhao, Chun Xia; Zuo, Hou Juan; Wang, Dao Wen

    2013-11-01

    To assess the impact of β1 -adrenoceptor blockers (β1 -blocker) and isoprenaline on the incidence of idiopathic repetitive ventricular arrhythmia that apparently decreases with preprocedural anxiety. From January 2010 to July 2012, six patients were identified who had idiopathic ventricular arrhythmias that apparently decreased (by greater than 90%) with preprocedural anxiety. The number of ectopic ventricular beats per hour (VPH) was calculated from Holter or telemetry monitoring to assess the ectopic burden. The mean VPH of 24 hours from Holter before admission (VPH-m) was used as baseline (100%) for normalization. β1 -Blockers, isoprenaline, and/or aminophylline were administrated successively on the ward and catheter lab to evaluate their effects on the ventricular arrhythmias. Among 97 consecutive patients with idiopathic ventricular arrhythmias, six had reduction in normalized VPHs in the hour before the scheduled procedure time from (104.6 ± 4.6%) to (2.8 ± 1.6%) possibly due to preprocedural anxiety (P < 0.05), then increased to (97.9 ± 9.7%) during β1 -blocker administration (P < 0.05), then quickly reduced to (1.6 ± 1.0%) during subsequent isoprenaline infusion. Repeated β1 -blocker quickly counteracted the inhibitory effect of isoprenaline, and VPHs increased to (120.9 ± 2.4%) from (1.6 ± 1.0%; P < 0.05). Isoprenaline and β1 -blocker showed similar effects on the arrhythmias in catheter lab. In some patients with structurally normal heart and ventricular arrhythmias there is a marked reduction of arrhythmias associated with preprocedural anxiety. These patients exhibit a reproducible sequence of β1 -blocker aggravation and catecholamine inhibition of ventricular arrhythmias, including both repetitive ventricular premature beats and monomorphic ventricular tachycardia. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  9. Analysis of Morphological Characteristics and Origins of Idiopathic Premature Ventricular Contractions Under a 12-Lead Electrocardiogram in Children with Structurally Normal Hearts.

    Science.gov (United States)

    Jiang, Jianbin; He, Yuee; Qiu, Huixian; Zhang, Yuanhai; Chu, Maoping; Li, Yuechun; Chen, Qi

    2017-10-21

    Up to 40% of healthy children have premature ventricular complexes or contractions (PVCs) detected with 24-hour Holter monitoring. We aimed to investigate the morphological characteristics and origins of idiopathic PVCs under a 12-lead electrocardiogram in children with structurally normal hearts. All asymptomatic monomorphic PVC patients with structurally normal hearts under 18 years of age were included in this retrospective study. Characteristics of PVCs in lead V 1 under a 12-lead electrocardiogram were classified as left bundle branch block (PVC-LBBB) or right bundle branch block (PVC-RBBB). According to limb leads, PVC-LBBB or PVC-RBBB was divided into: PVCs-LBBB type I; PVCs-LBBB type II; PVCs-RBBB type I; PVCs-RBBB type II; and PVCs-RBBB type III. Out of 178 PVC patients, 94 cases of PVCs-LBBB (PVCs-LBBB type I = 60; PVCs-LBBB type II = 34) and 84 cases of PVCs-RBBB (PVCs-RBBB type I = 3; PVCs-RBBB type II = 55; PVCs-RBBB type III = 26) were identified. The frequency of PVCs-LBBB type I increased with age and the frequency of PVCs-RBBB type II and III decreased with age. Among the children monitor tested, from 1 years old to 18 years old, PVCs originating from the left or right ventricular outflow tract gradually increased with age, while PVCs originating from the branch sources decreased with age.

  10. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left...

  11. Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the canine heart.

    Science.gov (United States)

    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

  12. Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the rabbit heart.

    Science.gov (United States)

    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.

  13. Control of ventricular ciliary beating by the Melanin Concentrating Hormone-expressing neurons of the lateral hypothalamus : a functional imaging survey.

    Directory of Open Access Journals (Sweden)

    Gregory eConductier

    2013-11-01

    Full Text Available The cyclic peptide Melanin-Concentrating Hormone (MCH is known to control a large number of brain functions in mammals such as food intake and metabolism, stress response, anxiety, sleep/wake cycle, memory and reward. Based on neuroanatomical and electrophysiological studies these functions were attributed to neuronal circuits expressing MCHR1, the single MCH receptor in rodents. In complement to our recently published work (Conductier et al. 2013 we provided here new data regarding the action of MCH on ependymocytes in the mouse brain. First, we establish that MCHR1 mRNA is expressed in the ependymal cells of the third ventricle epithelium. Second, we demonstated a tonic control of MCH-expressing neurons on ependymal cilia beat frequency using in vitro optogenics. Finally, we performed in vivo measurements of CSF flow using fluorescent micro-beads in wild-type and MCHR1 knockout mice. Collectively, our results demonstrated that MCH-expressing neurons modulate ciliary beating of ependymal cells at the third ventricle and could contribute to maintain cerebro-spinal fluid homeostasis.

  14. Beat Dreams?

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2009-01-01

    Two of the founding members of the Beat Generation of the 1950s wrote dream books with almost identical titles: Jack Kerouac's Book of Dreams (1961) and William Burroughs' My Education: A Book of Dreams (1995). This paper queries the function of such dream books, both from a perspective of seeing...... dream writing as a confessional genre, and from the perspective of didacticism implicit in sharing one's dream life with one's readers. What role does memory, politics, fantasies and reality play in communicating with and via dreams?...

  15. Low serum magnesium concentrations are associated with a high prevalence of premature ventricular complexes in obese adults with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Del Gobbo Liana C

    2012-03-01

    Full Text Available Abstract Background Premature ventricular complexes (PVC predict cardiovascular mortality among several adult populations. Increased arrhythmia prevalence has been reported during controlled magnesium (Mg depletion studies in adults. We thus hypothesized that serum magnesium (sMg concentrations are inversely associated with the prevalence of PVC in adults at high cardiovascular risk. Methods Anthropometric, demographic and lifestyle characteristics were assessed in 750 Cree adults, aged > 18 yrs, who participated in an age-stratified, cross-sectional health survey in Quebec, Canada. Holter electrocardiograms recorded heart rate variability and cardiac arrhythmias for two consecutive hours. Multivariate logistic regression was used to evaluate the associations between sMg and PVC. Results PVC prevalence in adults with hypomagnesemia (sMg ≤ 0.70 mmol/L was more than twice that of adults without hypomagnesemia (50% vs. 21%, p = 0.015; results were similar when adults with cardiovascular disease history were excluded. All hypomagnesemic adults with PVC had type 2 diabetes (T2DM. Prevalence of PVC declined across the sMg concentration gradient in adults with T2DM only (p 0.70 mmol/L was 0.24 (95% CI: 0.06-0.98 p = 0.046 compared to those with sMg ≤ 0.70 mmol/L. Conclusions sMg concentrations were inversely associated with the prevalence of PVC in patients with T2DM in a dose response manner, indicating that suboptimal sMg may be a contributor to arrhythmias among patients with T2DM.

  16. Obesity and exercise-induced ectopic ventricular arrhythmias in apparently healthy middle aged adults.

    Science.gov (United States)

    Sabbag, Avi; Sidi, Yechezkel; Kivity, Shaye; Beinart, Roy; Glikson, Michael; Segev, Shlomo; Goldenberg, Ilan; Maor, Elad

    2016-03-01

    Obesity and overweight are strongly associated with cardiovascular morbidity and mortality. However, there are limited data on the association between excess weight and the risk of ectopic ventricular activity. We investigated the association between body mass index (BMI) and the risk for ectopic ventricular activity (defined as multiple ventricular premature beats (≥3), ventricular bigeminy, nonsustained ventricular tachycardia or sustained ventricular tachycardia) during exercise stress testing among 22,516 apparently healthy men and women who attended periodic health screening examinations between the years 2000 and 2014. All subjects had completed maximal exercise stress testing annually according to the Bruce protocol. Subjects were divided at baseline into three groups: normal weight (BMI ≥ 18.5 kg/m(2) andexercise-induced ectopic ventricular activity arrhythmias was highest among obese subjects, intermediate among overweight subjects and lowest among subjects with normal weight (3.4%, 2.7% and 2.2% respectively; p exercise compared with subjects with normal weight (p = 0.005), and that each 1 kg/m(2) increase in BMI was associated with a significant 4% (p = 0.002) increased adjusted risk for exercise-induced ventricular arrhythmias. Obesity is independently associated with increased likelihood of ectopic ventricular arrhythmia during exercise. © The European Society of Cardiology 2015.

  17. Noninvasive imaging of three-dimensional cardiac activation sequence during pacing and ventricular tachycardia.

    Science.gov (United States)

    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.

  18. Early ventricular tachyarrhythmias after coronary artery bypass grafting surgery: Is it a real burden?

    Science.gov (United States)

    Mouws, Elisabeth M J P; Yaksh, Ameeta; Knops, Paul; Kik, Charles; Boersma, Eric; Bogers, Ad J J C; de Groot, Natasja M S

    2017-09-01

    The prevalence of ventricular dysrhythmias (VD) [ventricular premature beats (VPBs), ventricular couplets (Vcouplets), ventricular runs (Vruns)] after coronary artery bypass grafting (CABG) has so far not been examined. The goal of this study is to examine characteristics of VD and whether they precede ventricular tachyarrhythmias (VTA) during a postoperative follow-up period of 5 days using continuous rhythm registrations. In addition, we determined predictive factors of VD/VTA. Incidences and burdens of VD/VTA were calculated in patients (N=105, 83 male, 65±9 years) undergoing primary, on-pump CABG. Independent risk factors were examined using multivariate analysis. VPBs, Vcouplets, and Vruns occurred in respectively 100%, 82.9%, and 48.6% with corresponding burdens of 0.05%, 0%, and 0%. Sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) did not occur in our cohort. Independent risk factors for VD included male gender, mitral valve insufficiency, hyperlipidemia, and age ≥60 years. VD are common in patients with coronary artery disease after CABG. Despite high incidences of these dysrhythmias, corresponding burdens are low and sustained VT or VF did not occur. Incidences were highest on the first postoperative day and diminished over time. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  19. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes.

  20. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  1. Premature menopause.

    Science.gov (United States)

    Okeke, Tc; Anyaehie, Ub; Ezenyeaku, Cc

    2013-01-01

    Premature menopause affects 1% of women under the age of 40 years. The women are at risk of premature death, neurological diseases, psychosexual dysfunction, mood disorders, osteoporosis, ischemic heart disease and infertility. There is need to use simplified protocols and improved techniques in oocyte donation to achieve pregnancy and mother a baby in those women at risk. Review of the pertinent literature on premature menopause, selected references, internet services using the PubMed and Medline databases were included in this review. In the past, pregnancy in women with premature menopause was rare but with recent advancement in oocyte donation, women with premature menopause now have hoped to mother a child. Hormone replacement therapy is beneficial to adverse consequences of premature menopause. Women with premature menopause are at risk of premature death, neurological diseases, psychosexual dysfunction, mood disorders, osteoporosis, ischemic heart disease and infertility. Public enlightenment and education is important tool to save those at risk.

  2. Noninvasive cardiac activation imaging of ventricular arrhythmias during drug-induced QT prolongation in the rabbit heart.

    Science.gov (United States)

    Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; Zhou, Zhaoye; He, Bin

    2013-10-01

    Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis. © 2013 Heart Rhythm Society. All rights reserved.

  3. Binaural beat salience

    Science.gov (United States)

    Grose, John H.; Buss, Emily; Hall, Joseph W.

    2012-01-01

    Previous studies of binaural beats have noted individual variability and response lability, but little attention has been paid to the salience of the binaural beat percept. The purpose of this study was to gauge the strength of the binaural beat percept by matching its salience to that of sinusoidal amplitude modulation (SAM), and to then compare rate discrimination for the two types of fluctuation. Rate discrimination was measured for standard rates of 4, 8, 16, and 32 Hz – all in the 500-Hz carrier region. Twelve normal-hearing adults participated in this study. The results indicated that discrimination acuity for binaural beats is similar to that for SAM tones whose depths of modulation have been adjusted to provide equivalent modulation salience. The matched-salience SAM tones had relatively shallow depths of modulation, suggesting that the perceptual strength of binaural beats is relatively weak, although all listeners perceived them. The Weber fraction for detection of an increase in binaural beat rate is roughly constant across beat rates, at least for rates above 4 Hz, as is rate discrimination for SAM tones. PMID:22326292

  4. Binaural beat salience.

    Science.gov (United States)

    Grose, John H; Buss, Emily; Hall, Joseph W

    2012-03-01

    Previous studies of binaural beats have noted individual variability and response lability, but little attention has been paid to the salience of the binaural beat percept. The purpose of this study was to gauge the strength of the binaural beat percept by matching its salience to that of sinusoidal amplitude modulation (SAM), and to then compare rate discrimination for the two types of fluctuation. Rate discrimination was measured for standard rates of 4, 8, 16, and 32 Hz - all in the 500-Hz carrier region. Twelve normal-hearing adults participated in this study. The results indicated that discrimination acuity for binaural beats is similar to that for SAM tones whose depths of modulation have been adjusted to provide equivalent modulation salience. The matched-salience SAM tones had relatively shallow depths of modulation, suggesting that the perceptual strength of binaural beats is relatively weak, although all listeners perceived them. The Weber fraction for detection of an increase in binaural beat rate is roughly constant across beat rates, at least for rates above 4 Hz, as is rate discrimination for SAM tones. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Discrete potentials guided radiofrequency ablation for idiopathic outflow tract ventricular arrhythmias.

    Science.gov (United States)

    Liu, Enzhao; Xu, Gang; Liu, Tong; Ye, Lan; Zhang, Qitong; Zhao, Yanshu; Li, Guangping

    2015-03-01

    Discrete potentials (DPs) have been recorded and targeted as the site of ablation of the outflow tract arrhythmias. The aim of the present study was to investigate the significance of DPs with respect to mapping and ablation for idiopathic outflow tract premature ventricular contractions (PVCs) or ventricular tachycardias (VTs). Seventeen consecutive patients with idiopathic right or left ventricular outflow tract PVCs/VTs who underwent radiofrequency catheter ablation were included. Intracardiac electrograms during the mapping and ablation were analysed. During sinus rhythm, sharp high-frequency DPs that displayed double or multiple components were recorded following or buried in the local ventricular electrograms in all of the 17 patients, peak amplitude 0.51 ± 0.21 mV. The same potential was recorded prior to the local ventricular potential of the PVCs/VTs. Spontaneous reversal of the relationship of the DPs to the local ventricular electrogram during the arrhythmias was noted. The DPs were related to a region of low voltage showed by intracardiac high-density contact mapping. At the sites with DPs, lower unipolar and bipolar ventricular voltage of sinus beats were noted compared with the adjacent regions without DPs (unipolar: 6.1 ± 1.8 vs. 8.3 ± 2.3 mV, P Discrete potentials were not present in seven controls. Discrete potentials and related low-voltage regions were common in idiopathic outflow tract ventricular arrhythmias. Discrete potential- and substrate-guided ablation strategy will help to reduce the recurrence of idiopathic outflow tract arrhythmias. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  6. On binaural beats.

    Science.gov (United States)

    Fritze, W

    1985-01-01

    Binaural beats have been investigated in normal volunteers using high-stable synthesizers. There are considerable differences between the subjective rhythm heard and the difference of the two frequencies, indicating that this dissimilarity must be caused centrally.

  7. Premature infant

    Science.gov (United States)

    ... matter Infection or neonatal sepsis Low blood sugar (hypoglycemia) Neonatal respiratory distress syndrome, extra air in the tissue ... Outlook (Prognosis) Prematurity used to be a major cause of infant deaths. Improved medical and nursing techniques ...

  8. Wearable Beat to Beat Blood Pressure Monitor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A key component of NASA's human exploration programs is a system that monitors the health of the crew during space missions. The wearable beat-to-beat blood pressure...

  9. Ablação com radiofreqüência de extra-sístoles da via de saída do ventrículo direito Radiofrequency catheter ablation of premature ventricular contractions originating in the right ventricular outflow tract

    Directory of Open Access Journals (Sweden)

    Francisco C. C. Darrieux

    2007-03-01

    Full Text Available OBJETIVOS: Avaliar se a ablação com radiofreqüência é um procedimento eficiente para o tratamento das extra-sístoles da via de saída do ventrículo direito (EVSVD, e se resulta em melhora dos sintomas. MÉTODOS: Estudo prospectivo, com 30 pacientes consecutivos (idade média de 40±13 anos, 25 do sexo feminino, sem cardiopatia estrutural aparente, com EVSVD, muito freqüentes (densidade média de 1.263±593/h, sintomáticos por mais de 1 ano (média =74 meses e refratários aos fármacos antiarrítmicos (3±1,7, incluindo os beta-bloqueadores, que foram submetidos à ablação com radiofreqüência. RESULTADOS: Após o primeiro procedimento, houve 23 sucessos iniciais (76,6% e 7 iniciais insucessos (23,4%. Quatro pacientes tiveram recorrências, sendo que dois desses não se submeteram ao segundo procedimento. O segundo procedimento foi realizado em 9 pacientes (7 insucessos iniciais e 2 recorrências, e o sucesso ocorreu em 5 pacientes adicionais, sendo 1 caso por acesso epicárdico. A taxa de sucesso final foi de 80% (24/30, e nenhuma complicação maior ocorreu. Após um seguimento médio de 14±6 meses, no grupo de sucesso final houve uma redução de mais de 90% na densidade das extra-sístoles(24/24; pOBJECTIVES: To evaluate if radiofrequency catheter ablation is an effective procedure for the treatment of right ventricular outflow tract premature ventricular contractions (RVOT-PVC and ascertain if it results in an improvement of symptoms. METHODS: A prospective study with 30 consecutive patients (mean age 40 ± 13 years, 25 females, with no apparent structural cardiopathy, with very frequent (mean density of 1,263 ± 593/h RVOT-PVC, symptomatic for more than one year (mean = 74 months and resistant to antiarrhythmic drugs (3 ± 1.7, including beta-blockers, who underwent radiofrequency catheter ablation. RESULTS: After the first procedure, there were 23 initial successful cases (76.6% and 7 initial failures (23.4%. Four patients

  10. Oxidative shift in tissue redox potential increases beat-to-beat variability of action potential duration.

    Science.gov (United States)

    Kistamás, Kornél; Hegyi, Bence; Váczi, Krisztina; Horváth, Balázs; Bányász, Tamás; Magyar, János; Szentandrássy, Norbert; Nánási, Péter P

    2015-07-01

    Profound changes in tissue redox potential occur in the heart under conditions of oxidative stress frequently associated with cardiac arrhythmias. Since beat-to-beat variability (short term variability, SV) of action potential duration (APD) is a good indicator of arrhythmia incidence, the aim of this work was to study the influence of redox changes on SV in isolated canine ventricular cardiomyocytes using a conventional microelectrode technique. The redox potential was shifted toward a reduced state using a reductive cocktail (containing dithiothreitol, glutathione, and ascorbic acid) while oxidative changes were initiated by superfusion with H2O2. Redox effects were evaluated as changes in "relative SV" determined by comparing SV changes with the concomitant APD changes. Exposure of myocytes to the reductive cocktail decreased SV significantly without any detectable effect on APD. Application of H2O2 increased both SV and APD, but the enhancement of SV was the greater, so relative SV increased. Longer exposure to H2O2 resulted in the development of early afterdepolarizations accompanied by tremendously increased SV. Pretreatment with the reductive cocktail prevented both elevation in relative SV and the development of afterdepolarizations. The results suggest that the increased beat-to-beat variability during an oxidative stress contributes to the generation of cardiac arrhythmias.

  11. Premature Ejaculation

    Science.gov (United States)

    ... include the following: Anxiety about performance Guilty feelings Depression Stress Relationship problems Men who have a low amount of a special ... on your favorite sports team. Psychological assistance Anxiety, depression ... may help men who have premature ejaculation. Some antidepressants seem to ...

  12. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly

    Science.gov (United States)

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T.; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy.; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, Pacromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to arrhythmia. PMID:25915951

  13. Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Truin, Michiel; van Opstal, Jurren M

    2005-01-01

    Increased proarrhythmia in dogs with chronic AV block (AVB) has been explained by ventricular remodeling causing a decrease in repolarization reserve. Beat-to-beat variability of repolarization (BVR) has been suggested to reflect repolarization reserve, in which high variability represents...... diminished reserve and larger propensity for repolarization-dependent ventricular arrhythmia. A subset of chronic AVB dogs (10%) suffers sudden cardiac death (SCD). With the assumption that repolarization defects constitute a potentially lethal proarrhythmic substrate, we hypothesized that BVR in SCD dogs...... are larger than in matched control chronic AVB dogs. From a population of 200 chronic AVB dogs, initially two groups were chosen retrospectively: 8 dogs that died suddenly (SCD) and 8 control dogs. Control dogs had a longer lifespan after AVB (10 to 18 weeks) than SCD dogs (5 to 10 weeks). All dogs had...

  14. Premature delivery

    Directory of Open Access Journals (Sweden)

    Bernardita Donoso Bernales

    2012-09-01

    Full Text Available Preterm delivery is the single most important cause of perinatal morbidity and mortality. In Chile, preterm births have increased in the past decade, although neonatal morbidity and mortality attributable to it shows a downward trend, thanks to improvements in neonatal care of premature babies, rather than the success of obstetric preventive and therapeutic strategies. This article describes clinical entities, disease processes and conditions that constitute predisposing factors of preterm birth, as well as an outline for the prevention and clinical management of women at risk of preterm birth.

  15. Premature aging

    International Nuclear Information System (INIS)

    Sassaki, Hideo

    1992-01-01

    The hypothesis that radiation may accelerate aging phenomenon has been studied extensively, using the population of A-bomb survivors. In this paper, non-specific radiation-induced premature aging is discussed with a review of the literature. Cardiac lipofuscin, papillary fibrosis, aortic extensibility, hexamine/collagen ratio in the skin and aorta, testicular changes, giant hepatic cell nucleus, and neurofibril changes have so far been studied pathologically in the context of A-bomb radiation. Only testicular sclerosis has been found to correlate with distance from the hypocenter. Suggestive correlation was found to exist between the hexamine/collagen ratio in the skin and aorta and A-bomb radiation. Grip strength and hearing ability were decreased in the group of 100 rad and the group of 50-99 rad, respectively. The other physiological data did not definitely correlate with A-bomb radiation. Laboratory data, including erythrocyte sedimentation rate, α and β globulin levels, phytohemagglutinin reaction, T cell counts, erythrocyte glycophorin-A, the incidence of cerebral stroke, ischemic heart disease, and cataract were age-dependent and correlated with A-bomb radiation. These findings indicated that the occurrence of arteriosclerosis-related diseases, changes in immunological competence, and some pathological and physiological findings altered with advancing age, suggesting the correlation with A-bomb radiation. In general, it cannot be concluded that there is a positive correlation between A-bomb radiation and the premature aging. (N.K.) 51 refs

  16. Your Premature Baby

    Science.gov (United States)

    ... volunteer leader Partner Spotlight Become a partner World Prematurity Day What's happening in your area Find out ... 3 weeks after a premature birth. Retinopathy of prematurity (ROP) . This is an abnormal growth of blood ...

  17. Early or Premature Menopause

    Science.gov (United States)

    ... email updates Enter email Submit Early or premature menopause Menopause that happens before age 40 is called ... What is the difference between early and premature menopause? Early or premature menopause happens when ovaries stop ...

  18. Beat to beat variability in cardiovascular variables: noise or music?

    Science.gov (United States)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  19. Premature ejaculation

    Directory of Open Access Journals (Sweden)

    Chris G McMahon

    2007-01-01

    Full Text Available Premature ejaculation (PE is a common male sexual disorder. Recent normative data suggests that men with an intravaginal ejaculatory latency time (IELT of less than 1 minute have "definite" PE, while men with IELTs between 1 and 1.5 minutes have "probable" PE. Although there is insufficient empirical evidence to identify the etiology of PE, there is limited correlational evidence to suggest that men with PE have high levels of sexual anxiety and inherited altered sensitivity of central 5-HT (5-hydroxytryptamine, serotonin receptors. Pharmacological modulation of the ejaculatory threshold using off-label daily or on-demand selective serotonin re-uptake inhibitors is well tolerated and offers patients a high likelihood of achieving improved ejaculatory control within a few days of initiating treatment, consequential improvements in sexual desire and other sexual domains. Investigational drugs such as the ejaculo-selective serotonin transport inhibitor, dapoxetine represent a major development in sexual medicine. These drugs offer patients the convenience of on-demand dosing, significant improvements in IELT, ejaculatory control and sexual satisfaction with minimal adverse effects.

  20. Premature ejaculation.

    Science.gov (United States)

    McMahon, Chris G

    2007-04-01

    Premature ejaculation (PE) is a common male sexual disorder. Recent normative data suggests that men with an intravaginal ejaculatory latency time (IELT) of less than 1 minute have "definite" PE, while men with IELTs between 1 and 1.5 minutes have "probable" PE. Although there is insufficient empirical evidence to identify the etiology of PE, there is limited correlational evidence to suggest that men with PE have high levels of sexual anxiety and inherited altered sensitivity of central 5-HT (5-hydroxytryptamine, serotonin) receptors. Pharmacological modulation of the ejaculatory threshold using off-label daily or on-demand selective serotonin re-uptake inhibitors is well tolerated and offers patients a high likelihood of achieving improved ejaculatory control within a few days of initiating treatment, consequential improvements in sexual desire and other sexual domains. Investigational drugs such as the ejaculo-selective serotonin transport inhibitor, dapoxetine represent a major development in sexual medicine. These drugs offer patients the convenience of on-demand dosing, significant improvements in IELT, ejaculatory control and sexual satisfaction with minimal adverse effects.

  1. Detection of heart beats in multimodal data: a robust beat-to-beat interval estimation approach.

    Science.gov (United States)

    Antink, Christoph Hoog; Brüser, Christoph; Leonhardt, Steffen

    2015-08-01

    The heart rate and its variability play a vital role in the continuous monitoring of patients, especially in the critical care unit. They are commonly derived automatically from the electrocardiogram as the interval between consecutive heart beat. While their identification by QRS-complexes is straightforward under ideal conditions, the exact localization can be a challenging task if the signal is severely contaminated with noise and artifacts. At the same time, other signals directly related to cardiac activity are often available. In this multi-sensor scenario, methods of multimodal sensor-fusion allow the exploitation of redundancies to increase the accuracy and robustness of beat detection.In this paper, an algorithm for the robust detection of heart beats in multimodal data is presented. Classic peak-detection is augmented by robust multi-channel, multimodal interval estimation to eliminate false detections and insert missing beats. This approach yielded a score of 90.70 and was thus ranked third place in the PhysioNet/Computing in Cardiology Challenge 2014: Robust Detection of Heart Beats in Muthmodal Data follow-up analysis.In the future, the robust beat-to-beat interval estimator may directly be used for the automated processing of multimodal patient data for applications such as diagnosis support and intelligent alarming.

  2. Using music structure to improve beat tracking

    Science.gov (United States)

    Dannenberg, Roger B.

    2005-09-01

    Beats are an important feature of most music. Beats are used in music information retrieval systems for genre classification, similarity search, and segmentation. However, beats can be difficult to identify, especially in music audio. Traditional beat trackers attempt to (1) match predicted beats to observations of likely beats, and (2) maintain a fairly steady tempo. A third criterion can be added: when repetitions of musical passages occur, the beats in the first repetition should align with the beats in all other repetitions. This third criterion improves beat tracking performance significantly. Repetitions of musical passages are discovered in audio data by searching for similar sequences of chroma vectors. Beats are ``tracked'' by first locating a sequence of likely beats in the music audio using high frequency energy as an indicator of beat likelihood. This beat sequence is then extended by searching forward and backward for more matching beats, allowing slight variations in tempo, and using a relaxation algorithm to optimize the proposed beat locations with respect to the three criteria. Other high-level music features may offer further improvements in beat identification.

  3. The Nature of Ventricular Ectopic Beats in Chronic Ischaemic Heart ...

    African Journals Online (AJOL)

    1974-05-25

    " Goldschlager et al.' noted both an increase and a decrease of YEB with exercise in patients with coronary artery disease. Considerable study needs to be done to identify the factors which cause VEB to become manifest.

  4. The impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot.

    Science.gov (United States)

    Ávila, Pablo; Marcotte, François; Dore, Annie; Mercier, Lise-Andrée; Shohoudi, Azadeh; Mongeon, François-Pierre; Mondésert, Blandine; Proietti, Anna; Ibrahim, Reda; Asgar, Anita; Poirier, Nancy; Khairy, Paul

    2016-09-15

    Sudden death of presumed arrhythmic etiology is the leading cause of mortality in adults with tetralogy of Fallot. To assess the impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot. Adults with repaired tetralogy of Fallot were randomized in a 2:1 ratio to an open-label trial of standard care versus 12weeks of supervised combined aerobic/resistance training with continuous Holter monitoring. Proportion of premature ventricular complexes (PVC) and runs of non-sustained ventricular tachycardia (NSVT) were assessed by mixed and Poisson regression models with generalized estimating equations for repeated measures. A total of 152 Holters were performed in 17 patients, median age 35 (interquartile range [IQR] 28, 42) years, 65% male, 13 of whom were randomized to exercise training. Baseline characteristics were similar between groups. Exercise training resulted in significant increases in peak oxygen uptake (11±19%, p=0.028), metabolic equivalents (11±18%, p=0.027), and exercise duration (8±10%, p=0.009) compared to no changes in controls. Frequent (≥30 per hour) PVCs were present in 46% of patients, couplets in 62%, and 3 to 7 beat runs of NSVT in 31%. The median proportion of PVCs was 1.93‰ (IQR 0.41, 5.89) at baseline and 1.45‰ (IQR 0.08, 2.76) during the initial exercise session (p=0.722), and remained stable over time (ß coefficient=-0.031, p=0.408). Runs of NSVT decreased significantly over time (ß coefficient=-0.032, p=0.018). In adults with repaired tetralogy of Fallot, exercise training is safe, improves exercise capacity, and appears to confer a beneficial effect on ventricular arrhythmias. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Binaural beats at high frequencies.

    Science.gov (United States)

    McFadden, D; Pasanen, E G

    1975-10-24

    Binaural beats have long been believed to be audible only at low frequencies, but an interaction reminiscent of a binaural beat can sometimes be heard when different two-tone complexes of high frequency are presented to the two ears. The primary requirement is that the frequency separation in the complex at one ear be slightly different from that in the other--that is, that there be a small interaural difference in the envelope periodicities. This finding is in accord with other recent demonstrations that the auditory system is not deaf to interaural time differences at high frequencies.

  6. Apnea of prematurity

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007227.htm Apnea of prematurity To use the sharing features on this page, ... down or stops from any cause. Apnea of prematurity refers to short episodes of stopped breathing in ...

  7. Pharmacotherapy for premature ejaculation

    NARCIS (Netherlands)

    Waldinger, Marcel D

    2014-01-01

    PURPOSE OF REVIEW: As there are various drugs and different treatment strategies to delay ejaculation, a review of the current drug treatments for premature ejaculation is relevant for daily clinical practice. RECENT FINDINGS: There are four premature ejaculation subtypes: lifelong premature

  8. Retinopathy of Prematurity

    Science.gov (United States)

    Steinweg, Sue Byrd; Griffin, Harold C.; Griffin, Linda W.; Gingras, Happy

    2005-01-01

    The eyes of premature infants are especially vulnerable to injury after birth. A serious complication is called retinopathy of prematurity (ROP), which is abnormal growth of the blood vessels in an infant's eye. Retinopathy of prematurity develops when abnormal blood vessels grow and spread throughout the retina, which is the nerve tissue at the…

  9. Average beta-beating from random errors

    CERN Document Server

    Tomas Garcia, Rogelio; Langner, Andy Sven; Malina, Lukas; Franchi, Andrea; CERN. Geneva. ATS Department

    2018-01-01

    The impact of random errors on average β-beating is studied via analytical derivations and simulations. A systematic positive β-beating is expected from random errors quadratic with the sources or, equivalently, with the rms β-beating. However, random errors do not have a systematic effect on the tune.

  10. A case of appropriate inappropriate device therapy: Hyperkalemia-induced ventricular oversensing

    Science.gov (United States)

    Oudit, Gavin Y; Cameron, Doug; Harris, Louise

    2008-01-01

    The present case describes a patient who received inappropriate, but potentially life-saving, therapy from her implantable cardioverter defibrillator (ICD) in the setting of acute hyperkalemia (plasma potassium concentration = 8 mM). Hyperkalemia was associated with the development of a slow sinusoidal ventricular tachycardia, at a rate of 100 beats/min to 125 beats/min (610 ms to 480 ms) in a patient who is pacemaker-dependent. There was associated fractionation of the ICD electrogram and T wave oversensing, leading to ventricular oversensing with resultant detection in the ventricular fibrillation rate zone. This was followed by shock therapy, even though the ventricular tachycardia rate was below the programmed detection rate of the ICD. The subsequent emergency treatment of the hyperkalemia normalized the electrogram, corrected the ventricular oversensing and arrhythmia, and restored rate-adaptive single-chamber ventricular pacing. PMID:18340383

  11. A comparison of auditory evoked potentials to acoustic beats and to binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2010-04-01

    The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source current density estimates of ERP components to beats-evoked oscillations were determined and compared across beat types, beat frequencies and base (carrier) frequencies. All stimuli evoked tone-onset components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude in response to acoustic than to binaural beats, to 250 than to 1000 Hz base frequency and to 3 Hz than to 6 Hz beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left temporal lobe areas. Differences between estimated sources of potentials to acoustic and binaural beats were not significant. The perceptions of binaural beats involve cortical activity that is not different than acoustic beats in distribution and in the effects of beat- and base frequency, indicating similar cortical processing. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Losing the beat: deficits in temporal coordination

    Science.gov (United States)

    Palmer, Caroline; Lidji, Pascale; Peretz, Isabelle

    2014-01-01

    Tapping or clapping to an auditory beat, an easy task for most individuals, reveals precise temporal synchronization with auditory patterns such as music, even in the presence of temporal fluctuations. Most models of beat-tracking rely on the theoretical concept of pulse: a perceived regular beat generated by an internal oscillation that forms the foundation of entrainment abilities. Although tapping to the beat is a natural sensorimotor activity for most individuals, not everyone can track an auditory beat. Recently, the case of Mathieu was documented (Phillips-Silver et al. 2011 Neuropsychologia 49, 961–969. (doi:10.1016/j.neuropsychologia.2011.02.002)). Mathieu presented himself as having difficulty following a beat and exhibited synchronization failures. We examined beat-tracking in normal control participants, Mathieu, and a second beat-deaf individual, who tapped with an auditory metronome in which unpredictable perturbations were introduced to disrupt entrainment. Both beat-deaf cases exhibited failures in error correction in response to the perturbation task while exhibiting normal spontaneous motor tempi (in the absence of an auditory stimulus), supporting a deficit specific to perception–action coupling. A damped harmonic oscillator model was applied to the temporal adaptation responses; the model's parameters of relaxation time and endogenous frequency accounted for differences between the beat-deaf cases as well as the control group individuals. PMID:25385783

  13. Beat-to-beat systolic time-interval measurement from heart sounds and ECG

    International Nuclear Information System (INIS)

    Paiva, R P; Carvalho, P; Couceiro, R; Henriques, J; Antunes, M; Quintal, I; Muehlsteff, J

    2012-01-01

    Systolic time intervals are highly correlated to fundamental cardiac functions. Several studies have shown that these measurements have significant diagnostic and prognostic value in heart failure condition and are adequate for long-term patient follow-up and disease management. In this paper, we investigate the feasibility of using heart sound (HS) to accurately measure the opening and closing moments of the aortic heart valve. These moments are crucial to define the main systolic timings of the heart cycle, i.e. pre-ejection period (PEP) and left ventricular ejection time (LVET). We introduce an algorithm for automatic extraction of PEP and LVET using HS and electrocardiogram. PEP is estimated with a Bayesian approach using the signal's instantaneous amplitude and patient-specific time intervals between atrio-ventricular valve closure and aortic valve opening. As for LVET, since the aortic valve closure corresponds to the start of the S2 HS component, we base LVET estimation on the detection of the S2 onset. A comparative assessment of the main systolic time intervals is performed using synchronous signal acquisitions of the current gold standard in cardiac time-interval measurement, i.e. echocardiography, and HS. The algorithms were evaluated on a healthy population, as well as on a group of subjects with different cardiovascular diseases (CVD). In the healthy group, from a set of 942 heartbeats, the proposed algorithm achieved 7.66 ± 5.92 ms absolute PEP estimation error. For LVET, the absolute estimation error was 11.39 ± 8.98 ms. For the CVD population, 404 beats were used, leading to 11.86 ± 8.30 and 17.51 ± 17.21 ms absolute PEP and LVET errors, respectively. The results achieved in this study suggest that HS can be used to accurately estimate LVET and PEP. (paper)

  14. Family Perspectives on Prematurity

    Science.gov (United States)

    Zero to Three (J), 2003

    2003-01-01

    In this article, seven families describe their experiences giving birth to and raising a premature baby. Their perspectives vary, one from another, and shift over time, depending on each family's circumstances and the baby's developmental course. Experiences discussed include premature labor, medical interventions and the NICU, bringing the baby…

  15. Premature ovarian failure

    OpenAIRE

    Pacheco, José

    2011-01-01

    Premature ovarian failure is characterized by secondary amenorrhea affecting a woman before the age of 40, leading to hypoestrogenism, infertility, and consequences of premature menopause, such as osteoporosis, cardiovascular disease, neurovegetative alterations, and others. Follicular exhaustion is due to either follicles shortage or oocytes accelerated destruction. Main causes are genetic, autoimmune and iatrogenic. Among genetic causes Xq and Xp deletions, translocations, numeric aberratio...

  16. Electrical brain responses to beat irregularities in two cases of beat deafness

    NARCIS (Netherlands)

    Mathias, B.; Lidji, P.; Honing, H.; Palmer, C.; Peretz, I.

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to

  17. Association of ventricular arrhythmia and in-hospital mortality in stroke patients in Florida: A nonconcurrent prospective study.

    Science.gov (United States)

    Dahlin, Arielle A; Parsons, Chase C; Barengo, Noël C; Ruiz, Juan Gabriel; Ward-Peterson, Melissa; Zevallos, Juan Carlos

    2017-07-01

    Stroke remains one of the leading causes of death in the United States. Current evidence identified electrocardiographic abnormalities and cardiac arrhythmias in 50% of patients with an acute stroke. The purpose of this study was to assess whether the presence of ventricular arrhythmia (VA) in adult patients hospitalized in Florida with acute stroke increased the risk of in-hospital mortality.Secondary data analysis of 215,150 patients with ischemic and hemorrhagic stroke hospitalized in the state of Florida collected by the Florida Agency for Healthcare Administration from 2008 to 2012. The main outcome for this study was in-hospital mortality. The main exposure of this study was defined as the presence of VA. VA included the ICD-9 CM codes: paroxysmal ventricular tachycardia (427.1), ventricular fibrillation (427.41), ventricular flutter (427.42), ventricular fibrillation and flutter (427.4), and other - includes premature ventricular beats, contractions, or systoles (427.69). Differences in demographic and clinical characteristics and hospital outcomes were assessed between patients who developed versus did not develop VA during hospitalization (χ and t tests). Binary logistic regression was used to estimate unadjusted and adjusted odds ratios and 95% confidence intervals (CIs) between VA and in-hospital mortality.VA was associated with an increased risk of in-hospital mortality after adjusting for all covariates (odds ratio [OR]: 1.75; 95% CI: 1.6-1.2). There was an increased in-hospital mortality in women compared to men (OR: 1.1; 95% CI: 1.1-1.14), age greater than 85 years (OR: 3.9, 95% CI: 3.5-4.3), African Americans compared to Whites (OR: 1.1; 95% CI: 1.04-1.2), diagnosis of congestive heart failure (OR: 2.1; 95% CI: 2.0-2.3), and atrial arrhythmias (OR: 2.1, 95% CI: 2.0-2.2). Patients with hemorrhagic stroke had increased odds of in-hospital mortality (OR: 9.0; 95% CI: 8.6-9.4) compared to ischemic stroke.Identifying VAs in stroke patients may help in

  18. Cardioscopic tricuspid valve repair in a beating ovine heart.

    Science.gov (United States)

    Umakanthan, Ramanan; Ghanta, Ravi K; Rangaraj, Aravind T; Lee, Lawrence S; Laurence, Rita G; Fox, John A; Mihaljevic, Tomislav; Bolman, Ralph M; Cohn, Lawrence H; Chen, Frederick Y

    2009-04-01

    Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart. Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation. All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation. Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.

  19. The Simplest Demonstration on Acoustic Beats

    Science.gov (United States)

    Ganci, Alessio; Ganci, Salvatore

    2015-01-01

    The classical demonstration experiment on acoustic beats using two signal generators and a dual trace oscilloscope is an important ingredient in teaching the subject. This short laboratory note aims to point out what may be the simplest demonstrative experiment on acoustic beats to carry out in a classroom without employing any lab apparatus.

  20. A case of appropriate inappropriate device therapy: Hyperkalemia-induced ventricular oversensing

    OpenAIRE

    Oudit, Gavin Y; Cameron, Doug; Harris, Louise

    2008-01-01

    The present case describes a patient who received inappropriate, but potentially life-saving, therapy from her implantable cardioverter defibrillator (ICD) in the setting of acute hyperkalemia (plasma potassium concentration = 8 mM). Hyperkalemia was associated with the development of a slow sinusoidal ventricular tachycardia, at a rate of 100 beats/min to 125 beats/min (610 ms to 480 ms) in a patient who is pacemaker-dependent. There was associated fractionation of the ICD electrogram and T ...

  1. Premature rupture of membranes

    Science.gov (United States)

    ... gov/ency/patientinstructions/000512.htm Premature rupture of membranes To use the sharing features on this page, ... water that surrounds your baby in the womb. Membranes or layers of tissue hold in this fluid. ...

  2. Retinopathy of Prematurity (ROP)

    Science.gov (United States)

    ... developing severe ROP, especially those in underserved or remote areas. Currently in the U.S., evaluation of premature ... files require the free Adobe® Reader® software for viewing. This website is maintained by the NEI Office ...

  3. Feeling the beat: premotor and striatal interactions in musicians and non-musicians during beat perception

    Science.gov (United States)

    Grahn, Jessica A.; Rowe, James B.

    2009-01-01

    Little is known about the underlying neurobiology of rhythm and beat perception, despite its universal cultural importance. Here we used functional magnetic resonance imaging to study rhythm perception in musicians and non-musicians. Three conditions varied in the degree to which external reinforcement versus internal generation of the beat was required. The ‘Volume’ condition strongly externally marked the beat with volume changes, the ‘Duration’ condition marked the beat with weaker accents arising from duration changes, and the ‘Unaccented’ condition required the beat to be entirely internally generated. In all conditions, beat rhythms compared to nonbeat control rhythms revealed putamen activity. The presence of a beat was also associated with greater connectivity between the putamen and the supplementary motor area (SMA), the premotor cortex (PMC) and auditory cortex. In contrast, the type of accent within the beat conditions modulated the coupling between premotor and auditory cortex, with greater modulation for musicians than non-musicians. Importantly, the putamen's response to beat conditions was not due to differences in temporal complexity between the three rhythm conditions. We propose that a cortico-subcortical network including the putamen, SMA, and PMC is engaged for the analysis of temporal sequences and prediction or generation of putative beats, especially under conditions that may require internal generation of the beat. The importance of this system for auditory-motor interaction and development of precisely timed movement is suggested here by its facilitation in musicians. PMID:19515922

  4. Dichotic beats of mistuned consonances.

    Science.gov (United States)

    Feeney, M P

    1997-10-01

    The beats of mistuned consonances (BMCs) result from the presentation of two sinusoids at frequencies slightly mistuned from a ratio of small integers. Several studies have suggested that the source of dichotic BMCs is an interaction within a binaural critical band. In one case the mechanism has been explained as an aural harmonic of the low-frequency tone (f1) creating binaural beats with the high-frequency tone (f2). The other explanation involves a binaural cross correlation between the excitation pattern of f1 and the contralateral f2--occurring within the binaural critical band centered at f2. This study examined the detection of dichotic BMCs for the octave and fifth. In one experiment with the octave, narrow-band noise centered at f2 was presented to one ear along with f1. The other ear was presented with f2. The noise was used to prevent interactions in the binaural critical band centered at f2. Dichotic BMCs were still detected under these conditions, suggesting that binaural interaction within a critical band does not explain the effect. Localization effects were also observed under this masking condition for phase reversals of tuned dichotic octave stimuli. These findings suggest a new theory of dichotic BMCs as a between-channel phase effect. The modified weighted-image model of localization [Stern and Trahiotis, in Auditory Physiology and Perception, edited by Y. Cazals, L. Demany, and K. Horner (Pergamon, Oxford, 1992), pp. 547-554] was used to provide an explanation of the between-channel mechanism.

  5. Ventricular dyssynchrony as a cause of structural disease in the heart of Dorper sheep

    Directory of Open Access Journals (Sweden)

    J. Ker

    2004-11-01

    Full Text Available Ventricular dyssynchrony is a disturbance of the normal, organized electromechanical coupling of the two ventricles. This condition has many causes, such as left bundle branch block, ventricular preexcitation, right ventricular pacing and right ventricular premature ventricular complexes (PVCs. Ventricular dyssynchrony has many adverse haemodynamic effects on the left ventricle and we wanted to know whether these adverse haemodynamic effects might have any structural consequences on the left ventricles of such hearts. Six healthy Dorper wethers were subjected to numerous right ventricular PVCs to induce ventricular dyssynchrony in order to determine whether any structural consequences will occur in the left ventricles of these hearts. Myocarditis in the musculature of the left ventricles of all six these hearts was seen.

  6. Electrical Brain Responses to Beat Irregularities in Two Cases of Beat Deafness

    Science.gov (United States)

    Mathias, Brian; Lidji, Pascale; Honing, Henkjan; Palmer, Caroline; Peretz, Isabelle

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN) and P3 event-related potential (ERP) components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu—but not Marjorie—compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception. PMID:26941591

  7. Electrical brain responses to beat irregularities in two cases of beat deafness

    Directory of Open Access Journals (Sweden)

    Brian eMathias

    2016-02-01

    Full Text Available Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN and P3 event-related potential (ERP components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu – but not Marjorie – compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  8. Monitoring ventricular function at rest and during exercise with a nonimaging nuclear detector.

    Science.gov (United States)

    Wagner, H N; Rigo, P; Baxter, R H; Alderson, P O; Douglass, K H; Housholder, D F

    1979-05-01

    A portable nonimaging device, the nuclear stethoscope, for measuring beat to beat ventricular time-activity curves in normal people and patients with heart disease, both at rest and during exercise, is being developed and evaluated. The latest device has several operating modes that facilitate left ventricular and background localization, measurement of transit times and automatic calculation and display of left ventricular ejection fraction. The correlation coefficient of left ventricular ejection fraction obtained with the device and with a camera-computer system was 0.92 in 35 subjects. During bicycle exercise the ejection fraction in 15 normal persons increased from 44 to 64 percent (P less than 0.001), whereas among 12 patients with heart disease it was unchanged in 5 and decreased in 7.

  9. Monitoring ventricular function at rest and during exercise with a nonimaging nuclear detector

    International Nuclear Information System (INIS)

    Wagner, H.N. Jr.; Rigo, P.; Baxter, R.H.; Alderson, P.O.; Douglass, K.H.; Housholder, D.F.

    1979-01-01

    A portable nonimaging device, the nuclear stethoscope, for measuring beat to beat ventricular time-activity curves in normal people and patients with heart disease, both at rest and during exercise, is being developed and evaluated. The latest device has several operting modes that facilitate left ventricular and background localization, measurement of transit times and automatic calculation and display of left ventricular ejection fraction. The correlation coefficient of left ventricular ejection fraction obtained with the device and with a camera-computer system was 0.92 in 35 subjects. During bicycle exercise the ejection fraction in 15 normal persons increased from 44 to 64% (P less than 0.001), whereas among 12 patients with heart disease it was unchanged in 5 and decreased in 7

  10. Autoimmune premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Beata Komorowska

    2017-02-01

    Full Text Available Premature ovarian failure (POF, also termed as primary ovarian insufficiency (POI, is a highly heterogenous condition affecting 0.5-3.0% of women in childbearing age. These young women comprise quite a formidable group with unique physical and psychological needs that require special attention. Premature ovarian senescence (POS in all of its forms evolves insidiously as a basically asymptomatic process, leading to complete loss of ovarian function, and POI/POF diagnoses are currently made at relatively late stages. Well-known and well-documented risk factors exist, and the presence or suspicion of autoimmune disorder should be regarded as an important one. Premature ovarian failure is to some degree predictable in its occurrence and should be considered while encountering young women with loss of menstrual regularity, especially when there is a concomitant dysfunction in the immune system.

  11. Feeding premature neonate

    DEFF Research Database (Denmark)

    Dam, Mie S.; Juhl, Sandra M.; Sangild, Per T.

    2017-01-01

    Kinship, understood as biogenetic proximity, between a chosen animal model and a human patient counterpart, is considered essential to the process of ‘translating’ research from the experimental animal laboratory to the human clinic. In the Danish research centre, NEOMUNE, premature piglets are fed...... a novel milk diet (bovine colostrum) to model the effects of this new diet in premature infants. Our ethnographic fieldwork in an experimental pig laboratory and a neonatal intensive care unit (NICU) in 2013–2014 shows that regardless of biogenetics, daily practices of feeding, housing, and clinical care...... the researchers refer to as the ‘translatability’ of the results. In the NICU, parents of premature infants likewise imagine a kind of interspecies kinship when presented with the option to supplement mother's own milk with bovine colostrum for the first weeks after birth. However, in this setting the NICU...

  12. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Persani Luca

    2006-04-01

    Full Text Available Abstract Premature ovarian failure (POF is a primary ovarian defect characterized by absent menarche (primary amenorrhea or premature depletion of ovarian follicles before the age of 40 years (secondary amenorrhea. It is a heterogeneous disorder affecting approximately 1% of women e.g. Turner syndrome represent the major cause of primary amenorrhea associated with ovarian dysgenesis. Despite the description of several candidate genes, the cause of POF remains undetermined in the vast majority of the cases. Management includes substitution of the hormone defect by estrogen/progestin preparations. The only solution presently available for the fertility defect in women with absent follicular reserve is ovum donation.

  13. Beating Depression …Help Is Available

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Beating Depression …Help Is Available Past Issues / Summer 2007 Table ... treatments are available from your physician. Types of Depression Just like other illnesses, such as heart disease, ...

  14. Binaural beats and frequency-coding.

    Science.gov (United States)

    Fritze, W; Köhler, W

    1986-01-01

    Binaural beats were studied before and during a situation of temporary threshold shift, and no frequency shift could be found. In contrast, subjective binaural frequency comparison revealed a distinct shift. These findings demonstrate the two known modes of perception.

  15. Amplitude differences least squares method applied to temporal cardiac beat alignment

    International Nuclear Information System (INIS)

    Correa, R O; Laciar, E; Valentinuzzi, M E

    2007-01-01

    High resolution averaged ECG is an important diagnostic technique in post-infarcted and/or chagasic patients with high risk of ventricular tachycardia (VT). It calls for precise determination of the synchronism point (fiducial point) in each beat to be averaged. Cross-correlation (CC) between each detected beat and a reference beat is, by and large, the standard alignment procedure. However, the fiducial point determination is not precise in records contaminated with high levels of noise. Herein, we propose an alignment procedure based on the least squares calculation of the amplitude differences (LSAD) between the ECG samples and a reference or template beat. Both techniques, CC and LSAD, were tested in high resolution ECG's corrupted with white noise and 50 Hz line interference of varying amplitudes (RMS range: 0-100μV). Results point out that LSDA produced a lower alignment error in all contaminated records while in those blurred by power line interference better results were found only within the 0-40 μV range. It is concluded that the proposed method represents a valid alignment alternative

  16. Beat characteristics and beat maps of the King Seong-deok Divine Bell

    Science.gov (United States)

    Kim, Seock-Hyun; Lee, Chi-Wook; Lee, Jang-Moo

    2005-03-01

    King Seong-deok Divine Bell is the second oldest bell in Korea. The bell is considered to have the best sound quality among Korean bells. The beat phenomenon is one of the most important characteristics for the sound of the King Seong-deok Divine Bell. In this study, the relationships between the modal parameters and the peculiar beat phenomena of the bell are investigated. It is theoretically proved from the beat characteristics that the sound might indeed be heard differently depending on the listening positions. The beat map method is introduced to visualize the beat distribution properties. It is shown that the beat maps can be drawn with a theoretical model based on the modal data of the bell. Using the beat maps of the King Seong-deok Divine Bell, it is investigated why clear and unclear beats, large and small amplitudes of the vibrations are repeated periodically along the circumference of the bell. Furthermore, the effect of the striking position on the beat distribution property is examined systematically.

  17. [Clinical Experience of Beating Heart Atrial Septostomy Using a Device for Coronary Artery Anastomosis Site Creator].

    Science.gov (United States)

    Takahashi, Goro; Sai, Sadahiro; Konishi, Akinobu

    2015-09-01

    Intra-atrial communication was mandatory for several congenital cardiac diseases, such as pulmonary atresia with intact ventricular septum (PA/IVS), and either sided aortoventricular valve atresia. We assessed whether the new methods of atrial septal defect(ASD)creation was effective. We experienced 4 cases of the surgical atrial septostomy performed under on-pump beating. We used a new device, a circular punch out defect creator. All cases were alive. The mean ASD diameter was enlarged from 4.37 mm to 5.55 mm and the mean ASD shunt flow was significantly decreased from 1.47 m/s to 1.11 m/s. We performed the surgical atrial septostomy using an aortic puncher under beating heart effectively and safely.

  18. Your Premature Baby: Low Birthweight

    Science.gov (United States)

    ... volunteer leader Partner Spotlight Become a partner World Prematurity Day What's happening in your area Find out ... to remove damaged parts of intestine. Retinopathy of prematurity (also called ROP) . ROP affects blood vessels in ...

  19. Health Issues of Premature Babies

    Science.gov (United States)

    ... they leave the hospital for home. Retinopathy of Prematurity (ROP) What It Is: ROP is an eye ... sometimes seen in preterm babies include anemia of prematurity (a low red blood cell count) and heart ...

  20. The impact of binaural beats on creativity

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2013-11-01

    Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  1. The impact of binaural beats on creativity.

    Science.gov (United States)

    Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

    2013-01-01

    Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale-mood State questionnaire (PANAS-S) and an affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs). Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBRs were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  2. Myopia in premature babies with and without retinopathy of prematurity.

    OpenAIRE

    Nissenkorn, I; Yassur, Y; Mashkowski, D; Sherf, I; Ben-Sira, I

    1983-01-01

    One hundred and fifty-five premature infants weighing 600-2000 g were followed up during 1974-80 for the presence of retinopathy of prematurity (ROP) and for the existence of myopia. 50% of the premature infants who had ROP were myopic, while only 16% myopic premature infants were found among those who did not have ROP. There was a positive correlation between the degree of myopia and the severity of cicatricial ROP. No difference existed in the frequency and degree of myopia between prematur...

  3. Proarrhythmic electrical remodelling is associated with increased beat-to-beat variability of repolarisation

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Oros, Avram; Schoenmakers, Marieke

    2007-01-01

    Acquired long-QT syndrome in combination with increased beat-to-beat variability of repolarisation duration (BVR) is associated with lethal torsades de pointes arrhythmias (TdP) in dogs with remodelled heart after atrioventricular block (AVB). We evaluated the relative contributions of bradycardi...

  4. Measurement of ventricular function by ECG gating during atrial fibrillation

    International Nuclear Information System (INIS)

    Bacharach, S.L.; Green, M.V.; Bonow, R.O.; Findley, S.L.; Ostrow, H.G.; Johnston, G.S.

    1981-01-01

    The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR), and their times of occurrence (TPER, TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beam mean values were compared with the corresponding parameters calculated from one ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TACs irrespective of their length. For this population with slow heart rates, we find that the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF

  5. Dependence of Intramyocardial Pressure and Coronary Flow on Ventricular Loading and Contractility: A Model Study

    NARCIS (Netherlands)

    Bovendeerd, P.H.M.; Borsje, P.; Arts, M.G.J.; Vosse, van de F.N.

    2006-01-01

    The phasic coronary arterial inflow during the normal cardiac cycle has been explained with simple (waterfall, intramyocardial pump) models, emphasizing the role of ventricular pressure. To explain changes in isovolumic and low afterload beats, these models were extended with the effect of

  6. High beat-to-beat blood pressure variability in atrial fibrillation compared to sinus rhythm.

    Science.gov (United States)

    Olbers, Joakim; Gille, Adam; Ljungman, Petter; Rosenqvist, Mårten; Östergren, Jan; Witt, Nils

    2018-02-07

    Atrial fibrillation (AF) is associated with an increased risk for cardiovascular morbidity and mortality, not entirely explained by thromboembolism. The underlying mechanisms for this association are largely unknown. Similarly, high blood pressure (BP) increases the risk for cardiovascular events. Despite this the interplay between AF and BP is insufficiently studied. The purpose of this study was to examine and quantify the beat-to-beat blood pressure variability in patients with AF in comparison to a control group of patients with sinus rhythm. We studied 33 patients - 21 in atrial fibrillation and 12 in sinus rhythm - undergoing routine coronary angiography. Invasive blood pressure was recorded at three locations: radial artery, brachial artery and ascending aorta. Blood pressure variability, defined as average beat-to-beat blood pressure difference, was calculated for systolic and diastolic blood pressure at each site. We observed a significant difference (p blood pressure variability between the atrial fibrillation and sinus rhythm groups at all locations. Systolic blood pressure variability roughly doubled in the atrial fibrillation group compared to the sinus rhythm group (4.9 and 2.4 mmHg respectively). Diastolic beat-to-beat blood pressure variability was approximately 6 times as high in the atrial fibrillation group compared to the sinus rhythm group (7.5 and 1.2 mmHg respectively). No significant difference in blood pressure variability was seen between measurement locations. Beat-to-beat blood pressure variability in patients with atrial fibrillation was substantially higher than in patients with sinus rhythm. Hemodynamic effects of this beat-to-beat variation in blood pressure may negatively affect vascular structure and function, which may contribute to the increased cardiovascular morbidity and mortality seen in patients with atrial fibrillation.

  7. Retinopathy of prematurity

    International Nuclear Information System (INIS)

    Benavides Vargas, Ana Maria

    2013-01-01

    Retinopathy of prematurity has been the leading cause of childhood blindness. Early and effective screening has helped to diagnose the visual target of an infant by the difference between growing up with a disability or not. A joint effort between ophthalmologists and neonatologists is proposed to control this disease, ensuring success. An appropriate, early, effective and timely treatment has been the laser and cryotherapy like good choices for the neonate to prevent disease progression. Evaluation of screening program, to determine the incidence, compare statistics variables have been measures as other medical pathologies should be encouraged as research topics. A decrease in the incidence of retinopathy of prematurity is expected, controlling the risk factors during the child's stay in intrahospital neonatal unit [es

  8. Prematurely terminated slug tests

    International Nuclear Information System (INIS)

    Karasaki, K.

    1990-07-01

    A solution of the well response to a prematurely terminated slug test (PTST) is presented. The advantages of a PTST over conventional slug tests are discussed. A systematized procedure of a PTST is proposed, where a slug test is terminated in the midpoint of the flow point, and the subsequent shut-in data is recorded and analyzed. This method requires a downhole shut-in device and a pressure transducer, which is no more than the conventional deep-well slug testing. As opposed to slug tests, which are ineffective when a skin is present, more accurate estimate of formation permeability can be made using a PTST. Premature termination also shortens the test duration considerably. Because in most cases no more information is gained by completing a slug test to the end, the author recommends that conventional slug tests be replaced by the premature termination technique. This study is part of an investigation of the feasibility of geologic isolation of nuclear wastes being carried out by the US Department of Energy and the National Cooperative for the Storage of Radioactive Waste of Switzerland

  9. Pharmacokinetics of intravenously and orally administered sotalol hydrochloride in horses and effects on surface electrocardiogram and left ventricular systolic function.

    Science.gov (United States)

    Broux, B; De Clercq, D; Decloedt, A; De Baere, S; Devreese, M; Van Der Vekens, N; Ven, S; Croubels, S; van Loon, G

    2016-02-01

    Arrhythmias are common in horses. Some, such as frequent atrial or ventricular premature beats, may require long-term anti-arrhythmic therapy. In humans and small animals, sotalol hydrochloride (STL) is often used for chronic oral anti-arrhythmic therapy. STL prolongs repolarization and the effective refractory period in all cardiac tissues. No information on STL pharmacokinetics or pharmacodynamics in horses is available and the aim of this study was to evaluate the pharmacokinetics of intravenously (IV) and orally (PO) administered STL and the effects on surface electrocardiogram and left ventricular systolic function. Six healthy horses were given 1 mg STL/kg bodyweight either IV or PO. Blood samples to determine plasma STL concentrations were taken before and at several time points after STL administration. Electrocardiography and echocardiography were performed at different time points before and after IV STL administration. Mean peak plasma concentrations after IV and PO administration of STL were 1624 ng/mL and 317 ng/mL, respectively. The oral bioavailability was intermediate (48%) with maximal absorption after 0.94 h, a moderate distribution and a mean elimination half-life of 15.24 h. After IV administration, there was a significant increase in QT interval, but no significant changes in other electrocardiographic and echocardiographic parameters. Transient transpiration was observed after IV administration, but no adverse effects were noted after a single oral dose of 1 mg/kg STL in any of the horses. It was concluded that STL has an intermediate oral bioavailability in the horse and might be useful in the treatment of equine arrhythmias. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Acoustical sensing of cardiomyocyte cluster beating

    Energy Technology Data Exchange (ETDEWEB)

    Tymchenko, Nina; Kunze, Angelika [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Dahlenborg, Kerstin [Cellectis, 413 46 Göteborg (Sweden); Svedhem, Sofia, E-mail: sofia.svedhem@chalmers.se [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Steel, Daniella [Cellectis, 413 46 Göteborg (Sweden)

    2013-06-14

    Highlights: •An example of the application of QCM-D to live cell studies. •Detection of human pluripotent stem cell-derived cardiomyocyte cluster beating. •Clusters were studied in a thin liquid film and in a large liquid volume. •The QCM-D beating profile provides an individual fingerprint of the hPS-CMCs. -- Abstract: Spontaneously beating human pluripotent stem cell-derived cardiomyocytes clusters (CMCs) represent an excellent in vitro tool for studies of human cardiomyocyte function and for pharmacological cardiac safety assessment. Such testing typically requires highly trained operators, precision plating, or large cell quantities, and there is a demand for real-time, label-free monitoring of small cell quantities, especially rare cells and tissue-like structures. Array formats based on sensing of electrical or optical properties of cells are being developed and in use by the pharmaceutical industry. A potential alternative to these techniques is represented by the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, which is an acoustic surface sensitive technique that measures changes in mass and viscoelastic properties close to the sensor surface (from nm to μm). There is an increasing number of studies where QCM-D has successfully been applied to monitor properties of cells and cellular processes. In the present study, we show that spontaneous beating of CMCs on QCM-D sensors can be clearly detected, both in the frequency and the dissipation signals. Beating rates in the range of 66–168 bpm for CMCs were detected and confirmed by simultaneous light microscopy. The QCM-D beating profile was found to provide individual fingerprints of the hPS-CMCs. The presented results point towards acoustical assays for evaluation cardiotoxicity.

  11. A binaural beat constructed from a noise

    Science.gov (United States)

    Akeroyd, Michael A

    2012-01-01

    The binaural beat has been used for over one hundred years as a stimulus for generating the percept of motion. Classically the beat consists of a pure tone at one ear (e.g. 500 Hz) and the same pure tone at the other ear but shifted upwards or downwards in frequency (e.g., 501 Hz). An experiment and binaural computational analysis are reported which demonstrate that a more powerful motion percept can be obtained by applying the concept of the frequency shift to a noise, via an upwards or downwards shift in the frequency of the Fourier components of its spectrum. PMID:21218863

  12. Monitoring of right ventricular function by single probe system (nuclear stethoscope) and sup(81m)Kr

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Ohmine, Hiromi; Kimura, Motomasa [National Cardiovascular Center, Suita, Osaka (Japan)

    1982-12-01

    A single probe system (nuclear stethoscope) was developed to evaluate the monitoring of right ventricular function by sup(81m)Kr continuous infusion method. Optimal right ventricular and background positions were determined by position/monitor mode on beat-to-beat basis, and right ventricular ejection fraction (RVEF) was calculated by multi-gated method (MUGA). The correlation coefficient of nuclear stethoscope RVEF and camera-computer RVEF (MUGA) was 0.82, while the correlation coefficient of nuclear stethoscope RVEF and camera-computer RVEF (first-pass method) was 0.64. Therefore, the RVEF by nuclear stethoscope is useful for monitoring of right ventricular function. Clinical applications by sup(81m)Kr and nuclear stethoscope were as follows. 1. Exercise/rest RVEF is an extremely sensitive indicator to discriminate coronary artery disease (RCA occlusion) from normal subjects. 2. Beat-to-beat right ventricular volume response is useful for the monitoring of arrythmia such as atrial fibrillation.

  13. Monitoring of right ventricular function by single probe system (nuclear stethoscope) and sup(81m)Kr

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Ohmine, Hiromi; Kimura, Motomasa

    1982-01-01

    A single probe system (nuclear stethoscope) was developed to evaluate the monitoring of right ventricular function by sup(81m)Kr continuous infusion method. Optimal right ventricular and background positions were determined by position/monitor mode on beat-to-beat basis, and right ventricular ejection fraction (RVEF) was calculated by multi-gated method (MUGA). The correlation coefficient of nuclear stethoscope RVEF and camera-computer RVEF (MUGA) was 0.82, while the correlation coefficient of nuclear stethoscope RVEF and camera-computer RVEF (first-pass method) was 0.64. Therefore, the RVEF by nuclear stethoscope is useful for monitoring of right ventricular function. Clinical applications by sup(81m)Kr and nuclear stethoscope were as follows. 1. Exercise/rest RVEF is an extremely sensitive indicator to discriminate coronary artery disease (RCA occlusion) from normal subjects. 2. Beat-to-beat right ventricular volume response is useful for the monitoring of arrythmia such as atrial fibrillation. (author)

  14. Retinopathy of prematurity and neurodevelopmental disabilities in premature infants.

    Science.gov (United States)

    Beligere, Nagamani; Perumalswamy, Vijayalaksmi; Tandon, Manish; Mittal, Amit; Floora, Jayasheele; Vijayakumar, B; Miller, Marilyn T

    2015-10-01

    Prematurity is a major global health issue leading to high mortality and morbidity among the survivors. Neurodevelopmental disability (NDD) and retinopathy of prematurity (ROP) are the most common complications of prematurity. In fact, ROP is the second leading cause of childhood blindness in the world. Although there is much information regarding the occurrence of ROP and of NDD in premature infants, there have been few studies on ROP and its association with NDD. The objectives of this article are to review the current literature on the subject and to publish our own findings concerning the association between ROP and NDD in premature infants. The review suggests that although NDDs are related to degree of prematurity, NDD could also be the result of visual impairments resulting from ROP. Our own study shows a close association between NDD and zonal involvement of ROP: higher NDD if zone 1 is involved and less if zone 3 is involved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A comparison of auditory evoked potentials to acoustic beats and to binaural beats

    OpenAIRE

    Pratt, H; Starr, A; Michalewski, HJ; Dimitrijevic, A; Bleich, N; Mittelman, N

    2010-01-01

    The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source cur...

  16. Biomarkers of brain injury in the premature infant

    Directory of Open Access Journals (Sweden)

    Martha V. Douglas-Escobar

    2013-01-01

    Full Text Available The term encephalopathy of prematurity encompasses not only the acute brain injury (such as intraventricular hemorrhage but also complex disturbance on the infant’s subsequent brain development. In premature infants, the most frequent recognized source of brain injury is intraventricular hemorrhage (IVH and periventricular leukomalacia (PVL. Furthermore 20-25% infants with birth weigh less than 1,500 g will have IVH and that proportion increases to 45% if the birth weight is less than 500-750 g. In addition, nearly 60% of very low birth weight newborns will have hypoxic-ischemic injury. Therefore permanent lifetime neurodevelopmental disabilities are frequent in premature infants. Innovative approach to prevent or decrease brain injury in preterm infants requires discovery of biomarkers able to discriminate infants at risk for injury, monitor the progression of the injury and assess efficacy of neuroprotective clinical trials. In this article, we will review biomarkers studied in premature infants with IVH, Post-hemorrhagic ventricular dilation (PHVD and PVL including: S100b, Activin A, erythropoietin, chemokine CCL 18, GFAP and NFL will also be examined. Some of the most promising biomarkers for IVH are S100β and Activin. The concentrations of TGF-β1, MMP-9 and PAI-1 in cerebrospinal fluid could be used to discriminate patients that will require shunt after post-hemorrhagic ventricular dilation. Neonatal brain injury is frequent in premature infants admitted to the neonatal intensive care and we hope to contribute to the awareness and interest in clinical validation of established as well as novel neonatal brain injury biomarkers.

  17. Premature emphysema in AIDS

    International Nuclear Information System (INIS)

    Kuhlman, J.E.; Fishman, E.K.; Zerhouni, E.A.; Knowles, M.

    1988-01-01

    The CT scans of 55 patients with acquired immunodeficiency syndrome (AIDS) were reviewed for evidence of pulmonary emphysema. While the average age of patients in this series was 38 years, 25 of the 55 patients, or 45%, demonstrated CT evidence of emphysema. CT findings suggestive of emphysema included areas of low-attenuation, blebs and/or vascular disruption. The authors conclude there is an increased incidence of CT-detectable pulmonary emphysema that is premature for age in patients with AIDS. Destruction of pulmonary parenchyma may represent the response of the lung to repeated pulmonary infections or may be a direct result of the human immunodeficiency virus

  18. Analyzing the Acoustic Beat with Mobile Devices

    Science.gov (United States)

    Kuhn, Jochen; Vogt, Patrik; Hirth, Michael

    2014-01-01

    In this column, we have previously presented various examples of how physical relationships can be examined by analyzing acoustic signals using smartphones or tablet PCs. In this example, we will be exploring the acoustic phenomenon of small beats, which is produced by the overlapping of two tones with a low difference in frequency ?f. The…

  19. Beat my bass, pluck my drum

    NARCIS (Netherlands)

    Hengeveld, B.J.; Funk, M.; Doing, V.

    2014-01-01

    Beating a bass, plucking a drum -- new systems of instruments make it possible. In this paper we describe recent research into networked musical instruments for group improvisation; instruments that reciprocally influence each other's behaviour, making, contrary to what we are used to, the

  20. A Good Suit Beats a Good Idea.

    Science.gov (United States)

    Machiavelli, Nick

    1992-01-01

    Inspired by Niccolo Machiavelli, this column offers beleaguered school executives advice on looking good, dressing well, losing weight, beating the proper enemy, and saying nothing. Administrators who follow these simple rules should have an easier life, jealous colleagues, well-tended gardens, and respectful board members. (MLH)

  1. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  2. Epilepsy is associated with ventricular alterations following convulsive status epilepticus in children.

    Science.gov (United States)

    Ali, Wail; Bubolz, Beth A; Nguyen, Linh; Castro, Danny; Coss-Bu, Jorge; Quach, Michael M; Kennedy, Curtis E; Anderson, Anne E; Lai, Yi-Chen

    2017-12-01

    Convulsive status epilepticus can exert profound cardiovascular effects in adults including ventricular depolarization-repolarization abnormalities. Whether status epilepticus adversely affects ventricular electrical properties in children is less understood. Therefore, we sought to characterize ventricular alterations and the associated clinical factors in children following convulsive status epilepticus. We conducted a 2-year retrospective, case-control study. Children between 1 month and 21 years of age were included if they were admitted to the pediatric intensive care unit with primary diagnosis of convulsive status epilepticus and had 12-lead electrocardiogram (ECG) within 24 hours of admission. Children with heart disease, ion channelopathy, or on vasoactive medications were excluded. Age-matched control subjects had no history of seizures or epilepsy. The primary outcome was ventricular abnormalities represented by ST segment changes, abnormal T wave, QRS axis deviation, and corrected QT (QTc) interval prolongation. The secondary outcomes included QT/RR relationship, beat-to-beat QTc interval variability, ECG interval measurement between groups, and clinical factors associated with ECG abnormalities. Of 317 eligible children, 59 met the inclusion criteria. History of epilepsy was present in 31 children (epileptic) and absent in 28 children (non-epileptic). Compared with the control subjects (n = 31), the status epilepticus groups were more likely to have an abnormal ECG with overall odds ratio of 3.8 and 7.0 for the non-epileptic and the epileptic groups respectively. Simple linear regression analysis demonstrated that children with epilepsy exhibited impaired dependence and adaptation of the QT interval on heart rate. Beat-to-beat QTc interval variability, a marker of ventricular repolarization instability, was increased in children with epilepsy. Convulsive status epilepticus can adversely affect ventricular electrical properties and stability in children

  3. Model for the heart beat-to-beat time series during meditation

    Science.gov (United States)

    Capurro, A.; Diambra, L.; Malta, C. P.

    2003-09-01

    We present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a pacemaker, that simulates the membrane potential of the sinoatrial node, modulated by a periodic input signal plus correlated noise that simulates the respiratory input. The model was used to assess the waveshape of the respiratory signals needed to reproduce in the phase space the trajectory of experimental heart beat-to-beat interval data. The data sets were recorded during meditation practices of the Chi and Kundalini Yoga techniques. Our study indicates that in the first case the respiratory signal has the shape of a smoothed square wave, and in the second case it has the shape of a smoothed triangular wave.

  4. Relationship between age and location of the apex beat among ...

    African Journals Online (AJOL)

    Location of apex beat is an integral part of routine cardiovascular system examination in clinical practice. However, there is paucity of ... Apex beat location in the intercostal space was determined and distance of apex beat from the midline, midclavicular line and nipple lines were measured. The measured distances were ...

  5. Rhythmic regularity revisited : Is beat induction indeed pre-attentive?

    NARCIS (Netherlands)

    Bouwer, F.; Honing, H.; Cambouropoulos, E.; Tsougras, C.; Mavromatis, P.; Pastiadis, K.

    2012-01-01

    When listening to musical rhythm, regularity in time is often perceived in the form of a beat or pulse. External rhythmic events can give rise to the perception of a beat, through a process known as beat induction. In addition, internal processes, like long-term memory, working memory and automatic

  6. Model for the respiratory modulation of the heart beat-to-beat time interval series

    Science.gov (United States)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  7. Paediatric chest wall trauma causing delayed presentation of ventricular arrhythmia.

    Science.gov (United States)

    Tegethoff, Angela M; Raney, Emerald; Mendelson, Jenny; Minckler, Michael R

    2017-07-24

    This report describes a paediatric patient presenting with haemodynamically stable non-sustained ventricular tachycardia 1 day after minor blunt chest trauma. Initial laboratory studies, chest X-ray and echocardiography were normal; however, cardiac MRI revealed precordial haematoma, myocardial contusion and small pericardial effusion. Throughout her hospital course, she remained asymptomatic aside from frequent couplets and triplets of premature ventricular contractions. Ectopy was controlled with oral verapamil. This case highlights how significant cardiac injury may be missed with standard diagnostic algorithms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Lone ventricular cardiomyopathy,

    African Journals Online (AJOL)

    ... (I) cardiac catheterisation, including coronary arteriography and pulmonary ... described existence of lone ventricular idiopathic ... spectrum of classic idiopathic dilated cardiomyopathy. ... endomyocardial fibrosis, and from discussions at an.

  9. Premature ejaculation. 3. Therapy.

    Science.gov (United States)

    Piediferro, Guido; Colpi, Elisabetta M; Castiglioni, Fabrizio; Scroppo, Fabrizio I

    2004-12-01

    Serotonergic drugs (SSRIs) are the most commonly used, but they are characterized by relapse some time after medication interruption as well as by sexual side effects. The efficacy of phosphodiesterase-5 inhibitors seems excellent, but the risk of tachyphylaxis has been reported. The former (fluoxetine, paroxetine, sertraline, clomipramine) should be used in young patients with hyper-orgasmic forms, while the latter (sildenafil, tadalafil, vardenafil) should be used in hypo-orgasmic forms, in old age or when PE is associated with erectile dysfunction. Topical anesthetics provide satisfactory results in premature ejaculation due to hypersensitivity of the glans, and physiotherapy of the pelvic floor muscles proves successful in cases associated with pelvic floor dysfunction. Therapeutic associations and psycho-sexual therapy techniques may improve results, particularly in the long term.

  10. [Retinopathy of prematurity].

    Science.gov (United States)

    Promelle, V; Milazzo, S

    2017-05-01

    Retinopathy of prematurity is a retinal vasoproliferative disease affecting extremely preterm infants exposed to high concentrations of oxygen therapy. Infants born before 32 post-menstrual weeks or with a birth weight of less than 1500g should systematically have a dilated fundus examination. The time of screening and schedule for follow-up are guided by the various risk factors. This disease results from immaturity of the peripheral retinal vessels at the time of premature birth. The classification of ROP depends on the anteroposterior extent of involvement (from center to periphery: zone I, II and III), its extension in 30° sectors (clock hours) and its stage (stage 1 to 5). "Plus" disease is defined as dilation and tortuosity of the retinal blood vessels in the posterior pole of the eye and represents a major risk factor for rapid unfavorable progression. A majority of patients will spontaneously recover, but patients with a high risk of progression will require treatment to prevent retinal detachment and blindness. The indications for treatment are threshold disease and type 1 pre-threshold disease. The current treatment of choice is peripheral retinal ablation with transpupillary laser, but ab externo cryotherapy may be used instead. Intravitreal injection of vascular endothelial growth factor inhibitors may be an attractive therapeutic option and is currently under investigation. After laser treatment, unfavorable outcomes occur in only 9 to 14 % of eyes, but at the price of peripheral retinal destruction. For all patients, whether treated or not, a regular fundus examination should be insured until complete retinal vascularization has occurred. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    Directory of Open Access Journals (Sweden)

    Leila Chaieb

    2017-05-01

    Full Text Available Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz, alpha (10 Hz and gamma (40 Hz beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  12. The Impact of Monaural Beat Stimulation on Anxiety and Cognition.

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke C; Hoppe, Christian; Axmacher, Nikolai; Fell, Juergen

    2017-01-01

    Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz), alpha (10 Hz) and gamma (40 Hz) beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  13. Modeling of Nonlinear Beat Signals of TAE's

    Science.gov (United States)

    Zhang, Bo; Berk, Herbert; Breizman, Boris; Zheng, Linjin

    2012-03-01

    Experiments on Alcator C-Mod reveal Toroidal Alfven Eigenmodes (TAE) together with signals at various beat frequencies, including those at twice the mode frequency. The beat frequencies are sidebands driven by quadratic nonlinear terms in the MHD equations. These nonlinear sidebands have not yet been quantified by any existing codes. We extend the AEGIS code to capture nonlinear effects by treating the nonlinear terms as a driving source in the linear MHD solver. Our goal is to compute the spatial structure of the sidebands for realistic geometry and q-profile, which can be directly compared with experiment in order to interpret the phase contrast imaging diagnostic measurements and to enable the quantitative determination of the Alfven wave amplitude in the plasma core

  14. The impact of binaural beats on creativity

    OpenAIRE

    Susan A. Reedijk; Susan A. Reedijk; Anne eBolders; Anne eBolders; Bernhard eHommel; Bernhard eHommel

    2013-01-01

    Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through st...

  15. Cortical evoked potentials to an auditory illusion: binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2009-08-01

    To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

  16. Ventricular Effective Refraction Period and Ventricular Repolarization Analysis in Experimental Tachycardiomyopathy in Swine.

    Science.gov (United States)

    Noszczyk-Nowak, Agnieszka; Pasławska, Urszula; Gajek, Jacek; Janiszewski, Adrian; Pasławski, Robert; Zyśko, Dorota; Nicpoń, Józef

    2016-01-01

    Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals. The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC). The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed. A one-chamber pacemaker was implanted in each of the 28 pigs. Electrocardiographic, echocardiographic and electrophysiological studies were carried out prior to the pacemaker implantation and at subsequent 4-week intervals. All electrocardiographic, echocardiographic and short electrophysiological study measurements in all swine were done under general anesthesia (propofol) after premedication with midazolam, medetomidine, and ketamine. No significant changes in the duration of QT interval and corrected QT interval (QTc) were observed during consecutive weeks of the experiment. The duration of the QTc interval of female pigs was shown to be significantly longer than that of the males throughout the whole study period. Beginning from the 12th week of rapid ventricular pacing, a significant increase in duration of VERP was observed in both male and female pigs. Males and females did not differ significantly in terms of VERP duration determined throughout the whole study period. Ventricular pacing, stimulation with 2 and 3 premature impulses at progressively shorter coupling intervals and an imposed rhythm of 130 bpm or 150 bpm induced transient ventricular tachycardia in one female pig and four male pigs. One episode of permanent ventricular tachycardia was observed. The number of induced arrhythmias increased proportionally to the severity of heart failure and duration of the experiment. However, relatively aggressive protocols of stimulation were required in order to induce

  17. Antiarrhythmic Effects of Dantrolene in Patients with Catecholaminergic Polymorphic Ventricular Tachycardia and Replication of the Responses Using iPSC Models.

    Directory of Open Access Journals (Sweden)

    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.

  18. Beat-to-beat heart rate estimation fusing multimodal video and sensor data.

    Science.gov (United States)

    Antink, Christoph Hoog; Gao, Hanno; Brüser, Christoph; Leonhardt, Steffen

    2015-08-01

    Coverage and accuracy of unobtrusively measured biosignals are generally relatively low compared to clinical modalities. This can be improved by exploiting redundancies in multiple channels with methods of sensor fusion. In this paper, we demonstrate that two modalities, skin color variation and head motion, can be extracted from the video stream recorded with a webcam. Using a Bayesian approach, these signals are fused with a ballistocardiographic signal obtained from the seat of a chair with a mean absolute beat-to-beat estimation error below 25 milliseconds and an average coverage above 90% compared to an ECG reference.

  19. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session. PMID:24324421

  20. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation.

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session.

  1. Apnea of Prematurity (For Parents)

    Science.gov (United States)

    ... mature enough to allow nonstop breathing. This causes large bursts of breath followed by periods of shallow breathing or stopped breathing. Apnea of prematurity usually ends on its own after a few ...

  2. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  3. Elastohydrodynamic synchronization of adjacent beating flagella

    Science.gov (United States)

    Goldstein, Raymond E.; Lauga, Eric; Pesci, Adriana I.; Proctor, Michael R. E.

    2016-11-01

    It is now well established that nearby beating pairs of eukaryotic flagella or cilia typically synchronize in phase. A substantial body of evidence supports the hypothesis that hydrodynamic coupling between the active filaments, combined with waveform compliance, provides a robust mechanism for synchrony. This elastohydrodynamic mechanism has been incorporated into bead-spring models in which the beating flagella are represented by microspheres tethered by radial springs as they are driven about orbits by internal forces. While these low-dimensional models reproduce the phenomenon of synchrony, their parameters are not readily relatable to those of the filaments they represent. More realistic models, which reflect the underlying elasticity of the axonemes and the active force generation, take the form of fourth-order nonlinear partial differential equations (PDEs). While computational studies have shown the occurrence of synchrony, the effects of hydrodynamic coupling between nearby filaments governed by such continuum models have been examined theoretically only in the regime of interflagellar distances d large compared to flagellar length L . Yet in many biological situations d /L ≪1 . Here we present an asymptotic analysis of the hydrodynamic coupling between two extended filaments in the regime d /L ≪1 and find that the form of the coupling is independent of the microscopic details of the internal forces that govern the motion of the individual filaments. The analysis is analogous to that yielding the localized induction approximation for vortex filament motion, extended to the case of mutual induction. In order to understand how the elastohydrodynamic coupling mechanism leads to synchrony of extended objects, we introduce a heuristic model of flagellar beating. The model takes the form of a single fourth-order nonlinear PDE whose form is derived from symmetry considerations, the physics of elasticity, and the overdamped nature of the dynamics. Analytical

  4. ECOLE POLYTECHNIQUE: Acceleration by plasma beat waves

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    An experiment by a multi-disciplinary team including laser, plasma, accelerator and particle detector specialists at the École Polytechnique, Palaiseau, France, has confirmed the principle of particle acceleration by the 'beating' of laser waves. The first accelerated electrons were detected in May 1994, just after the apparatus had been completely assembled, during the subsequent set of experiments in July, and again in January. In the continual quest for new acceleration methods, such ideas had been proposed for several decades, but it was only about ten years ago that experimental verification of these effects began. In existing accelerators using radiofrequency cavities the electric field is limited to some hundred megavolts per metre, beyond which breakdowns occur. The joint use of power lasers and plasmas, however, should make it possible to generate fields very much greater than a GV/m. The light wave fulfils the same purpose as radiofrequency and the material medium required to couple the electromagnetic energy to the particle beam is provided by the plasma which - already fully ionized - is not destroyed by a breakdown. In the wave-beating method, proposed in 1979 by Dawson and Tajima, two laser waves of adjacent frequencies are transmitted and produce 'beats'. If the frequency of these is equal to the natural oscillation frequency of the plasma electrons, there is resonant energy transfer. The resultant longitudinal electric field is propagated at slightly below the speed of light and may be used to accelerate particles injected into the plasma in the right phase

  5. Record low β beating in the LHC

    Directory of Open Access Journals (Sweden)

    R. Tomás

    2012-09-01

    Full Text Available The LHC is currently operating with a proton energy of 4 TeV and β^{*} functions at the ATLAS and CMS interaction points of 0.6 m. This is close to the design value at 7 TeV (β^{*}=0.55  m and represented a challenge for various aspects of the machine operation. In particular, a huge effort was put into the optics commissioning and an unprecedented peak β beating of around 7% was achieved in a high energy hadron collider.

  6. Ventricular Septal Defect (VSD)

    Science.gov (United States)

    ... Call your doctor if your baby or child: Tires easily when eating or playing Is not gaining ... heart procedures. Risk factors Ventricular septal defects may run in families and sometimes may occur with other ...

  7. Beats on the Table: Beat Writing in the Chicago Review and Big Table

    Directory of Open Access Journals (Sweden)

    Jaap van der Bent

    2012-07-01

    Full Text Available Normal 0 21 false false false NL X-NONE X-NONE MicrosoftInternetExplorer4 Kleine literaire tijdschriften, zogenaamde little magazines, hebben een belangrijke rol gespeeld bij de doorbraak, in de loop van de jaren vijftig, van de Amerikaanse Beat Generation. Aangezien grotere uitgeverijen en de gevestigde tijdschriften lange tijd terugschrokken voor de zowel inhoudelijk als formeel van de norm afwijkende uitingen van de Beats, verscheen hun werk aanvankelijk vooral in kleinere tijdschriften als de twee waaraan in dit artikel aandacht wordt besteed: de Chicago Review en Big Table. Aan de hand van een beschrijving van de inhoud van deze twee tijdschriften wordt geprobeerd duidelijk te maken hoe het werk van de Beat Generation zich in deze tijdschriften gaandeweg een eigen plaats verwierf. Speciale aandacht wordt besteed aan de rol van de redacteuren Irving Rosenthal en Paul Carroll; door zijn uitgekiende strategie om voor het omstreden werk van Beat-auteur William S. Burroughs geleidelijk een steeds grotere plaats in te ruimen, bepaalde vooral Rosenthal het veranderende karakter van de Chicago Review. De veranderingen bij dat tijdschrift verliepen niet zonder slag of stoot en waren voor de eigenaar ervan, de University of Chicago, op een gegeven moment aanleiding om de Chicago Review aan censuur te onderwerpen. Ook deze censuur en de reactie erop, de oprichting van Big Table, worden in het artikel belicht.

  8. Premature pubarche is niet altijd onschuldig

    NARCIS (Netherlands)

    Backes, Manouk; Zwaveling-Soonawala, Nitash; Kamp, Gerdine A.

    2012-01-01

    Premature pubarche is defined as growth of pubic hair before the age of 8 years in girls and 9 years in boys. In most cases, it is caused by premature adrenarche, which is a premature increased synthesis of androgens in the adrenal gland and is considered to be relatively harmless. Premature

  9. Binaural auditory beats affect vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

    1998-01-01

    When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

  10. Nonlinear amplitude dynamics in flagellar beating.

    Science.gov (United States)

    Oriola, David; Gadêlha, Hermes; Casademunt, Jaume

    2017-03-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive cross-linkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatio-temporal dynamics of dynein populations and flagellum shape for different regimes of motor activity, medium viscosity and flagellum elasticity. Unstable modes saturate via the coupling of dynein kinetics and flagellum shape without the need of invoking a nonlinear axonemal response. Hence, our work reveals a novel mechanism for the saturation of unstable modes in axonemal beating.

  11. The role of local voltage potentials in outflow tract ectopy

    DEFF Research Database (Denmark)

    Thomsen, P.E.B.; Johannessen, A.; Jons, C.

    2010-01-01

    in the ventricular premature beats. In 10 patients, ventricular parasystole was suggested by varying coupling intervals > 100 ms, and fusion beats allowing for the estimation of the least common denominator of R-R intervals. In 23 of the 25 patients, the 12-lead electrocardiogram (ECG) and intracardiac contact...... of depressed conductivity known to be a prerequisite for experimental ventricular ectopy including parasystole....

  12. Prenatal stress, prematurity and asthma

    Science.gov (United States)

    Medsker, Brock; Forno, Erick; Simhan, Hyagriv; Celedón, Juan C.

    2016-01-01

    Asthma is the most common chronic disease of childhood, affecting millions of children in the U.S. and worldwide. Prematurity is a risk factor for asthma, and certain ethnic or racial minorities such as Puerto Ricans and non-Hispanic Blacks are disproportionately affected by both prematurity and asthma. In this review, we examine current evidence to support maternal psychosocial stress as a putative link between prematurity and asthma, while also focusing on disruption of the hypothalamic-pituitary-adrenal (HPA) axis and immune responses as potential underlying mechanisms for stress-induced “premature asthma”. Prenatal stress may not only cause abnormalities in the HPA axis but also epigenetic changes in the fetal glucocorticoid receptor gene (NR3C1), leading to impaired glucocorticoid metabolism. Moreover, maternal stress can alter fetal cytokine balance, favoring Th2 (allergic) immune responses characteristic of atopic asthma: IL-6, which has been associated with premature labor, can promote Th2 responses by stimulating production of IL-4 and IL-13. Given a link among stress, prematurity, and asthma, future research should include birth cohorts aimed at confirming and better characterizing “premature asthma”. If confirmed, clinical trials of prenatal maternal stress reduction would be warranted to reduce the burden of these common co-morbidities. While awaiting the results of such studies, sound policies to prevent domestic and community violence (e.g. from firearms) are justified, not only by public safety but also by growing evidence of detrimental effects of violence-induced stress on psychiatric and somatic health. PMID:26676148

  13. Systolic ventricular filling.

    Science.gov (United States)

    Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

    2004-03-01

    The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles

  14. Left ventricular function in right ventricular overload

    International Nuclear Information System (INIS)

    Iwanaga, Shiro; Handa, Shunnosuke; Abe, Sumihisa; Onishi, Shohei; Nakamura, Yoshiro; Kunieda, Etsuo; Ogawa, Koichi; Kubo, Atsushi

    1989-01-01

    This study clarified regional and global functions of the distorted left ventricle due to right ventricular overload by gated radionuclide ventriculography (RNV). Cardiac catheterization and RNV were performed in 13 cases of atrial septal defect (ASD), 13 of pure mitral stenosis (MS), 10 of primary pulmonary hypertension (PPH), and 10 of normal subjects (NL). Right ventricular systolic pressure (RVSP) was 32.9±13.9, 45.0±12.2, 88.3±17.1, and 21.2±4.5 mmHg, respectively. The end-systolic LAO view of the left ventricle was halved into septal and free-wall sides. The end-diastolic halves were determined in the same plane. Ejection fractions of the global left ventricle (LVEF), global right ventricle (RVEF), the septal half of the left ventricle (SEPEF), and the free-wall half of the left ventricle (FWEF) were obtained. LVEF was 56.8±9.8% in NL, 52.8±10.5% in ASD, and 49.5±12.9% in PPH. In MS, LVEF (47.0±13.0%) was smaller than those in the other groups. RVEF was 37.0±5.2% in NL, 43.7±15.5% in ASD, and 32.8±11.5% in MS. In PPH, RVEF (25.0±10.6%) was smaller than those in the other groups. SEPEF was smaller in ASD (42.5±13.2%), MS (40.4±13.1%), PPH (40.5±12.5%) than in NL (53.5±8.5%). Systolic function of the septal half of the left ventricle was disturbed by right ventricular overload. RVEF (r=-0.35, p<0.05) and SEPEF (r=-0.51, p<0.01) had negative correlations with RVSP. As RVSP rose, systolic function of the septal half of the left ventricle was more severely disturbed. FWEF was the same among the four groups; NL (57.0±12.6%), ASD (48.6±15.2%), MS (50.5±12.0%), and PPH (51.1±12.3%). There was a good correlation between SEPEF and LVEF in NL (r=0.81), although in PPH this correlation was poor (r=0.64). These data showed that the distorted left ventricular due to right ventricular overload maintains its global function with preserved function of the free-wall side. (J.P.N.)

  15. Evaluation of the influence of change in heart rate on left ventricular diastolic function indices

    International Nuclear Information System (INIS)

    Kimura, Motomasa; Yamagishi, Hiroaki; Seino, Yasuyuki; Odano, Ikuo; Sakai, Kunio; Yamamoto, Tomohiko; Tsuda, Takashi

    1988-01-01

    In order to assess the influence of change in heart rate on left ventricular diastolic function indices, ECG gated cardiac pool study was performed in 6 patients with implanted programmable AAI pacemakers. Heart rate was changed by atrial pacing from 50 to 120 beats/min, every 10 beats/min. The filling fraction during first third of diastole (1/3FF), the peak filling rate (PFR), mean first third filling rate (1/3FR-mean) and early filling volume ratio (%EFV), being used as the indices of left ventricular diastolic performance, were assessed. In accordance with increase in heart rate, 1/3FF decreased significantly. PFR were fairly stable from 50 to 80 beats/min, but increased significantly from 90 to 120 beats/min. 1/3FR-mean and %EFV did not change significantly, but 1/3FR-mean showed decreasing tendency and %EFV showed increasing tendency as the heart rate was increased. %EFV was more changeable index than other indices among clinical cases. These results indicate that PFR and 1/3FR-mean were appropriate diastolic phase indices at rest. (author)

  16. Educational paper: Retinopathy of prematurity.

    Science.gov (United States)

    Casteels, Ingele; Cassiman, Catherine; Van Calster, Joachim; Allegaert, Karel

    2012-06-01

    Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease affecting the premature infant with an incompletely vascularized retina. The spectrum of ophthalmological findings in ROP exists from minimal sequelae, which do not affect vision, to bilateral retinal detachment and total blindness. With the increased survival of very small infants, retinopathy of prematurity has become one of the leading causes of childhood blindness. Over the past two decades, major advances have been made in understanding the pathogenesis of ROP, to a large extent as a result of changes in clinical risk factors (oxygen and non-oxygen related) and characteristics observed in ROP cases. This article provides a literature review on the evolution in clinical characteristics, classification and treatment modalities and indications of ROP. Special attention is hereby paid to the neonatal factors influencing the development of ROP and to the necessity for everyone caring for premature babies to have a well-defined screening and treatment protocol for ROP. Such screening protocol needs to be based on a unit-specific ROP risk profile and, consequently, may vary between different European regions. Retinopathy of prematurity is an important cause of ocular morbidity and blindness in children. With better understanding of the pathogenesis, screening and treatment guidelines have changed over time and are unit specific.

  17. Classification of ECG beats using deep belief network and active learning.

    Science.gov (United States)

    G, Sayantan; T, Kien P; V, Kadambari K

    2018-04-12

    A new semi-supervised approach based on deep learning and active learning for classification of electrocardiogram signals (ECG) is proposed. The objective of the proposed work is to model a scientific method for classification of cardiac irregularities using electrocardiogram beats. The model follows the Association for the Advancement of medical instrumentation (AAMI) standards and consists of three phases. In phase I, feature representation of ECG is learnt using Gaussian-Bernoulli deep belief network followed by a linear support vector machine (SVM) training in the consecutive phase. It yields three deep models which are based on AAMI-defined classes, namely N, V, S, and F. In the last phase, a query generator is introduced to interact with the expert to label few beats to improve accuracy and sensitivity. The proposed approach depicts significant improvement in accuracy with minimal queries posed to the expert and fast online training as tested on the MIT-BIH Arrhythmia Database and the MIT-BIH Supra-ventricular Arrhythmia Database (SVDB). With 100 queries labeled by the expert in phase III, the method achieves an accuracy of 99.5% in "S" versus all classifications (SVEB) and 99.4% accuracy in "V " versus all classifications (VEB) on MIT-BIH Arrhythmia Database. In a similar manner, it is attributed that an accuracy of 97.5% for SVEB and 98.6% for VEB on SVDB database is achieved respectively. Graphical Abstract Reply- Deep belief network augmented by active learning for efficient prediction of arrhythmia.

  18. What makes a rhythm complex? The influence of musical training and accent type on beat perception.

    Science.gov (United States)

    Bouwer, Fleur L; Burgoyne, J Ashley; Odijk, Daan; Honing, Henkjan; Grahn, Jessica A

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are "missing" on the beat, the beat is more difficult to find. However, it is unclear whether accents occurring off the beat alter beat perception similarly to missing accents on the beat. Moreover, no one has examined whether intensity accents influence beat perception more or less strongly than temporal accents, nor how musical expertise affects sensitivity to each type of accent. In two experiments, we obtained ratings of difficulty in finding the beat in rhythms with either temporal or intensity accents, and which varied in the number of accents on the beat as well as the number of accents off the beat. In both experiments, the occurrence of accents on the beat facilitated beat detection more in musical experts than in musical novices. In addition, the number of accents on the beat affected beat finding more in rhythms with temporal accents than in rhythms with intensity accents. The effect of accents off the beat was much weaker than the effect of accents on the beat and appeared to depend on musical expertise, as well as on the number of accents on the beat: when many accents on the beat are missing, beat perception is quite difficult, and adding accents off the beat may not reduce beat perception further. Overall, the different types of accents were processed qualitatively differently, depending on musical expertise. Therefore, these findings indicate the importance of designing ecologically valid stimuli when testing beat perception in musical novices, who may need different types of accent information than musical experts to be able to find a beat. Furthermore, our findings stress the importance of carefully designing rhythms for social and clinical applications of beat perception, as not

  19. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap seimconductors (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas

  20. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap semiconductor (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas. (author). 7 refs

  1. Dependence of intramyocardial pressure and coronary flow on ventricular loading and contractility: a model study.

    Science.gov (United States)

    Bovendeerd, Peter H M; Borsje, Petra; Arts, Theo; van De Vosse, Frans N

    2006-12-01

    The phasic coronary arterial inflow during the normal cardiac cycle has been explained with simple (waterfall, intramyocardial pump) models, emphasizing the role of ventricular pressure. To explain changes in isovolumic and low afterload beats, these models were extended with the effect of three-dimensional wall stress, nonlinear characteristics of the coronary bed, and extravascular fluid exchange. With the associated increase in the number of model parameters, a detailed parameter sensitivity analysis has become difficult. Therefore we investigated the primary relations between ventricular pressure and volume, wall stress, intramyocardial pressure and coronary blood flow, with a mathematical model with a limited number of parameters. The model replicates several experimental observations: the phasic character of coronary inflow is virtually independent of maximum ventricular pressure, the amplitude of the coronary flow signal varies about proportionally with cardiac contractility, and intramyocardial pressure in the ventricular wall may exceed ventricular pressure. A parameter sensitivity analysis shows that the normalized amplitude of coronary inflow is mainly determined by contractility, reflected in ventricular pressure and, at low ventricular volumes, radial wall stress. Normalized flow amplitude is less sensitive to myocardial coronary compliance and resistance, and to the relation between active fiber stress, time, and sarcomere shortening velocity.

  2. Experimental Observation of Chaotic Beats in Oscillators Sharing Nonlinearity

    Science.gov (United States)

    Paul Asir, M.; Jeevarekha, A.; Philominathan, P.

    This paper deals with the generation of chaotic beats in a system of two forced dissipative LCR oscillators sharing a nonlinear element. The presence of two external periodic excitations and a common nonlinear element in the chosen system enables the facile generation of chaotic beats. Thus rendered chaotic beats were characterized in both time domain and phase space. Lyapunov exponents and envelope of the beats were computed to diagnose the chaotic nature of the signals. The role of common nonlinearity on the complexity of the generated beats is discussed. Real-time experimental hardware implementation has also been done to confirm the subsistence of the phenomenon, for the first time. Extensive Multisim simulations were carried out to understand, a bit more about the shrinkage and revivals of state variables in phase space.

  3. Usefulness of ventricular endocardial electric reconstruction from body surface potential maps to noninvasively localize ventricular ectopic activity in patients

    Science.gov (United States)

    Lai, Dakun; Sun, Jian; Li, Yigang; He, Bin

    2013-06-01

    As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23-77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.

  4. Beating Social Democracy on Its Own Turf

    DEFF Research Database (Denmark)

    Arndt, Christoph

    2014-01-01

    -right parties to flourish in contexts where welfare issues have a natural salience as in the case of universal welfare states. In contrast, Scandinavian universal welfare states ought to benefit social democracy when it comes to issue voting on welfare issues. It is argued in this article that centre......-right parties can beat social democrats by credibly converging to its social democratic opponent on issues of universal welfare. Issue ownership voting to the benefit of centre-right parties will then be strongest among voters perceiving the centre-right to have converged to social democracy and perceiving...... the centre-right as issue-owner. Using Danish National Election Studies, 1998–2007, the article shows that the Danish Liberal Party outperformed the Social Democrats on traditional welfare issues among those voters perceiving the Liberals to be ideologically close to the social democrats. The findings help...

  5. Beat wave current drive experiment on DDT

    International Nuclear Information System (INIS)

    Hwang, D.Q.

    1991-03-01

    Several improvements have been made to the beat wave experiment this year. We are now able to vary the magnetic field over a much larger range, the plasma density is more uniform, and the electron temperature is significantly higher than last year (making it easier to couple energy from the electrostatic wave into the electron distribution). We have found evidence that at higher magnetic fields, ω ce /ω pe > 1, that numerous electrostatic modes are excited. This may be due to the fact that for a bounded plasma, ω pe is allowed (for small wave numbers). Although we are still not sure why the rvec k matching criteria (rvec k 0 = rvec k 1 + rvec k e ) is not more restrictive. A 35 GHz microwave scattering diagnostic has been designed, built, and tested in order to make a less perturbing measure of the electrostatic wave

  6. Arrhythmogenic right ventricular dysplasia

    International Nuclear Information System (INIS)

    Vignolo Puglia, W.; Freire Colla, D.; Rivara Urrutia, D.; Lujambio Grene, M.; Arbiza Bruno, T.; Oliveira, G.; Cobas Rodriguez, J.

    1997-01-01

    The arrhythmogenic right ventricular dysplasia is a condition predominantly well defined with arrhythmic events. We analyze three cases diagnosed by the group. These cases were presented as ventricular tachycardia with a morphology of left bundle branch block, presenting one of them aborted sudden death in evolution. The baseline electrocardiogram and signal averaging were abnormal in two of the three cases, like the echocardiogram. The electrophysiological study was able to induce in the three patients with sustained monomorphic ventricular tachycardia morphology of left bundle branch block. The definitive diagnosis was made by right ventriculography in two cases and magnetic resonance imaging in the other. Treatment included antiarrhythmic drugs in the three cases and the placement of an automatic defibrillator which survived a sudden death (Author)

  7. The impact of beat-to-beat variability in optimising the acute hemodynamic response in cardiac resynchronisation therapy

    Directory of Open Access Journals (Sweden)

    Steven Niederer

    2015-12-01

    Conclusion: The beat-to-beat variation in AHR is significant in the context of CRT cut off values. A LOS optimisation offers a novel index to identify the optimal pacing site that accounts for both the mean and variation of the baseline measurement and pacing protocol.

  8. Beating time: How ensemble musicians' cueing gestures communicate beat position and tempo.

    Science.gov (United States)

    Bishop, Laura; Goebl, Werner

    2018-01-01

    Ensemble musicians typically exchange visual cues to coordinate piece entrances. "Cueing-in" gestures indicate when to begin playing and at what tempo. This study investigated how timing information is encoded in musicians' cueing-in gestures. Gesture acceleration patterns were expected to indicate beat position, while gesture periodicity, duration, and peak gesture velocity were expected to indicate tempo. Same-instrument ensembles (e.g., piano-piano) were expected to synchronize more successfully than mixed-instrument ensembles (e.g., piano-violin). Duos performed short passages as their head and (for violinists) bowing hand movements were tracked with accelerometers and Kinect sensors. Performers alternated between leader/follower roles; leaders heard a tempo via headphones and cued their partner in nonverbally. Violin duos synchronized more successfully than either piano duos or piano-violin duos, possibly because violinists were more experienced in ensemble playing than pianists. Peak acceleration indicated beat position in leaders' head-nodding gestures. Gesture duration and periodicity in leaders' head and bowing hand gestures indicated tempo. The results show that the spatio-temporal characteristics of cueing-in gestures guide beat perception, enabling synchronization with visual gestures that follow a range of spatial trajectories.

  9. HEART: an automated beat-to-beat cardiovascular analysis package using Matlab.

    Science.gov (United States)

    Schroeder, M J Mark J; Perreault, Bill; Ewert, D L Daniel L; Koenig, S C Steven C

    2004-07-01

    A computer program is described for beat-to-beat analysis of cardiovascular parameters from high-fidelity pressure and flow waveforms. The Hemodynamic Estimation and Analysis Research Tool (HEART) is a post-processing analysis software package developed in Matlab that enables scientists and clinicians to document, load, view, calibrate, and analyze experimental data that have been digitally saved in ascii or binary format. Analysis routines include traditional hemodynamic parameter estimates as well as more sophisticated analyses such as lumped arterial model parameter estimation and vascular impedance frequency spectra. Cardiovascular parameter values of all analyzed beats can be viewed and statistically analyzed. An attractive feature of the HEART program is the ability to analyze data with visual quality assurance throughout the process, thus establishing a framework toward which Good Laboratory Practice (GLP) compliance can be obtained. Additionally, the development of HEART on the Matlab platform provides users with the flexibility to adapt or create study specific analysis files according to their specific needs. Copyright 2003 Elsevier Ltd.

  10. Prognostic Significance of Blood Pressure Variability on Beat-to-Beat Monitoring After Transient Ischemic Attack and Stroke.

    Science.gov (United States)

    Webb, Alastair J S; Mazzucco, Sara; Li, Linxin; Rothwell, Peter M

    2018-01-01

    Visit-to-visit and day-to-day blood pressure (BP) variability (BPV) predict an increased risk of cardiovascular events but only reflect 1 form of BPV. Beat-to-beat BPV can be rapidly assessed and might also be predictive. In consecutive patients within 6 weeks of transient ischemic attack or nondisabling stroke (Oxford Vascular Study), BPV (coefficient of variation) was measured beat-to-beat for 5 minutes (Finometer), day-to-day for 1 week on home monitoring (3 readings, 3× daily), and on awake ambulatory BP monitoring. BPV after 1-month standard treatment was related (Cox proportional hazards) to recurrent stroke and cardiovascular events for 2 to 5 years, adjusted for mean systolic BP. Among 520 patients, 26 had inadequate beat-to-beat recordings, and 22 patients were in atrial fibrillation. Four hundred five patients had all forms of monitoring. Beat-to-beat BPV predicted recurrent stroke and cardiovascular events independently of mean systolic BP (hazard ratio per group SD, stroke: 1.47 [1.12-1.91]; P =0.005; cardiovascular events: 1.41 [1.08-1.83]; P =0.01), including after adjustment for age and sex (stroke: 1.47 [1.12-1.92]; P =0.005) and all risk factors (1.40 [1.00-1.94]; P =0.047). Day-to-day BPV was less strongly associated with stroke (adjusted hazard ratio, 1.29 [0.97-1.71]; P =0.08) but similarly with cardiovascular events (1.41 [1.09-1.83]; P =0.009). BPV on awake ambulatory BP monitoring was nonpredictive (stroke: 0.89 [0.59-1.35]; P =0.59; cardiovascular events: 1.08 [0.77-1.52]; P =0.65). Despite a weak correlation ( r =0.119; P =0.02), beat-to-beat BPV was associated with risk of recurrent stroke independently of day-to-day BPV (1.41 [1.05-1.90]; P =0.02). Beat-to-beat BPV predicted recurrent stroke and cardiovascular events, independently of mean systolic BP and risk factors but short-term BPV on ambulatory BP monitoring did not. Beat-to-beat BPV may be a useful additional marker of cardiovascular risk. © 2017 The Authors.

  11. PREMATURE RUPTURE OF THE MEMBRANES*

    African Journals Online (AJOL)

    In patients presenting with premature rupture of the membranes there are two factors which influence the foetal morbidity and mortality. These factors are prema- turity and intra-uterine infection. The purpose of this analysis was to elucidate which factor carried the greater risk to the foetus. Recently there has been a spate of.

  12. Mothers' Retrospections of Premature Childbirth.

    Science.gov (United States)

    Kalmar, Magda; And Others

    This study examined Hungarian mothers' recollections, 8 years after the birth of their premature baby, of their stress at the time of the baby's birth. Interviews were conducted with 30 mothers whose babies had been born between 30 and 37 weeks gestational age. At the time of the follow-up, all children had normal IQs and were attending normal…

  13. Noninvasive Ventilation in Premature Neonates.

    Science.gov (United States)

    Flanagan, Keri Ann

    2016-04-01

    The use of noninvasive ventilation is a constantly evolving treatment option for respiratory disease in the premature infant. The goals of these noninvasive ventilation techniques are to improve gas exchange in the premature infant's lungs and to minimize the need for intubation and invasive mechanical ventilation. The goals of this article are to consider various uses of nasal interfaces, discuss skin care and developmental positioning concerns faced by the bedside nurse, and discuss the medical management aimed to reduce morbidity and mortality. This article explores the nursing role, the advances in medical strategies for noninvasive ventilation, and the team approach to noninvasive ventilation use in this population. Search strategy included a literature review on medical databases, such as EBSCOhost, CINAHL, PubMed, and NeoReviews. Innovative products, nursing research on developmental positioning and skin care, and advanced medical management have led to better and safer outcomes for premature infants requiring noninvasive ventilation. The medical focus of avoiding long-term mechanical ventilation would not be possible without the technology to provide noninvasive ventilation to these premature infants and the watchful eye of the nurse in terms of careful positioning, preventing skin breakdown and facial scarring, and a proper seal to maximize ventilation accuracy. This article encourages nursing-based research to quantify some of the knowledge about skin care and positioning as well as research into most appropriate uses for noninvasive ventilation devices.

  14. Music Therapy with Premature Infants

    Science.gov (United States)

    Standley, Jayne

    2003-01-01

    Over 20 years of research and clinical practice in music therapy with premature infants has been compiled into this text designed for Board Certified Music Therapists specializing in Neonatal Intensive Care clinical services, for NICU medical staff incorporating research-based music therapy into developmental care plans, and for parents of…

  15. Complications of Prematurity - An Infographic

    Science.gov (United States)

    Chandrasekharan, Praveen; Rawat, Munmun; Lakshminrusimha, Satyan

    2017-01-01

    Infographics or information graphics are easy-to-understand visual representation of knowledge. An infographic outlining the course of an extremely preterm infant and various potential complications encountered during a neonatal intensive care unit (NICU) stay was developed. This infographic can be used to discuss outcomes of prematurity during prenatal counseling and while the infant is in the NICU. PMID:29138522

  16. Ventricular performance during exercise in patients with chronic obstructive pulmonary disease (COPD)

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Iwao; Akashiba, Tsuneto; Horie, Takashi [Nihon Univ., Tokyo (Japan). School of Medicine

    1992-01-01

    We assessed ventricular performance during exercise in 16 chronic obstructive pulmonary disease (COPD) patients and 8 normal control subjects by means of radionuclide equilibrium angiography using technetium-99m as a tracer. Supine exercise on a bicycle ergometer was performed until symptom-limited exhaustion. Data were accumulated for 300 heart beats at rest and 150 heart beats during exercise. We used the standard voxel count method to calculate the ventricular volumes. Age, FEV{sub 1.0}%, %VC, PaO{sub 2} and PaCO{sub 2} of the COPD patients were 63{+-}8 yr, 46{+-}11%, 69{+-}18%, 68{+-}11 Torr and 44{+-}7 Torr (mean{+-}SD), respectively. Systolic dysfunction of both the left and right ventricles was well confirmed in the present study. In 12 patients who also underwent hemodynamic studies, resting total pulmonary vascular resistance index (TPVRI) and mean pulmonary artery pressure (P-barpa) significantly correlated with right ventricular end-systolic volume index (RVESVI) obtained by RI angiography; {gamma}=0.769 (p<0.01) and {gamma}=0.631 (p<0.05), respectively. A significant relationship was also observed between left ventricular dysfunction and the degree of hypercapnia. In response to exercise testing, 10 of 16 patients exhibited insufficient augmentation of stroke volume, and both left and right end-diastolic volumes decreased in half of 10 patients. It is suggested that cardiac function may be disturbed by mechanical factors such as pulmonary hyperinflation in COPD patients. (author).

  17. A clinical trial of the beta blocker propranolol in premature ejaculation.

    Science.gov (United States)

    Cooper, A J; Magnus, R V

    1984-01-01

    Twelve male patients, with a primary complaint of premature ejaculation in a setting of chronic anxiety with prominent somatic manifestations, participated in a double-blind trial: propranolol against placebo. The study consisted of 5 X 4 week phases: run-in, propranolol or placebo--120 mg/day allocated randomly, wash-out; placebo or propranolol and run-out, in a balanced design. Anxiety was rated initially, and every 2 weeks, throughout the trial using the Hamilton Rating Scale. Sitting blood pressure and pulse were also noted. The time to coital ejaculation (every 3 days) was recorded using a stopwatch, and subjects were also required to rate "overall coital satisfaction" and "quality of erection". Neither prematurity nor other signs/symptoms of anxiety improved on the preparations, which were statistically equivalent. Moderate beta-blockade was achieved with propranolol as evidenced by a median reduction in pulse rate of 5 beats/min.

  18. Measuring and characterizing beat phenomena with a smartphone

    Science.gov (United States)

    Osorio, M.; Pereyra, C. J.; Gau, D. L.; Laguarda, A.

    2018-03-01

    Nowadays, smartphones are in everyone’s life. Apart from being excellent tools for work and communication, they can also be used to perform several measurements of simple physical magnitudes, serving as a mobile and inexpensive laboratory, ideal for use physics lectures in high schools or universities. In this article, we use a smartphone to analyse the acoustic beat phenomena by using a simple experimental setup, which can complement lessons in the classroom. The beats were created by the superposition of the waves generated by two tuning forks, with their natural frequencies previously characterized using different applications. After the characterization, we recorded the beats and analysed the oscillations in time and frequency.

  19. Aggressive Posterior Retinopathy of Prematurity in a Premature Male Infant

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2017-07-01

    Full Text Available A premature male infant was born at 30 weeks’ gestation with a birth weight of 1,700 g in a rural hospital. He was diagnosed with respiratory distress syndrome and received continuous positive airway pressure treatment for 26 days. At 26 days after birth, the patient was transferred to our hospital for further evaluation and management. A comprehensive eye examination revealed a stage 3 retinopathy of prematurity (ROP involving zone 2 in both eyes. The patient was recommended to a provincial-level eye hospital for emergency laser therapy. Five months after birth, the feedback from the eye hospital showed that the patient had a high risk of blindness in both eyes. Our case report shows that delaying first screening examination increases the possibility of developing aggressive posterior ROP in infants with ROP. Doctors in rural hospitals should be aware of this possibility and trained for early screening and treatment in high-risk infants.

  20. Haemodynamic effects of dual-chamber pacing versus ventricular pacing during a walk test in patients with depressed or normal left ventricular function

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, Adele; Salvatore, Marco; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructure and Bioimages of the National Council of Research, Naples (Italy); Duilio, Carlo; Santomauro, Maurizio [University Federico II, Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)

    2005-09-01

    Dual-chamber rate-modulated pacing provides haemodynamic benefits compared with ventricular pacing at rest, but it is unclear whether this also holds true during physical exercise in patients with heart failure. This study assessed the haemodynamic response to a walk test during dual-chamber pacing and ventricular pacing in patients with depressed or normal left ventricular (LV) function. Twelve patients with an LV ejection fraction <50% and 11 patients with an LV ejection fraction {>=}50% underwent two randomised 6-min walk tests under dual-chamber rate-modulated pacing and ventricular pacing at a fixed rate of 70 beats/min. All patients had a dual-chamber pacemaker implanted for complete heart block. LV function was monitored by a radionuclide ambulatory system. In patients with depressed LV function, the change from dual-chamber pacing to ventricular pacing induced a decrease in end-systolic volume at the peak of the walk test (P<0.05), with no difference in end-diastolic volume. As a consequence, higher increases in LV ejection fraction (P<0.0001) and stroke volume (P<0.01) were observed during ventricular pacing. No difference in cardiac output was found between the two pacing modes. In patients with normal LV function, the change from dual-chamber pacing to ventricular pacing induced a significant decrease in cardiac output (P<0.005 at rest and P<0.05 at the peak of the walk test). Compared with dual-chamber rate-modulated pacing, ventricular pacing improves cardiac function and does not affect cardiac output during physical activity in patients with depressed LV function, whereas it impairs cardiac output in those with normal function. (orig.)

  1. Haemodynamic effects of dual-chamber pacing versus ventricular pacing during a walk test in patients with depressed or normal left ventricular function

    International Nuclear Information System (INIS)

    Ferro, Adele; Salvatore, Marco; Cuocolo, Alberto; Duilio, Carlo; Santomauro, Maurizio

    2005-01-01

    Dual-chamber rate-modulated pacing provides haemodynamic benefits compared with ventricular pacing at rest, but it is unclear whether this also holds true during physical exercise in patients with heart failure. This study assessed the haemodynamic response to a walk test during dual-chamber pacing and ventricular pacing in patients with depressed or normal left ventricular (LV) function. Twelve patients with an LV ejection fraction <50% and 11 patients with an LV ejection fraction ≥50% underwent two randomised 6-min walk tests under dual-chamber rate-modulated pacing and ventricular pacing at a fixed rate of 70 beats/min. All patients had a dual-chamber pacemaker implanted for complete heart block. LV function was monitored by a radionuclide ambulatory system. In patients with depressed LV function, the change from dual-chamber pacing to ventricular pacing induced a decrease in end-systolic volume at the peak of the walk test (P<0.05), with no difference in end-diastolic volume. As a consequence, higher increases in LV ejection fraction (P<0.0001) and stroke volume (P<0.01) were observed during ventricular pacing. No difference in cardiac output was found between the two pacing modes. In patients with normal LV function, the change from dual-chamber pacing to ventricular pacing induced a significant decrease in cardiac output (P<0.005 at rest and P<0.05 at the peak of the walk test). Compared with dual-chamber rate-modulated pacing, ventricular pacing improves cardiac function and does not affect cardiac output during physical activity in patients with depressed LV function, whereas it impairs cardiac output in those with normal function. (orig.)

  2. Outcomes for Extremely Premature Infants

    Science.gov (United States)

    Glass, Hannah C.; Costarino, Andrew T.; Stayer, Stephen A.; Brett, Claire; Cladis, Franklyn; Davis, Peter J.

    2015-01-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for four years and is now approximately 11.5%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23–24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal EDC. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (ELBW) (CPAP, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91–95% (compared to 85–89%) avoids excess mortality. However, final analyses of data from these trials have not been published, so definitive recommendations are still pending The development of neonatal neurocognitive care visits may improve neurocognitive outcomes in this high-risk group. Long-term follow up to detect and address developmental, learning, behavioral, and social problems is critical for children born at these early gestational ages. The striking similarities in response to extreme prematurity in the lung and brain imply that agents and

  3. "'Jackin’ for Beats'": DJing for Citation Critique

    Directory of Open Access Journals (Sweden)

    Todd Craig

    2013-10-01

    Full Text Available A challenge in teaching English composition is helping students envision plagiarism as “borrowing” – showing love to author(s and/or text(s that further their argument(s, versus “stealing” – biting someone’s style and words. Alastair Pennycook (1996 and Sarah Wakefield (2006 have contributed pieces to the elaborate plagiarism/citation puzzle, while Houston Baker situated the hip-hop DJ in seminal text Black Studies, Rap and the Academy (1993. Merging these moments introduces critical questions: Did Diddy invent “the remix” or become the illest beat-biter ever? How did DJ/Producers Pete Rock and Large Professor pay homage to previous musical genres to further hip-hop remix production without just taking 4-8 bar samples, copying sources and claiming unethical ownership? And how can this discussion provide students a window into citation conversations? This article will remix these “texts” to introduce the idea of DJ Rhetoric to discuss plagiarism. Through the lens of the hip-hop DJ in writing classrooms, one can foster an appreciation of the difference between “love and theft” in student citation. This article will couple examples from hip-hop music/culture while simultaneously remixing interviews from various hip-hop DJ/producers to help answer these difficult questions.

  4. Speed of light demonstration using Doppler beat

    Science.gov (United States)

    Bernal, Luis; Bilbao, Luis

    2018-05-01

    From an apparatus previously designed for measuring the Doppler shift using a rotating mirror, an improved, versatile version was developed for speed of light demonstrations in a classroom or a teaching laboratory. By adding a second detector and adequate beam-splitter and mirrors, three different configurations are easily assembled. One configuration is used for time-of-flight measurements between a near and a far detector, allowing one to measure the speed of light provided that the path length between detectors is known. Another variation is the interferometric method obtained by superposing the far and near signals in such a way that a minimum of the combined signal is obtained when the time delay makes the signals arrive out of phase by π radians. Finally, the standard Doppler configuration allows the measurement of the frequency beat as a function of the rotation frequency. The main advantages of the apparatus are (a) the experimental setup is simple and completely accessible to undergraduate students, (b) the light is visible, students can see the rays, which, with the use of appropriate screens, can be blocked at any point along their paths, (c) the experiment can take place entirely within the teaching laboratory or demonstration room (using the interferometric method, the shortest distance to the far mirror was as small as 0.5 m), and (d) different configurations can be built, including some economical setups within the budget of teaching laboratories.

  5. Receiver operating characteristics of diagnostic efficacy of resting left ventricular performance (evaluating with a non-imaging ECG gated scintillation detector - nuclear stethoscope)

    International Nuclear Information System (INIS)

    Kotlyarov, E.V.; Reba, R.C.; Lindsay, J.

    1983-01-01

    Receiver operating characteristic (ROC) analysis of left ventricular performance at rest was applied to evaluate diagnostic utility of non-imaging nuclear detector (''Nuclear Stethoscope''), for screening patients with coronary artery disease (CAD). Thirty-one patients without CAD and normal rest and stress radionuclide ventriculography (MUGA) were used as a control group. Another 62 patients with abnormal left ventricular reserve and segmental wall motion abnormalities at rest were also studied. All 93 patients were studied with the Nuclear Stethoscope (30 minutes after conventional MUGA testing) both in beat-to-beat and gated equilibrium modes. ROC analysis showed that along with ejection fraction, stroke and end-diastolic volumes, evaluation of the left ventricular filling phase has a great potential for the identification of patients with a segmental wall motion abnormality and, therefore, significant CAD

  6. [Regeneration of the ciliary beat of human ciliated cells].

    Science.gov (United States)

    Wolf, G; Koidl, B; Pelzmann, B

    1991-10-01

    The influence of an isotonic, alkaline saline solution (diluted "Emser Sole" or brine from the spa of Bad Ems) on the ciliary beat of isolated cultured human ciliated cells of the upper respiratory tract was investigated. The ciliary beat was observed via an inverted phase contrast microscope (Zeiss Axiomat IDPC) and measured microphotometrically under physiological conditions and after the damaging influence of 1% propanal solution. Under physiological conditions the saline solution had a positive, although statistically not significant influence on the frequency of the ciliary beat. After damage of the cultivated cells by 1% propanal solution, the saline solution had a significant better influence on the regeneration of the cultured cells than a physiological sodium chloride solution. It is concluded that diluted brine from Bad Ems has a positive effect on the ciliary beat of the respiratory epithelium and accelerates its regeneration after damage by viral and bacterial infections, surgery or inhaled noxae.

  7. Keep the Beat Recipes | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... the Beat Recipes: Deliciously Healthy Dinners. The new cookbook features 75 simple and delicious recipes influenced by ... nhlbi.nih.gov/files/docs/public/heart/Dinners_Cookbook_508-compliant.pdf . Fall 2011 Issue: Volume 6 ...

  8. Association of Smoking, Sleep Apnea, and Plasma Alkalosis With Nocturnal Ventricular Arrhythmias in Men With Systolic Heart Failure

    Science.gov (United States)

    Shukla, Rakesh; Wexler, Laura

    2012-01-01

    Background: Excess sudden death due to ventricular tachyarrhythmias remains a major mode of mortality in patients with systolic heart failure. The aim of this study was to determine the association of nocturnal ventricular arrhythmias in patients with low ejection fraction heart failure. We incorporated a large number of known pathophysiologic triggers to identify potential targets for therapy to reduce the persistently high incidence of sudden death in this population despite contemporary treatment. Methods: Eighty-six ambulatory male patients with stable low (≤ 45%) ejection fraction heart failure underwent full-night attendant polysomnography and simultaneous Holter recordings. Patients were divided into groups according to the presence or absence of couplets (paired premature ventricular excitations) and ventricular tachycardia (VT) (at least three consecutive premature ventricular excitations) during sleep. Results: In multiple regression analysis, four variables (current smoking status, increased number of arousals, plasma alkalinity, and old age) were associated with VT and two variables (apnea-hypopnea index and low right ventricular ejection fraction) were associated with couplets during sleep. Conclusions: We speculate that cessation of smoking, effective treatment of sleep apnea, and plasma alkalosis could collectively decrease the incidence of nocturnal ventricular tachyarrhythmias and the consequent risk of sudden death, which remains high despite the use of β blockades. PMID:22172636

  9. Does training with beat gestures favour children's narrative discourse abilities?

    OpenAIRE

    Vilà Giménez, Ingrid

    2016-01-01

    There is consensus evidence that gestures and prosody are important precursors of children’s early language abilities and development. Previous literature has investigated the beneficial role of beat gestures in the recall of information by preschoolers (Igualada, Esteve-Gibert, & Prieto, under review; Austin & Sweller, 2014). However, to our knowledge, little is known about whether the use of beat gestures can promote children’s later linguistic abilities and specifically whether training wi...

  10. Beat gestures and prosodic prominence: impact on learning

    OpenAIRE

    Kushch, Olga

    2018-01-01

    Previous research has shown that gestures are beneficial for language learning. This doctoral thesis centers on the effects of beat gestures– i.e., hand and arm gestures that are typically associated with prosodically prominent positions in speech - on such processes. Little is known about how the two central properties of beat gestures, namely how they mark both information focus and rhythmic positions in speech, can be beneficial for learning either a first or a second language. The main go...

  11. Beat frequency ultrasonic microsphere contrast agent detection system

    Science.gov (United States)

    Pretlow, III, Robert A. (Inventor); Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    1997-01-01

    A system for and method of detecting and measuring concentrations of an ultrasonically-reflective microsphere contrast agent involving detecting non-linear sum and difference beat frequencies produced by the microspheres when two impinging signals with non-identical frequencies are combined by mixing. These beat frequencies can be used for a variety of applications such as detecting the presence of and measuring the flow rates of biological fluids and industrial liquids, including determining the concentration level of microspheres in the myocardium.

  12. Beat gestures help preschoolers recall and comprehend discourse information.

    Science.gov (United States)

    Llanes-Coromina, Judith; Vilà-Giménez, Ingrid; Kushch, Olga; Borràs-Comes, Joan; Prieto, Pilar

    2018-08-01

    Although the positive effects of iconic gestures on word recall and comprehension by children have been clearly established, less is known about the benefits of beat gestures (rhythmic hand/arm movements produced together with prominent prosody). This study investigated (a) whether beat gestures combined with prosodic information help children recall contrastively focused words as well as information related to those words in a child-directed discourse (Experiment 1) and (b) whether the presence of beat gestures helps children comprehend a narrative discourse (Experiment 2). In Experiment 1, 51 4-year-olds were exposed to a total of three short stories with contrastive words presented in three conditions, namely with prominence in both speech and gesture, prominence in speech only, and nonprominent speech. Results of a recall task showed that (a) children remembered more words when exposed to prominence in both speech and gesture than in either of the other two conditions and that (b) children were more likely to remember information related to those words when the words were associated with beat gestures. In Experiment 2, 55 5- and 6-year-olds were presented with six narratives with target items either produced with prosodic prominence but no beat gestures or produced with both prosodic prominence and beat gestures. Results of a comprehension task demonstrated that stories told with beat gestures were comprehended better by children. Together, these results constitute evidence that beat gestures help preschoolers not only to recall discourse information but also to comprehend it. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. A quantitative electroencephalographic study of meditation and binaural beat entrainment.

    Science.gov (United States)

    Lavallee, Christina F; Koren, Stanley A; Persinger, Michael A

    2011-04-01

    The study objective was to determine the quantitative electroencephalographic correlates of meditation, as well as the effects of hindering (15 Hz) and facilitative (7 Hz) binaural beats on the meditative process. The study was a mixed design, with experience of the subject as the primary between-subject measure and power of the six classic frequency bands (δ, θ, low α, high α, β, γ), neocortical lobe (frontal, temporal, parietal, occipital), hemisphere (left, right), and condition (meditation only, meditation with 7-Hz beats, meditation with 15-Hz beats) as the within-subject measures. The study was conducted at Laurentian University in Sudbury, Ontario, Canada. The subjects comprised novice (mean of 8 months experience) and experienced (mean of 18 years experience) meditators recruited from local meditation groups. Experimental manipulation included application of hindering and facilitative binaural beats to the meditative process. Experienced meditators displayed increased left temporal lobe δ power when the facilitative binaural beats were applied, whereas the effect was not observed for the novice subjects in this condition. When the hindering binaural beats were introduced, the novice subjects consistently displayed more γ power than the experienced subjects over the course of their meditation, relative to baseline. Based on the results of this study, novice meditators were not able to maintain certain levels of θ power in the occipital regions when hindering binaural beats were presented, whereas when the facilitative binaural beats were presented, the experienced meditators displayed increased θ power in the left temporal lobe. These results suggest that the experienced meditators have developed techniques over the course of their meditation practice to counter hindering environmental stimuli, whereas the novice meditators have not yet developed those techniques.

  14. Human auditory steady state responses to binaural and monaural beats.

    Science.gov (United States)

    Schwarz, D W F; Taylor, P

    2005-03-01

    Binaural beat sensations depend upon a central combination of two different temporally encoded tones, separately presented to the two ears. We tested the feasibility to record an auditory steady state evoked response (ASSR) at the binaural beat frequency in order to find a measure for temporal coding of sound in the human EEG. We stimulated each ear with a distinct tone, both differing in frequency by 40Hz, to record a binaural beat ASSR. As control, we evoked a beat ASSR in response to both tones in the same ear. We band-pass filtered the EEG at 40Hz, averaged with respect to stimulus onset and compared ASSR amplitudes and phases, extracted from a sinusoidal non-linear regression fit to a 40Hz period average. A 40Hz binaural beat ASSR was evoked at a low mean stimulus frequency (400Hz) but became undetectable beyond 3kHz. Its amplitude was smaller than that of the acoustic beat ASSR, which was evoked at low and high frequencies. Both ASSR types had maxima at fronto-central leads and displayed a fronto-occipital phase delay of several ms. The dependence of the 40Hz binaural beat ASSR on stimuli at low, temporally coded tone frequencies suggests that it may objectively assess temporal sound coding ability. The phase shift across the electrode array is evidence for more than one origin of the 40Hz oscillations. The binaural beat ASSR is an evoked response, with novel diagnostic potential, to a signal that is not present in the stimulus, but generated within the brain.

  15. Deep learning based beat event detection in action movie franchises

    Science.gov (United States)

    Ejaz, N.; Khan, U. A.; Martínez-del-Amor, M. A.; Sparenberg, H.

    2018-04-01

    Automatic understanding and interpretation of movies can be used in a variety of ways to semantically manage the massive volumes of movies data. "Action Movie Franchises" dataset is a collection of twenty Hollywood action movies from five famous franchises with ground truth annotations at shot and beat level of each movie. In this dataset, the annotations are provided for eleven semantic beat categories. In this work, we propose a deep learning based method to classify shots and beat-events on this dataset. The training dataset for each of the eleven beat categories is developed and then a Convolution Neural Network is trained. After finding the shot boundaries, key frames are extracted for each shot and then three classification labels are assigned to each key frame. The classification labels for each of the key frames in a particular shot are then used to assign a unique label to each shot. A simple sliding window based method is then used to group adjacent shots having the same label in order to find a particular beat event. The results of beat event classification are presented based on criteria of precision, recall, and F-measure. The results are compared with the existing technique and significant improvements are recorded.

  16. Binaural auditory beats affect long-term memory.

    Science.gov (United States)

    Garcia-Argibay, Miguel; Santed, Miguel A; Reales, José M

    2017-12-08

    The presentation of two pure tones to each ear separately with a slight difference in their frequency results in the perception of a single tone that fluctuates in amplitude at a frequency that equals the difference of interaural frequencies. This perceptual phenomenon is known as binaural auditory beats, and it is thought to entrain electrocortical activity and enhance cognition functions such as attention and memory. The aim of this study was to determine the effect of binaural auditory beats on long-term memory. Participants (n = 32) were kept blind to the goal of the study and performed both the free recall and recognition tasks after being exposed to binaural auditory beats, either in the beta (20 Hz) or theta (5 Hz) frequency bands and white noise as a control condition. Exposure to beta-frequency binaural beats yielded a greater proportion of correctly recalled words and a higher sensitivity index d' in recognition tasks, while theta-frequency binaural-beat presentation lessened the number of correctly remembered words and the sensitivity index. On the other hand, we could not find differences in the conditional probability for recall given recognition between beta and theta frequencies and white noise, suggesting that the observed changes in recognition were due to the recollection component. These findings indicate that the presentation of binaural auditory beats can affect long-term memory both positively and negatively, depending on the frequency used.

  17. Detecting abnormalities in left ventricular function during exercise by respiratory measurement

    International Nuclear Information System (INIS)

    Koike, A.; Itoh, H.; Taniguchi, K.; Hiroe, M.

    1989-01-01

    The degree of exercise-induced cardiac dysfunction and its relation to the anaerobic threshold were evaluated in 23 patients with chronic heart disease. A symptom-limited exercise test was performed with a cycle ergometer with work rate increased by 1 W every 6 seconds. Left ventricular function, as reflected by ejection fraction, was continuously monitored with a computerized cadmium telluride detector after the intravenous injection of technetium-labeled red blood cells. The anaerobic threshold (mean, 727 ± 166 ml/min) was determined by the noninvasive measurement of respiratory gas exchange. As work rate rose, the left ventricular ejection fraction increased but reached a peak value at the anaerobic threshold and then fell below resting levels. Ejection fraction at rest, anaerobic threshold, and peak exercise were 41.4 ± 11.3%, 46.5 ± 12.0%, and 37.2 ± 11.0%, respectively. Stroke volume also increased from rest (54.6 ± 17.0 ml/beat) to the point of the anaerobic threshold (65.0 ± 21.2 ml/beat) and then decreased at peak exercise (52.4 ± 18.7 ml/beat). The slope of the plot of cardiac output versus work rate decreased above the anaerobic threshold. The anaerobic threshold occurred at the work rate above which left ventricular function decreased during exercise. Accurate determination of the anaerobic threshold provides an objective, noninvasive measure of the oxygen uptake above which exercise-induced deterioration in left ventricular function occurs in patients with chronic heart disease

  18. Pulsatile flow in ventricular catheters for hydrocephalus

    Science.gov (United States)

    Giménez, Á.; Galarza, M.; Thomale, U.; Schuhmann, M. U.; Valero, J.; Amigó, J. M.

    2017-05-01

    The obstruction of ventricular catheters (VCs) is a major problem in the standard treatment of hydrocephalus, the flow pattern of the cerebrospinal fluid (CSF) being one important factor thereof. As a first approach to this problem, some of the authors studied previously the CSF flow through VCs under time-independent boundary conditions by means of computational fluid dynamics in three-dimensional models. This allowed us to derive a few basic principles which led to designs with improved flow patterns regarding the obstruction problem. However, the flow of the CSF has actually a pulsatile nature because of the heart beating and blood flow. To address this fact, here we extend our previous computational study to models with oscillatory boundary conditions. The new results will be compared with the results for constant flows and discussed. It turns out that the corrections due to the pulsatility of the CSF are quantitatively small, which reinforces our previous findings and conclusions. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

  19. 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.

  20. Beat-to-beat variability of cardiac action potential duration: underlying mechanism and clinical implications.

    Science.gov (United States)

    Nánási, Péter P; Magyar, János; Varró, András; Ördög, Balázs

    2017-10-01

    Beat-to-beat variability of cardiac action potential duration (short-term variability, SV) is a common feature of various cardiac preparations, including the human heart. Although it is believed to be one of the best arrhythmia predictors, the underlying mechanisms are not fully understood at present. The magnitude of SV is basically determined by the intensity of cell-to-cell coupling in multicellular preparations and by the duration of the action potential (APD). To compensate for the APD-dependent nature of SV, the concept of relative SV (RSV) has been introduced by normalizing the changes of SV to the concomitant changes in APD. RSV is reduced by I Ca , I Kr , and I Ks while increased by I Na , suggesting that ion currents involved in the negative feedback regulation of APD tend to keep RSV at a low level. RSV is also influenced by intracellular calcium concentration and tissue redox potential. The clinical implications of APD variability is discussed in detail.

  1. Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Khuansiri Narajeenron

    2017-04-01

    Full Text Available Audience: The audience for this classic team-based learning (cTBL session is emergency medicine residents, faculty, and students; although this topic is applicable to internal medicine and family medicine residents. Introduction: A left ventricular assist device (LVAD is a mechanical circulatory support device that can be placed in critically-ill patients who have poor left ventricular function. After LVAD implantation, patients have improved quality of life.1 The number of LVAD patients worldwide continues to rise. Left-ventricular assist device patients may present to the emergency department (ED with severe, life-threatening conditions. It is essential that emergency physicians have a good understanding of LVADs and their complications. Objectives: Upon completion of this cTBL module, the learner will be able to: 1 Properly assess LVAD patients’ circulatory status; 2 appropriately resuscitate LVAD patients; 3 identify common LVAD complications; 4 evaluate and appropriately manage patients with LVAD malfunctions. Method: The method for this didactic session is cTBL.

  2. Beat-to-beat variability of QT intervals is increased in patients with drug-induced long-QT syndrome

    DEFF Research Database (Denmark)

    Hinterseer, Martin; Thomsen, Morten Bækgaard; Beckmann, Britt-Maria

    2008-01-01

    Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT inte...... intervals. Here, we evaluate variability of QT intervals in patients with a history of drug-induced long QT syndrome (dLQTS) and TdP in absence of a mutation in any of the major LQTS genes.......Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT...

  3. Adaptive singular value cancelation of ventricular activity in single-lead atrial fibrillation electrocardiograms

    International Nuclear Information System (INIS)

    Alcaraz, Raúl; Rieta, José Joaquín

    2008-01-01

    The proper analysis and characterization of atrial fibrillation (AF) from surface electrocardiographic (ECG) recordings requires to cancel out the ventricular activity (VA), which is composed of the QRS complex and the T wave. Historically, for single-lead ECGs, the averaged beat subtraction (ABS) has been the most widely used technique. However, this method is very sensitive to QRST wave variations and, moreover, high-quality cancelation templates may be difficult to obtain when only short length and single-lead recordings are available. In order to overcome these limitations, a new QRST cancelation method based on adaptive singular value cancelation (ASVC) applied to each single beat is proposed. In addition, an exhaustive study about the optimal set of complexes for better cancelation of every beat is also presented for the first time. The whole study has been carried out with both simulated and real AF signals. For simulated AF, the cancelation performance was evaluated making use of a cross-correlation index and the normalized mean square error (nmse) between the estimated and the original atrial activity (AA). For real AF signals, two additional new parameters were proposed. First, the ventricular residue (VR) index estimated the presence of ventricular activity in the extracted AA. Second, the similarity (S) evaluated how the algorithm preserved the AA segments out of the QRST interval. Results indicated that for simulated AF signals, mean correlation, nmse, VR and S values were 0.945 ± 0.024, 0.332 ± 0.073, 1.552 ± 0.386 and 0.986 ± 0.012, respectively, for the ASVC method and 0.866 ± 0.042, 0.424 ± 0.120, 2.161 ± 0.564 and 0.922 ± 0.051 for ABS. In the case of real signals, the mean VR and S values were 1.725 ± 0.826 and 0.983 ± 0.038, respectively, for ASVC and 3.159 ± 1.097 and 0.951 ± 0.049 for ABS. Thus, ASVC provides a more accurate beat-to-beat ventricular QRST representation than traditional techniques. As a consequence, VA cancelation

  4. Adaptive control with self-tuning for non-invasive beat-by-beat blood pressure measurement.

    Science.gov (United States)

    Nogawa, Masamichi; Ogawa, Mitsuhiro; Yamakoshi, Takehiro; Tanaka, Shinobu; Yamakoshi, Ken-ichi

    2011-01-01

    Up to now, we have successfully carried out the non-invasive beat-by-beat measurement of blood pressure (BP) in the root of finger, superficial temporal and radial artery based on the volume-compensation technique with reasonable accuracy. The present study concerns with improvement of control method for this beat-by-beat BP measurement. The measurement system mainly consists of a partial pressurization cuff with a pair of LED and photo-diode for the detection of arterial blood volume, and a digital self-tuning control method. Using healthy subjects, the performance and accuracy of this system were evaluated through comparison experiments with the system using a conventional empirically tuned PID controller. The significant differences of BP measured in finger artery were not showed in systolic (SBP), p=0.52, and diastolic BP (DBP), p=0.35. With the advantage of the adaptive control with self-tuning method, which can tune the control parameters without disturbing the control system, the application area of the non-invasive beat-by-beat measurement method will be broadened.

  5. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatation...... [high left ventricular end-diastolic volume (EDV) index and concentricity (LVM/EDV)] in hypertensive patients....

  6. xidative Stress and Retinopathy of Prematurity

    OpenAIRE

    Ümeyye Taka Aydın; Hatip Aydın; Osman Çekiç

    2014-01-01

    Oxidative stress plays an important role in the etiology of retinopathy of prematurity. Insufficient antioxidant system and increased oxidative stress in premature infants lead to the development of the disease. Understanding the mechanism of oxidative stress and antioxidant system and the related signaling pathways contribute to the development of novel options for diagnosis and treatment of retinopathy of prematurity. The current review aimed to evaluate the relationship between ox...

  7. A microcomputerized system of nuclear probe for left ventricular function evaluation

    International Nuclear Information System (INIS)

    Piva, R.M.V.

    1987-01-01

    In this work, it is presented the development of a system, consisting in a nuclear probe and a 16 bits microcomputer, for left ventricular function (LVF) monitoring and analysis. Previously used in renal and thyroid studies, the nuclear probe, 2''x2''NaI(Tl) crystal, was adapted for its new application. The alterations include the design and construction of appropriate colimators and unterfacing to a strip-chart register and a magnetic tape recorder. After a single injection of Tc-99m labelling red blood cells, the probe is placed over the patient's chest on a convenient left anterior oblique position and a left ventricle time activity curve is obtained. This curve and the patient's eletrocardiogram (ECG) are recorded for posterior processing. The software, in PASCAL language, transfers the data from the magnetic tape to the microcomputer and provides the LVF and ECG curves to be displayed on beat-to-beat mode or as mean curves. From these curves one can extract ventricular parameter such as: ejection fraction, ejection rate, systolic and diastolic intervals and heart rate, by manually positioning three cursors on the points of interest. A critical evaluation of this method is performed and its advantages as well as its limitations are discussed. This approach provides an easy to operate and a low cost device that can be useful in many clinical situations, for example, the continuous monitoring in ICUs, the screening in out-patient departments. The assessment of drugs effects on left ventricular function is also possible. (author) [pt

  8. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    International Nuclear Information System (INIS)

    Sultana, R.; Sultana, N.; Rashid, A.; Rasheed, S.Z.; Ahmed, M.; Ishaq, M.; Samad, A.

    2010-01-01

    Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

  9. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Sultana, R; Sultana, N; Rashid, A; Rasheed, S Z; Ahmed, M; Ishaq, M; Samad, A [Karachi Institute of Heart Diseases, Karachi (Pakistan)

    2010-10-15

    Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

  10. [Laser treatment for retinopathy of prematurity in neonatal intensive care units. Premature Eye Rescue Program].

    Science.gov (United States)

    Maka, Erika; Imre, László; Somogyvári, Zsolt; Németh, János

    2015-02-01

    Retinopathy of prematurity is a leading cause of childhood blindness around the world. The Department of Ophthalmology at the Semmelweis University and the Peter Cerny Neonatal Emergency and Ambulance Service started an innovative Premature Eye Rescue Program to reduce the non-essential transport of premature babies suffering from retinopathy of prematurity. During the first 5 years 186 eyes of 93 premature babies were treated at the bedside with stage 3 retinopathy of prematurity in the primary hospitals. In this first 5-years period the authors reduced the number of transports of premature babies for laser treatment; 93 children avoided the unnecessary transport, saving altogether a distance of 21,930 kilometers for children, as well as the ambulance service. The Premature Eye Rescue Program offers a good and effective alternative for treatment of retinopathy in the primary hospitals. The authors propose the national extension of this program.

  11. Genetics Home Reference: arrhythmogenic right ventricular cardiomyopathy

    Science.gov (United States)

    ... cardiomyopathy Merck Manual Consumer Version: Cardiomyopathy Merck Manual Consumer Version: Overview of Abnormal Heart Rhythms Orphanet: Arrhythmogenic right ventricular cardiomyopathy Orphanet: Familial isolated arrhythmogenic right ventricular ...

  12. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  13. Left ventricular function in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Takahashi, Hiromi; Yamaguchi, Ryutaro; Ifuku, Masayasu

    1985-01-01

    The present study was to investigate of left ventricular (LV) function during exercise in 26 patients with hypertrophic cardiomyopathy(HCM) usingTc-99m equilibrium angiocardiography, and to elucidate the mechanism of impaired functional reserve during exercise. In patients with HCM, LV ejection fraction decreased from 65 ± 8 (mean ± SD) % at rest to 59 ± 18 % at peak exercise, in contrast to an increase among controls (from 56 ± 9 % to 64 ± 9 %). As compared with resting values, cardiac output increased to 168 ± 24 % at peak exercise in HCM, but the increase was significantly less than that in controls (215 ± 47 %). Stroke volume decreased gradually to 83 ± 16 % during exercise in HCM, while it increased to 114 ± 10 % at an exercise level of half intensity, and it decreased slightly to 106 ± 16 % at peak exercise. LV end-systolic volume decreased among controls to 78 ± 27 % at peak exercise, but remained unchanged in HCM (118 ± 58 %). An increase in peak ejection rate at peak exercise was less in HCM than in controls (143 ± 26 % vs 170 ± 42 %). No significant differences were observed between the two groups concerning changes in indices of LV diastolic function including LV end-diastolic volume, peak filling rate or 1/3 filling rate during exercise. In the analysis of LV function curves, pulmonary arterial diastolic pressure increased to a greater extent in HCM than in controls (19 ± 6 mmHg vs 11 ± 6 mmHg); whereas, an increase in the stroke work index was less in HCM (80 ± 26 g.m/m 2 /beat vs 121 ± 21 g.m/m 2 /beat) at peak exercise. Thus, the LV function curve shifted downward and to the right in patients with HCM. The above findings indicate that LV functional reserve during exercise is impaired, especially as to systolic function in patients with HCM, while deterioration of diastolic function may be partly compromised by elevated filling pressure. (J.P.N.)

  14. AV nodal reentrant tachycardia with a 2:1 right bundle branch block missed as bidirectional ventricular tachycardia in the first superficial evaluation

    Directory of Open Access Journals (Sweden)

    Akbarzadeh Mohammad Ali

    2017-06-01

    Full Text Available A 95-year old woman was admitted to our emergency unit because of acute abdominal pain. After urgent surgery according to the acute abdomen, she was referred to intensive care unit (ICU of the emergency unit as she was intubated. It was developed a run of new arrhythmia which was diagnosed by cardiology resident as bidirectional ventricular tachycardia due to beat to beat changing the axis of the QRS. However, a second and more precise evaluation of the abnormal ECG suggested a narrow supraventricular tachycardia, most probably AV nodal reentrant tachycardia with a 2:1 right bundle branch block.

  15. Some nonlinear processes relevant to the beat wave accelerator

    International Nuclear Information System (INIS)

    Bingham, R.; Mori, W.B.

    1985-03-01

    The beat wave accelerator depends on the generation of a large amplitude plasma wave with a phase velocity close to the velocity of light c. The plasma wave (ωsub(p), ksub(p)) is generated by beating colinear laser beams (ω 1 , k 1 ) and (ω 2 ,k 2 ) with ωsub(p) = ω 1 -ω 2 , ksub(p) = k 1 -k 2 . Since the process involves both large amplitude transverse and longitudinal waves, various nonlinear instabilities associated with either wave may occur. The object of the article is to discuss some of the processes that may compete with the beat wave generation listing their threshold and growth rate. (author)

  16. Continuing studies of the plasma beat wave accelerator

    International Nuclear Information System (INIS)

    Joshi, C.

    1990-01-01

    This is a proposal for the release of third year funds for the ''Plasma Beat Wave Accelerator'' program (PBWA) at UCLA under the direction of Professor C. Joshi. This report is also a summary of progress on this project since March 1990; i.e., the date of the last report to the DOE. Once again we note that although the program is for historical reasons called the Plasma Beat Wave Accelerator Program, our group is active in all areas of applications of lasers and plasmas in future high energy accelerators. These are as follows: heat gradient plasma structures; excited by plasma beat wave technique; laser wake field technique; and plasma wake field technique. Development of a photoinjector-driven, 20 MeV linac; and theoretical studies of the plasma lens and use of plasmas at the final focus

  17. Human sperm steer with second harmonics of the flagellar beat.

    Science.gov (United States)

    Saggiorato, Guglielmo; Alvarez, Luis; Jikeli, Jan F; Kaupp, U Benjamin; Gompper, Gerhard; Elgeti, Jens

    2017-11-10

    Sperm are propelled by bending waves traveling along their flagellum. For steering in gradients of sensory cues, sperm adjust the flagellar waveform. Symmetric and asymmetric waveforms result in straight and curved swimming paths, respectively. Two mechanisms causing spatially asymmetric waveforms have been proposed: an average flagellar curvature and buckling. We image flagella of human sperm tethered with the head to a surface. The waveform is characterized by a fundamental beat frequency and its second harmonic. The superposition of harmonics breaks the beat symmetry temporally rather than spatially. As a result, sperm rotate around the tethering point. The rotation velocity is determined by the second-harmonic amplitude and phase. Stimulation with the female sex hormone progesterone enhances the second-harmonic contribution and, thereby, modulates sperm rotation. Higher beat frequency components exist in other flagellated cells; therefore, this steering mechanism might be widespread and could inspire the design of synthetic microswimmers.

  18. Basal cardiomyopathy develops in rabbits with ventricular tachyarrhythmias induced by a single injection of adrenaline.

    Science.gov (United States)

    Ashida, Terunao; Takato, Tetsuya; Matsuzaki, Gen; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

    2014-01-01

    We have recently demonstrated that basal cardiomyopathy develops in rabbits with ventricular tachyarrhythmias that have been induced by electrical stimulation of the cervical vagus. This study investigated whether similar basal cardiomyopathy would develop in rabbits with ventricular tachyarrhythmias induced by a single injection of adrenaline. Adrenaline was intravenously infused for 10-360 seconds in anesthetized rabbits. Colloidal carbon was injected after adrenaline infusion. Wall movement velocity of the left ventricular base was assessed by tissue Doppler echocardiography. Animals were killed either 1 week or 3-4 weeks later. Pathological lesions were identified by deposits of carbon particles. Animals were divided into two groups according to the infused dose of adrenaline. The small-dose group (group S, n = 15) received 1-10 μg and the large-dose group (group L, n = 23) received 15-60 μg of adrenaline. Adrenaline infusion induced premature ventricular contractions followed by monomorphic ventricular tachycardias in 22 of 23 animals in group L, but in only 1 of 15 animals in group S. Wall movement velocity of the left ventricular base decreased just after adrenaline infusion, remained low after 1 week, and recovered to near-baseline levels after 3-4 weeks in group L. Unique cardiac lesions identified by deposits of carbon particles were frequently observed on the left ventricular basal portion, almost always associated with the mitral valve and papillary muscles, but were never observed in the apical area. Lesions involving all areas of the left ventricular basal portion were observed in 22 of 23 animals in group L, but in only 2 of 15 animals in group S. Basal cardiomyopathy developed in rabbits with ventricular tachycardias induced by a single injection of adrenaline.

  19. Justification of Wife Beating in Adolescents: Associated Beliefs and Behaviors.

    Science.gov (United States)

    Devenish, Bethany; Hooley, Merrilyn; Mellor, David

    2018-04-01

    Socioeconomically disadvantaged adolescents who are exposed to social norms related to violence against women are more likely to experience or be perpetrators of intimate partner violence. This study evaluated factors hypothesized to be associated with acceptance of wife beating among 240 male and female adolescents aged 10-16 years participating in a World Vision program in Armenia. Acceptance of wife beating was associated with relational victimization, perceived social support, and parent and community boundaries and expectations, but was not associated with overt victimization or aggression. These findings highlight several areas that may be important for violence prevention research.

  20. A model-based Bayesian framework for ECG beat segmentation

    International Nuclear Information System (INIS)

    Sayadi, O; Shamsollahi, M B

    2009-01-01

    The study of electrocardiogram (ECG) waveform amplitudes, timings and patterns has been the subject of intense research, for it provides a deep insight into the diagnostic features of the heart's functionality. In some recent works, a Bayesian filtering paradigm has been proposed for denoising and compression of ECG signals. In this paper, it is shown that this framework may be effectively used for ECG beat segmentation and extraction of fiducial points. Analytic expressions for the determination of points and intervals are derived and evaluated on various real ECG signals. Simulation results show that the method can contribute to and enhance the clinical ECG beat segmentation performance

  1. Nuclear renaissance or premature try

    International Nuclear Information System (INIS)

    Coderch, M.

    2008-01-01

    After the economic failure of the 70's and not having been able to solve for decades its multiple problems, the nuclear industry was suffering a slow but inescapable agony. However, the need to reduce CO 2 emissions and the likely arrival of the worldwide peak of oil production have infused new life to the nuclear option, and it has again become one of the main topics of discussion in the worldwide energy debate. But in this debate we tend to forget that the causes of the abrupt end of the first nuclear era have not disappeared, and that for this reason it may well be that we are lead to a repetition of the events that induced its first demise. The much talked nuclear renaissance is thus likely to end up as a premature miscarriage. (Author)

  2. Retinopathy of Prematurity in Triplets

    Directory of Open Access Journals (Sweden)

    Mehmet Ali Şekeroğlu

    2016-06-01

    Full Text Available Objectives: To investigate the incidence, severity and risk factors of retinopathy of prematurity (ROP in triplets. Materials and Methods: The medical records of consecutive premature triplets who had been screened for ROP in a single maternity hospital were analyzed and presence and severity of ROP; birth weight, gender, gestational age of the infant; route of delivery and the mode of conception were recorded. Results: A total of 54 triplets (40 males, 14 females who were screened for ROP between March 2010 and February 2013 were recruited for the study. All triplets were delivered by Caesarean section and 36 (66.7% were born following an assisted conception. During follow-up, seven (13% of the infants developed ROP of any stage and two (3.7% required laser photocoagulation. The mean gestational age of triplets with ROP was 27.6±1.5 (27-31 weeks whereas it was 32.0±1.5 (30-34 weeks in those without ROP (p=0.002. The mean birth weights of triplets with and without ROP were 1290.0±295.2 (970-1600 g and 1667.5±222.2 (1130-1960 g, respectively (p<0.001. The presence of ROP was not associated with gender (p=0.358 or mode of conception (p=0.674. Conclusion: ROP in triplets seems to be mainly related to low gestational age and low birth weight. Further prospective randomized studies are necessary to demonstrate risk factors of ROP in triplets and to determine if and how gemelarity plays a role in the development of ROP.

  3. A simulation of T-wave alternans vectocardiographic representation performed by changing the ventricular heart cells action potential duration.

    Science.gov (United States)

    Janusek, D; Kania, M; Zaczek, R; Zavala-Fernandez, H; Maniewski, R

    2014-04-01

    The presence of T wave alternans (TWA) in the surface ECG signals has been recognized as a marker of electrical instability, and is hypothesized to be related to patients at increased risk for ventricular arrhythmias. In this paper we present a TWA simulation study. The TWA phenomenon was simulated by changing the duration of the ventricular heart cells action potential. The magnitude was calculated in the surface ECG with the use of the time domain method. The spatially concordant TWA, where during one heart beat all ventricular cells display a short-duration action potential and during the next beat they exhibit a long-duration action potential, as well as the discordant TWA, where at least one region is out of phase, was simulated. The vectocardiographic representation was employed. The obtained results showed a high level of T-loop pattern and location disturbances connected to the discordant TWA simulation in contrast to the concordant one. This result may be explained by the spatial heterogeneity of the ventricular repolarization process, which could be higher for the discordant TWA than for the concordant TWA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Human cytomegalovirus infections in premature infants by ...

    African Journals Online (AJOL)

    Freezing breast milk may be protective for the preterm infant until the titer of CMV antibody increases. However clinical importance of CMV infection in premature infants by breast-feeding is still unclear. This minireview focuses on recent advances in the study of CMV infection in premature infants by breastfeeding.

  5. 7 CFR 29.1050 - Prematurity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Prematurity. 29.1050 Section 29.1050 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1050 Prematurity. A condition of growth and development characteristic of the lower...

  6. Premature infants' health at multiple induced pregnancy.

    Directory of Open Access Journals (Sweden)

    Chernenkov Yu.V.

    2015-09-01

    Full Text Available Objective: to define the risk factors adversely influencing prenatal development at premature birth at use of methods of assisted reproductive technology (ART; to estimate premature' infants health from multiple induced pregnancy according to Perinatal Center of Saratov for last 3 years. Material and Methods. Under supervision there were 139 pregnant women with application ART. 202 children (51 twins were born and 5 triplet babies, from them 83 premature infants born from multiple induced pregnancy have been analyzed. Results. The newborns examined by method ART, were distributed as follows: 22-28 weeks — 19 children; 29-32 weeks — 23; 33-36 weeks — 41. Asphyxia at birth was marked at all premature infants. Respiratory insufficiency at birth is revealed in 87,3% of cases. The most frequent pathologies in premature infants are revealed: neurologic infringements and bronchopulmonary pathology occured at all children, developmental anomaly — 33, 8%, retinopathies in premature infants — 26,5%. The mortality causes include: extreme immaturity, cerebral leukomalacia, IVN 3 degrees. Conclusion. The risk factors, premature birth at application of methods ART are revealed: aged primiparas, pharmacological influence, absence of physiological conditions of prenatal development; multifetation. The high percent of birth of children with ELBW and ULBW is revealed. RDCN with further BPD development, retinopathies in premature infants and CNS defeat is more often occured.

  7. Level of anxiety in parents of high-risk premature twins.

    Science.gov (United States)

    Zanardo, V; Freato, F; Cereda, C

    1998-01-01

    We attempted to define parental anxiety in a population of parents of high-risk premature twins (mean birth weight 1,493 +/- 227 kg; mean gestational age 33 +/- 3.5 weeks), admitted to III level NICU. We specifically examined the following factors; gestational age of the twins, whether or not the twins had ventilatory support, pulmonary sequelae, major malformations or intra-ventricular hemorrhage, parental gender and highest level of education obtained by the parent. In the immediate pre-discharge period and a month later, a questionnaire (State-Trait Anxiety Inventory) was given to all parents of premature twins presenting for the discharge. The parents of 30 twins entered the study twice, at the discharge of their first twin (mean postnatal age 40 +/- 32 days), and one month later. They included 15 mothers and 11 fathers, aged 33 +/- 5.5 and 33 +/- 4.2 years, and at the second evaluation 11 mothers and 10 fathers, respectively. As case-controls we examined parental anxiety of fifteen consecutive singleton high-risk prematures, with equal gestational age, discharged immediately after. Our results indicate that the parents of high-risk twin and singleton prematures present an elevated, lasting state-trait anxiety level. Pre- and post-discharge parental anxiety is more elevated (not significant) in twinning with respect to the prematurity alone. When assessed separately by parental gender, in both these groups an increased (not significant) anxiety was persistently found in the mothers. We recommend that, although neonatologists generally define the discharge of the high-risk premature based upon the acquired stabilization of vital parameters, they pay special attention to the twin group we have identified which is at increased risk for predischarge parental anxiety.

  8. The brain responses to different frequencies of binaural beat sounds on QEEG at cortical level.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2015-01-01

    Beat phenomenon is occurred when two slightly different frequency waves interfere each other. The beat can also occur in the brain by providing two slightly different frequency waves separately each ear. This is called binaural beat. The brain responses to binaural beat are in discussion process whether the brain side and the brain area. Therefore, this study aims to figure out the brain responses to binaural beat by providing different binaural beat frequencies on 250 carrier tone continuously for 30 minutes to participants and using quantitative electroencephalography (QEEG) to interpret the data. The result shows that different responses appear in different beat frequency. Left hemisphere dominance occur in 3 Hz beat within 15 minutes and 15 Hz beat within 5 minutes. Right hemisphere dominance occurs in 10 Hz beat within 25 minute. 6 Hz beat enhances all area of the brain within 10 minutes. 8 Hz and 25 Hz beats have no clearly responses while 40 Hz beat enhances the responses in frontal lobe. These brain responses can be used for brain modulation application to induce the brain activity in further studies.

  9. Human milk for the premature infant

    Science.gov (United States)

    Underwood, Mark A.

    2012-01-01

    Synopsis Premature infants are a heterogeneous group with widely differing needs for nutrition and immune protection with risk of growth failure, developmental delays, necrotizing enterocolitis, and late-onset sepsis increasing with decreasing gestational age and birth weight. Human milk from women delivering prematurely has more protein and higher levels of many bioactive molecules compared to milk from women delivering at term. Human milk must be fortified for small premature infants to achieve adequate growth. Mother’s own milk improves growth and neurodevelopment and decreases the risk of necrotizing enterocolitis and late-onset sepsis and should therefore be the primary enteral diet of premature infants. Donor milk is a valuable resource for premature infants whose mothers are unable to provide an adequate supply of milk, but presents significant challenges including the need for pasteurization, nutritional and biochemical deficiencies and a limited supply. PMID:23178065

  10. Cardiac output by Doppler echocardiography in the premature baboon: Comparison with radiolabeled microspheres

    International Nuclear Information System (INIS)

    Kinsella, J.P.; Morrow, W.R.; Gerstmann, D.R.; Taylor, A.F.; deLemos, R.A.

    1991-01-01

    Pulsed-Doppler echocardiography (PDE) is a useful noninvasive method for determining left ventricular output (LVO). However, despite increasingly widespread use in neonatal intensive care units, validation studies in prematures with cardiopulmonary disease are lacking. The purpose of this study was to compare radiolabeled microsphere (RLM) and PDE measurements of LVO, using the critically ill premature baboon as a model of the human neonate. Twenty-two paired RLM and PDE measurements of LVO were obtained in 14 animals between 3 and 24 h of age. Average PDE LVO was 152 ml/min/kg (range, 40-258 ml/min/kg) compared to 158 ml/min/kg (range, 67-278 ml/min/kg) measured by RLM. Linear regression analysis of the paired measurements showed good correlation with a slope near unity (gamma = 0.94x + 4.20, r = 0.91, SEE = 25.7 ml). The authors conclude that PDE determinations of LVO compare well with those measured by RLM in the premature baboon. PDE appears to provide a valid estimate of LVO and should be useful in human prematures with cardiopulmonary distress

  11. Bilateral renal agenesis, a severe anomaly in a premature infant with VACTERL association: A case report

    Directory of Open Access Journals (Sweden)

    Erol Basuguy

    2017-11-01

    Full Text Available We report on a preterm male (birth weight 1,100 g with bilateral renal agenesis, a lethal malformation. Additionally, the child suffered from an atrial septal defect, ventricular septal defect, right aortic arch anomaly, a high type of anal atresia, vertebral anomalies, limbs defects (VACTERL association. The infant during first day of life was treated with an emergency sigmoid ostomy and peritoneal dialysis because of increasing abdominal dilatation and high urea and creatinine levels in blood. Important congenital anomalies associated with VACTERL association and prematurity are very serious causes of mortality in the early period

  12. Increased left ventricular mass in normotensive type 1 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Sato, A; Tarnow, L; Parving, H H

    1998-01-01

    in normotensive type 1 diabetic patients with and without nephropathy. RESEARCH DESIGN AND METHODS: M-mode and Doppler echocardiography was performed in 17 type 1 diabetic patients with nephropathy (albuminuria [median (range)], 345 (135-2,846) mg/24 h) and compared with 34 normotensive, normoalbuminuric (10 [3......-30] mg/24 h) type 1 diabetic patients matched for arterial blood pressure (mean +/- SD) ([134/77] +/- [13/7] vs. [129/78] +/- [12/7] mmHg), age (40 +/- 11 vs. 42 +/- 10 years), duration of diabetes (28 +/- 7 vs. 28 +/- 6 years), and BMI (24.2 +/- 4.2 vs. 24.6 +/- 2.4 kg/m2). RESULTS: Left ventricular......OBJECTIVE: Diabetic nephropathy increases the risk of premature cardiovascular disease and sudden death, particularly in type 1 diabetic patients. One possible mechanism for this risk may be left ventricular hypertrophy. In our study, we aimed to evaluate left ventricular structure and function...

  13. Attenuated ventricular β-adrenergic response and reduced repolarization reserve in a rabbit model of chronic heart failure

    DEFF Research Database (Denmark)

    Nissen, Jakob Dahl; Thomsen, Morten Bækgaard; Bentzen, Bo Hjorth

    2012-01-01

    Animal models of pacing-induced heart failure (HF) are often associated with high acute mortality secondary to high pacing frequencies. The present study therefore exploits lower-frequency left ventricular pacing (300 beats per minute) in rabbits for 11 weeks to produce chronic HF with low acute...... mortality but profound structural, functional, and electrical remodeling and compare with nonpaced controls. Pacing increased heart weight/body weight ratio and decreased left ventricular fractional shortening in tachypaced only. Electrocardiogram recordings during sinus rhythm revealed QTc prolongation...... in paced animals. Ventricular arrhythmias or sudden death was not observed. Isoproterenol increased heart rate similarly in both groups but showed a blunted QT-shortening effect in tachypaced rabbits compared with controls. Langendorff experiments revealed significant monophasic action potential duration...

  14. Energy cascading in the beat-wave accelerator

    International Nuclear Information System (INIS)

    McKinstrie, C.J.; Batha, S.H.

    1987-01-01

    A review is given of energy cascading in the beat-wave accelerator. The properties of the electromagnetic cascade and the corresponding plasma-wave evolution are well understood within the framework of an approximate analytic model. Based on this model, idealized laser-plasma coupling efficiencies of the order of 10% do not seem unreasonable. 28 refs

  15. Popular Music in Southeast Asia : Banal Beats, Muted Histories

    NARCIS (Netherlands)

    Barendregt, Bart; Keppy, Peter; Schulte Nordholt, Henk

    2017-01-01

    'Popular Music in Southeast Asia: Banal Beats, Muted Histories' offers a cultural history of modern Southeast Asia from the original vantage point of popular music since the 1920s up to the present. By creatively connecting indigenous musical styles with foreign musical genres, Southeast Asians

  16. Wife beating amongst Africans as a challenge to pastoral care

    Directory of Open Access Journals (Sweden)

    Magezi E. Baloyi

    2013-11-01

    Full Text Available Traditional African people are known for respecting their marriage. Even though marriage is so highly regarded, it is astonishing to realise that wife beating has become an extremely common practice amongst them. It therefore becomes an important research question to ask about the extent to which deeply-seated traditional customs regarding wife beating as a form of stamping down authority and of trying to keep the household in order, will have to be confronted with what is deemed to be good practice from the perspective of the law, community and pastoral caregivers. There are women who live with scars on their faces and bodies, having been beaten by their husbands. Although there are many forms of abuse towards women in family situations, this article aims particularly to focus on wife beating that is practiced for traditional as well as other related reasons. This research will involve itself with establishing whether the reasons for wife beating are part of the traditional system for keeping the household in order and interrogate both legal and pastoral interventions that attempt to eliminate or avoid such behaviour.

  17. Subdividing the beat: auditory and motor contributions to synchronization

    NARCIS (Netherlands)

    Loehr, J.D.; Palmer, C.

    2009-01-01

    THE CURRENT STUDY EXAMINED HOW AUDITORY AND kinematic information influenced pianists' ability to synchronize musical sequences with a metronome. Pianists performed melodies in which quarter-note beats were subdivided by intervening eighth notes that resulted from auditory information (heard tones),

  18. Analysis of fluid flow around a beating artificial cilium

    Directory of Open Access Journals (Sweden)

    Mojca Vilfan

    2012-02-01

    Full Text Available Biological cilia are found on surfaces of some microorganisms and on surfaces of many eukaryotic cells where they interact with the surrounding fluid. The periodic beating of the cilia is asymmetric, resulting in directed swimming of unicellular organisms or in generation of a fluid flow above a ciliated surface in multicellular ones. Following the biological example, externally driven artificial cilia have recently been successfully implemented as micropumps and mixers. However, biomimetic systems are useful not only in microfluidic applications, but can also serve as model systems for the study of fundamental hydrodynamic phenomena in biological samples. To gain insight into the basic principles governing propulsion and fluid pumping on a micron level, we investigated hydrodynamics around one beating artificial cilium. The cilium was composed of superparamagnetic particles and driven along a tilted cone by a varying external magnetic field. Nonmagnetic tracer particles were used for monitoring the fluid flow generated by the cilium. The average flow velocity in the pumping direction was obtained as a function of different parameters, such as the rotation frequency, the asymmetry of the beat pattern, and the cilium length. We also calculated the velocity field around the beating cilium by using the analytical far-field expansion. The measured average flow velocity and the theoretical prediction show an excellent agreement.

  19. Beat-wave accelerator studies at the Rutherford Appleton Laboratory

    International Nuclear Information System (INIS)

    Lawson, J.D.

    1985-01-01

    The study carried out in 1982-83 at the Rutherford Appleton Laboratory to examine how one might use the beat-wave principle to construct a useful high energy accelerator is reviewed, and comments are made on later developments. A number of problems are evident to which solutions cannot at present be foreseen. (author)

  20. Intimate partner abuse: wife beating among civil servants in Ibadan ...

    African Journals Online (AJOL)

    Wife beating is one of the most common forms of violence against women by husbands ... Consuming alcohol and growing up in an environment where parents fight publicly ... There is an urgent need for education of the women on their rights, ...

  1. Robust electrocardiogram (ECG) beat classification using discrete wavelet transform

    International Nuclear Information System (INIS)

    Minhas, Fayyaz-ul-Amir Afsar; Arif, Muhammad

    2008-01-01

    This paper presents a robust technique for the classification of six types of heartbeats through an electrocardiogram (ECG). Features extracted from the QRS complex of the ECG using a wavelet transform along with the instantaneous RR-interval are used for beat classification. The wavelet transform utilized for feature extraction in this paper can also be employed for QRS delineation, leading to reduction in overall system complexity as no separate feature extraction stage would be required in the practical implementation of the system. Only 11 features are used for beat classification with the classification accuracy of ∼99.5% through a KNN classifier. Another main advantage of this method is its robustness to noise, which is illustrated in this paper through experimental results. Furthermore, principal component analysis (PCA) has been used for feature reduction, which reduces the number of features from 11 to 6 while retaining the high beat classification accuracy. Due to reduction in computational complexity (using six features, the time required is ∼4 ms per beat), a simple classifier and noise robustness (at 10 dB signal-to-noise ratio, accuracy is 95%), this method offers substantial advantages over previous techniques for implementation in a practical ECG analyzer

  2. Using Science and Much More to Beat the Flood

    Science.gov (United States)

    Seeley, Claire

    2014-01-01

    The Beat the Flood challenge involves designing and building a model flood-proof home, which is then tested in "flood" conditions. It is set on the fictitious Watu Island. The children form teams, with each team member being assigned a responsibility for the duration of the task--team leader, chief recorder, and resource manager. This…

  3. Asynchronous beating of cilia enhances particle capture rate

    Science.gov (United States)

    Ding, Yang; Kanso, Eva

    2014-11-01

    Many aquatic micro-organisms use beating cilia to generate feeding currents and capture particles in surrounding fluids. One of the capture strategies is to ``catch up'' with particles when a cilium is beating towards the overall flow direction (effective stroke) and intercept particles on the downstream side of the cilium. Here, we developed a 3D computational model of a cilia band with prescribed motion in a viscous fluid and calculated the trajectories of the particles with different sizes in the fluid. We found an optimal particle diameter that maximizes the capture rate. The flow field and particle motion indicate that the low capture rate of smaller particles is due to the laminar flow in the neighbor of the cilia, whereas larger particles have to move above the cilia tips to get advected downstream which decreases their capture rate. We then analyzed the effect of beating coordination between neighboring cilia on the capture rate. Interestingly, we found that asynchrony of the beating of the cilia can enhance the relative motion between a cilium and the particles near it and hence increase the capture rate.

  4. An empirical investigation of attitudes towards wife-beating among ...

    African Journals Online (AJOL)

    With the exception of Uganda, women working for pay were more likely to justify wife-beating than non-working women were. The results indicate that dominant social and cultural norms create images of \\"ideal\\" women among both men and women that include definition and widespread acceptance of gender roles as well ...

  5. Efficiency of brainwave entrainment by binaural beats in reducing anxiety

    Directory of Open Access Journals (Sweden)

    Ahmad Alipoor

    2014-04-01

    Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

  6. Midbrain adaptation may set the stage for the perception of musical beat

    Science.gov (United States)

    2017-01-01

    The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain preprocessing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat. PMID:29118141

  7. The Effect of Aortic Compliance on Left Ventricular Power Requirement

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2009-11-01

    Aortic compliance depends on both geometry and mechanical properties of the aorta. Reduction in arterial compliance has been associated with aging, smoking, and multiple cardiovascular diseases. Increased stiffness of the aorta affects the wave dynamics in the aorta by increasing both pulse pressure amplitude and wave speed. We hypothesized that decreased aortic compliance leads to an increased left ventricular power requirement for a fixed cardiac output due to altered pulse pressure and pulse wave velocity. We used a computational approach using the finite element method for solid and fluid domains coupled to each other by using the direct coupling method. A nonlinear material model was used for the solid wall. The fluid flow model was considered to be Newtonian, incompressible, and laminar. The simulation was performed for a heart rate of 75 beats per minute for six different compliances while keeping the cardiac output and the peripheral resistance constant. The results show a trend towards increased left ventricular energy expenditure per cycle with decreased compliance. The relevance of these findings to clinical observations will be discussed.

  8. Psychosocial interventions for premature ejaculation

    Directory of Open Access Journals (Sweden)

    Tamara Melnik

    Full Text Available BACKGROUND: Premature ejaculation (PE is a very common sexual dysfunction among patients, and with varying prevalence estimates ranging from 3% to 20%. Although psychological issues are present in most patients with premature PE, as a cause or as a consequence, research on the effects of psychological approaches for PE has in general not been controlled or randomised and is lacking in long-term follow up. OBJECTIVE: To assess the efficacy of psychosocial interventions for PE. CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW: Trials were searched in computerized general and specialized databases, such as: MEDLINE by PubMed (1966 to 2010; PsycINFO (1974 to 2010; EMBASE (1980 to 2010; LILACS (1982 to 2010; the Cochrane Central Register of Controlled Trials (Cochrane Library, 2010; and by checking bibliographies, and contacting manufacturers and researchers. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating psychosocial interventions compared with different psychosocial interventions, pharmacological interventions, waiting list, or no treatment for PE. DATA COLLECTION AND ANALYSIS: Information on patients, interventions, and outcomes was extracted by at least two independent reviewers using a standard form. The primary outcome measure for comparing the effects of psychosocial interventions to waiting list and standard medications was improvement in IELT (i.e., time from vaginal penetration to ejaculation. The secondary outcome was change in validated PE questionnaires. MAIN RESULTS: In one study behavioral therapy (BT was significantly better than waiting list for duration of intercourse (MD (mean difference 407.90 seconds, 95% CI 302.42 to 513.38, and couples' sexual satisfaction (MD -26.10, CI -50.48 to -1.72. BT was also significantly better for a new functional-sexological treatment (FS (MD 412.00 seconds, 95% CI 305.88 to 518.12, change over time in subjective perception of duration of intercourse (Women: MD 2

  9. Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal

    Directory of Open Access Journals (Sweden)

    Fran López-Caballero

    2017-11-01

    Full Text Available When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma were presented binaurally and acoustically for epochs of 3 min (Beat epochs, preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively. In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR. For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

  10. Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal.

    Science.gov (United States)

    López-Caballero, Fran; Escera, Carles

    2017-01-01

    When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG) bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma) were presented binaurally and acoustically for epochs of 3 min (Beat epochs), preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively). In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR). For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

  11. Beating HF waves to generate VLF waves in the ionosphere

    Science.gov (United States)

    Kuo, Spencer; Snyder, Arnold; Kossey, Paul; Chang, Chia-Lie; Labenski, John

    2012-03-01

    Beat-wave generation of very low frequency (VLF) waves by two HF heaters in the ionosphere is formulated theoretically and demonstrated experimentally. The heater-induced differential thermal pressure force and ponderomotive force, which dominate separately in the D and F regions of the ionosphere, drive an electron current for the VLF emission. A comparison, applying appropriate ionospheric parameters shows that the ponderomotive force dominates in beat-wave generation of VLF waves. Three experiments, one in the nighttime in the absence of D and E layers and two in the daytime in the presence of D and E layers, were performed. X mode HF heaters of slightly different frequencies were transmitted at CW full power. VLF waves at 10 frequencies ranging from 3.5 to 21.5 kHz were generated. The frequency dependencies of the daytime and nighttime radiation intensities are quite similar, but the nighttime radiation is much stronger than the daytime one at the same radiation frequency. The intensity ratio is as large as 9 dB at 11.5 kHz. An experiment directly comparing VLF waves generated by the beat-wave approach and by the amplitude modulation (AM) approach was also conducted. The results rule out the likely contribution of the AM mechanism acting on the electrojet and indicate that beat-wave in the VLF range prefers to be generated in the F region of the ionosphere through the ponderomotive nonlinearity, consistent with the theory. In the nighttime experiment, the ionosphere was underdense to the HF heaters, suggesting a likely setting for effective beat-wave generation of VLF waves by the HF heaters.

  12. Measurement of ventricular function using Doppler ultrasound

    International Nuclear Information System (INIS)

    Teague, S.M.

    1986-01-01

    Doppler has wide application in the evaluation of valvular heart disease. The need to know ventricular function is a much more common reason for an echocardiographic evaluation. Interestingly, Doppler examinations can assess ventricular function from many perspectives. Description of ventricular function entails measurement of the timing, rate and volume of ventricular filling and ejection. Doppler ultrasound examination reveals all of these aspects of ventricular function noninvasively, simply, and without great expense or radiation exposure, as described in this chapter

  13. 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.

  14. Observational cohort study of ventricular arrhythmia in adults with Marfan syndrome caused by FBN1 mutations.

    Directory of Open Access Journals (Sweden)

    Ali Aydin

    Full Text Available Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation.We performed an observational cohort study of 80 consecutive adults (30 men, 50 women aged 42±15 years with Marfan syndrome caused by FBN1 mutations. We assessed ventricular arrhythmia on baseline ambulatory electrocardiography as >10 premature ventricular complexes per hour (>10 PVC/h, as ventricular couplets (Couplet, or as non-sustained ventricular tachycardia (nsVT, and during 31±18 months of follow-up as ventricular tachycardia (VT events (VTE such as sudden cardiac death (SCD, and sustained ventricular tachycardia (sVT. We identified >10 PVC/h in 28 (35%, Couplet/nsVT in 32 (40%, and VTE in 6 patients (8%, including 3 with SCD (4%. PVC>10/h, Couplet/nsVT, and VTE exhibited increased N-terminal pro-brain natriuretic peptide serum levels(P10/h and Couplet/nsVT also related to increased indexed end-systolic LV diameters (P = .024 and P = .020, to moderate mitral valve regurgitation (P = .018 and P = .003, and to prolonged QTc intervals (P = .001 and P = .006, respectively. Moreover, VTE related to mutations in exons 24-32 (P = .021. Kaplan-Meier analysis corroborated an association of VTE with increased NT-proBNP (P<.001 and with mutations in exons 24-32 (P<.001.Marfan syndrome with causative FBN1 mutations is associated with an increased risk for arrhythmia, and affected persons may require life-long monitoring. Ventricular arrhythmia on electrocardiography, signs of myocardial dysfunction and mutations in exons 24-32 may be risk factors of VTE.

  15. Non-model-based correction of respiratory motion using beat-to-beat 3D spiral fat-selective imaging.

    Science.gov (United States)

    Keegan, Jennifer; Gatehouse, Peter D; Yang, Guang-Zhong; Firmin, David N

    2007-09-01

    To demonstrate the feasibility of retrospective beat-to-beat correction of respiratory motion, without the need for a respiratory motion model. A high-resolution three-dimensional (3D) spiral black-blood scan of the right coronary artery (RCA) of six healthy volunteers was acquired over 160 cardiac cycles without respiratory gating. One spiral interleaf was acquired per cardiac cycle, prior to each of which a complete low-resolution fat-selective 3D spiral dataset was acquired. The respiratory motion (3D translation) on each cardiac cycle was determined by cross-correlating a region of interest (ROI) in the fat around the artery in the low-resolution datasets with that on a reference end-expiratory dataset. The measured translations were used to correct the raw data of the high-resolution spiral interleaves. Beat-to-beat correction provided consistently good results, with the image quality being better than that obtained with a fixed superior-inferior tracking factor of 0.6 and better than (N = 5) or equal to (N = 1) that achieved using a subject-specific retrospective 3D translation motion model. Non-model-based correction of respiratory motion using 3D spiral fat-selective imaging is feasible, and in this small group of volunteers produced better-quality images than a subject-specific retrospective 3D translation motion model. (c) 2007 Wiley-Liss, Inc.

  16. What makes a rhythm complex? The influence of musical training and accent type on beat perception

    NARCIS (Netherlands)

    Bouwer, F.L.; Burgoyne, J.A.; Odijk, D.; Honing, H.; Grahn, J.A.

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are “missing” on the beat,

  17. Left ventricular apical ballooning syndrome

    International Nuclear Information System (INIS)

    Rahman, N.; Tai, J.; Soofi, A.

    2007-01-01

    The transient left ventricular apical ballooning syndrome, also known as Takotsubo cardiomyopathy, is characterized by transient left ventricular dysfunction in the absence of obstructive epicardial coronary disease. Although the syndrome has been reported in Japan since 1990, it is rare in other regions. Rapid recognition of the syndrome can modify the diagnostic and therapeutic attitude i.e. avoiding thrombolysis and performing catheterization in the acute phase. (author)

  18. Acute appendicitis in a premature baby

    International Nuclear Information System (INIS)

    Beluffi, Giampiero; Alberici, Elisa

    2002-01-01

    A case of acute appendicitis in a premature baby in whom diagnosis was suggested on plain films of the abdomen is presented. In this baby air in a hollow viscus suspected of being an enlarged appendix was the clue to diagnosis. The diagnostic dilemma of this rare and life-threatening condition in premature babies and newborns is underlined. The relevance of different imaging modalities and of different findings in this age group is discussed. Awareness of this rare condition and possible differential diagnosis in newborns and premature babies is stressed. (orig.)

  19. Social support for parents of premature infants

    Directory of Open Access Journals (Sweden)

    Agnieszka Skurzak

    2018-03-01

    Full Text Available Prematurity is still an actual medical problem. Significant increase in the survival rate of premature babies is observed due to the progress in perinatal care .Usually, parents are not prepared for a premature birth, for the majority of them the hospitalization of a child in neonatal intensive care unit is a source of fear,  moreover parents often blame themselves for the situation. Appearing emotions and questions require a compatible response from the therapeutic team. The most important activity in the practice of the team is emotional, informative, evaluative support.

  20. The epidemiology of premature ejaculation.

    Science.gov (United States)

    Saitz, Theodore Robert; Serefoglu, Ege Can

    2016-08-01

    Vast advances have occurred over the past decade with regards to understanding the epidemiology, pathophysiology and management of premature ejaculation (PE); however, we still have much to learn about this common sexual problem. As a standardized evidence-based definition of PE has only recently been established, the reported prevalence rates of PE prior to this definition have been difficult to interpret. As a result, a large range of conflicting prevalence rates have been reported. In addition to the lack of a standardized definition and operational criteria, the method of recruitment for study participation and method of data collection have obviously contributed to the broad range of reported prevalence rates. The new criteria and classification of PE will allow for continued research into the diverse phenomenology, etiology and pathogenesis of the disease to be conducted. While the absolute pathophysiology and true prevalence of PE remains unclear, developing a better understanding of the true prevalence of the disease will allow for the completion of more accurate analysis and treatment of the disease.

  1. [Psychologic management of extreme prematurity].

    Science.gov (United States)

    Granboulan, V; Danan, C; Dassieu, G; Janaud, J C; Durand, B

    1995-05-01

    The ongoing progress in neonatal intensive care is modifying the psychic context of prematurity for all the partners, infants as well as parents and physicians. Comfort and prognosis of preterm infants have much improved. Since newborns under 24 weeks of gestational age are now surviving, they spend approximately half the duration of pregnancy out of the maternal uterus. All the psychological issues of such an early separation have to be considered, including the developmental outcome of a sensorial environment which is quite different from the intra-uterine one. Research has been developing in this field. The cooperation between neonatalogists and psychologists has been profitable to parents. Problems linked to the separation, such as difficulty in representing the infant, are no more frequent owing to the attention paid to the mother-child bond and subsequent early contacts. What is forward now is the impact of an hyper technical world of intensive care on the parents, and of the strange aspect of the tiny baby surrounded by engines and tubes. Such an overpresence of reality often results in a reaction of traumatic daziness among parents. The cooperation of the whole staff is necessary for the resumption of an imaginary process of psychic functioning. Finally, the survival of very-low-birth-weight infants confronts the neonatalogists with some delicate ethical questions. Psychiatrists and psychologists might have an important part to play in aiding the profession in its sorting out of these ethical issues.

  2. Passive and active ventricular elastances of the left ventricle

    Directory of Open Access Journals (Sweden)

    Ng Eddie YK

    2005-02-01

    Full Text Available Abstract Background Description of the heart as a pump has been dominated by models based on elastance and compliance. Here, we are presenting a somewhat new concept of time-varying passive and active elastance. The mathematical basis of time-varying elastance of the ventricle is presented. We have defined elastance in terms of the relationship between ventricular pressure and volume, as: dP = EdV + VdE, where E includes passive (Ep and active (Ea elastance. By incorporating this concept in left ventricular (LV models to simulate filling and systolic phases, we have obtained the time-varying expression for Ea and the LV-volume dependent expression for Ep. Methods and Results Using the patient's catheterization-ventriculogram data, the values of passive and active elastance are computed. Ea is expressed as: ; Epis represented as: . Ea is deemed to represent a measure of LV contractility. Hence, Peak dP/dt and ejection fraction (EF are computed from the monitored data and used as the traditional measures of LV contractility. When our computed peak active elastance (Ea,max is compared against these traditional indices by linear regression, a high degree of correlation is obtained. As regards Ep, it constitutes a volume-dependent stiffness property of the LV, and is deemed to represent resistance-to-filling. Conclusions Passive and active ventricular elastance formulae can be evaluated from a single-beat P-V data by means of a simple-to-apply LV model. The active elastance (Ea can be used to characterize the ventricle's contractile state, while passive elastance (Ep can represent a measure of resistance-to-filling.

  3. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  4. The overloaded right heart and ventricular interdependence.

    Science.gov (United States)

    Naeije, Robert; Badagliacca, Roberto

    2017-10-01

    The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights

  5. Maternal assessment of pain in premature infants

    Directory of Open Access Journals (Sweden)

    Maria Carolina Correia dos Santos

    2015-12-01

    Full Text Available Objective: to identify mothers' perceptions about the pain in their premature babies in the Neonatal Intensive Care Unit. Methods: evaluative, quantitative study with investigative nature conducted with 19 mothers of hospitalized premature newborns. Data were obtained from closed questions, answered by mothers. Results: from the participants, two (10.5% reported that newborns are unable to feel pain. From the 17 mothers who said that premature babies can feel pain, the majority (94.1% identified crying as a characteristic of pain sensation. Eleven (64.7% stated that uneasiness is a sign of pain in newborns. Conclusion: for the proper management of neonatal pain it is essential that mothers know the signs of pain in premature newborns, and that health professionals instruct this recognition, through the enhancement of the maternal presence and practice of effective communication between professionals and newborns’ families.

  6. Retinal vascular speed prematurity requiring treatment.

    Science.gov (United States)

    Solans Pérez de Larraya, Ana M; Ortega Molina, José M; Fernández, José Uberos; Escudero Gómez, Júlia; Salgado Miranda, Andrés D; Chaves Samaniego, Maria J; García Serrano, José L

    2018-03-01

    To analyse the speed of temporal retinal vascularisation in preterm infants included in the screening programme for retinopathy of prematurity. A total of 185 premature infants were studied retrospectively between 2000 and 2017 in San Cecilio University Hospital of Granada, Spain. The method of binocular indirect ophthalmoscopy with indentation was used for the examination. The horizontal disc diameter was used as a unit of length. Speed of temporal retinal vascularisation (disc diameter/week) was calculated as the ratio between the extent of temporal retinal vascularisation (disc diameter) and the time in weeks. The weekly temporal retinal vascularisation (0-1.25 disc diameter/week, confidence interval) was significantly higher in no retinopathy of prematurity (0.73 ± 0.22 disc diameter/week) than in stage 1 retinopathy of prematurity (0.58 ± 0.22 disc diameter/week). It was also higher in stage 1 than in stages 2 (0.46 ± 0.14 disc diameter/week) and 3 of retinopathy of prematurity (0.36 ± 0.18 disc diameter/week). The rate of temporal retinal vascularisation (disc diameter/week) decreases when retinopathy of prematurity stage increases. The area under the receiver operating characteristic curve was 0.85 (95% confidence interval: 0.79-0.91) for retinopathy of prematurity requiring treatment versus not requiring treatment. The best discriminative cut-off point was a speed of retinal vascularisation prematurity may be required. However, before becoming a new standard of care for treatment, it requires careful documentation, with agreement between several ophthalmologists.

  7. Premature dental eruption: report of case.

    LENUS (Irish Health Repository)

    McNamara, C M

    2011-08-05

    This case report reviews the variability of dental eruption and the possible sequelae. Dental eruption of the permanent teeth in cleft palate children may be variable, with delayed eruption the most common phenomenon. A case of premature dental eruption of a maxillary left first premolar is demonstrated, however, in a five-year-old male. This localized premature dental eruption anomaly was attributed to early extraction of the primary dentition, due to caries.

  8. Frequency of neonatal complications after premature delivery

    Directory of Open Access Journals (Sweden)

    Gordana Grgić

    2013-04-01

    Full Text Available Introduction: Preterm delivery is the delivery before 37 weeks of gestation are completed. The incidence of preterm birth ranges from 5 to 15%. Aims of the study were to determine the average body weight, Apgar score after one and five minutes, and the frequency of the most common complications in preterminfants.Methods: The study involved a total of 631 newborns, of whom 331 were born prematurely Aims of this study were to (24th-37th gestational weeks-experimental group, while 300 infants were born in time (37-42 weeks of gestation-control group.Results: Average body weight of prematurely born infants was 2382 grams, while the average Apgar score in this group after the fi rst minute was 7.32 and 7.79 after the fifth minute. The incidence of respiratory distress syndrome was 50%, intracranial hemorrhage, 28.1% and 4.8% of sepsis. Respiratory distresssyndrome was more common in infants born before 32 weeks of gestation. Mortality of premature infants is present in 9.1% and is higher than that of infants born at term.Conclusions: Birth body weight and Apgar scores was lower in preterm infants. Respiratory distress syndrome is the most common fetal complication of prematurity. Intracranial hemorrhage is the second most common complication of prematurity. Mortality of premature infants is higher than the mortality of infants born at term birth.

  9. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Directory of Open Access Journals (Sweden)

    Christine Beauchene

    Full Text Available Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  10. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  11. Angiographic characteristics of premature coronary artery disease in pakistan population; a prospective cross-sectional study

    International Nuclear Information System (INIS)

    Mustafa, B.; Rahman, H.U.

    2015-01-01

    Objective: To study the angiographic characteristics of premature coronary artery disease in our population. Methodology: From April 2014 to March 2015, coronary angiograms of 102 patients less than 40 years of age with a definitive diagnosis of ischemic heart disease were studied. Traditional risk factors of atherosclerosis were documented. Mode of presentation and symptoms were recorded along with angiographic findings of coronary artery disease severity, degree of coronary involvement, culprit vessel, lesion morphology, coronary dominance, coronary ectasia and left ventricular systolic function. Results: Mean age was 36.4 ± 4.1 years and 91% were male. Overall, left ventricular systolic function were fairly preserved (82%). 52% patients had single vessel CAD, 25% had double vessel while 19% had triple vessel coronary artery disease. Four patients had no luminal stenosis on coronary angiogram. LAD was the culprit vessel in 58.8%, RCA in 24.5% and left circumflex artery in 16.7% cases. More than 82% culprit lesions were severe or critical. 58% lesions were morphologically complex B2/C type while only 42% lesions were type A/B1. Coronary ectasia was seen in nearly 25% cases and all had ACS presentation. Right dominance was more common than left (57.8% vs 37.3%) while only 4.9% cases had dual posterior septal supply. Conclusion: Premature CAD in our population is acutely symptomatic, severe, complex (B2/C), single vessel disease. (author)

  12. Nonlinear beat excitation of low frequency wave in degenerate plasmas

    Science.gov (United States)

    Mir, Zahid; Shahid, M.; Jamil, M.; Rasheed, A.; Shahbaz, A.

    2018-03-01

    The beat phenomenon due to the coupling of two signals at slightly different frequencies that generates the low frequency signal is studied. The linear dispersive properties of the pump and sideband are analyzed. The modified nonlinear dispersion relation through the field coupling of linear modes against the beat frequency is derived in the homogeneous quantum dusty magnetoplasmas. The dispersion relation is used to derive the modified growth rate of three wave parametric instability. Moreover, significant quantum effects of electrons through the exchange-correlation potential, the Bohm potential, and the Fermi pressure evolved in macroscopic three wave interaction are presented. The analytical results are interpreted graphically describing the significance of the work. The applications of this study are pointed out at the end of introduction.

  13. Mechanisms of Wing Beat Sound in Flapping Wings of Beetles

    Science.gov (United States)

    Allen, John

    2017-11-01

    While the aerodynamic aspects of insect flight have received recent attention, the mechanisms of sound production by flapping wings is not well understood. Though the harmonic structure of wing beat frequency modulation has been reported with respect to biological implications, few studies have rigorously quantified it with respect directionality, phase coupling and vortex tip scattering. Moreover, the acoustic detection and classification of invasive species is both of practical as well scientific interest. In this study, the acoustics of the tethered flight of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) is investigated with four element microphone array in conjunction with complementary optical sensors and high speed video. The different experimental methods for wing beat determination are compared in both the time and frequency domain. Flow visualization is used to examine the vortex and sound generation due to the torsional mode of the wing rotation. Results are compared with related experimental studies of the Oriental Flower Beetle. USDA, State of Hawaii.

  14. First Beta-Beating Measurement in the LHC

    CERN Document Server

    Aiba, M; Franchi, A; Giovannozzi, M; Kain, V; Morita, A; Tomás, R; Vanbavinckhove, G; Wenninger, J

    2009-01-01

    This note reports on the first LHC beta-beating and coupling measurements. Thanks to an excellent functioning of the BPM system and the related software, injection oscillations were recorded for the first 90 turns at all BPMs of Beam 2. Three different algorithms are used to measure the optics parameters from the BPM data. All algorithms show consistent measurements but feature different accuracy. The Singular Value Decomposition (SVD) approach shows a high resolution despite the limited number of turns. The vertical beta-beating is observed to be about a factor of two larger than in the horizontal plane. This asymetry is partly due to sextupoles misalignments but also suggests the possible existance of focusing errors at defocussing locations. Rather large coupling is observed since no skew quadrupole was excited at the time of the data acquisition. We also report a list of suspected malfunctioning BPMs identified through various analyses.

  15. Auditory beat stimulation and its effects on cognition and mood states

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2015-05-01

    Full Text Available Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood-states. Here we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation. We have summarized relevant studies investigating the neurophysiological changes related to auditory beat stimulation and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural beat stimulation, we then discuss the role of monaural and binaural beat frequencies in cognition and mood-states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of auditory beat stimulation.

  16. Measuring of beat up force on weaving machines

    Directory of Open Access Journals (Sweden)

    Bílek Martin

    2017-01-01

    Full Text Available The textile material (warp is stressed cyclically at a relative high frequency during the weaving process. Therefore, the special measuring device for analysis of beat up force in the textile material during the weaving process, has been devised in the Weaving Laboratory of the TUL. This paper includes a description of this measuring device. The experimental part includes measurements results for various materials (PES and VS and various warp thread densities of the produced fabric.

  17. 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.

  18. Moving to the Beat and Singing are Linked in Humans

    Science.gov (United States)

    Dalla Bella, Simone; Berkowska, Magdalena; Sowiński, Jakub

    2015-01-01

    The abilities to sing and to move to the beat of a rhythmic auditory stimulus emerge early during development, and both engage perceptual, motor, and sensorimotor processes. These similarities between singing and synchronization to a beat may be rooted in biology. Patel (2008) has suggested that motor synchronization to auditory rhythms may have emerged during evolution as a byproduct of selection for vocal learning (“vocal learning and synchronization hypothesis”). This view predicts a strong link between vocal performance and synchronization skills in humans. Here, we tested this prediction by asking occasional singers to tap along with auditory pulse trains and to imitate familiar melodies. Both vocal imitation and synchronization skills were measured in terms of accuracy and precision or consistency. Accurate and precise singers tapped more in the vicinity of the pacing stimuli (i.e., they were more accurate) than less accurate and less precise singers. Moreover, accurate singers were more consistent when tapping to the beat. These differences cannot be ascribed to basic motor skills or to motivational factors. Individual differences in terms of singing proficiency and synchronization skills may reflect the variability of a shared sensorimotor translation mechanism. PMID:26733370

  19. Beliefs About Wife Beating Among Social Work Students in Taiwan.

    Science.gov (United States)

    Haj-Yahia, Muhammad M; Shen, April Chiung-Tao

    2017-07-01

    Based on an integrative framework, this study addresses the beliefs that a group of social work students from Taiwan had about wife beating. A self-administered questionnaire was filled out by 790 students (76.5% female, 23.5% male) spanning all 4 years of undergraduate studies. The results show that male students exhibited a greater tendency than their female counterparts to justify wife beating and to hold battered women responsible for violence against them. This tendency was also found among students who held traditional attitudes toward women, students who held patriarchal expectations of marriage, and students who had witnessed interparental violence in childhood. In addition, male students and students with traditional attitudes toward women exhibited the strongest tendency to believe that wives benefit from beating. Conversely, female students expressed more willingness than their male counterparts to help battered women, as did students who held liberal attitudes toward women and students who held egalitarian expectations of marriage. Furthermore, female students and those with liberal attitudes toward women tended to hold violent husbands responsible for their behavior, and to express support for punishing violent husbands. This article concludes with a discussion of the study's limitations and the results' implications for future research on the topic.

  20. Effectiveness of binaural beats in reducing preoperative dental anxiety.

    Science.gov (United States)

    Isik, B K; Esen, A; Büyükerkmen, B; Kilinç, A; Menziletoglu, D

    2017-07-01

    Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200Hz for the left ear and 209.3Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p=0.625), while that in the experimental group showed a significant reduction in anxiety (p=0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Right atrial and right ventricular ultrasound-guided biopsy technique in standing horses.

    Science.gov (United States)

    Decloedt, A; de Clercq, D; Ven, S; van der Vekens, N; Chiers, K; van Loon, G

    2016-05-01

    Endomyocardial biopsies could be a valuable tool in equine cardiology for diagnosing myocardial disease, which is probably underdiagnosed in horses because of lack of specific diagnostic measures and limitations of currently available diagnostic methods. To describe a technique for serial right atrial and right ventricular endomyocardial biopsy in standing horses using a percutaneous approach through the jugular vein. Prospective study. Biopsy was performed in 10 healthy standing horses sedated with detomidine, under continuous electrocardiography monitoring. A 10 cm (n = 6), 45 cm (n = 1) or 98 cm (n = 3) introducer sheath was inserted into the right jugular vein. Under echocardiographic guidance, a biopsy forceps was introduced through the sheath into the right ventricle and right atrium and endomyocardial biopsies were acquired. In all horses, 3 right ventricular biopsies were obtained from the right ventricular apex and 3 right atrial biopsies were obtained from the dorsal right atrial wall near the tuberculum intervenosum. The presence of myocardial tissue was confirmed by histology. All horses showed atrial and ventricular premature depolarisations associated with acquisition of the biopsies. In 9 horses, the arrhythmia disappeared after retraction of the forceps and introducer sheath. In one horse, ventricular premature depolarisations disappeared only after 8 h. No other complications were observed. Endomyocardial biopsy of the right atrium and right ventricle could be performed in standing horses using a percutaneous approach through the jugular vein and was not associated with complications other than temporary arrhythmias. This technique may be useful for research purposes or as a diagnostic tool, although further research is needed to establish the safety of the technique in clinical patients with myocardial disease. © 2015 EVJ Ltd.

  2. Prematures with and without Regressed Retinopathy of Prematurity: Comparison of Long-Term (6-10 Years) Ophthalmological Morbidity.

    Science.gov (United States)

    Cats, Bernard P.; Tan, Karel E. W. P.

    Reporting long-term ophthalmologic sequelae among ex-prematures at 6 to 10 years of age, this study compares 42 ex-premature infants who had had regressed forms of retinopathy of prematurity (ROP) during the neonatal period with 42 matched non-ROP ex-premature controls at 6 to 10 years of age. Subjects were subdivided into four groups: (1) ROP…

  3. Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia

    International Nuclear Information System (INIS)

    Courtis, J.; Vasallo, J.; Arabia, L.; Dimitroff, M.; Gonzalez, A.; Tibaldi, M.

    2012-01-01

    Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [es

  4. Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load

    Directory of Open Access Journals (Sweden)

    A’roch Roman

    2012-06-01

    Full Text Available Abstract Background Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV contractility. Methods Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon’s Signed Rank test. Results The inferior vena cava balloon occlusion (IVCBO load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p  Conclusions Peak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

  5. Noninvasive beat-to-beat finger arterial pressure monitoring during orthostasis : a comprehensive review of normal and abnormal responses at different ages

    NARCIS (Netherlands)

    van Wijnen, V K; Finucane, C; Harms, M P M; Nolan, H; Freeman, R L; Westerhof, B. E.; Kenny, R A; Ter Maaten, J C; Wieling, W

    2017-01-01

    Over the past 30years, noninvasive beat-to-beat blood pressure (BP) monitoring has provided great insight into cardiovascular autonomic regulation during standing. Although traditional sphygmomanometric measurement of BP may be sufficient for detection of sustained orthostatic hypotension, it fails

  6. Study on the Relationship among Parents' Cognition on China Anti-Domestic Violence, Attitude of Beating Children and Frequency of Beating Children

    Science.gov (United States)

    Song, Shi

    2018-01-01

    This research aims at analyzing the correlation between parents' awareness of anti-domestic violence in China, attitude and frequency of beating children. According to the literature analysis, this paper sets children's parents' anti-domestic violence cognition and attitude of beating children as independent variable, and the frequency of beating…

  7. Right Ventricular Pseudoaneurysm Following Endomyocardial Biopsy.

    Science.gov (United States)

    Pita; Santos; Manteiga; Rodriguez; Beiras

    1996-03-01

    Ventricular perforation is an unusual complication after endomyocardial biopsy in heart transplanted patients. We report a case of asymptomatic right ventricular perforation and pseudoaneurysm formation, secondary to endomyocardial biopsy, diagnosed by angiography. The spontaneous obliteration of the pseudoaneurysm was observed.

  8. Neural Entrainment and Sensorimotor Synchronization to the Beat in Children with Developmental Dyslexia: An EEG Study

    Directory of Open Access Journals (Sweden)

    Lincoln J. Colling

    2017-07-01

    Full Text Available Tapping in time to a metronome beat (hereafter beat synchronization shows considerable variability in child populations, and individual differences in beat synchronization are reliably related to reading development. Children with developmental dyslexia show impairments in beat synchronization. These impairments may reflect deficiencies in auditory perception of the beat which in turn affect auditory-motor mapping, or may reflect an independent motor deficit. Here, we used a new methodology in EEG based on measuring beat-related steady-state evoked potentials (SS-EPs, Nozaradan et al., 2015 in an attempt to disentangle neural sensory and motor contributions to behavioral beat synchronization in children with dyslexia. Children tapped with both their left and right hands to every second beat of a metronome pulse delivered at 2.4 Hz, or listened passively to the beat. Analyses of preferred phase in EEG showed that the children with dyslexia had a significantly different preferred phase compared to control children in all conditions. Regarding SS-EPs, the groups differed significantly for the passive Auditory listening condition at 2.4 Hz, and showed a trend toward a difference in the Right hand tapping condition at 3.6 Hz (sensorimotor integration measure. The data suggest that neural rhythmic entrainment is atypical in children with dyslexia for both an auditory beat and during sensorimotor coupling (tapping. The data are relevant to a growing literature suggesting that rhythm-based interventions may help language processing in children with developmental disorders of language learning.

  9. Prostanoid Receptors Involved in Regulation of the Beating Rate of Neonatal Rat Cardiomyocytes

    Science.gov (United States)

    Mechiche, Hakima; Grassin-Delyle, Stanislas; Robinet, Arnaud; Nazeyrollas, Pierre; Devillier, Philippe

    2012-01-01

    Although prostanoids are known to be involved in regulation of the spontaneous beating rate of cultured neonatal rat cardiomyocytes, the various subtypes of prostanoid receptors have not been investigated in detail. In our experiments, prostaglandin (PG)F2α and prostanoid FP receptor agonists (fluprostenol, latanoprost and cloprostenol) produced a decrease in the beating rate. Two prostanoid IP receptor agonists (iloprost and beraprost) induced first a marked drop in the beating rate and then definitive abrogation of beating. In contrast, the prostanoid DP receptor agonists (PGD2 and BW245C) and TP receptor agonists (U-46619) produced increases in the beating rate. Sulprostone (a prostanoid EP1 and EP3 receptor agonist) induced marked increases in the beating rate, which were suppressed by SC-19220 (a selective prostanoid EP1 antagonist). Butaprost (a selective prostanoid EP2 receptor agonist), misoprostol (a prostanoid EP2 and EP3 receptor agonist), 11-deoxy-PGE1 (a prostanoid EP2, EP3 and EP4 receptor agonist) did not alter the beating rate. Our results strongly suggest that prostanoid EP1 receptors are involved in positive regulation of the beating rate. Prostanoid EP1 receptor expression was confirmed by western blotting with a selective antibody. Hence, neonatal rat cardiomyocytes express both prostanoid IP and FP receptors (which negatively regulate the spontaneous beating rate) and prostanoid TP, DP1 and EP1 receptors (which positively regulate the spontaneous beating rate). PMID:22984630

  10. Healthcare performance and the effects of the binaural beats on human blood pressure and heart rate.

    Science.gov (United States)

    Carter, Calvin

    2008-01-01

    Binaural beats are the differences in two different frequencies (in the range of 30-1000 Hz). Binaural beats are played through headphones and are perceived by the superior olivary nucleus of each hemisphere of the brain. The brain perceives the binaural beat and resonates to its frequency (frequency following response). Once the brain is in tune with the binaural beat it produces brainwaves of that frequency altering the listener's state of mind. In this experiment, the effects of the beta and theta binaural beat on human blood pressure and pulse were studied. Using headphones, three sounds were played for 7 minutes each to 12 participants: the control,- the sound of a babbling brook (the background sound to the two binaural beats), the beta binaural beat (20 Hz), and the theta binaural beat (7 Hz). Blood pressure and pulse were recorded before and after each sound was played. Each participant was given 2 minutes in-between each sound. The results showed that the control and the two binaural beats did not affect the 12 participant's blood pressure or pulse (p > 0.05). One reason for this may be that the sounds were not played long enough for the brain to either perceive and/or resonate to the frequency. Another reason why the sounds did not affect blood pressure and pulse may be due to the participant's age since older brains may not perceive the binaural beats as well as younger brains.

  11. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  12. Premature Ejaculation and Utilization of Cognitive Techniques

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-03-01

    Full Text Available Introduction: Premature ejaculation is the most common male sexual dysfunction leading to distress in many couples. Master and Johnson emphasized the concept of early learned experiences and Kaplan emphasized lack of sensory awareness. For treatment sex therapists mainly utilize start-stop and squeeze techniques as homework. Couples enter sex therapy with some cognitive distortions and beliefs about sex and sexuality. These beliefs are also named sexual myths. For some couples using techniques to challenge cognitive distortions and maladaptive beliefs about sex and sexuality can be used. In this paper by presenting a case we discussed how cognitive techniques can be used along with behaviour techniques with couples. Case: Presenting clients are five years married couple who are thirty and twenty nine years old respectively. They attended to the outpatient clinic with the request of the female client. Their main complaint was premature ejaculation. They were diagnosed premature ejaculation using clinical interview. In treatment besides start and stop technique, cognitive techniques were utilized to address dysfunctional beliefs about sexuality. Discussion: Premature ejaculation is a male sexual dysfunction that causes distress and intimacy problems between couples. Stop start and squeeze techniques were accepted as the choice of treatment but their effectiveness is questioned recently. Also cognitive distortions and maladaptive beliefs may hamper therapy progress. Besides that, behavioral techniques utilizing cognitive techniques to lessen the degree of dysfunctional beliefs about sex and sexuality may help the couple to overcome premature ejaculation and enhance sexual satisfaction and intimacy.

  13. A Preliminary Study of Left Ventricular Rotational Mechanics in Children with Noncompaction Cardiomyopathy: Do They Influence Ventricular Function?

    Science.gov (United States)

    Nawaytou, Hythem M; Montero, Andrea E; Yubbu, Putri; Calderón-Anyosa, Renzo J C; Sato, Tomoyuki; O'Connor, Matthew J; Miller, Kelley D; Ursell, Philip C; Hoffman, Julien I E; Banerjee, Anirban

    2018-04-13

    Current diagnostic criteria for noncompaction cardiomyopathy (NCC) lack specificity, and the disease lacks prognostic indicators. Reverse apical rotation (RAR) with abnormal rotation of the cardiac apex in the same clockwise direction as the base has been described in adults with NCC. The aim of this study was to test the hypothesis that RAR might differentiate between symptomatic NCC and benign hypertrabeculations and might be associated with ventricular dysfunction. Echocardiograms from 28 children with NCC without cardiac malformations were prospectively compared with those from 29 age-matched normal control subjects. A chart review was performed to identify the patients' histories and clinical characteristics. Speckle-tracking was used to measure longitudinal strain, circumferential strain, and rotation. RAR occurred in 39% of patients with NCC. History of left ventricular (LV) dysfunction or arrhythmia was universal in, but not exclusive to, patients with RAR. Patients with RAR had lower LV longitudinal strain but similar ejection fractions compared with patients without RAR (median, -15.6% [interquartile range, -12.9% to -19.3%] vs -19% [interquartile range, -14.5% to -21.9%], P interquartile range, 43% to 68%] vs 61% [interquartile range, 58% to 67%], P = .08). Only a pattern of contraction with RAR, early arrest of twisting by mid-systole, and premature untwisting was associated with lower ejection fraction (46%; interquartile range, 43% to 52%; P = .006). RAR is not a sensitive but is a specific indicator of complications in children with NCC. Therefore, RAR may have prognostic rather than diagnostic value. Premature untwisting of the left ventricle during ejection may be an even more worrisome indicator of LV dysfunction. Copyright © 2018 American Society of Echocardiography. All rights reserved.

  14. Ultrasound functional imaging in an ex vivo beating porcine heart platform

    Science.gov (United States)

    Petterson, Niels J.; Fixsen, Louis S.; Rutten, Marcel C. M.; Pijls, Nico H. J.; van de Vosse, Frans N.; Lopata, Richard G. P.

    2017-12-01

    In recent years, novel ultrasound functional imaging (UFI) techniques have been introduced to assess cardiac function by measuring, e.g. cardiac output (CO) and/or myocardial strain. Verification and reproducibility assessment in a realistic setting remain major issues. Simulations and phantoms are often unrealistic, whereas in vivo measurements often lack crucial hemodynamic parameters or ground truth data, or suffer from the large physiological and clinical variation between patients when attempting clinical validation. Controlled validation in certain pathologies is cumbersome and often requires the use of lab animals. In this study, an isolated beating pig heart setup was adapted and used for performance assessment of UFI techniques such as volume assessment and ultrasound strain imaging. The potential of performing verification and reproducibility studies was demonstrated. For proof-of-principle, validation of UFI in pathological hearts was examined. Ex vivo porcine hearts (n  =  6, slaughterhouse waste) were resuscitated and attached to a mock circulatory system. Radio frequency ultrasound data of the left ventricle were acquired in five short axis views and one long axis view. Based on these slices, the CO was measured, where verification was performed using flow sensor measurements in the aorta. Strain imaging was performed providing radial, circumferential and longitudinal strain to assess reproducibility and inter-subject variability under steady conditions. Finally, strains in healthy hearts were compared to a heart with an implanted left ventricular assist device, simulating a failing, supported heart. Good agreement between ultrasound and flow sensor based CO measurements was found. Strains were highly reproducible (intraclass correlation coefficients  >0.8). Differences were found due to biological variation and condition of the hearts. Strain magnitude and patterns in the assisted heart were available for different pump action, revealing

  15. Radiation-induced premature menopause: a misconception

    International Nuclear Information System (INIS)

    Madsen, Berit L.; Giudice, Linda; Donaldson, Sarah S.

    1995-01-01

    Purpose: To disprove the common view that women who have undergone irradiation to fields excluding the pelvis are at risk for radiation-induced premature menopause, we reviewed menstrual function and fertility among women treated with subtotal lymphoid irradiation for Hodgkin's Disease. Methods and Materials: Treatment and follow-up records of all women less than age 50 at the time of diagnosis of Stage I or II supradiaphragmatic Hodgkin's Disease, treated with subtotal lymphoid irradiation alone and enrolled in radiotherapy trials from 1967 to 1985, were reviewed. In addition, patients were surveyed regarding their menstrual status and fertility history. Results: Thirty-six women, aged 10 to 40 years, with normal menstrual function at the time of Hodgkin's diagnosis, were identified. Mean follow-up was 14 years, with a range of 1.25-22.75 years. The average radiation dose to mantle and paraaortic fields was 40-44 Gy; the calculated scatter radiation dose to the pelvis at the ovaries was 3.2 Gy. There were 38 pregnancies in 18 women; all offspring are normal. One of 36 women (2.7%) experienced premature menopause. The reported rate of premature menopause in women who have not undergone irradiation is 1-3%; not significantly different than the rate in our study. There is a syndrome whereby antibodies to several endocrine organs occur (including the ovary), which is associated with premature ovarian failure. This syndrome may be associated with prior radiation to the thyroid, such as that given by mantle-irradiation for Hodgkin's Disease. We report such a case. Conclusion: There is little risk of premature menopause in women treated with radiation fields that exclude the pelvis. Women with presumed radiation-induced premature menopause warrant an evaluation to exclude other causes of ovarian failure, such as autoimmune disorders

  16. Signal analysis of ventricular fibrillation

    NARCIS (Netherlands)

    Herbschleb, J.N.; Heethaar, R.M.; Tweel, L.H. van der; Zimmerman, A.N.E.; Meijler, F.L.

    Signal analysis of electro(cardio)grams during ventricular fibrillation (VF) in dogs and human patients indicates more organization and regularity than the official WHO definition suggests. The majority of the signal is characterized by a power spectrum with narrow, equidistant peaks. In a further

  17. Dyssynchronous Ventricular Activation in Asymptomatic Wolff-Parkinson-White Syndrome: A Risk Factor for Development of Dilated Cardiomyopathy

    Science.gov (United States)

    Udink ten Cate, Floris EA; Wiesner, Nathalie; Trieschmann, Uwe; Khalil, Markus; Sreeram, Narayanswami

    2010-01-01

    A subset of children and adults with Wolff-Parkinson-White (WPW) syndrome develop dilated cardiomyopathy (DCM). Although DCM may occur in symptomatic WPW patients with sustained tachyarrhythmias, emerging evidence suggests that significant left ventricular dysfunction may arise in WPW in the absence of incessant tachyarrhythmias. An invariable electrophysiological feature in this non-tachyarrhythmia type of DCM is the presence of a right-sided septal or paraseptal accessory pathway. It is thought that premature ventricular activation over these accessory pathways induces septal wall motion abnormalities and ventricular dyssynchrony. LV dyssynchrony induces cellular and structural ventricular remodelling, which may have detrimental effects on cardiac performance. This review summarizes recent evidence for development of DCM in asymptomatic patients with WPW, discusses its pathogenesis, clinical presentation, management and treatment. The prognosis of accessory pathway-induced DCM is excellent. LV dysfunction reverses following catheter ablation of the accessory pathway, suggesting an association between DCM and ventricular preexcitation. Accessory pathway-induced DCM should be suspected in all patients presenting with heart failure and overt ventricular preexcitation, in whom no cause for their DCM can be found. PMID:20552060

  18. Premature Ejaculation and Utilization of Cognitive Techniques

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-04-01

    Discussion: Premature ejaculation is a male sexual dysfunction that causes distress and intimacy problems between couples. Stop start and squeeze techniques were accepted as the choice of treatment but their effectiveness is questioned recently. Also cognitive distortions and maladaptive beliefs may hamper therapy progress. Besides that, behavioral techniques utilizing cognitive techniques to lessen the degree of dysfunctional beliefs about sex and sexuality may help the couple to overcome premature ejaculation and enhance sexual satisfaction and intimacy. [JCBPR 2013; 2(1.000: 47-52

  19. The circadian variation of premature atrial contractions

    DEFF Research Database (Denmark)

    Larsen, Bjørn Strøier; Kumarathurai, Preman; Nielsen, Olav W

    2016-01-01

    AIMS: The aim of the study was to assess a possible circadian variation of premature atrial contractions (PACs) in a community-based population and to determine if the daily variation could be used to assess a more vulnerable period of PACs in predicting later incidence of atrial fibrillation (AF...... variation in heart rate. After adjusting for relevant risk factors, the risk of AF was equal in all time intervals throughout the day. CONCLUSION: Premature atrial contractions showed a circadian variation in subjects with frequent PACs. No specific time interval of the day was more predictive of AF than...

  20. Beat map drawing method for large oriental bell based on operational deflection shape method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joong Hyeok; Kim, Seock Hyun [Dept. of Advanced Mechanical Engineering, Kangwon National University, Chuncheon (Korea, Republic of); Park, In Seok [TB Tires Development 1 Team, R and D Center, Kumho Tire, Yongin (Korea, Republic of)

    2016-10-15

    Oriental bells produce a peculiar sound in the form of beats, which are periodic repetitions of strong and weak sounds. A beating sound with a proper period gives the illusion of the bell being alive and breathing. To produce a good beating sound, appropriate modal parameters are required for beat tuning after casting the bell. Conventionally, modal parameters were extracted using frequency response functions of the excitation and response signals. However, a large oriental bell is usually struck by a heavy wooden hammer and hence, only the response signal can be measured. In this study, we extract the modal parameters using the response signal only and employ the data to predict the beat properties of the bell sound. Finally, the validity of the predicted beat properties is experimentally verified for a large oriental bell.

  1. Alternative right ventricular pacing sites.

    Science.gov (United States)

    Łuciuk, Dariusz; Łuciuk, Marek; Gajek, Jacek

    2015-01-01

    The main adverse effect of chronic stimulation is stimulation-induced heart failure in case of ventricular contraction dyssynchrony. Because of this fact, new techniques of stimulation should be considered to optimize electrotherapy. One of these methods is pacing from alternative right ventricular sites. The purpose of this article is to review currently accumulated data about alternative sites of cardiac pacing. Medline and PubMed bases were used to search English and Polish reports published recently. Recent studies report a deleterious effect of long term apical pacing. It is suggested that permanent apical stimulation, by omitting physiological conduction pattern with His-Purkinie network, may lead to electrical and mechanical dyssynchrony of heart muscle contraction. In the long term this pathological situation can lead to severe heart failure and death. Because of this, scientists began to search for some alternative sites of cardiac pacing to reduce the deleterious effect of stimulation. Based on current accumulated data, it is suggested that the right ventricular outflow tract, right ventricular septum, direct His-bundle or biventricular pacing are better alternatives due to more physiological electrical impulse propagation within the heart and the reduction of the dyssynchrony effect. These methods should preserve a better left ventricular function and prevent the development of heart failure in permanent paced patients. As there is still not enough, long-term, randomized, prospective, cross-over and multicenter studies, further research is required to validate the benefits of using this kind of therapy. The article should pay attention to new sites of cardiac stimulation as a better and safer method of treatment.

  2. Gaussian-state entanglement in a quantum beat laser

    International Nuclear Information System (INIS)

    Tahira, Rabia; Ikram, Manzoor; Nha, Hyunchul; Zubairy, M. Suhail

    2011-01-01

    Recently quantum beat lasers have been considered as a source of entangled radiation [S. Qamar, F. Ghafoor, M. Hillery, and M. S. Zubairy, Phys. Rev. A 77, 062308 (2008)]. We investigate and quantify the entanglement of this system when the initial cavity modes are prepared in a Gaussian two-mode state, one being a nonclassical state and the other a thermal state. It is investigated how the output entanglement varies with the nonclassicality of the input Gaussian state, thermal noise, and the strength of the driving field.

  3. Wife beating amongst Africans as a challenge to pastoral care

    Directory of Open Access Journals (Sweden)

    Magezi E. Baloyi

    2013-11-01

    Full Text Available Traditional African people are known for respecting their marriage. Even though marriage is so highly regarded, it is astonishing to realise that wife beating has become an extremely common practice amongst them. It therefore becomes an important research question to ask about the extent to which deeply-seated traditional customs regarding wife beating as a form of stamping down authority and of trying to keep the household in order, will have to be confronted with what is deemed to be good practice from the perspective of the law, community and pastoral caregivers. There are women who live with scars on their faces and bodies, having been beaten by their husbands. Although there are many forms of abuse towards women in family situations, this article aims particularly to focus on wife beating that is practiced for traditional as well as other related reasons. This research will involve itself with establishing whether the reasons for wife beating are part of the traditional system for keeping the household in order and interrogate both legal and pastoral interventions that attempt to eliminate or avoid such behaviour. Tradisionele Afrikane is nog altyd daarvoor bekend dat hulle die instelling van die huwelik respekteer. Verbasend genoeg is vroueslanery egter ’n ou gevestigde gebruik wat vandag algemeen onder Afrikane voorkom. Die mate waartoe diepgewortelde gebruike soos vroueslanery as ’n manier om gesag af te dwing en orde in die huis te handhaaf, gekonfronteer sal moet word met wat as goeie praktyk beskou word vanuit die gesigspunt van die reg, die gemeenskap en pastorale versorgers, is dus ’n belangrike navorsingsvraag. Baie vroue dra fisiese en emosionele littekens wat deur hulle eggenote veroorsaak is. Alhoewel daar baie vorme van vrouemishandeling in familiesituasies voorkom, fokus hierdie artikel veral op vroueslanery wat om tradisionele en verwante redes beoefen word. Hierdie navorsing probeer vasstel of die redes vir

  4. MHD simulation of a beat frequency heated plasma

    International Nuclear Information System (INIS)

    Milroy, R.D.; Capjack, C.E.; James, C.R.; McMullin, J.N.

    1976-01-01

    The heating of a plasma in a solenoid, with a beat frequency harmonic which is excited at a frequency near to that of a Langmuir mode in a plasma, is examined. It is shown that at high temperatures the heating rate is very insensitive to changes in plasma density. The amount of energy that can be coupled to a plasma in a solenoid with this heating scheme is investigated by using a one-dimensional computer code which incorporates an exact solution of the relevant MHD equations. The absorption of energy from a high powered laser is shown to be significantly enhanced with this process. (author)

  5. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  6. Individual Differences in Beat Perception Affect Gait Responses to Low- and High-Groove Music

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A.

    2014-01-01

    Slowed gait in patients with Parkinson’s disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the “beat,” which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation. PMID:25374521

  7. Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization.

    Science.gov (United States)

    Kuwada, S; Yin, T C; Wickesberg, R E

    1979-11-02

    The interaural phase sensitivity of neurons was studied through the use of binaural beat stimuli. The response of most cells was phase-locked to the beat frequency, which provides a possible neural correlate to the human sensation of binaural beats. In addition, this stimulus allowed the direction and rate of interaural phase change to be varied. Some neurons in our sample responded selectively to manipulations of these two variables, which suggests a sensitivity to direction or speed of movement.

  8. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity

    OpenAIRE

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, hav...

  9. Follow-up study on premature infants with and without retinopathy of prematurity.

    OpenAIRE

    Robinson, R; O'Keefe, M

    1993-01-01

    The ocular complications in population of 131 premature infants, with and without retinopathy of prematurity (ROP) are reported. An increased incidence of strabismus (20% with ROP and 25% without ROP) and myopia (27.5% with ROP and 8.8% without ROP) was shown. Significant visual loss occurred in 10.7% overall, increasing to 35% with stage 3 disease and 100% with stage 4. With the increased survival rate of premature infants, the relevance to future management of this expanding group of young ...

  10. Four cases of right ventricular dysplasia

    International Nuclear Information System (INIS)

    Takamura, Ichiro; Ando, Joji; Miyamoto, Atsushi; Kobayashi, Takeshi; Sakamoto, Sanya; Yasuda, Hisakazu

    1985-01-01

    Finding of 81 Kr right ventriculography and 201 Tl myocardial perfusion imaging in 4 patients with right ventricular dysplasia (RVD) were compared with those in 28 patients with dilated cardiomyopathy. Remarkably dilated right ventricle was detected on 201 Tl myocardial perfusion imaging in the RVD group. In a patient with RVD who died suddenly, perfusion defect of the left ventricular myocardium, a decreased right ventricular ejection fraction, and an increased right ventricular end diastolic volume were seen. Perfusion defect of the left ventricular myocardium was seen in 10 of the 28 patients with dilated cardiomyopathy, 4 of whom died suddenly. In these 4 patients, a decreased left ventricular ejection fraction and an increased right ventricular end diastolic volume were seen. These findings obtained by the radionuclide techniques suggested that there are differences in cardiac dysfunction of the both ventricles between the groups with RVD and dilated cardiomyopathy. (Namekawa, K.)

  11. Enhanced timing abilities in percussionists generalize to rhythms without a musical beat.

    Science.gov (United States)

    Cameron, Daniel J; Grahn, Jessica A

    2014-01-01

    The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  12. Enhanced Timing Abilities in Percussionists Generalize to Rhythms Without a Musical Beat

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2014-12-01

    Full Text Available The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played, continuation of the beat (as a second sequence was introduced and played simultaneously, and switching to a second beat (the initial sequence finished, leaving only the second. The metres of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals. In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists’ superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  13. Premature ovarian failure and ovarian autoimmunity

    NARCIS (Netherlands)

    J.A. Schoemaker (Joop); H.A. Drexhage (Hemmo); A. Hoek (Annemieke)

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a

  14. Optimal oxygen saturation in premature infants

    Directory of Open Access Journals (Sweden)

    Meayoung Chang

    2011-09-01

    Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

  15. Osteopenia (metabolic bone disease) of prematurity

    Science.gov (United States)

    Osteopenia is defined as postnatal bone mineralization that is inadequate to fully mineralize bones. Osteopenia occurs commonly in very low birth weight (VLBW) infants. Prior to the use of high-mineral containing diets for premature infants, which is the current practice, significant radiographic ch...

  16. Psychological and Educational Sequelae of Prematurity

    Science.gov (United States)

    Rubin, Rosalyn A.; And Others

    1973-01-01

    Psychological and educational correlates of prematurity in children during four periods, the last at 7 years of age, were assessed as part of a prospective longitudinal study of 241 infants classified by birth weight, gestational age, and sex to determine later functioning in school. (Author/MC)

  17. AMH as Predictor of Premature Ovarian Insufficiency

    DEFF Research Database (Denmark)

    Lunding, Stine Aa; Aksglæde, Lise; Anderson, Richard A

    2015-01-01

    CONTEXT: The majority of Turner syndrome (TS) patients suffer from accelerated loss of primordial follicles. Low circulating levels of anti-Müllerian hormone (AMH) may predict the lack of spontaneous puberty in prepubertal girls and imminent premature ovarian insufficiency (POI) in TS women...

  18. Morbidities, concordance, and predictors of preterm premature ...

    African Journals Online (AJOL)

    2015-12-05

    Dec 5, 2015 ... Background: Preterm premature rupture of membranes (PPROM) is a challenging complication of ... PROM (P < 0.000), latency period (P < 0.000), and birth weight (P < 0.001). ..... J Obstet Gynecol 2000;183:271‑6. 25. Mercer ...

  19. The right ventricular response to ventricular hypofunction in anteroseptal infarction

    International Nuclear Information System (INIS)

    Kanayama, Sugako

    1992-01-01

    Thirty-seven patients with acute anteroseptal infarction but not significant right coronary artery stenosis were examined by using thallium-201 (Tl-201) myocardial perfusion SPECT to determine how the right ventricular (RV) free wall responded to a severely impaired ventricular septum. The patients were divided into the group in which RV free wall was visualized on Tl-201 myocardial SPECT (n=19, RV(+) Group) and the group in which it was not visualized (n=18, RV(-) Group). The relationship between visualization of RV free wall and both RV and left ventricular (LV) function was evaluated. RV(+) Group had larger extent of anteroseptal necrosis and severer impairment of RV free wall, as compared with RV(-) Group. LV ejection fraction (LVEF) was significantly lower in RV(+) Group than RV(-) Group in both acute and chronic phases. Although RV ejection fraction (RVEF) in acute phase was significantly lower in RV(+) Group than RV(-) Group, it did not differ in chronic phase between the two groups. In RV(+) Group, RV stroke work index (RVSWI), pulmonary artery end diastolic pressure (PAEDP), and mean pulmonary artery pressure (MPA) in chronic phase showed a statistically significant increase compared with those in acute phase; these hemodynamic variables in chronic phase were also significantly higher than those in RV(-) Group. RV/LV ratio inversely correlated with LVEF, and both necrotic extent and impairment severity positively correlated with both PAEDP and MPA. RV free wall could be visualized more clearly, corresponding to extremely decreased LV function. These findings suggest that RV free wall may play an important role in maintaining LV and RV function when ventricular septum is severely impaired by anteroseptal infarction. (N.K.)

  20. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    Directory of Open Access Journals (Sweden)

    Maria URSACHI (BOLOTA

    2016-12-01

    Full Text Available The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amniotic sac (PRAS is defined as rupture of membranes before the onset of labor. Premature rupture of the fetal membrane, which occurs before 37 weeks of gestation, usually, refers to preterm premature rupture of membranes. Despite advances in the care period, premature rupture of membranes and premature rupture of membranes preterm continue to be regarded as serious obstetric complications. On the term 8% - 10% of pregnant women have premature rupture of membranes; these women are at increased risk of intrauterine infections, where the interval between membrane rupture and expulsion is rolled-over. Premature rupture of membranes preterm occurs in approximately 1% of all pregnancies and is associated with 30% -40% of preterm births. Thus, it is important to identify the cause of pre-term birth (after less than 37 completed weeks of "gestation" and its complications, including respiratory distress syndrome, neonatal infection and intraventricular hemorrhage. Objectives: the development of the protocol of the clinical trial on patients with impending preterm birth, study clinical and statistical on the socio-demographic characteristics of patients with imminent preterm birth; clinical condition of patients and selection of cases that could benefit from the application of interventional therapy; preclinical investigation (biological and imaging of patients with imminent preterm birth; the modality therapy; clinical investigation of the effectiveness of short

  1. Effect of Cilia Beat Frequency on Mucociliary Clearance

    Directory of Open Access Journals (Sweden)

    Sedaghat M. H.

    2016-12-01

    Full Text Available Background: The airway surface liquid (ASL, which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM has been used to solve the momentum equations and to simulate cilia forces, and also the PCLmucus interface more accurately, immersed boundary method (IBM has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF.

  2. PEP-II Beta Beat Fixes with MIA

    International Nuclear Information System (INIS)

    Yan, Y

    2004-01-01

    We first find a virtual accelerator for the HER or the LER through determination of all quadrupole strengths and sextupole feed-downs as well as all BPM gains and BPM cross-plane couplings by an SVD-enhanced Least-squares fitting of the quantities derivable from a complete set of orbits. These quantities are the phase advances, the Green's functions, and the tilt angles and axis ratios of the coupling eigen ellipses. They are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a high-resolution model-independent analysis (MIA). Once the virtual accelerator is found, we select a limited number of key quadrupoles, for example, the linear trombone quadrupoles and the global skews, for Least-square fitting of their strengths to minimize the beta beat while keeping other optics characters unchanged if not improved. We then dial in these limited number of quadrupole strength changes to the real accelerator (HER or LER) to achieve a better-performance PEP-II. Noticeable achievement by this MIA technique has been that MIA has helped PEP-II achieve its breaking record peak luminosity of 6.5 x 10 33 cm -2 s -1 in 2003 by bringing the LER working tune to near half integer and simultaneously fixing the beta beat, which would, otherwise, be difficult without MIA because of the strong LER coupling effect

  3. Analysis of the forces acting on beating cilia

    International Nuclear Information System (INIS)

    Sangani, Ashok S; Vidyadharan, Jyothish; Foster, Kenneth W

    2016-01-01

    Detailed analysis of the forces acting on a uniform-diameter beating cilium is carried out to determine the moment generated by the inter-doublet forces acting along the length of a cilium and the results are compared with the sliding-control theory according to which the moment is a function of the interdoublet sliding. In the central part of the cilium the inter-doublet forces are found to be proportional to the inter-doublet sliding. However, in spite of the uniformity of the diameter of the cilium, the proportionality constant, known as the dynamic stiffness, is not constant along its entire length. Significant variations are observed in the regions both near the tip of the cilium and proximal to the cell body. In the tip region the magnitude of the dynamic stiffness is found to decrease. This decrease is probably due to decrease in the number density of the molecular motors in that region and in the number of doublet microtubules. The behavior in the proximal region, on the other hand, does not appear to be well described by the sliding control theory. Our analysis therefore suggests that the dynamics of ciliary beating cannot be adequately described by a simple sliding-control theory with constant dynamic stiffness. Our analysis suggests that the cilium is differentiated into a basal region optimized for the creation of a wave and a central region optimized to support a traveling wave that provides the thrust for the cell. (paper)

  4. Efficient heart beat detection using embedded system electronics

    Science.gov (United States)

    Ramasamy, Mouli; Oh, Sechang; Varadan, Vijay K.

    2014-04-01

    The present day bio-technical field concentrates on developing various types of innovative ambulatory and wearable devices to monitor several bio-physical, physio-pathological, bio-electrical and bio-potential factors to assess a human body's health condition without intruding quotidian activities. One of the most important aspects of this evolving technology is monitoring heart beat rate and electrocardiogram (ECG) from which many other subsidiary results can be derived. Conventionally, the devices and systems consumes a lot of power since the acquired signals are always processed on the receiver end. Because of this back end processing, the unprocessed raw data is transmitted resulting in usage of more power, memory and processing time. This paper proposes an innovative technique where the acquired signals are processed by a microcontroller in the front end of the module and just the processed signal is then transmitted wirelessly to the display unit. Therefore, power consumption is considerably reduced and clearer data analysis is performed within the module. This also avoids the need for the user to be educated about usage of the device and signal/system analysis, since only the number of heart beats will displayed at the user end. Additionally, the proposed concept also eradicates the other disadvantages like obtrusiveness, high power consumption and size. To demonstrate the above said factors, a commercial controller board was used to extend the monitoring method by using the saved ECG data from a computer.

  5. Unraveling the nature of coherent beatings in chlorosomes

    Energy Technology Data Exchange (ETDEWEB)

    Dostál, Jakub [Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund (Sweden); Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague (Czech Republic); Mančal, Tomáš; Pšenčík, Jakub [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague (Czech Republic); Vácha, František [Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice (Czech Republic); Zigmantas, Donatas, E-mail: donatas.zigmantas@chemphys.lu.se [Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund (Sweden)

    2014-03-21

    Coherent two-dimensional (2D) spectroscopy at 80 K was used to study chlorosomes isolated from green sulfur bacterium Chlorobaculum tepidum. Two distinct processes in the evolution of the 2D spectrum are observed. The first being exciton diffusion, seen in the change of the spectral shape occurring on a 100-fs timescale, and the second being vibrational coherences, realized through coherent beatings with frequencies of 91 and 145 cm{sup −1} that are dephased during the first 1.2 ps. The distribution of the oscillation amplitude in the 2D spectra is independent of the evolution of the 2D spectral shape. This implies that the diffusion energy transfer process does not transfer coherences within the chlorosome. Remarkably, the oscillatory pattern observed in the negative regions of the 2D spectrum (dominated by the excited state absorption) is a mirror image of the oscillations found in the positive part (originating from the stimulated emission and ground state bleach). This observation is surprising since it is expected that coherences in the electronic ground and excited states are generated with the same probability and the latter dephase faster in the presence of fast diffusion. Moreover, the relative amplitude of coherent beatings is rather high compared to non-oscillatory signal despite the reported low values of the Huang-Rhys factors. The origin of these effects is discussed in terms of the vibronic and Herzberg-Teller couplings.

  6. Angiotensin infusion effects on left ventricular function. Assessment in normal subjects and in patients with coronary disease.

    Science.gov (United States)

    Bianco, J A; Laskey, W K; Makey, D G; Shafer, R B

    1980-02-01

    Radionuclide multigating of the cardiac cycle was employed to assess effects of angiotensin infusion on left ventricular function. In six normal subjects, angiotensin infusion decreased heart rate (HR) from 72 +/- SEM 2 to 57 +/- 2 beats/min (P less than 0.001); while systolic blood pressure (BP) increased from 119 +/- 2 to 178 +/- 1 mm Hg (P less than 0.001), and ejection fraction (EF) declined from 58 +/- 1 to 47 +/- 2 percent (P less than 0.05). In contrast, in 11 normal subjects, supine exercise increased HR and systolic BP by 55 and 49 percent, whereas EF increased from 64 +/- 1 to 71 +/- 1 (P less than 0.001). In ten patients with CAD, angiotensin infusion produced no change in HR, increased systolic BP by 34 percent, and decreased EF by 11 percent. Angiotensin infusion induced left ventricular depression in normal subjects and in patients with CAD. It cannot substitute for exercise in intervention radionuclide ventriculography.

  7. Effects of sedation on echocardiographic variables of left atrial and left ventricular function in healthy cats.

    Science.gov (United States)

    Ward, Jessica L; Schober, Karsten E; Fuentes, Virginia Luis; Bonagura, John D

    2012-10-01

    Although sedation is frequently used to facilitate patient compliance in feline echocardiography, the effects of sedative drugs on echocardiographic variables have been poorly documented. This study investigated the effects of two sedation protocols on echocardiographic indices in healthy cats, with special emphasis on the assessment of left atrial size and function, as well as left ventricular diastolic performance. Seven cats underwent echocardiography (transthoracic two-dimensional, spectral Doppler, color flow Doppler and tissue Doppler imaging) before and after sedation with both acepromazine (0.1 mg/kg IM) and butorphanol (0.25 mg/kg IM), or acepromazine (0.1 mg/kg IM), butorphanol (0.25 mg/kg IM) and ketamine (1.5 mg/kg IV). Heart rate increased significantly following acepromazine/butorphanol/ketamine (mean±SD of increase, 40±26 beats/min) and non-invasive systolic blood pressure decreased significantly following acepromazine/butorphanol (mean±SD of decrease, 12±19 mmHg). The majority of echocardiographic variables were not significantly different after sedation compared with baseline values. Both sedation protocols resulted in mildly decreased left ventricular end-diastolic dimension and mildly increased left ventricular end-diastolic wall thickness. This study therefore failed to demonstrate clinically meaningful effects of these sedation protocols on echocardiographic measurements, suggesting that sedation with acepromazine, butorphanol and/or ketamine can be used to facilitate echocardiography in healthy cats.

  8. [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.

  9. Risk Factors for premature birth in a hospital 1

    OpenAIRE

    Ahumada-Barrios, Margarita E.; Alvarado, German F.

    2016-01-01

    Abstract Objective: to determine the risk factors for premature birth. Methods: retrospective case-control study of 600 pregnant women assisted in a hospital, with 298 pregnant women in the case group (who gave birth prematurely

  10. 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.

  11. Intracranial electroencephalography power and phase synchronization changes during monaural and binaural beat stimulation.

    Science.gov (United States)

    Becher, Ann-Katrin; Höhne, Marlene; Axmacher, Nikolai; Chaieb, Leila; Elger, Christian E; Fell, Juergen

    2015-01-01

    Auditory stimulation with monaural or binaural auditory beats (i.e. sine waves with nearby frequencies presented either to both ears or to each ear separately) represents a non-invasive approach to influence electrical brain activity. It is still unclear exactly which brain sites are affected by beat stimulation. In particular, an impact of beat stimulation on mediotemporal brain areas could possibly provide new options for memory enhancement or seizure control. Therefore, we examined how electroencephalography (EEG) power and phase synchronization are modulated by auditory stimulation with beat frequencies corresponding to dominant EEG rhythms based on intracranial recordings in presurgical epilepsy patients. Monaural and binaural beat stimuli with beat frequencies of 5, 10, 40 and 80 Hz and non-superposed control signals were administered with low amplitudes (60 dB SPL) and for short durations (5 s). EEG power was intracranially recorded from mediotemporal, temporo-basal and temporo-lateral and surface sites. Evoked and total EEG power and phase synchronization during beat vs. control stimulation were compared by the use of Bonferroni-corrected non-parametric label-permutation tests. We found that power and phase synchronization were significantly modulated by beat stimulation not only at temporo-basal, temporo-lateral and surface sites, but also at mediotemporal sites. Generally, more significant decreases than increases were observed. The most prominent power increases were seen after stimulation with monaural 40-Hz beats. The most pronounced power and synchronization decreases resulted from stimulation with monaural 5-Hz and binaural 80-Hz beats. Our results suggest that beat stimulation offers a non-invasive approach for the modulation of intracranial EEG characteristics. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. Premature graying of hair: An independent risk marker for coronary ...

    African Journals Online (AJOL)

    The presence of premature graying of hair was associated with 3.24 times the risk of CAD on multiple logistic regression analysis. CONCLUSION: The presence of premature graying of hair was associated with an increased risk of CAD in young smokers. Premature graying of hair can be used as preliminary evidence by ...

  13. Myocardial gated single photon emission tomography (GSPECT) in men and women with low probability of coronary artery disease - qualitative assessment of beating slices and polar plots

    International Nuclear Information System (INIS)

    Dziuk, M.; Canizales, A.; Britton, K.E.

    2001-01-01

    Assessment of the variability of regional wall motion and thickening in men and women with normal left ventricular contraction and low probability of CAD by GSPECT. The rest 99mTcMyoview GSPECT protocol (700 Mbq) was performed in 28 women and 14 men. Qualitative beating slices - QLGS and polar plots - QGS were analyzed independently by scoring the colour scale (1 - severe impairment, 4 - normal). Then the regional wall motion and thickening in the anterior, lateral, inferior walls, the septum and apex were estimated. In all patients the motion in the inferior wall and septum assessed on polar maps were significantly different than one in QLGS but better in the apex. Regional wall thickening was underestimated in QGS polar plots in the anterior wall, septum, inferior and lateral wall. End diastolic and end systolic volumes were significantly greater in men (90±29, 69±25, p<0.02 and 40±20, 22±12, p<0.002 for EDV and ESV respectively). In the later group all walls except the inferior showed higher QGS thickening score in comparison to men. The motion score in the anterior wall was also significantly bigger (p<0.05). The visual regional motion and thickening assessment on beating slices in gated SPECT seems to be more reliable than polar plots in patients with normal left ventricular contraction and low probability of coronary artery disease. Gated SPECT polar maps show better myocardial thickening in women probably due to the smaller left ventricle size and subsequent partial volume effect. (author)

  14. Right ventricular function in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    Araki, Haruo; Hisano, Ryuichi; Nagata, Yoshiyuki; Caglar, N.; Nakamura, Motoomi

    1985-01-01

    Thirty-five patients with ischemic heart disease (IHD) and 10 normal subjects were studied. Right and left ventricular ejecction fractions (EF) were determined using equilibrium radionuclide ventriculography with technetium-99m. Furthermore, abnormal motion of the right ventricular septal wall was obtained by cardiac cathetelization, and its relation to the right ventricular EF was examined. In IHD patients with anterior myocardial infarction, left ventricular EF decreased, but right ventricular EF was normal. This suggested that left ventricular dysfunction does not always have an effect on right ventricular function. Right ventricular EF was normal even when akinesis or dyskinesis was present in the ventricular septul, suggesting that abnormal motion of the ventricular septal wall has no significantly stimulant effect on right ventricular function. A decreased right ventricular EF was likely to occur only when the right ventricular free wall became ischemic or necrotic simultaneously with occurrence of posterior myocardial infarction. (Namekawa, K.)

  15. Arrhythmogenic Right Ventricular Cardiomyopathy in an Endurance Athlete Presenting with Ventricular Tachycardia and Normal Right Ventricular Function.

    Science.gov (United States)

    Hedley, Jeffrey S; Al Mheid, Ibhar; Alikhani, Zoubin; Pernetz, Maria A; Kim, Jonathan H

    2017-08-01

    Arrhythmogenic right ventricular cardiomyopathy, a genetically inherited disease that results in fibrofatty replacement of normal cardiac myocytes, has been associated with sudden cardiac death in athletes. Long-term participation in endurance exercise hastens the development of both the arrhythmic and structural arrhythmogenic right ventricular cardiomyopathy phenotypes. We describe the unusual case of a 34-year-old, symptomatic, female endurance athlete who had arrhythmogenic right ventricular cardiomyopathy in the presence of a structurally normal right ventricle. Clinicians should be aware of this infrequent presentation when evaluating athletic patients who have ventricular arrhythmias and normal findings on cardiac imaging studies.

  16. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music.

    Directory of Open Access Journals (Sweden)

    Pauline Tranchant

    Full Text Available The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music-bouncing and clapping-in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat.

  17. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music

    Science.gov (United States)

    Tranchant, Pauline; Vuvan, Dominique T.; Peretz, Isabelle

    2016-01-01

    The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music–bouncing and clapping–in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat. PMID:27471854

  18. Direct Visualization of Mechanical Beats by Means of an Oscillating Smartphone

    Science.gov (United States)

    Giménez, Marcos H.; Salinas, Isabel; Monsoriu, Juan A.; Castro-Palacio, Juan C.

    2017-10-01

    The resonance phenomenon is widely known in physics courses. Qualitatively speaking, resonance takes place in a driven oscillating system whenever the frequency approaches the natural frequency, resulting in maximal oscillatory amplitude. Very closely related to resonance is the phenomenon of mechanical beating, which occurs when the driving and natural frequencies of the system are slightly different. The frequency of the beat is just the difference of the natural and driving frequencies. Beats are very familiar in acoustic systems. There are several works in this journal on visualizing the beats in acoustic systems. For instance, the microphone and the speaker of two mobile devices were used in previous work to analyze the acoustic beats produced by two signals of close frequencies. The formation of beats can also be visualized in mechanical systems, such as a mass-spring system or a double-driven string. Here, the mechanical beats in a smartphone-spring system are directly visualized in a simple way. The frequency of the beats is measured by means of the acceleration sensor of a smartphone, which hangs from a spring attached to a mechanical driver. This laboratory experiment is suitable for both high school and first-year university physics courses.

  19. The Short Supply of Saints: Limits on Replication of Models that "Beat the Odds"

    Science.gov (United States)

    Wilder, Tamara; Jacobsen, Rebecca

    2010-01-01

    Researchers have identified effective practices that allow schools to "beat the odds" and close the reading achievement gap. Although identifying these practices is important, researchers have paid little attention to the work it takes to implement them. Through interviews with teachers who work at schools identified as beating the odds, this…

  20. Midbrain adaptation may set the stage for the perception of musical beat.

    Science.gov (United States)

    Rajendran, Vani G; Harper, Nicol S; Garcia-Lazaro, Jose A; Lesica, Nicholas A; Schnupp, Jan W H

    2017-11-15

    The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain preprocessing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat. © 2017 The Authors.

  1. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    Directory of Open Access Journals (Sweden)

    Fleur L Bouwer

    Full Text Available The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN, an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

  2. Peak misdetection in heart-beat-based security : Characterization and tolerance

    NARCIS (Netherlands)

    Seepers, Robert M; Strydis, Christos; Peris-Lopez, Pedro; Sourdis, Ioannis; De Zeeuw, Chris I

    The Inter-Pulse-Interval (IPI) of heart beats has previously been suggested for security in mobile health (mHealth) applications. In IPI-based security, secure communication is facilitated through a security key derived from the time difference between heart beats. However, there currently exists no

  3. Beat-wave laser accelerators, further comment including note on the 'Surfatron' concept

    International Nuclear Information System (INIS)

    Lawson, J.D.

    1984-07-01

    The paper deals with the Rutherford Appleton Laboratory (RAL) study of the beat-wave particle accelerator, intended for high energy physics. Three factors; the build-up of beat-wave, the surfatron concept and the self-focusing effects are considered in the context of the RAL study. (U.K.)

  4. Beat-by-beat analysis of cardiac output and blood pressure responses to short-term barostimulation in different body positions

    Science.gov (United States)

    Hildebrandt, Wulf; Schütze, Harald; Stegemann, J.

    Rapid quantification of the human baro-reflex control of heart rate has been achieved on a beat-by-beat basis using a neck-chamber with quick ECG-triggered pressure changes. Referring to recent findings on heart rate and stroke volume, the present study uses this technique to compare cardiac output as well as blood pressure changes in supine and upright position to investigate feedback effects and to confirm postural reflex modifications not revealed by RR-interval changes. A suction profile starting at +40 mmHg and running 7 steps of pressure decrease down to -65 mmHg was examined in 0° and 90° tilting position while beat-by-beat recordings were done of heart rate, stroke volume (impedance-cardiography) and blood pressure (Finapres tm) (n=16). The percentual heart rate decrease failed to be significantly different between positions. A suction-induced stroke volume increase led to a cardiac output almost maintained when supine and significantly increased when upright. A decrease in all blood pressure values was found during suction, except for systolic values in upright position which increased. Conclusively, (a) it is confirmed that different inotropy accounts for the seen gravitational effect on the cardiac output not represented by heart rate; (b) identical suction levels in different positions lead to different stimuli at the carotid receptor. This interference has to be considered in microgravity studies by beat-by-beat measurement of cardiac output and blood pressure.

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

    Science.gov (United States)

    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.

  6. Influences of rolling method on deformation force in cold roll-beating forming process

    Science.gov (United States)

    Su, Yongxiang; Cui, Fengkui; Liang, Xiaoming; Li, Yan

    2018-03-01

    In process, the research object, the gear rack was selected to study the influence law of rolling method on the deformation force. By the mean of the cold roll forming finite element simulation, the variation regularity of radial and tangential deformation was analysed under different rolling methods. The variation of deformation force of the complete forming racks and the single roll during the steady state under different rolling modes was analyzed. The results show: when upbeating and down beating, radial single point average force is similar, the tangential single point average force gap is bigger, the gap of tangential single point average force is relatively large. Add itionally, the tangential force at the time of direct beating is large, and the dire ction is opposite with down beating. With directly beating, deformation force loading fast and uninstall slow. Correspondingly, with down beating, deformat ion force loading slow and uninstall fast.

  7. More attentional focusing through binaural beats: evidence from the global-local task.

    Science.gov (United States)

    Colzato, Lorenza S; Barone, Hayley; Sellaro, Roberta; Hommel, Bernhard

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task. While the size of the congruency effect (indicating the failure to suppress task-irrelevant information) was unaffected by the binaural beats, the global-precedence effect (reflecting attentional focusing) was considerably smaller after gamma-frequency binaural beats than after the control condition. Our findings suggest that high-frequency binaural beats bias the individual attentional processing style towards a reduced spotlight of attention.

  8. Auditory beat stimulation and its effects on cognition and mood States.

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke Caroline; Reber, Thomas P; Fell, Juergen

    2015-01-01

    Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood states. Here, we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation (ABS). We have summarized relevant studies investigating the neurophysiological changes related to ABS and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural-beat stimulation, we then discuss the role of monaural- and binaural-beat frequencies in cognition and mood states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of ABS.

  9. Ion channels and beating heart: the players and the music

    Directory of Open Access Journals (Sweden)

    Charles Antzelevitch

    2011-12-01

    Full Text Available Soft gentle music accompanies us throughout our lifetime; it is the music of our heart beating. Although at times it is questionable as to who serves as conductor of the orchestra, there is little doubt that our ion channels are the main players. Whenever one of them plays too loudly, too softly or simply off key, disharmony results, sometimes leading to total disruption of the rate and rhythm. Ion channels can disrupt the music of our heart by different mechanisms. Sometimes their function is correct, but their expression is altered by underlying cardiac diseases (i.e. heart failure; sometimes the defect is in their structure, because of an underlying genetic defect, and in this case a channelopathy is present.

  10. The quantum beat principles and applications of atomic clocks

    CERN Document Server

    Major, F

    2007-01-01

    This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in the quartz-controlled clocks. While the book makes no pretense at being a history of atomic clocks, it nevertheless takes a historical perspective in its treatment of the subject. Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of "optical molasses," and the cesium "fountain" stand...

  11. MD 979: Beta-beating measurements on colliding beams

    CERN Document Server

    Goncalves Jorge, Patrik; Pieloni, Tatiana; Buffat, Xavier; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fol, Elena; Langner, Andy Sven; Medina Medrano, Luis Eduardo; Olexa, Jakub; Tomas Garcia, Rogelio; Valuch, Daniel; Wegscheider, Andreas; CERN. Geneva. ATS Department

    2017-01-01

    The HL-LHC high brightness beams will give a large β-beating due to the head-on and long-range interactions since a beam-beam parameter of 0.01 per Interaction Point (IP) is expected. The β-heating induced by two head-on collision reaches 15%. A third IP, i.e. IP8, could bring the β-heating up to 24%. The aim of the Machine Development (MD) study was to test optics measurements with AC dipole and ADT on colliding beams at injection and to implement a correction of the β-heating due to to head-on collision in the two experiments IP1&5. Int his note, we summarize the first results of this test performed in the LHC.

  12. Conceptualizing pathways linking women's empowerment and prematurity in developing countries.

    Science.gov (United States)

    Afulani, Patience A; Altman, Molly; Musana, Joseph; Sudhinaraset, May

    2017-11-08

    Globally, prematurity is the leading cause of death in children under the age of 5. Many efforts have focused on clinical approaches to improve the survival of premature babies. There is a need, however, to explore psychosocial, sociocultural, economic, and other factors as potential mechanisms to reduce the burden of prematurity. Women's empowerment may be a catalyst for moving the needle in this direction. The goal of this paper is to examine links between women's empowerment and prematurity in developing settings. We propose a conceptual model that shows pathways by which women's empowerment can affect prematurity and review and summarize the literature supporting the relationships we posit. We also suggest future directions for research on women's empowerment and prematurity. The key words we used for empowerment in the search were "empowerment," "women's status," "autonomy," and "decision-making," and for prematurity we used "preterm," "premature," and "prematurity." We did not use date, language, and regional restrictions. The search was done in PubMed, Population Information Online (POPLINE), and Web of Science. We selected intervening factors-factors that could potentially mediate the relationship between empowerment and prematurity-based on reviews of the risk factors and interventions to address prematurity and the determinants of those factors. There is limited evidence supporting a direct link between women's empowerment and prematurity. However, there is evidence linking several dimensions of empowerment to factors known to be associated with prematurity and outcomes for premature babies. Our review of the literature shows that women's empowerment may reduce prematurity by (1) preventing early marriage and promoting family planning, which will delay age at first pregnancy and increase interpregnancy intervals; (2) improving women's nutritional status; (3) reducing domestic violence and other stressors to improve psychological health; and (4) improving

  13. Multiple ventricular septal defects: a new strategy.

    Science.gov (United States)

    Corno, Antonio F; Kandakure, Pramod R; Dhannapuneni, Ramana Rao V; Gladman, Gordon; Venugopal, Prem; Alphonso, Nelson

    2013-01-01

    A multicenter prospective study was conducted to evaluate a new strategy for multiple Ventricular Septal Defects (VSDs). From 2004 to 2012 17 consecutive children (3 premature, 14 infants), mean age 3.2 months (9 days-9 months), mean body weight 4.2 kg (3.1-6.1 kg), with multiple VSDs underwent Pulmonary Artery Banding (PAB) with an adjustable FloWatch-PAB(®). Associated cardiac anomalies included patent ductus arteriosus (1), aortic coarctation (2), hypoplastic aortic arch (2), and left isomerism (3). Five patients (5/17 = 29.4%) required pre-operative mechanical ventilation, with a mean duration of 64 days (7-240 days) There were no early or late deaths during a mean follow-up of 48 months (7-98 months), with either FloWatch removal or last observation as end-points. FloWatch-PAB(®) adjustments were required in all patients: a mean of 4.8 times/patient (2-9) to tighten the PAB, and a mean of 1.1 times/patient (0-3) to release the PAB with the patient's growth. After a mean interval of 29 months (8-69 months) 10/17 (59%) patients underwent re-operation: 7/10 PAB removal, with closure of a remaining unrestrictive VSD in 6 (peri-membranous in 3 patients, mid-muscular in 2, and inlet in 1) and Damus-Kaye-Stansel, bi-directional Glenn, and atrial septectomy in 1; 3/9 patients required only PAB removal. All muscular multiple VSDs had closed in all 10 patients. PA reconstruction was required in 1/10 patient. In 5/7 of the remaining patients with the PAB still in situ, all muscular VSDs had already closed. The only 2 patients with persistent muscular multiple VSDs are the 2 patients with the shortest follow-up. This reproducible new strategy with an adjustable PAB simplifies the management of infants with multiple VSDs and provides the following advantages: (a) good results (0% mortality), delayed surgery with a high incidence (15/17 = 88%) of spontaneous closure of multiple muscular VSDs, and facilitated closure of residual unrestrictive

  14. MULTIPLE VENTRICULAR SEPTAL DEFECTS: A NEW STRATEGY

    Directory of Open Access Journals (Sweden)

    Antonio Francesco Corno

    2013-07-01

    Full Text Available INTRODUCTIONA multicenter prospective study was conducted to evaluate a new strategy for multiple Ventricular Septal Defects (VSDs.MATERIALS AND METHODSFrom 2004 to 2012 17 consecutive children (3 premature, 14 infants, mean age 3.2months (9 days to 9 months, mean body weight 4.2kg (3.1 to 6.1 kg, with multiple VSDs underwent Pulmonary Artery Banding (PAB with an adjustable FloWatch-PAB. Associated cardiac anomalies included patent ductus arteriosus (9, aortic coarctation (2, hypoplastic aortic arch (2 and left isomerism (1. Five patients (5/17 =29.4% required pre-operative mechanical ventilation, with a mean duration of 64 days (7 to 240 daysRESULTSThere were no early or late deaths during a mean follow-up of 48 months (7 to 98 months, with either FloWatch removal or last observation as end-points.FloWatch-PAB adjustments were required in all patients: a mean of 4.8 times/patient (2 to 9 to tighten the PAB, and a mean of 1.1 times/patient (0 to 3 to release the PAB with the patient’s growth. After a mean interval of 29 months (8 to 69 months 10/17 (59% patients underwent reoperation: 7/10 PAB removal, with closure of a remaining peri-membranous VSD in 6 and Damus-Kaye-Stansel, bi-directional Glenn, and atrial septectomy in 1; 3/9 patients required only PAB removal. All muscular multiple VSDs had closed in all 10 patients. PA reconstruction was required in 1/10 patient. In 5/7 of the remaining patients with the PAB still in situ, all muscular VSDs had already closed. The only 2 patients with persistent muscular multiple VSDs are the 2 patients with the shortest follow-up.CONCLUSIONS This reproducible new strategy with an adjustable PAB simplifies the management of infants with multiple VSDs and provides the following advantages: a good results (0% mortality, delayed surgery with a high incidence (15/17=88% of spontaneous closure of multiple muscular VSDs, and facilitated closure of residual peri-membranous VSD at an older age and h

  15. Premature ovarian failure and ovarian autoimmunity

    OpenAIRE

    Schoemaker, Joop; Drexhage, Hemmo; Hoek, Annemieke

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heterogeneous disorder with a multicausal pathogenesis involving chromosomal, genetic, enzymatic, infectious, and iatrogenic causes. There remains, however, a group of POF patients without a known etiology, the so-called "idiopathic...

  16. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    OpenAIRE

    Maria URSACHI (BOLOTA); Emil ANTON; Sorana Caterina ANTON

    2016-01-01

    The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amn...

  17. The effect of binaural beats on verbal working memory and cortical connectivity

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

    2017-04-01

    Objective. Synchronization in activated regions of cortical networks affect the brain’s frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain’s response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. Approach. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. Main results. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant’s accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Significance. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

  18. The effect of binaural beats on verbal working memory and cortical connectivity.

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

    2017-04-01

    Synchronization in activated regions of cortical networks affect the brain's frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain's response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant's accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

  19. Increased Short-Term Beat-to-Beat QT Interval Variability in Patients with Impaired Glucose Tolerance

    Directory of Open Access Journals (Sweden)

    Andrea Orosz

    2017-06-01

    Full Text Available Prediabetic states and diabetes are important risk factors for cardiovascular morbidity and mortality. Determination of short-term QT interval variability (STVQT is a non-invasive method for assessment of proarrhythmic risk. The aim of the study was to evaluate the STVQT in patients with impaired glucose tolerance (IGT. 18 IGT patients [age: 63 ± 11 years, body mass index (BMI: 31 ± 6 kg/m2, fasting glucose: 6.0 ± 0.4 mmol/l, 120 min postload glucose: 9.0 ± 1.0 mmol/l, hemoglobin A1c (HbA1c: 5.9 ± 0.4%; mean ± SD] and 18 healthy controls (age: 56 ± 9 years, BMI: 27 ± 5 kg/m2, fasting glucose: 5.2 ± 0.4 mmol/l, 120 min postload glucose: 5.5 ± 1.3 mmol/l, HbA1c: 5.4 ± 0.3% were enrolled into the study. ECGs were recorded, processed, and analyzed off-line. The RR and QT intervals were expressed as the average of 30 consecutive beats, the temporal instability of beat-to-beat repolarization was characterized by calculating STVQT as follows: STVQT = Σ|QTn + 1 − QTn| (30x√2−1. Autonomic function was assessed by means of standard cardiovascular reflex tests. There were no differences between IGT and control groups in QT (411 ± 43 vs 402 ± 39 ms and QTc (431 ± 25 vs 424 ± 19 ms intervals or QT dispersion (44 ± 13 vs 42 ± 17 ms. However, STVQT was significantly higher in IGT patients (5.0 ± 0.7 vs 3.7 ± 0.7, P < 0.0001. The elevated temporal STVQT in patients with IGT may be an early indicator of increased instability of cardiac repolarization during prediabetic conditions.

  20. Arrhythmogenic right ventricular dysplasia: MRI findings

    International Nuclear Information System (INIS)

    Wall, E.E. van der; Bootsma, M.M.; Schalij, M.J.; Kayser, H.W.M.; Roos, A. de

    2000-01-01

    Arrhythmogenic right ventricular dysplasia (ARVD) is a heart muscle disorder of unknown cause that is characterized pathologically by fibrofatty replacement of the right ventricular myocardium. Clinical manifestations include structural and functional malformations of the right ventricle, electrocardiographic abnormalities, and presentation with ventricular tachycardias with left bundle branch pattern or sudden death. The disease is often familial with an autosomal inheritance. In addition to right ventricular dilatation, right ventricular aneurysms are typical deformities of ARVD and they are distributed in the so-called ''triangle of dysplasia'', i. e., right ventricular outflow tract, apex, and infundibulum. Ventricular aneurysms at these sites can be considered pathognomonic of ARVD. Another typical hallmark of ARVD is fibrofatty infiltration of the right ventricular free wall. These functional and morphologic characteristics are relevant to clinical imaging investigations such as contrast angiography, echocardiography, radionuclide angiography, ultrafast computed tomography, and magnetic resonance imaging (MRI). Among these techniques, MRI allows the clearest visualization of the heart, in particular because the right ventricle is involved, which is usually more difficult to explore with the other imaging modalities. Furthermore, MRI offers the specific advantage of visualizing adipose infiltration as a bright signal of the right ventricular myocardium. MRI provides the most important anatomic, functional, and morphologic criteria for diagnosis of ARVD within one single study. As a result, MRI appears to be the optimal imaging technique for detecting and following patients with clinical suspicion of ARVD. (orig.) [de

  1. Retinopathy of prematurity: the need for prevention

    Science.gov (United States)

    Liegl, Raffael; Hellström, Ann; Smith, Lois EH

    2016-01-01

    More than 450,000 babies are born prematurely in the USA every year. The improved survival of even the most vulnerable low body weight preterm infants has, despite improving health outcomes, led to the resurgence in preterm complications including one of the major causes for blindness in children, retinopathy of prematurity (ROP). The current mainstay in ROP therapy is laser photocoagulation and the injection of vascular endothelial growth factor (VEGF) antibodies in the late stages of the disease after the onset of neovascularization. Both are proven options for ophthalmologists to treat the severe forms of late ROP. However, laser photocoagulation destroys major parts of the retina, and the injection of VEGF antibodies, although rather simple to administer, may cause a systemic suppression of normal vascularization, which has not been studied in sufficient depth. However, the use of neither VEGF antibody nor laser treatment prevents ROP, which should be the long-term goal. It should be possible to prevent ROP by more closely mimicking the intrauterine environment after preterm birth. Such preventive measures include preventing the toxic postbirth influences (eg, oxygen excess) as well as providing the missing intrauterine factors (eg, insulin growth factor 1) and are likely to also reduce other complications of premature birth as well as ROP. This review is meant to summarize the current knowledge on the prevention of ROP with a particular emphasize on the use of insulin growth factor 1 supplementation. PMID:28539804

  2. Patent Ductus Arteriosus in Premature Neonates

    Science.gov (United States)

    Mezu-Ndubuisi, Olachi J.; Agarwal, Ghanshyam; Raghavan, Aarti; Pham, Jennifer T.; Ohler, Kirsten H.; Maheshwari, Akhil

    2015-01-01

    Persistent patency of the ductus arteriosus is a major cause of morbidity and mortality in premature infants. In infants born prior to 28 weeks of gestation, a hemodynamically-significant patent ductus arteriosus (PDA) can cause cardiovascular instability, exacerbate respiratory distress syndrome, prolong the need for assisted ventilation, and increase the risk of bronchopulmonary dysplasia, intraventricular hemorrhage, renal dysfunction, intraventricular hemorrhage, cerebral palsy, and mortality. In this article, we review the pathophysiology, clinical features, and assessment of hemodynamic significance, and provide a rigorous appraisal of the quality of evidence to support current medical and surgical management of PDA of prematurity. Cyclo-oxygenase inhibitors such as indomethacin and ibuprofen remain the mainstay of medical therapy for PDA, and can be used both for prophylaxis as well as rescue therapy to achieve PDA closure. Surgical ligation is also effective and is used in infants who do not respond to medical management. Although both medical and surgical treatment have proven efficacy in closing the ductus, both modalities are associated with significant adverse effects. Because the ductus does undergo spontaneous closure in some premature infants, improved and early identification of infants most likely to develop a symptomatic PDA could help in directing treatment to the at-risk infants and allow others to receive expectant management. PMID:22564132

  3. Open bite in prematurely born children.

    Science.gov (United States)

    Harila, V; Heikkinen, T; Grön, M; Alvesalo, L

    2007-01-01

    The aims of this study were to: examine the expression of open bite in prematurely born children and discuss the etiological factors that may lead to bite it. The subjects were 328 prematurely born (cross-sectional study of the Collaborative Perinatal Project in the 1960s and 1970s. Dental documents, including casts and photographs, were taken once at the age of 6-12 years in the mixed dentition. The occlusion was recorded by examining and measuring the hard stone casts. Vertical open bite was recorded only for full erupted teeth. The statistical method used was chi-square analysis. Significant differences in the incidence of anterior open bite (from left to right canine) was found between the preterm and control groups and between gender and ethnic groups. The prevalence of anterior open bite was nearly 9% in the preterm group and almost 7% in the control group. African Americans (9%) had a significantly greater incidence of open bite than Caucasians (3%; Pbite than boys (8% vs 6%; Pbite was increased--especially in preterm African American boys compared to controls (11% vs 8%). The results show differences in the development of anterior open bite between ethnic and gender groups. Premature birth may also influence dental occlusal development. Of importance are the patient's: general health condition; respiratory infections; inadequate nasal- and mouth-breathing; oral habits; and other medical problems. Preterm children may be relatively more predisposed to etiological factors for the development of anterior open bite.

  4. Improvement of Left Ventricular Function by Permanent Direct His-Bundle Pacing in a Case with Dilated Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Yukiko Sashida, MD

    2006-01-01

    Full Text Available The patient was a 67-year-old female diagnosed with dilated cardiomyopathy. She had chronic atrial fibrillation (AF with bradycardia and low left ventricular function (left ventricular ejection fraction (LVEF 40%. She was admitted for congestive heart failure. She remained New York Heart Association (NYHA functional class III due to AF bradycardia. Pacemaker implantation was necessary for treatment of heart failure and administration of dose intensive β-blockers. As she had normal His-Purkinje activation, we examined the optimal pacing sites. Hemodynamics of His-bundle pacing and biventricular pacing were compared. Pulmonary capillary wedge pressure (PCWP was significantly lower on Hisbundle pacing than right ventricular (RV apical pacing and biventricular pacing (13mmHg, 19mmHg, and 19mmHg, respectively with an almost equal cardiac index. Based on the examination we implanted a permanent pacemaker for Direct His-bundle pacing (DHBP. After the DHBP implantation, the LVEF immediately improved from 40% to 55%, and BNP level decreased from 422 pg/ml to 42 pg/ml. The number of premature ventricular complex (PVC was decreased, and non sustained ventricular tachycardia (NSVT disappeared. Pacing threshold for His-bundle pacing has remained at the same level. His-bundle pacing has been maintained during 27 months and her long-term DHBP can improve cardiac function and the NYHA functional class.

  5. Prematurity Affects Age of Presentation of Pyloric Stenosis.

    Science.gov (United States)

    Costanzo, Caitlyn M; Vinocur, Charles; Berman, Loren

    2017-02-01

    Term infants with hypertrophic pyloric stenosis (HPS) typically present between 4 and 6 weeks. There is limited consensus, however, regarding age of presentation of premature infants. We aim to determine if there is an association between the degree of prematurity and chronological age of presentation of HPS. A total of 2988 infants who had undergone a pyloromyotomy for HPS were identified from the 2012 and 2013 NSQIP-P Participant Use Files. Two hundred seventeen infants (7.3%) were born prematurely. A greater degree of prematurity was associated with an older chronological age of presentation ( P Prematurity was significantly associated with an increase in overall postoperative morbidity, reintubation, readmission, and postoperative length of stay. When clinicians evaluate an infant with nonbilious emesis with a history of prematurity, they should consider pyloric stenosis if the calculated postconceptional age is between 44 and 50 weeks. When counseling families of premature infants, surgeons should discuss the increased incidence of postpyloromyotomy morbidity.

  6. Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

    International Nuclear Information System (INIS)

    Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun; Lee, Hyong Woo; Chung, Jin Hong

    1990-01-01

    Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

  7. Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun [Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, Hyong Woo; Chung, Jin Hong [Yeongnam National University College of Medicine, Daegu (Korea, Republic of)

    1990-07-15

    Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Accuracy of unfolded map method for determining the left ventricular border. Evaluation of the cut-off value from autopsy finding

    International Nuclear Information System (INIS)

    Sugibayashi, Keiichi; Abe, Yoshiteru; Suga, Yutaka

    1996-01-01

    To improve the quantification of the left ventricular surface area (LVSA) by unfolded map method, we evaluated the cut-off value for determining the left ventricular border. The LVSA measured by unfolded map was compared with those measured using myocardial phantom and autopsy findings. The relative error (RE) was calculated as difference between LVSA in phantom and area of unfolded map. In phantom study, the cut-off value was calculated as 73.3±0.5% when the RE was zero. In autopsy study, the cut-off value was 74.0±7.2%. The area of unfolded map had good correlation with LVSA at autopsy when the cut-off value was 74% (r=0.83, p<0.003). The diameter of left ventricle at autopsy was compared with that of beating heart obtained by two-dimensional echocardiography, because the area of unfolded map was greater than LVSA at autopsy. The ratio of LVSA at autopsy to beating heart was calculated as 1.37. The suitable cut-off value was evaluated as 55.6% when the unfolded map area obtained by autopsy was increased 1.37 magnifications. There was a good correlation between LVSA of unfolded map (cut-off=56%) and the LVSA at autopsy (r=0.90, p<0.001). These results suggest that the cut-off value for determining the left ventricular border in vivo is 56%. (author)

  10. The effect of beat frequency on eye movements during free viewing.

    Science.gov (United States)

    Maróti, Emese; Knakker, Balázs; Vidnyánszky, Zoltán; Weiss, Béla

    2017-02-01

    External periodic stimuli entrain brain oscillations and affect perception and attention. It has been shown that background music can change oculomotor behavior and facilitate detection of visual objects occurring on the musical beat. However, whether musical beats in different tempi modulate information sampling differently during natural viewing remains to be explored. Here we addressed this question by investigating how listening to naturalistic drum grooves in two different tempi affects eye movements of participants viewing natural scenes on a computer screen. We found that the beat frequency of the drum grooves modulated the rate of eye movements: fixation durations were increased at the lower beat frequency (1.7Hz) as compared to the higher beat frequency (2.4Hz) and no music conditions. Correspondingly, estimated visual sampling frequency decreased as fixation durations increased with lower beat frequency. These results imply that slow musical beats can retard sampling of visual information during natural viewing by increasing fixation durations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Effects of single cycle binaural beat duration on auditory evoked potentials.

    Science.gov (United States)

    Mihajloski, Todor; Bohorquez, Jorge; Özdamar, Özcan

    2014-01-01

    Binaural beat (BB) illusions are experienced as continuous central pulsations when two sounds with slightly different frequencies are delivered to each ear. It has been shown that steady-state auditory evoked potentials (AEPs) to BBs can be captured and investigated. The authors recently developed a new method of evoking transient AEPs to binaural beats using frequency modulated stimuli. This methodology was able to create single BBs in predetermined intervals with varying carrier frequencies. This study examines the effects of the BB duration and the frequency modulating component of the stimulus on the binaural beats and their evoked potentials. Normal hearing subjects were tested with a set of four durations (25, 50, 100, and 200 ms) with two stimulation configurations, binaural dichotic (binaural beats) and diotic (frequency modulation). The results obtained from the study showed that out of the given durations, the 100 ms beat, was capable of evoking the largest amplitude responses. The frequency modulation effect showed a decrease in peak amplitudes with increasing beat duration until their complete disappearance at 200 ms. Even though, at 200 ms, the frequency modulation effects were not present, the binaural beats were still perceived and captured as evoked potentials.

  12. Ventricular shape and relative position abnormalities in preterm neonates

    Directory of Open Access Journals (Sweden)

    N. Paquette

    2017-01-01

    Full Text Available Recent neuroimaging findings have highlighted the impact of premature birth on subcortical development and morphological changes in the deep grey nuclei and ventricular system. To help characterize subcortical microstructural changes in preterm neonates, we recently implemented a multivariate tensor-based method (mTBM. This method allows to precisely measure local surface deformation of brain structures in infants. Here, we investigated ventricular abnormalities and their spatial relationships with surrounding subcortical structures in preterm neonates. We performed regional group comparisons on the surface morphometry and relative position of the lateral ventricles between 19 full-term and 17 preterm born neonates at term-equivalent age. Furthermore, a relative pose analysis was used to detect individual differences in translation, rotation, and scale of a given brain structure with respect to an average. Our mTBM results revealed broad areas of alterations on the frontal horn and body of the left ventricle, and narrower areas of differences on the temporal horn of the right ventricle. A significant shift in the rotation of the left ventricle was also found in preterm neonates. Furthermore, we located significant correlations between morphology and pose parameters of the lateral ventricles and that of the putamen and thalamus. These results show that regional abnormalities on the surface and pose of the ventricles are also associated with alterations on the putamen and thalamus. The complementarity of the information provided by the surface and pose analysis may help to identify abnormal white and grey matter growth, hinting toward a pattern of neural and cellular dysmaturation.

  13. Electrical Signs predictors of malignant ventricular arrhythmias

    International Nuclear Information System (INIS)

    Aleman Fernandez, Ailema Amelia; Dorantes Sanchez, Margarita

    2012-01-01

    Recurrence of malignant ventricular arrhythmia is frequent in cardioverter-defibrillators related patients. The risk stratification is difficult, there are numerous electrocardiographic predictors but his sensibility and specificity are not absolute. The limit between normal and pathological is not defined, besides the complexity of ventricular arrhythmias. We expose different electrocardiographic predictors that can help to better individual risk stratification

  14. Bidirectional ventricular tachycardia of unusual etiology

    Directory of Open Access Journals (Sweden)

    Praloy Chakraborty

    2015-11-01

    Full Text Available Bidirectional ventricular tachycardia (BDVT is a rare form of ventricular arrhythmia, characterized by changing QRS axis of 180 degrees. Digitalis toxicity is considered as commonest cause of BDVT; other causes include aconite toxicity, myocarditis, myocardial infarction, metastatic cardiac tumour and cardiac channelopathies. We describe a case of BDVT in a patient with Anderson-Tawil syndrome.

  15. Assessment of hormonal activity in patients with premature ejaculation

    Directory of Open Access Journals (Sweden)

    Lütfi Canat

    Full Text Available ABSTRACT Purpose Premature ejaculation is considered the most common type of male sexual dysfunction. Hormonal controls of ejaculation have not been exactly elucidated. The aim of our study is to investigate the role of hormonal factors in patients with premature ejaculation. Materials and Methods Sixty-three participants who consulted our outpatient clinics with complaints of premature ejaculation and 39 healthy men as a control group selected from volunteers were included in the study. A total of 102 sexual active men aged between 21 and 76 years were included. Premature ejaculation diagnostic tool questionnaires were used to assessment of premature ejaculation. Serum levels of follicle stimulating hormone, luteinizing hormone, prolactin, total and free testosterone, thyroid-stimulating hormone, free triiodothyronine and thyroxine were measured. Results Thyroid-stimulating hormone, luteinizing hormone, and prolactin levels were significantly lower in men with premature ejaculation according to premature ejaculation diagnostic tool (p=0.017, 0.007 and 0.007, respectively. Luteinizing hormone level (OR, 1.293; p=0.014 was found to be an independent risk factor for premature ejaculation. Conclusions Luteinizing hormone, prolactin, and thyroid-stimulating hormone levels are associated with premature ejaculation which was diagnosed by premature ejaculation diagnostic tool questionnaires. The relationship between these findings have to be determined by more extensive studies.

  16. A new way of thinking about complications of prematurity.

    Science.gov (United States)

    Moore, Tiffany A; Berger, Ann M; Wilson, Margaret E

    2014-01-01

    The morbidity and mortality of preterm infants are impacted by their ability to maintain physiologic homeostasis using metabolic, endocrine, and immunologic mechanisms independent of the mother's placenta. Exploring McEwen's allostatic load model in preterm infants provides a new way to understand the altered physiologic processes associated with frequently occurring complications of prematurity such as bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity. The purpose of this article is to present a new model to enhance understanding of the altered physiologic processes associated with complications of prematurity. The model of allostatic load and complications of prematurity was derived to explore the relationship between general stress of prematurity and complications of prematurity. The proposed model uses the concepts of general stress of prematurity, allostasis, physiologic response patterns (adaptive-maladaptive), allostatic load, and complications of prematurity. These concepts are defined and theoretical relationships in the proposed model are interpreted using the four maladaptive response patterns of repeated hits, lack of adaptation, prolonged response, and inadequate response. Empirical evidence for cortisol, inflammation, and oxidative stress responses are used to support the theoretical relationships. The proposed model provides a new way of thinking about physiologic dysregulation in preterm infants. The ability to describe and understand complex physiologic mechanisms involved in complications of prematurity is essential for research. Advancing the knowledge of complications of prematurity will advance clinical practice and research and lead to testing of interventions to reduce negative outcomes in preterm infants.

  17. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm.

    Science.gov (United States)

    Bouwer, Fleur L; Werner, Carola M; Knetemann, Myrthe; Honing, Henkjan

    2016-05-01

    Beat perception is the ability to perceive temporal regularity in musical rhythm. When a beat is perceived, predictions about upcoming events can be generated. These predictions can influence processing of subsequent rhythmic events. However, statistical learning of the order of sounds in a sequence can also affect processing of rhythmic events and must be differentiated from beat perception. In the current study, using EEG, we examined the effects of attention and musical abilities on beat perception. To ensure we measured beat perception and not absolute perception of temporal intervals, we used alternating loud and soft tones to create a rhythm with two hierarchical metrical levels. To control for sequential learning of the order of the different sounds, we used temporally regular (isochronous) and jittered rhythmic sequences. The order of sounds was identical in both conditions, but only the regular condition allowed for the perception of a beat. Unexpected intensity decrements were introduced on the beat and offbeat. In the regular condition, both beat perception and sequential learning were expected to enhance detection of these deviants on the beat. In the jittered condition, only sequential learning was expected to affect processing of the deviants. ERP responses to deviants were larger on the beat than offbeat in both conditions. Importantly, this difference was larger in the regular condition than in the jittered condition, suggesting that beat perception influenced responses to rhythmic events in addition to sequential learning. The influence of beat perception was present both with and without attention directed at the rhythm. Moreover, beat perception as measured with ERPs correlated with musical abilities, but only when attention was directed at the stimuli. Our study shows that beat perception is possible when attention is not directed at a rhythm. In addition, our results suggest that attention may mediate the influence of musical abilities on beat

  18. Systolic and Diastolic Left Ventricular Mechanics during and after Resistance Exercise.

    Science.gov (United States)

    Stöhr, Eric J; Stembridge, Mike; Shave, Rob; Samuel, T Jake; Stone, Keeron; Esformes, Joseph I

    2017-10-01

    To improve the current understanding of the impact of resistance exercise on the heart, by examining the acute responses of left ventricular (LV) strain, twist, and untwisting rate ("LV mechanics"). LV echocardiographic images were recorded in systole and diastole before, during and immediately after (7-12 s) double-leg press exercise at two intensities (30% and 60% of maximum strength, one-repetition maximum). Speckle tracking analysis generated LV strain, twist, and untwisting rate data. Additionally, beat-by-beat blood pressure was recorded and systemic vascular resistance (SVR) and LV wall stress were calculated. Responses in both exercise trials were statistically similar (P > 0.05). During effort, stroke volume decreased, whereas SVR and LV wall stress increased (P mechanics (P 0.05). Immediately after exercise, systolic LV mechanics returned to baseline levels (P mechanics, but increases diastolic mechanics after exercise, suggesting that resistance exercise has a differential impact on systolic and diastolic heart muscle function. The findings may explain why acute resistance exercise has been associated with reduced stroke volume but chronic exercise training may result in increased LV volumes.

  19. Predictors of the left ventricular dysfunction induced by ventricular arrhythmia

    Directory of Open Access Journals (Sweden)

    А. І. Vytryhovskiy

    2016-08-01

    Full Text Available The most powerful predictor of life-threatening arrhythmia risk is a combination of low heart rate variability with low ejection fraction (EF of the left ventricle. Aim. To identify predictors of left ventricle dysfunction which is induced by ventricular arrhythmia. Materials and methods. To diagnose structural changes of left ventricular functional capacity and reserves in patients with previous myocardial infarction and patients with high and very high cardiovascular risk by SCORE scale and for establishment the relationship between morphological heart changes and pathological phenomenon of heart turbulence echocardiography and study of heart rate turbulence variability were performed. 603 patients were selected for the research. All patients were divided into groups: group 1 – patients with coronary heart disease, but without associated risk factors, such as smoking, obesity, metabolic syndrome; group 2 – patients who smoke tobacco more than 2 years (very high cardiovascular risk by scale SCORE; group 3 – patients with metabolic syndrome without coronary heart disease or arterial hypertension (very high cardiovascular risk by scale SCORE. The control group consisted of 149 persons. Results. The feature of structural changes in patients with myocardial infarction and in patients with a high cardiovascular risk by SCORE with heart rate turbulence compared with cases without НRT is considerably thickening of the left interventricular septum in systole. Based on this, it can be argued that the emergence of ventricular arrhythmia and accordingly phenomenon of heart rate turbulence in patients with existing cardiovascular diseases and risk factors has both morphological and functional character. Significant difference of echocardioscopy parameters in patients with postinfarction cardiosclerosis and risk factors by the SCORE system was established by index of intraventricular septum thickness in systole, and in persons with high risk – in

  20. Activating and relaxing music entrains the speed of beat synchronized walking

    OpenAIRE

    Leman, Marc; Moelants, Dirk; Varewyck, Matthias; Styns, Frederik; van Noorden, Leon; Martens, Jean-Pierre

    2013-01-01

    Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musi...

  1. Quantum beat and entanglement of multi-qubits interacting with a common reservoir

    International Nuclear Information System (INIS)

    Sato, Arata; Ishi-Hayase, Junko; Minami, Fujio; Sasaki, Masahide

    2006-01-01

    The qubits can be entangled when they interact with a common Ohmic reservoir. We analyze how the reservoir-induced entanglement of qubits can be observed as the beat signal in the decay curve of the macroscopic polarization. The origin of this effect is the Lamb phase shift on the qubit array. We quantify the amount of the reservoir-induced entanglement and show how to experimentally evaluate it from the decay curve of the macroscopic polarization. We discuss how the beat signal can be discriminated from the other kinds of beat signals. We also show that our analysis can be used to estimate the reservoir characteristics

  2. The pathophysiology of lifelong premature ejaculation

    Science.gov (United States)

    2016-01-01

    For many decades it has been thought that lifelong premature ejaculation (PE) is only characterized by persistent early ejaculations. Despite enormous progress of in vivo animal research, and neurobiological, genetic and pharmacological research in men with lifelong PE, our current understanding of the mechanisms behind early ejaculations is far from complete. The new classification of PE into four PE subtypes has shown that the symptomatology of lifelong PE strongly differs from acquired PE, subjective PE and variable PE. The phenotype of lifelong PE and therefore also the pathophysiology of lifelong PE is much more complex. A substantial number of men with lifelong PE not only have PE, but also premature erection and premature penile detumescence as part of an acute hypertonic or hypererotic state when engaged in an erotic situation or when making love. As both erectio praecox, ejaculatio praecox, detumescentia praecox, and the hypererotic state are part of the phenotype lifelong PE, it is argued that lifelong PE is not only a disturbance of the timing of ejaculation but also a disturbance of the timing of erection, detumescence and arousal. Since 1998, the pathophysiology of lifelong PE was thought to be mainly mediated by the central serotonergic system in line with genetic polymorphisms of specific serotonergic genes. However, by accepting that lifelong PE is characterized by the reversible hypertonic state the hypothesis of mainly serotonergic dysfunction is no longer tenable. Instead, it has been postulated that the pathophysiology of lifelong PE is mediated by a very complex interplay of central and peripheral serotonergic, dopaminergic, oxytocinergic, endocrinological, genetic and probably also epigenetic factors. Progress in research of lifelong PE can only be accomplished when a stopwatch is used to measure the IELT and the cut-off point of 1 minute for the definition of lifelong PE is maintained. Current use of validated questionnaires, neglect of

  3. Premature menopause linked to CVD and osteoporosis.

    Science.gov (United States)

    Park, Claire; Overton, Caroline

    2010-03-01

    Premature menopause affects 1% of women under the age of 40, the usual age of the menopause is 51. Most women will present with irregular periods or no periods at all with or without climacteric symptoms. Around 10% of women present with primary amenorrhoea. A careful history and examination are required. It is important to ask specifically about previous chemotherapy or radiotherapy and to look for signs of androgen excess e.g. polycystic ovarian syndrome, adrenal problems e.g. galactorrhoea and thyroid goitres. Once pregnancy has been excluded, a progestagen challenge test can be performed in primary care. Norethisterone 5 mg tds po for ten days or alternatively medroxyprogesterone acetate 10 mg daily for ten days is prescribed. A withdrawal bleed within a few days of stopping the norethisterone indicates the presence of oestrogen and bleeding more than a few drops is considered a positive withdrawal bleed. The absence of a bleed indicates low levels of oestrogen, putting the woman at risk of CVD and osteoporosis. FSH levels above 30 IU/l are an indicator that the ovaries are failing and the menopause is approaching or has occurred. It should be remembered that FSH levels fluctuate during the month and from one month to the next, so a minimum of two measurements should be made at least four to six weeks apart. The presence of a bleed should not exclude premature menopause as part of the differential diagnosis as there can be varying and unpredictable ovarian function remaining. The progestagen challenge test should not be used alone, but in conjunction with FSH, LH and oestradiol. There is no treatment for premature menopause. Women desiring pregnancy should be referred to a fertility clinic and discussion of egg donation. Women not wishing to become pregnant should be prescribed HRT until the age of 50 to control symptoms of oestrogen deficiency and reduce the risks of osteoporosis and CVD.

  4. Premature closure of the Trojan Nuclear Plant

    International Nuclear Information System (INIS)

    Kononetz, B.P.

    1995-01-01

    The premature closure of the Trojan Nuclear Plant is discussed in outline form. The topics discussed include: an overview of Trojan; events leading to shutdown decision; Trojan's lifetime O ampersand M performance; Trojan's Regulatory performance; historical Trojan regulatory versus economic performance; applicable Oregon law; least-cost planning process; 1992 least cost plan; 1993 LCP update; LCP limitations; comparative performance analysis; management assessments; Trojan O ampersand M analysis; steam generator issues; quantification of deficiencies; quantification of impact of steam generator degradation; 'net benefits' test; conclusions from net benefits analysis; total disallowances; and conclusions and ramifications

  5. Human milk: medicine for premature babies.

    Science.gov (United States)

    Hilton, Sioned

    2011-12-01

    Following years of research there have been some significant developments in the understanding and subsequent support being offered to Neonatal Intensive Care Unit (NICU) families. In addition, ground breaking advances in the treatment of premature infants, with specific interest in the role of human milk, are now available. New information was presented by leading international researcher, Professor Meier, at an international symposium earlier this year. This article seeks to share this insightful information and provide support to those working in or around the NICU.

  6. The economic burden of prematurity in Canada.

    Science.gov (United States)

    Johnston, Karissa M; Gooch, Katherine; Korol, Ellen; Vo, Pamela; Eyawo, Oghenowede; Bradt, Pamela; Levy, Adrian

    2014-04-05

    Preterm birth is a major risk factor for morbidity and mortality among infants worldwide, and imposes considerable burden on health, education and social services, as well as on families and caregivers. Morbidity and mortality resulting from preterm birth is highest among early (prematurity due to the larger number of late preterm infants relative to early and moderate preterm infants. The aim in this study was to characterize the burden of premature birth in Canada for early, moderate, and late premature infants, including resource utilization, direct medical costs, parental out-of-pocket costs, education costs, and mortality, using a validated and published decision model from the UK, and adapting it to a Canadian setting based on analysis of administrative, population-based data from Québec. Two-year survival was estimated at 56.0% for early preterm infants, 92.8% for moderate preterm infants, and 98.4% for late preterm infants. Per infant resource utilization consistently decreased with age. For moderately preterm infants, hospital days ranged from 1.6 at age two to 0.09 at age ten. Cost per infant over the first ten years of life was estimated to be $67,467 for early preterm infants, $52,796 for moderate preterm infants, and $10,010 for late preterm infants. Based on population sizes this corresponds to total national costs of $123.3 million for early preterm infants, $255.6 million for moderate preterm infants, $208.2 million for late preterm infants, and $587.1 million for all infants. Premature birth results in significant infant morbidity, mortality, healthcare utilization and costs in Canada. A comprehensive decision-model based on analysis of a Canadian population-based administrative data source suggested that the greatest national-level burden is associated with moderate preterm infants due to both a large cost per infant and population size while the highest individual-level burden is in early preterm infants and the largest total population size is

  7. Lactoferrin and prematurity: a promising milk protein?

    Science.gov (United States)

    Ochoa, Theresa J; Sizonenko, Stéphane V

    2017-02-01

    Lactoferrin (Lf) is the major whey protein in milk, with multiple beneficial health effects including direct antimicrobial activities, anti-inflammatory effects, and iron homeostasis. Oral Lf supplementation in human preterm infants has been shown to reduce the incidence of sepsis and necrotizing enterocolitis. In preclinical models of antenatal stress and perinatal brain injury, bovine Lf protected the developing brain from neuronal loss, improved connectivity, increased neurotrophic factors, and decreased inflammation. It also supported brain development and cognition. Further, Lf can prevent preterm delivery by reducing proinflammatory factors and inhibiting premature cervix maturation. We review here the latest research on Lf in the field of neonatology.

  8. Path analysis of risk factors leading to premature birth.

    Science.gov (United States)

    Fields, S J; Livshits, G; Sirotta, L; Merlob, P

    1996-01-01

    The present study tested whether various sociodemographic, anthropometric, behavioral, and medical/physiological factors act in a direct or indirect manner on the risk of prematurity using path analysis on a sample of Israeli births. The path model shows that medical complications, primarily toxemia, chorioammionitis, and a previous low birth weight delivery directly and significantly act on the risk of prematurity as do low maternal pregnancy weight gain and ethnicity. Other medical complications, including chronic hypertension, preclampsia, and placental abruption, although significantly correlated with prematurity, act indirectly on prematurity through toxemia. The model further shows that the commonly accepted sociodemographic, anthropometric, and behavioral risk factors act by modifying the development of medical complications that lead to prematurity as opposed to having a direct effect on premature delivery. © 1996 Wiley-Liss, Inc. Copyright © 1996 Wiley-Liss, Inc.

  9. Automatic analysis of ciliary beat frequency using optical flow

    Science.gov (United States)

    Figl, Michael; Lechner, Manuel; Werther, Tobias; Horak, Fritz; Hummel, Johann; Birkfellner, Wolfgang

    2012-02-01

    Ciliary beat frequency (CBF) can be a useful parameter for diagnosis of several diseases, as e.g. primary ciliary dyskinesia. (PCD). CBF computation is usually done using manual evaluation of high speed video sequences, a tedious, observer dependent, and not very accurate procedure. We used the OpenCV's pyramidal implementation of the Lukas-Kanade algorithm for optical flow computation and applied this to certain objects to follow the movements. The objects were chosen by their contrast applying the corner detection by Shi and Tomasi. Discrimination between background/noise and cilia by a frequency histogram allowed to compute the CBF. Frequency analysis was done using the Fourier transform in matlab. The correct number of Fourier summands was found by the slope in an approximation curve. The method showed to be usable to distinguish between healthy and diseased samples. However there remain difficulties in automatically identifying the cilia, and also in finding enough high contrast cilia in the image. Furthermore the some of the higher contrast cilia are lost (and sometimes found) by the method, an easy way to distinguish the correct sub-path of a point's path have yet to be found in the case where the slope methods doesn't work.

  10. Beating-heart registration for organ-mounted robots.

    Science.gov (United States)

    Wood, Nathan A; Schwartzman, David; Passineau, Michael J; Moraca, Robert J; Zenati, Marco A; Riviere, Cameron N

    2018-03-06

    Organ-mounted robots address the problem of beating-heart surgery by adhering to the heart, passively providing a platform that approaches zero relative motion. Because of the quasi-periodic deformation of the heart due to heartbeat and respiration, registration must address not only spatial registration but also temporal registration. Motion data were collected in the porcine model in vivo (N = 6). Fourier series models of heart motion were developed. By comparing registrations generated using an iterative closest-point approach at different phases of respiration, the phase corresponding to minimum registration distance is identified. The spatiotemporal registration technique presented here reduces registration error by an average of 4.2 mm over the 6 trials, in comparison with a more simplistic static registration that merely averages out the physiological motion. An empirical metric for spatiotemporal registration of organ-mounted robots is defined and demonstrated using data from animal models in vivo. Copyright © 2018 John Wiley & Sons, Ltd.

  11. Electromyographic activity of beating and reaching during simulated boardsailing.

    Science.gov (United States)

    Buchanan, M; Cunningham, P; Dyson, R J; Hurrion, P D

    1996-04-01

    This study examined the responses of six competitive boardsailors (three males, three females) during laboratory-based simulation tasks while the electromyographic activity of up to 13 muscles was recorded. A sailboard, mounted in a steel frame and resting on a waterbed, allowed simulation of roll and pitch movements. Wind force was simulated by attaching the boom to a weight stack with a hydraulically controlled buffered release phase. The progression of the simulation test was controlled by the sailor copying movements on an edited video of each subject boardsailing on the open water. Analysis of individual pumping movements for mean peak percentage of maximal enveloped voluntary contraction (%MEVC) in 'beating' and 'reaching' showed that muscular activity in the arm (flexor carpi ulnaris, extensor carpi radialis and biceps brachii) was greatest (66-94% MEVC), with considerable activity (58-75% MEVC) in the deltoid and trapezius shoulder muscles, but much less activity in the leg muscles (16-40% MEVC). For the combined upper and lower body muscles there was a significant difference (P reflecting the current dynamic nature of the sport.

  12. Application of binaural beat phenomenon with aphasic patients.

    Science.gov (United States)

    Barr, D F; Mullin, T A; Herbert, P S

    1977-04-01

    We investigated whether six aphasics and six normal subjects could binaurally fuse two slightly differing frequencies of constant amplitude. The aphasics were subdivided into two groups: (1) two men who had had mild cerebrovascular accidents (CVAs) during the past 15 months; (2) four men who had had severe CVAs during the last 15 months. Two tones of different frequency levels but equal in intensity were presented dichotically to the subjects at 40 dB sensation level. All subjects had normal hearing at 500 Hz (0 to 25 dB). All six normal subjects and the two aphasics who had had mild CVAs could hear the binaural beats. The four aphasics who had had severe CVAs could not hear them. A 2 X 2 design resulting from this study was compared using chi2 test with Yates correction and was found to be significantly different (P less than .05). Two theories are presented to explain these findings: the "depression theory" and the "temporal time-sequencing theory." Therapeutic implications are also discussed relative to cerebral and/or brain stem involvement in the fusion of binaural stimuli.

  13. RESEARCHES RELATED TO THE REDUCTION OF PREMATURITY THROUGH PREMATURE RUPTURE OF MEMBRANES IN 2017

    Directory of Open Access Journals (Sweden)

    Maria BOLOTA

    2017-06-01

    Full Text Available Data from literature, especially from the US, has provided data on prediction, prevention and treatment of premature membrane rupture (RPM. RPM is a significant cause of premature birth and can cause complications of a term task. Considerable research on RPM has led to a better understanding of the mechanism of spontaneous breakage of membranes, risk factors, and good results for newborns resulting from such obstetrical events. Spontaneous rupture of the membranes increases the risk of intrauterine infection and umbilical cord compression as well as the risk of premature detachment of placenta. Newborn babies resulting from RPM have an increased risk of morbidity compared to gestational age, and the risk of infection is increased compared with other premature babies due to ancillary causes. If RPM occurs in the second trimester, there is an additional risk of pulmonary hypoplasia and hip dysplasia. Pre-term conservative treatment prolongs latency to birth. Antibiotics reduce the risk of infection while corticosteroid treatment (dexamethasone reduces respiratory complications and interventricular haemorrhage without increasing the risk of infection. Birth is necessary or unavoidable in many cases by RPMs and because conservative treatment often results in no results; That is why studies are needed to identify all risk factors and the need to treat pregnant women at risk of RPM; 17-hydroxy-progesterone is a specific treatment for preventing recurrent membrane rupture. (http://www.ginecologultau.ro/ruptura-prematura-a-membranelor, 2013.

  14. Ichthyosis prematurity syndrome: a well-defined congenital ichthyosis subtype

    DEFF Research Database (Denmark)

    Bygum, Anette; Westermark, Per; Brandrup, Flemming

    2008-01-01

    Ichthyosis prematurity syndrome is a rare syndrome characterized by the clinical triad of premature birth, thick caseous desquamating epidermis, and neonatal asphyxia. We describe two siblings with ichthyosis prematurity syndrome. The index patient was born at gestational week 34. Immediately aft...... in the stratum corneum and stratum granulosum. Diagnosing this syndrome is important to reassure parents, obstetricians, and pediatricians about its benign course after complications in the perinatal period....

  15. 'Rush' type retinopathy of prematurity: report of three cases.

    OpenAIRE

    Nissenkorn, I; Kremer, I; Gilad, E; Cohen, S; Ben-Sira, I

    1987-01-01

    Three premature infants observed to develop severe stage III retinopathy of prematurity (ROP) at 3 to 5 weeks of age received immediate treatment by cryoablation and photocoagulation, with good results. The critical importance of the ophthalmic examination of premature babies from the age of 2 weeks, so as not to overlook such cases of 'rush' type ROP is stressed and the difficulty involved in treating such small neonates is discussed.

  16. Neuro-ophthalmic manifestations of prematurity

    Directory of Open Access Journals (Sweden)

    Preeti Patil Chhablani

    2014-01-01

    Full Text Available Increasing rates of preterm births coupled with better survival of these infants have resulted in higher prevalence of systemic and ocular complications associated with prematurity. In addition to retinopathy of prematurity, infants who are born preterm may suffer from severe visual impairment as a result of hypoxic ischemic encephalopathy, hypoglycemia, and other metabolic imbalances. The effect of these processes on the anterior visual pathway may result in optic atrophy, optic nerve hypoplasia or optic disc cupping and affection of the posterior visual pathway leads to cortical visual impairment (CVI. Other ocular associations include strabismus, nystagmus, and ocular motor abnormalities such as tonic down gaze and defective saccades and pursuits. Cortical and subcortical involvement also manifests as defects in functional vision and these have not yet been completely understood. Children with CVI may have visual field defects, photophobia, defective visual processing, and deficient color vision. Since most of these children also suffer from additional systemic disabilities, evaluation, and management remains a challenge. However, early diagnosis and initiation of rehabilitation therapy can prove to be of significant benefit in these children.

  17. Premature ovarian insufficiency: Pathogenesis and management

    Directory of Open Access Journals (Sweden)

    Anna J Fenton

    2015-01-01

    Full Text Available The term premature ovarian insufficiency (POI describes a continuum of declining ovarian function in a young woman, resulting in an earlier than average menopause. It is a term that reflects the variable nature of the condition and is substantially less emotive than the formerly used "premature ovarian failure" which signaled a single event in time. Contrary to the decline in the age of menarche seen over the last 3-4 decades there has been no similar change in the age of menopause. In developed nations, the average age for cessation of menstrual cycles is 50-52 years. The age is younger among women from developing nations. Much has been written about POI despite a lack of good data on the incidence of this condition. It is believed that 1% of women under the age of 40 years and 0.1% under the age of 30 years will develop POI. Research is increasingly providing information about the pathogenesis and treatments are being developed to better preserve ovarian function during cancer treatment and to improve fertility options. This narrative review summarizes the current literature to provide an approach to best practice management of POI.

  18. Treatment of threshold retinopathy of prematurity

    Directory of Open Access Journals (Sweden)

    Deshpande Dhanashree

    1998-01-01

    Full Text Available This report deals with our experience in the management of threshold retinopathy of prematurity (ROP. A total of 45 eyes of 23 infants were subjected to treatment of threshold ROP. 26.1% of these infants had a birth weight of >l,500 gm. The preferred modality of treatment was laser indirect photocoagulation, which was facilitated by scleral depression. Cryopexy was done in cases with nondilating pupils or medial haze and was always under general anaesthesia. Retreatment with either modality was needed in 42.2% eyes; in this the skip areas were covered. Total regression of diseases was achieved in 91.1% eyes with no sequelae. All the 4 eyes that progressed to stage 5 despite treatment had zone 1 disease. Major treatment-induced complications did not occur in this series. This study underscores the importance of routine screening of infants upto 2,000 gm birth weight for ROP and the excellent response that is achieved with laser photocoagulation in inducing regression of threshold ROP. Laser is the preferred method of treatment in view of the absence of treatment-related morbidity to the premature infants.

  19. The Neural Retina in Retinopathy of Prematurity

    Science.gov (United States)

    Hansen, Ronald M.; Moskowitz, Anne; Akula, James D.; Fulton, Anne B.

    2016-01-01

    Retinopathy of prematurity (ROP) is a neurovascular disease that affects prematurely born infants and is known to have significant long term effects on vision. We conducted the studies described herein not only to learn more about vision but also about the pathogenesis of ROP. The coincidence of ROP onset and rapid developmental elongation of the rod photoreceptor outer segments motivated us to consider the role of the rods in this disease. We used noninvasive electroretinographic (ERG), psychophysical, and retinal imaging procedures to study the function and structure of the neurosensory retina. Rod photoreceptor and post-receptor responses are significantly altered years after the preterm days during which ROP is an active disease. The alterations include persistent rod dysfunction, and evidence of compensatory remodeling of the post-receptor retina is found in ERG responses to full-field stimuli and in psychophysical thresholds that probe small retinal regions. In the central retina, both Mild and Severe ROP delay maturation of parafoveal scotopic thresholds and are associated with attenuation of cone mediated multifocal ERG responses, significant thickening of post-receptor retinal laminae, and dysmorphic cone photoreceptors. These results have implications for vision and control of eye growth and refractive development and suggest future research directions. These results also lead to a proposal for noninvasive management using light that may add to the currently invasive therapeutic armamentarium against ROP. PMID:27671171

  20. Application of a "relative" procedure to a problem in binaural beat perception.

    Science.gov (United States)

    1963-08-01

    The existence of binaural beats has long been considered an indication of binaural interaction for timing and for periodicity of information. In the past, bilaterally matched sound pressure or sensation levels have been used in the investigation of t...

  1. 3D force control for robotic-assisted beating heart surgery based on viscoelastic tissue model.

    Science.gov (United States)

    Liu, Chao; Moreira, Pedro; Zemiti, Nabil; Poignet, Philippe

    2011-01-01

    Current cardiac surgery faces the challenging problem of heart beating motion even with the help of mechanical stabilizer which makes delicate operation on the heart surface difficult. Motion compensation methods for robotic-assisted beating heart surgery have been proposed recently in literature, but research on force control for such kind of surgery has hardly been reported. Moreover, the viscoelasticity property of the interaction between organ tissue and robotic instrument further complicates the force control design which is much easier in other applications by assuming the interaction model to be elastic (industry, stiff object manipulation, etc.). In this work, we present a three-dimensional force control method for robotic-assisted beating heart surgery taking into consideration of the viscoelastic interaction property. Performance studies based on our D2M2 robot and 3D heart beating motion information obtained through Da Vinci™ system are provided.

  2. The role of nonlinear beating currents on parametric instabilities in magnetoplasmas

    International Nuclear Information System (INIS)

    Kuo, S.P.

    1996-01-01

    A general coupled mode equation for the low-frequency decay modes of parametric instabilities in magnetoplasmas is derived. The relative importance of the nonlinear contributions from the ponderomotive force, nonlinear beating current, and anisotropic effect to the parametric coupling is then manifested by the coupling terms of the equation. It is first shown in the unmagnetized case, that the contribution of the nonlinear beating current is negligibly small because of the small coefficient (i.e., weight) of this current contribution, instead of the beating current itself. It then follows that the weight of the beating current contribution increases significantly in the magnetized case, and consequently, this contribution to the parametric coupling is found to be important, as exemplified by two specific examples. copyright 1996 American Institute of Physics

  3. Computed tomography of the head of new born premature infants

    International Nuclear Information System (INIS)

    Ohno, Tsutomu; Mizobe, Naoki; Takehiro, Hideo

    1983-01-01

    Evaluation of the extracerebral space on CT resulted as follows: The existence of the etracerebral space in the parieto-occipital region (PO-ECS) was physiological findings characteristic to premature infants. Its incidence was higher and the width of the space was greater, in those of premature infants. Generally PO-ECS disappeared around 40 weeks of gestation, while it tended to remaine beyond 40 weeks in premature infants born after less than 30 weeks of pregnancy. The appearance and disappearance of the PO-ECS may present some approach to learning the development of the brain in premature infants. (Ueda, J.)

  4. Association between human breast milk and retinopathy of prematurity.

    Science.gov (United States)

    Fonseca, Luciana Teixeira; Senna, Denise C; Eckert, Gabriela Unchalo; Silveira, Rita de Cássia; Procianoy, Renato Soibelmann

    2018-04-01

    To evaluate the possible protective effect of breast milk against retinopathy of prematurity by comparing the amount of breast milk received by patients who developed retinopathy of prematurity and those who did not and to determine both the required minimum amount of breast milk and the time of life during which neonates need to receive breast milk for this effect to be significant. Cohort study of newborns with a birth weight of prematurity of any degree was 31% (100 of 323 patients) and that of severe retinopathy of prematurity was of 9% (29 of 323 patients). The median amounts of breast milk received daily by patients with and without retinopathy of prematurity were 4.9 mL/kg (interquartile range, 0.3-15.4) and 10.2 mL/kg (1.5-25.5), respectively. The amount of breast milk received in the first 6 weeks of life was inversely associated with the incidence of both retinopathy of prematurity of any degree and severe retinopathy of prematurity in the univariate analyses. However, the statistical significance was maintained only during the sixth week of life in a per-period multivariate analysis controlling for confounding factors. Small amounts of breast milk are inadequate to prevent retinopathy of prematurity in premature newborns at risk for the disease.

  5. “Would you like to meet the secret Beat?” – Tram Combs and a Beat poetry less celebrated

    DEFF Research Database (Denmark)

    Sørensen, Bent

    of the poetry of Tram Combs, “the secret Beat”, whose 1957 collection Pilgrim’s Terrace contained forewords by both William Carlos Williams and Kenneth Rexroth, and whose collaborators included Allen Ginsberg – yet whose name is persistently left out of the Beat canon. One wonders why, when he is an example...... directly at Gorm, and asked: “Would you like to meet the secret Beat, then?” The old gentleman proceeded to introduce himself as Tram Combs, poet, bookseller, nude model and gay man about town, and for the next few days he took Gorm to art museums, gallery openings and story-telling sessions in his...

  6. Binaural beat technology in humans: a pilot study to assess neuropsychologic, physiologic, and electroencephalographic effects.

    Science.gov (United States)

    Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather; Zajdel, Dan

    2007-03-01

    When two auditory stimuli of different frequency are presented to each ear, binaural beats are perceived by the listener. The binaural beat frequency is equal to the difference between the frequencies applied to each ear. Our primary objective was to assess whether steady-state entrainment of electroencephalographic activity to the binaural beat occurs when exposed to a specific binaural beat frequency as has been hypothesized. Our secondary objective was to gather preliminary data on neuropsychologic and physiologic effects of binaural beat technology. A randomized, blinded, placebo-controlled crossover experiment in 4 healthy adult subjects. Subjects were randomized to experimental auditory stimulus of 30 minutes of binaural beat at 7 Hz (carrier frequencies: 133 Hz L; 140 Hz R) with an overlay of pink noise resembling the sound of rain on one session and control stimuli of the same overlay without the binaural beat carrier frequencies on the other session. Data were collected during two separate sessions 1 week apart. Neuropsychologic and blood pressure data were collected before and after the intervention; electroencephalographic data were collected before, during, and after listening to either binaural beats or control. Neuropsychologic measures included State Trait Anxiety Inventory, Profile of Mood States, Rey Auditory Verbal List Test, Stroop Test, and Controlled Oral Word Association Test. Spectral and coherence analysis was performed on the electroencephalogram (EEG), and all measures were analyzed for changes between sessions with and without binaural beat stimuli. There were no significant differences between the experimental and control conditions in any of the EEG measures. There was an increase of the Profile of Mood States depression subscale in the experimental condition relative to the control condition (p = 0.02). There was also a significant decrease in immediate verbal memory recall (p = 0.03) in the experimental condition compared to control

  7. Refractive status and optical components of premature babies with or without retinopathy of prematurity at 3-4 years old.

    Science.gov (United States)

    Ouyang, Li-Juan; Yin, Zheng-Qin; Ke, Ning; Chen, Xin-Ke; Liu, Qin; Fang, Jing; Chen, Lin; Chen, Xiu-Rong; Shi, Hui; Tang, Ling; Pi, Lian-Hong

    2015-01-01

    To investigate the refractive status and optical components of premature babies with or without retinopathy of prematurity (ROP) at 3-4 years old, and to explore the influence of prematurity and ROP on the refractive status and optical components. Premature babies receiving fundus examination were recruited into ROP group and non-ROP group, with age-matched full-term babies as controls. The incidence of myopia was the highest in ROP (3/59, 5.08%). The incidence of astigmatism was significantly different between ROP (37.29%, 22/59) and controls (17.86%, 15/84). The corneal refractive power in ROP and non-ROP was more potent compared with controls (PPremature babies with or without ROP are susceptible to myopia and astigmatism. ROP, prematurity and low birth-weight synergistically influence the development of refractive status and optical components, of which the prematurity and low birth-weight are more important.

  8. Incidence of ventricular tachyarrhythmias during permanent pacemaker therapy in low-risk patients results from the German multicentre EVENTS study.

    Science.gov (United States)

    Faber, Thomas S; Gradinger, Robert; Treusch, Sven; Morkel, Carsten; Brachmann, Johannes; Bode, Christoph; Zehender, Manfred

    2007-09-01

    Current studies found an incidence of 12-31% ventricular tachyarrhythmias and sudden cardiac death during cardiac pacing months or even years after pacemaker insertion. MADIT(12) and MUSTT(13) demonstrated that patients with poor LV function after Myocardial infarction (MI) showing non-sustained ventricular tachycardia (nsVT) and inducibility during electrophysiologic testing benefit from an ICD. The present study was dedicated to assess the global incidence of non-sustained ventricular arrhythmias in a general population of pacemaker patients. Special regard was on patients with a potential ICD indication, e.g. those matching the MADIT/MUSTT criteria. Two hundred and thirty-one patients (72 +/- 11 years; 134 men) with an indication for dual chamber pacing entered the study. In all patients pacemaker systems capable of automatic storing of intracardiac electrocardiograms were implanted (Pulsar, Discovery, Guidant). Follow-up time was 15 months after inclusion. In 54 (25.7%) of 210 patients with at least one follow-up, episodes of nsVT were documented by stored electrocardiograms (up to >30 beats, >200 b.p.m.). Multiple-up to nine-episodes of ventricular tachycardia were retrieved in 31 of these patients. Three out of 14 patients with an LVEF <40% after MI presented nsVT during the follow-up. One of these patients received an ICD. A significant number of pacemaker patients present with ventricular tachycardia. Intracardiac electrocardiograms and alert functions from pacemakers may enhance physicians' awareness of the patient's intrinsic arrhythmic profile and help uncover underlying mechanisms of arrhythmias by storing the initiation of the arrhythmia.

  9. Left ventricular approach for recording His bundle potential in man.

    Science.gov (United States)

    Lee, Y S; Lien, W P

    1975-06-01

    The electrical potentials of the His bundle (HB) were recorded from the left ventricular endocardial surface in 28 patients ranging from 16 to 63 years of age. In 14 of the patients the left bundle branch (LB) potentials were also obtained. Placement of a bipolar electrode catheter tip toward the interventricular septum, right at and also 1 to 2 cm below the aortic valve, resulted in stable recordings of both potentials in successive cardiac cycles even at performing atrial or HB pacing from the right heart. The following intervals were measured in milliseconds (msec): P-A, A-H, H, H-V, LB, and LB-V. The average values in 12 patients (average age 26 plus or minus 7 years and average heart rate 90 plus or minus 16 beats per minute) with normal A-V conduction were as follows: P-A 28 plus or minus 7, A-H 76 plus or minus 16, H 19 plus or minus 3 and H-V 45 plus or minus 6 msec. The average values for LB and LB-V in 10 of these 12 patients were 15 plus or minus 3 and 25 plus or minus 3 msec respectively. Validation of the His bundle electrogram (HBE) from the left ventricular endocardial surface was based on simultaneous recordings of the intracardiac electrograms from both left and right sides of the heart in 18 patients. The individual average values for the intervals obtained from both sides of the heart in these patients were statistically not different, except that the H potential was slightly longer in duration fr m the left heart (P equals 0.05). Among these, 16 showed simultaneous onset of the H potentials, and the LB-V and RB-V conduction times from comparable points were almost the same. Indications for the left sided electro-physiologic studies include the following situations: (a) inability to record H from the right of the heart; (b) giant right atrium; and (c) possibly during atrial fibrillation.

  10. Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ning; ZHANG Hui-Min; LIU Zhi-Qiang; DING Xue-Li; YANG Ming-Hao; GU Hua-Guang; REN Wei

    2009-01-01

    Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

  11. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    OpenAIRE

    Namdeo, S.; Onck, P. R.

    2016-01-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dyneins. The dyneins deliver the required mechanical work through the hydrolysis of ATP. Although the dynein-ATP cycle, the axoneme microstructure, and the flagellar-beating kinematics are well studied, ...

  12. The Effect of Iconic and Beat Gestures on Memory Recall in Greek's First and Second Language

    OpenAIRE

    Eleni Ioanna Levantinou

    2016-01-01

    Gestures play a major role in comprehension and memory recall due to the fact that aid the efficient channel of the meaning and support listeners’ comprehension and memory. In the present study, the assistance of two kinds of gestures (iconic and beat gestures) is tested in regards to memory and recall. The hypothesis investigated here is whether or not iconic and beat gestures provide assistance in memory and recall in Greek and in Greek speakers’ second language. Two gr...

  13. Pengaruh Brand Image (Citra Merek) Terhadapkeputusan Pembelian Sepeda Motor Honda Beat (Studipadamahasiswa/I Fisip Usu)

    OpenAIRE

    M, Hary Christian

    2017-01-01

    130907100 Penelitian ini bertujuan untuk mengetahui pengaruh Brand Image (Citra Merek) terhadap keputusan pembelian sepeda motor Honda Beat pada mahasiswa/i FISIP USU. Populasi dalam penelitian ini adalah mahasiwa/i FISIP USU yang memiliki dan menggunakan sepeda motor Honda Beat. Data dikumpulkan melalui melalui metode kuesioner terhadap 70 responden.Teknik pengambilan sampel dalam penelitian ini dilakukan dengan teknik Probability Sampling dengan pendekatan Simple Random Sampling.Jeni...

  14. More attentional focusing through binaural beats: Evidence from the global-local task

    OpenAIRE

    Colzato, L.S.; Barone, H.; Sellaro, R.; Hommel, B.

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40?Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340?Hz (control condition) for 3?min before and during a global?local task. While the size of the ...

  15. Mismatch negativity to acoustical illusion of beat: how and where the change detection takes place?

    Science.gov (United States)

    Chakalov, Ivan; Paraskevopoulos, Evangelos; Wollbrink, Andreas; Pantev, Christo

    2014-10-15

    In case of binaural presentation of two tones with slightly different frequencies the structures of brainstem can no longer follow the interaural time differences (ITD) resulting in an illusionary perception of beat corresponding to frequency difference between the two prime tones. Hence, the beat-frequency does not exist in the prime tones presented to either ear. This study used binaural beats to explore the nature of acoustic deviance detection in humans by means of magnetoencephalography (MEG). Recent research suggests that the auditory change detection is a multistage process. To test this, we employed 26 Hz-binaural beats in a classical oddball paradigm. However, the prime tones (250 Hz and 276 Hz) were switched between the ears in the case of the deviant-beat. Consequently, when the deviant is presented, the cochleae and auditory nerves receive a "new afferent", although the standards and the deviants are heard identical (26 Hz-beats). This allowed us to explore the contribution of auditory periphery to change detection process, and furthermore, to evaluate its influence on beats-related auditory steady-state responses (ASSRs). LORETA-source current density estimates of the evoked fields in a typical mismatch negativity time-window (MMN) and the subsequent difference-ASSRs were determined and compared. The results revealed an MMN generated by a complex neural network including the right parietal lobe and the left middle frontal gyrus. Furthermore, difference-ASSR was generated in the paracentral gyrus. Additionally, psychophysical measures showed no perceptual difference between the standard- and deviant-beats when isolated by noise. These results suggest that the auditory periphery has an important contribution to novelty detection already at sub-cortical level. Overall, the present findings support the notion of hierarchically organized acoustic novelty detection system. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Orthogonal linear polarization tunable-beat ring laser with a superluminescent diode

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Y.; Yoshino, T. [Department of Electronic Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376 (Japan)

    1997-09-01

    An orthogonal linear polarization operated ring laser with a superluminescent diode has been demonstrated to generate a tunable optical beat signal. The ring cavity contains a superluminescent diode as the optical gain medium, Faraday rotators, and a variable phase retarder (Babinet-Soleil compensator). By controlling the retarder, we changed the beat frequency in the range from a few tens of megahertz to 100 MHz. {copyright} 1997 Optical Society of America

  17. Abnormal ventricular development in preterm neonates with visually normal MRIs

    Science.gov (United States)

    Shi, Jie; Wang, Yalin; Lao, Yi; Ceschin, Rafael; Mi, Liang; Nelson, Marvin D.; Panigrahy, Ashok; Leporé, Natasha

    2015-12-01

    Children born preterm are at risk for a wide range of neurocognitive and neurobehavioral disorders. Some of these may stem from early brain abnormalities at the neonatal age. Hence, a precise characterization of neonatal neuroanatomy may help inform treatment strategies. In particular, the ventricles are often enlarged in neurocognitive disorders, due to atrophy of surrounding tissues. Here we present a new pipeline for the detection of morphological and relative pose differences in the ventricles of premature neonates compared to controls. To this end, we use a new hyperbolic Ricci flow based mapping of the ventricular surfaces of each subjects to the Poincaré disk. Resulting surfaces are then registered to a template, and a between group comparison is performed using multivariate tensor-based morphometry. We also statistically compare the relative pose of the ventricles within the brain between the two groups, by performing a Procrustes alignment between each subject's ventricles and an average shape. For both types of analyses, differences were found in the left ventricles between the two groups.

  18. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    Science.gov (United States)

    Namdeo, S.; Onck, P. R.

    2016-10-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dyneins. The dyneins deliver the required mechanical work through the hydrolysis of ATP. Although the dynein-ATP cycle, the axoneme microstructure, and the flagellar-beating kinematics are well studied, their integration into a coherent picture of ATP-powered flagellar beating is still lacking. Here we show that a time-delayed negative-work-based switching mechanism is able to convert the individual sliding action of hundreds of dyneins into a regular overall beating pattern leading to propulsion. We developed a computational model based on a minimal representation of the axoneme consisting of two representative doublet microtubules connected by nexin links. The relative sliding of the microtubules is incorporated by modeling two groups of ATP-powered dyneins, each responsible for sliding in opposite directions. A time-delayed switching mechanism is postulated, which is key in converting the local individual sliding action of multiple dyneins into global beating. Our results demonstrate that an overall nonreciprocal beating pattern can emerge with time due to the spatial and temporal coordination of the individual dyneins. These findings provide insights in the fundamental working mechanism of axonemal dyneins and could possibly open new research directions in the field of flagellar motility.

  19. Effect of depth beating on the fiber properties and enzymatic saccharification efficiency of softwood kraft pulp.

    Science.gov (United States)

    Gao, Wenhua; Xiang, Zhouyang; Chen, Kefu; Yang, Rendang; Yang, Fei

    2015-01-01

    Commercial bleached softwood kraft pulp was mechanically fibrillated by a PFI-mill with beating revolution from 5000 to 30,000 r. The extent of fibrillating on the pulp was evaluated by beating degree, fiber morphological properties (fiber length, width, coarseness and curls index), water retention value (WRV) and physical properties of paper made from the pulp. Depth beating process significantly affected the pulp fibrillations as showed by the decreased fiber length and width as well as the SEM analysis, but the effects were limited after beating revolution of 15,000. Depth beating process also improved the total internal pore and inter-fibril surface areas as shown by the increased WRV values. Substrate enzymatic digestibility (SED) of beaten pulp at 5000 revolutions could reach 95% at cellulase loading of 15 FPU/g of glucan. After the enzymatic hydrolysis, the size of the pulp residues was reduced to micro-scale, and a relative uniform size distribution of the residues appeared at 10,000 r beating revolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing.

    Science.gov (United States)

    Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

    2014-10-15

    When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations. Copyright © 2014 the American Physiological Society.

  1. A high-density EEG investigation into steady state binaural beat stimulation.

    Directory of Open Access Journals (Sweden)

    Peter Goodin

    Full Text Available Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz or Beta (16 Hz frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

  2. A high-density EEG investigation into steady state binaural beat stimulation.

    Science.gov (United States)

    Goodin, Peter; Ciorciari, Joseph; Baker, Kate; Carey, Anne-Marie; Carrey, Anne-Marie; Harper, Michelle; Kaufman, Jordy

    2012-01-01

    Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

  3. Remodelado ventricular y cirugía

    Directory of Open Access Journals (Sweden)

    Ignacio Moriones

    2008-01-01

    Se han diseñado anillos mitrales como el de Carpentier- McCarthy-Adams (IMR ETlogix™ para pacientes isquémicos, o el Edwards-Geoform™ en miocardiopatías. La asistencia ventricular puede conseguir en determinados casos recuperación permanente del volumen de la cavidad y función ventricular, particularmente en miocarditis y determinadas miocardiopatías. Paralelamente, se han iniciado experiencias con el sistema de contención CorCap o el sistema Myosplint. Finalmente, la actuación sobre las valvulopatías y la revascularización favorecen la restauración ventricular.

  4. Frequency-dependent left ventricular performance in women and men.

    Science.gov (United States)

    Wainstein, Rodrigo V; Sasson, Zion; Mak, Susanna

    2012-06-01

    We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac catheterization-based study for force-interval relationships of the LV. HR was controlled by right atrial (RA) pacing, and LV +dP/dt(max) and volume were assessed by micromanometer-tipped catheter and Doppler echocardiography, respectively. Analysis of approximated LV pressure-volume relationships was performed using a time-varying model of elastance. External stroke work was also calculated. The relationship between HR and LV +dP/dt(max) was expressed as LV +dP/dt(max) = b + mHR. The slope (m) of the relationship was steeper in women compared with men (11.8 ± 4.0 vs. 6.1 ± 4.1 mmHg·s(-1)·beats(-1)·min(-1), P = 0.01). The greater increase in contractility in women was reproducibly observed after normalizing LV +dP/dt(max) to LV end-diastolic volume (LVVed) or by measuring end-systolic elastance. LVVed and stroke volume decreased more in women. Thus, despite greater increases in contractility, HR was associated with a lesser rise in cardiac output and a steeper fall in external stroke work in women. Compared with men, women exhibit greater inotropic responses to incremental RA pacing, which occurs at the same time as a steeper decline in external stroke work. In older adults, we observed sexual dimorphism in determinants of LV mechanical performance.

  5. Excito-oscillatory dynamics as a mechanism of ventricular fibrillation.

    Science.gov (United States)

    Gray, Richard A; Huelsing, Delilah J

    2008-04-01

    The instabilities associated with reentrant spiral waves are of paramount importance to the initiation and maintenance of tachyarrhythmias, especially ventricular fibrillation (VF). In addition to tissue heterogeneities, there are only a few basic purported mechanisms of spiral wave breakup, most notably restitution. We test the hypothesis that oscillatory membrane properties act to destabilize spiral waves. We recorded transmembrane potential (V(m)) from isolated rabbit myocytes using a constant current stimulation protocol. We developed a mathematical model that included both the stable excitable equilibrium point at resting V(m) (-80 mV) and the unstable oscillatory equilibrium point at elevated V(m) (-10 mV). Spiral wave dynamics were studied in 2-dimensional grids using variants of the model. All models showed restitution and reproduced the experimental values of transmembrane resistance at rest and during the action potential plateau. Stable spiral waves were observed when the model showed only 1 equilibrium point. However, spatio-temporal complexity was observed if the model showed both excitable and oscillatory equilibrium points (i.e., excito-oscillatory models). The initial wave breaks resulted from oscillatory waves expanding in all directions; after a few beats, the patterns were characterized by a combination of unstable spiral waves and target patterns consistent with the patterns observed on the heart surface during VF. In our model, this VF-like activity only occurred when the single cell period of V(m) oscillations was within a specific range. The VF-like patterns observed in our excito-oscillatory models could not be explained by the existing proposed instability mechanisms. Our results introduce the important suggestion that membrane dynamics responsible for V(m) oscillations at elevated V(m) levels can destabilize spiral waves and thus may be a novel therapeutic target for preventing VF.

  6. [The reasonable use of right ventricular protection strategy in right ventricular outflow tract reconstruction].

    Science.gov (United States)

    Zhang, Y; Yuan, H Y; Liu, X B; Wen, S S; Xu, G; Cui, H J; Zhuang, J; Chen, J M

    2018-06-01

    As a result of right ventricular outflow tract reconstruction, which is the important and basic step of complex cardiac surgery, the blood flow of right ventricular outflow tract is unobstructed, while pulmonary valve regurgitation and right heart dysfunction could be happened. These problems are often ignored in early days, more and more cases of right heart dysfunction need clinical intervention, which is quite difficult and less effective. How to protect effectively the right ventricular function is the focus. At present main methods to protect the right ventricular function include trying to avoid or reduce length of right ventricular incision, reserving or rebuilding the function of the pulmonary valve, using growth potential material for surgery. The protection of the right ventricular function is a systemic project, it involves many aspects, single measures is difficult to provide complete protection, only the comprehensive use of various protection strategy, can help to improve the long-term prognosis.

  7. Prematurity, atopy, and childhood asthma in Puerto Ricans.

    Science.gov (United States)

    Rosas-Salazar, Christian; Ramratnam, Sima K; Brehm, John M; Han, Yueh-Ying; Boutaoui, Nadia; Forno, Erick; Acosta-Pérez, Edna; Alvarez, María; Colón-Semidey, Angel; Canino, Glorisa; Celedón, Juan C

    2014-02-01

    Puerto Rican children share a disproportionate burden of prematurity and asthma in the United States. Little is known about prematurity and childhood asthma in Puerto Rican subjects. We sought to examine whether prematurity is associated with asthma in Puerto Rican children. We performed a case-control study of 678 children aged 6 to 14 years with (n = 351) and without (n = 327) asthma living in San Juan, Puerto Rico. Prematurity was defined by parental report for our primary analysis. In a secondary analysis, we only included children whose parents reported prematurity that required admission to the neonatal intensive care unit. Asthma was defined as physician-diagnosed asthma and wheeze in the prior year. We used logistic regression for analysis. All multivariate models were adjusted for age, sex, household income, atopy (≥1 positive IgE level to common allergens), maternal history of asthma, and early-life exposure to environmental tobacco smoke. In a multivariate analysis there was a significant interaction between prematurity and atopy on asthma (P = .006). In an analysis stratified by atopy, prematurity was associated with a nearly 5-fold increased odds of asthma in atopic children (adjusted odds ratio, 4.7; 95% CI, 1.5-14.3; P = .007). In contrast, there was no significant association between prematurity and asthma in nonatopic children. Similar results were obtained in our analysis of prematurity requiring admission to the neonatal intensive care unit and asthma. Our results suggest that atopy modifies the estimated effect of prematurity on asthma in Puerto Rican children. Prematurity might explain, in part, the high prevalence of atopic asthma in this ethnic group. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  8. NEONATAL COMPLICATIONS OF PREMATURE RUPTURE OF MEMBRANES

    Directory of Open Access Journals (Sweden)

    F. Nili AA. Shams Ansari

    2003-07-01

    Full Text Available Premature rupture of membranes (PROM is one of the most common complications of pregnancy that has a major impact on neonatal outcomes. With respect to racial, nutritional and cultural differences between developed and developing countries, this study was conducted to detect the prevalence of neonatal complications following PROM and the role of the duration of rupture of membranes in producing morbidities and mortalities in these neonates in our hospital. Among 2357 pregnant women, we found 163 (6.91% cases of premature rupture of the fetal membranes in Tehran Vali-e-Asr Hospital during April 2001 to April 2002. Route of delivery was cesarean section in 65.6% of women. Urinary tract infection occured in 1.8%, maternal leukocytosis and fever in 20.2% and 5.5%, chorioamnionitis in 6.1%, fetal tachycardia in 1.2% and olygohydramnios in 4.9%. Gestational age in 138 (86% of neonates was less than 37 completed weeks. Thirty five infants (21.47% had respiratory distress syndrome and 33 (20.245% had clinical sepsis. Pneumonia in 6 (3.7% and skeletal deformity in 7 (4.294% were seen. Rupture of membrane of more than 24 hours duration occurred in 71 (43.6% of the patients. Comparison of morbidities between two groups of neonates and their mothers according to the duration of PROM (less and more than 24 hours showed significant differences in NICU admission, olygohydramnios, maternal fever, leukocytosis and chorioamnionitis rates (p24 hr of PROM with an odds ratio of 2.68 and 2.73, respectively. Positive blood and eye cultures were detected in 16 cases during 72 hours of age. Staphylococcus species, klebsiella, E.coli and streptococcus were the predominant organisms among positive blood cultures. Mortality was seen in 18 (11% of neonates because of respiratory failure, disseminated intravascular coagulation, septic shock, and a single case of congenital toxoplasmosis. In this study, the prevalence of prematurity, sepsis and prolonged rupture of membrane

  9. Measurement of ciliary beat frequency using Doppler optical coherence tomography.

    Science.gov (United States)

    Lemieux, Bryan T; Chen, Jason J; Jing, Joseph; Chen, Zhongping; Wong, Brian J F

    2015-11-01

    Measuring ciliary beat frequency (CBF) is a technical challenge and difficult to perform in vivo. Doppler optical coherence tomography (D-OCT) is a mesoscopic noncontact imaging modality that provides high-resolution tomographic images and detects micromotion simultaneously in living tissues. In this work we used D-OCT to measure CBF in ex vivo tissue as the first step toward translating this technology to clinical use. Fresh ex vivo samples of rabbit tracheal mucosa were imaged using both D-OCT and phase-contrast microscopy (n = 5). The D-OCT system was designed and built to specification in our lab (1310-nm swept source vertical-cavity surface-emitting laser [VCSEL], 6-μm axial resolution). The samples were placed in culture and incubated at 37°C. A fast Fourier transform was performed on the D-OCT signal recorded on the surface of the samples to gauge CBF. High-speed digital video of the epithelium recorded via phase-contrast microscopy was analyzed to confirm the CBF measurements. The D-OCT system detected Doppler signal at the epithelial layer of ex vivo rabbit tracheal samples suggestive of ciliary motion. CBF was measured at 9.36 ± 1.22 Hz using D-OCT and 9.08 ± 0.48 Hz using phase-contrast microscopy. No significant differences were found between the 2 methods (p > 0.05). D-OCT allows for the quantitative measurement of CBF without the need to resolve individual cilia. Furthermore, D-OCT technology can be incorporated into endoscopic platforms that allow clinicians to readily measure CBF in the office and provide a direct measurement of mucosal health. © 2015 ARS-AAOA, LLC.

  10. Determinants of Indices of Cerebral Volume in Former Very Premature Infants at Term Equivalent Age.

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    Aurelie Naud

    Full Text Available Conventional magnetic resonance imaging (MRI at term equivalent age (TEA is suggested to be a reliable tool to predict the outcome of very premature infants. The objective of this study was to determine simple reproducible MRI indices, in premature infants and to analyze their neonatal determinants at TEA. A cohort of infants born before 32 weeks gestational age (GA underwent a MRI at TEA in our center. Two axial images (T2 weighted, were chosen to realize nine measures. We defined 4 linear indices (MAfhlv: thickness of lateral ventricle; CSI: cortex-skull index; VCI: ventricular-cortex index; BOI: bi occipital index and 1 surface index (VS.A: volume slice area. Perinatal data were recorded. Sixty-nine infants had a GA (median (interquartile range of 30.0 weeks GA (27.0; 30.0 and a birth weight of 1240 grams (986; 1477. MRI was done at 41.0 (40.0; 42.0 weeks post menstrual age (PMA. The inter-investigator reproducibility was good. Twenty one MRI (30.5% were quoted abnormal. We observed an association with retinopathy of prematurity (OR [95CI] = 4.205 [1.231-14.368]; p = 0.017, surgery for patent ductus arteriosus (OR = 4.688 [1.01-21.89]; p = 0.036, early onset infection (OR = 4.688 [1.004-21.889]; p = 0.036 and neonatal treatment by cefotaxime (OR = 3.222 [1.093-9.497]; p = 0.03. There was a difference for VCI between normal and abnormal MRI (0.412 (0.388; 0.429 vs. 0.432 (0.418; 0.449; p = 0,019; BOI was higher when fossa posterior lesions were observed; VS.A seems to be the best surrogate for cerebral volume, 80% of VS.As' variance being explained by a multiple linear regression model including 7 variables (head circumference at birth and at TEA, PMA, dopamine, ibuprofen treatment, blood and platelets transfusions. These indices, easily and rapidly achievable, seem to be useful but need to be validated in a large population to allow generalization for diagnosis and follow-up of former premature infants.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Left ventricular function in patients with ventricular arrhythmias and aortic valve disease

    International Nuclear Information System (INIS)

    Santinga, J.T.; Kirsh, M.M.; Brady, T.J.; Thrall, J.; Pitt, B.

    1983-01-01

    Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease

  14. Rest and exercise ventricular function in adults with congenital ventricular septal defects

    International Nuclear Information System (INIS)

    Jablonsky, G.; Hilton, J.D.; Liu, P.P.; Morch, J.E.; Druck, M.N.; Bar-Shlomo, B.Z.; McLaughlin, P.R.

    1983-01-01

    Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD). Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise. All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects and resting right ventricular ejection fraction was lower in Group 3 versus control subjects. Thus left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; lifelong volume overload may be detrimental to myocardial function

  15. [Genetic aspects of premature ovarian failure].

    Science.gov (United States)

    Warenik-Szymankiewicz, Alina; Słopień, Radosław

    2005-01-01

    Among the causes of premature ovarian failure (POF) two groups of factors are reported: factors which lead to decrease of follicular number and factors which stimulate follicular atresia. In the first group genetic factors are the most important whereas in the second: enzymatic autoimmunological, iatrogenic, toxins and infections are reported. In 1986 familiar POF on the background of long arm of chromosome X deletion was reported. Other chromosomes which are important for normal ovarian function are: chromosome 21 (AIRE gene), chromosome 11 (gene of beta FSH, ATM gene), chromosome 3 (gene responsible for BEPS syndrome) and chromosome 2 (genes of FSH and LH receptors). In this review the role of these genes and results of several epidemiological studies are reported.

  16. Wife beating refusal among women of reproductive age in urban and rural Ethiopia.

    Science.gov (United States)

    Gurmu, Eshetu; Endale, Senait

    2017-03-16

    Wife beating is the most common and widespread form of intimate partner violence in Ethiopia. It results in countless severe health, socio-economic and psychological problems and has contributed to the violation of human rights including the liberty of women to enjoy conjugal life. The main purpose of this study is to assess the levels and patterns of wife beating refusal and its associated socio-cultural and demographic factors in rural and urban Ethiopia. The 2011 Ethiopian Demographic and Health Survey (EDHS) data based on 11,097 and 5287 women in the reproductive age group (i.e. 15-49 years) living in rural and urban areas, respectively,were used in this study. Cronbach's alpha was used to assess the internal consistency of the measure of women's attitudes towards wife beating. The Statistical Package for Social Sciences was applied to analyze the data. A binary logistic regression model was fitted to identify variables that significantly predict respondents' refusal of wife beating. Separate analysis by a place of residence was undertaken as attitude towards wife beating vary between rural and urban areas. The likelihood of refusing wife beating in Ethiopia was significantly higher among urban women (54.2%) than rural women (24.5%). Although there was a significant variations in attitude towards refusing wife beating among different regions in Ethiopia, increasing educational level, high access to media, age of respondents were associated with high level of refusal of wife beating. In contrast, rural residence, being in marital union, high number of living children, being followers of some religions (Muslim followers in urban and Protestants in rural) were associated with low level of refusal of wife beating. The findings of this study reveal that wife beating in Ethiopia is a function of demographic and socio-cultural factors among which age and educational attainment of respondents, number of living children, religious affiliation, marital commitment and

  17. Arrhythmogenic right ventricular dysplasia: A case report

    Directory of Open Access Journals (Sweden)

    Tessa Negrín Valdés

    2015-10-01

    Full Text Available Arrhythmogenic right ventricular dysplasia is a heart muscle disease that predominantly affects the right ventricle, bringing about the replacement of normal myocardium with fatty or fibrofatty tissue and causing sudden death in young individuals. Ventricular tachycardia is an important clinical manifestation, although there are reports of right or global heart failure. The diagnosis is confirmed by echocardiography and magnetic resonance imaging. The case of a 65-year-old former smoker, with hypertension and ischemic heart disease, a history of effort syncope symptoms and proven non-sustained ventricular tachycardia, with morphology of left bundle branch block, is reported. Relevant diagnostic studies were performed, and echocardiographic elements which were compatible with arrhythmogenic right ventricular dysplasia were found. Therefore, an implantable cardioverter defibrillator was implanted, after which the patient has had a favorable outcome.

  18. Ventricular repolarization measures for arrhythmic risk stratification

    Institute of Scientific and Technical Information of China (English)

    Francesco Monitillo; Marta Leone; Caterina Rizzo; Andrea Passantino; Massimo Iacoviello

    2016-01-01

    Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave(QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice.

  19. Lung function and exercise capacity in young adults born prematurely

    NARCIS (Netherlands)

    Vrijlandt, EJLE; Gerritsen, J; Boezen, HM; Grevink, RG; Duiverman, EJ

    2006-01-01

    Rationale: Limited information is available about the long-term outcome of lung function and exercise capacity in young adults born prematurely. Objective: To determine long-term effects of prematurity on lung function (volumes, diffusing capacity) and exercise capacity in expreterms compared with

  20. Prematurity Stereotype: Effects of Labeling on Adults' Perceptions of Infants.

    Science.gov (United States)

    Stern, Marilyn; Hildebrandt, Katherine A.

    1984-01-01

    Two studies were conducted in which college students and mothers were asked to rate unfamiliar infants shown on videotapes. Infants were described as either full-term or premature and as either male or female. Infants labeled premature were rated more negatively than those labeled full-term, but infants labeled male and female were rated…

  1. Histological Chorioamnionitis: Effects on Premature Delivery and Neonatal Prognosis

    Directory of Open Access Journals (Sweden)

    Gulin Erdemir

    2013-08-01

    Conclusion: Chorioamnionitis not only causes premature deliveries, but is also associated with neonatal complications and increased mortality. Clinical findings and infectious markers in mother or infant do not predict the diagnosis of histological chorioamnionitis. Therefore, placental histopathology may have a role in predicting neonatal outcome in premature deliveries, especially those below 30 weeks.

  2. Acetaminophen developmental pharmacokinetics in premature neonates and infants

    DEFF Research Database (Denmark)

    Anderson, Brian J; van Lingen, Richard A; Hansen, Tom G

    2002-01-01

    The aim of this study was to describe acetaminophen developmental pharmacokinetics in premature neonates through infancy to suggest age-appropriate dosing regimens.......The aim of this study was to describe acetaminophen developmental pharmacokinetics in premature neonates through infancy to suggest age-appropriate dosing regimens....

  3. Impact of Prematurity on Language Skills at School Age

    Science.gov (United States)

    Smith, Jamie Mahurin; DeThorne, Laura Segebart; Logan, Jessica A. R.; Channell, Ron W.; Petrill, Stephen A.

    2014-01-01

    Purpose: The existing literature on language outcomes in children born prematurely focuses almost exclusively on standardized test scores rather than discourse-level abilities. The authors of this study looked longitudinally at school-age language outcomes and potential moderating variables for a group of twins born prematurely versus a control…

  4. Anemia of prematurity : time for a change in transfusion management?

    NARCIS (Netherlands)

    Khodabux, Chantal Muriel

    2013-01-01

    In this thesis we investigated clinical effects of allogeneic red blood cell (RBC) transfusions in premature infants, different transfusion volumes in relation to neonatal outcome in premature infants and the use of autologous cord blood (CB) as an alternative for allogeneic transfusions. Despite

  5. Bartter syndrome: presentation in an extremely premature neonate.

    Science.gov (United States)

    Flores, F X; Ojeda, F J; Calhoun, D A

    2013-08-01

    Reports of Bartter syndrome in premature neonates are rare. We describe the presentation and clinical course of a neonate born at 25.6 weeks estimated gestational age with polyuria, hyponatremia, hypokalemia and hypercalciuria ,who was diagnosed with neonatal Bartter syndrome. The evaluation, diagnosis and management of neonatal Bartter syndrome in this premature neonate are discussed.

  6. Antibiotics after preterm premature rupture of the membranes.

    Science.gov (United States)

    Singh, Katherine; Mercer, Brian

    2011-06-01

    Preterm premature rupture of the membranes remains a common cause of preterm deliveries and neonatal morbidities. The goal of this study is to review the evidence with regard to the antibiotic treatment after preterm premature rupture of the membranes, long-term outcomes related to antibiotic treatment, and possible complications with treatment. Future research goals are also discussed.

  7. Salbutamol Abuse is Associated with Ventricular Fibrillation

    Directory of Open Access Journals (Sweden)

    Emin UYSAL

    2015-06-01

    Full Text Available SUMMARY: Salbutamol-induced cardiac complications are well-established. Herein, we describe a case of a 24-year female who was admitted to the emergency department because of a suicide attempt with salbutamol (76 mg. Salbutamol abuse induced the development of supraventricular tachycardia and ventricular fibrillation. Regular sinus rhythm was restored with defibrillation. The hypokalemic patient who stayed in the intensive care unit was discharged after 48 hours of hospitalization. Key words: Salbutamol, suicide, ventricular fibrillation

  8. Clustering Of Left Ventricular Wall Motion Patterns

    Science.gov (United States)

    Bjelogrlic, Z.; Jakopin, J.; Gyergyek, L.

    1982-11-01

    A method for detection of wall regions with similar motion was presented. A model based on local direction information was used to measure the left ventricular wall motion from cineangiographic sequence. Three time functions were used to define segmental motion patterns: distance of a ventricular contour segment from the mean contour, the velocity of a segment and its acceleration. Motion patterns were clustered by the UPGMA algorithm and by an algorithm based on K-nearest neighboor classification rule.

  9. 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....

  10. Minimally invasive estimation of ventricular dead space volume through use of Frank-Starling curves.

    Directory of Open Access Journals (Sweden)

    Shaun Davidson

    Full Text Available This paper develops a means of more easily and less invasively estimating ventricular dead space volume (Vd, an important, but difficult to measure physiological parameter. Vd represents a subject and condition dependent portion of measured ventricular volume that is not actively participating in ventricular function. It is employed in models based on the time varying elastance concept, which see widespread use in haemodynamic studies, and may have direct diagnostic use. The proposed method involves linear extrapolation of a Frank-Starling curve (stroke volume vs end-diastolic volume and its end-systolic equivalent (stroke volume vs end-systolic volume, developed across normal clinical procedures such as recruitment manoeuvres, to their point of intersection with the y-axis (where stroke volume is 0 to determine Vd. To demonstrate the broad applicability of the method, it was validated across a cohort of six sedated and anaesthetised male Pietrain pigs, encompassing a variety of cardiac states from healthy baseline behaviour to circulatory failure due to septic shock induced by endotoxin infusion. Linear extrapolation of the curves was supported by strong linear correlation coefficients of R = 0.78 and R = 0.80 average for pre- and post- endotoxin infusion respectively, as well as good agreement between the two linearly extrapolated y-intercepts (Vd for each subject (no more than 7.8% variation. Method validity was further supported by the physiologically reasonable Vd values produced, equivalent to 44.3-53.1% and 49.3-82.6% of baseline end-systolic volume before and after endotoxin infusion respectively. This method has the potential to allow Vd to be estimated without a particularly demanding, specialised protocol in an experimental environment. Further, due to the common use of both mechanical ventilation and recruitment manoeuvres in intensive care, this method, subject to the availability of multi-beat echocardiography, has the potential to

  11. To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

    Directory of Open Access Journals (Sweden)

    Alyssa D. Ammazzalorso

    2015-08-01

    Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.

  12. Premature ejaculation: A clinical review for the general physician.

    Science.gov (United States)

    Chung, Eric; Gilbert, Brent; Perera, Marlon; Roberts, Matthew J

    2015-10-01

    Premature ejaculation is one of the most common sexual dysfunctions in men. Recent epidemiological studies suggest its prevalence in Australia may range from 21-31% This article will discuss the current definition of premature ejaculation from a urological perspective. It will provide an understanding of the pathogenesis of premature ejaculation, as well as assessment and management options. Premature ejaculation can have a significant adverse effect on the quality of life for the patient and his sexual partners. It can potentially lead to psychological distress, diminished self- esteem, anxiety, erectile dysfunction, reduced libido and poor interpersonal relationships. Most men feel reluctant to discuss premature ejaculation with their general practitioner despite its psychological, emotional and relational effects. Effective, evidence-based treatment options are available and physicians should feel confident when exploring ways to improve the quality of life for men with sexual dysfunction.

  13. Adequacy of published screening criteria for retinopathy of prematurity.

    Science.gov (United States)

    Taranath, Deepa A; Oh, Dickson D-S; Keane, Miriam C; Fabel, Helen; Marshall, Peter

    2016-03-01

    Criteria for screening preterm infants for retinopathy of prematurity vary around the world. We aimed to analyse the efficacy of alternative screening criteria. We collected retrospective data at a tertiary level neonatal nursery. Our participants were 1007 babies, born between 1997 and 2011, at prematurity. We determined whether disease would be detected using an alternative Australian screening model (gestational age prematurity is our main outcome. Using several of the alternative criteria, two neonates with clinically significant retinopathy of prematurity, one of whom required laser treatment to preserve sight, would not have been screened, and their disease may have gone undetected. Use of prematurity may risk clinically significant cases being missed and others may screen babies unnecessarily. Alternative criteria should be considered and '<30 weeks gestational age and/or <1500 g birth weight' appears a viable option. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  14. Long-term impact of prematurity on postnatal neurohormonal regulation

    Directory of Open Access Journals (Sweden)

    M. I. Ziborova

    2016-01-01

    Full Text Available This article considers the psychophysiological and neuroendocrine differences characteristic of premature children, which are as a result of long-term perinatal consequences. Particular emphasis is laid on the effects of the hypothalamic-pituitary-adrenocortical stress system, the performance of which is reprogramed during complicated pregnancy, labor, and postnatal period under pain stress due to medical manipulations. Being extremely sensitive to all these exposures, the brain of a premature infant develops during activation of the stress system and takes on a few distinctive properties in addition to independent neuroanatomical distinctions due to premature birth. The altered neurohormonal patterns revealed in very prematurely born children and adolescents involve the regulation of mental processes, behavior, metabolism, and circadian rhythms (sleep-wake regulation, which differ from those in their maturely born peers. These cases allow learning and behavior problems and lower cognitive estimates to be considered in normally developing children born extremely prematurely who have also hormonal dysregulation.

  15. Resolving the True Ventricular Mural Architecture

    Directory of Open Access Journals (Sweden)

    Robert S. Stephenson

    2018-06-01

    Full Text Available The precise nature of packing together of the cardiomyocytes within the ventricular walls has still to be determined. The spiraling nature of the chains of interconnected cardiomyocytes has long been recognized. As long ago as the end of the nineteenth century, Pettigrew had emphasized that the ventricular cone was not arranged on the basis of skeletal muscle. Despite this guidance, subsequent anatomists described entities such as “bulbo-spiral muscles”, with this notion of subunits culminating in the suggestion that the ventricular cone could be unwrapped so as to produce a “ventricular myocardial band”. Others, in contrast, had suggested that the ventricular walls were arranged on the basis of “sheets”, or more recently “sheetlets”, with investigators seeking to establishing the angulation of these entities using techniques such as magnetic resonance imaging. Our own investigations, in contrast, have shown that the cardiomyocytes are aggregated together within the supporting fibrous matrix so as to produce a three-dimensional myocardial mesh. In this review, we summarize the previous accounts, and provide the anatomical evidence we have thus far accumulated to support the model of the myocardial mesh. We show how these anatomic findings underscore the concept of the myocardial mesh functioning in antagonistic fashion. They lend evidence to support the notion that the ventricular myocardium works as a muscular hydrostat.

  16. Association of Maternal Preeclampsia With Infant Risk of Premature Birth and Retinopathy of Prematurity.

    Science.gov (United States)

    Shulman, Julia P; Weng, Cindy; Wilkes, Jacob; Greene, Tom; Hartnett, M Elizabeth

    2017-09-01

    Studies report conflicting associations between preeclampsia and retinopathy of prematurity (ROP). This study provides explanations for the discrepancies to clarify the relationship between preeclampsia and ROP. To evaluate the association of maternal preeclampsia and risk of ROP among infants in an unrestricted birth cohort and a restricted subcohort of preterm, very low birth weight (P-VLBW) infants. A retrospective review of 290 992 live births within the Intermountain Healthcare System in Utah from January 1, 2001, through December 31, 2010, was performed. Generalized estimating equations for logistic regressions with covariate adjustment were applied to relate ROP to preeclampsia among the full cohort and in a subcohort of P-VLBW infants born at younger than 31 weeks' gestation and weighing less than 1500 g. The occurrence of ROP was related to maternal preeclampsia in the full cohort and in a subcohort of P-VLBW infants. In the full cohort, 51% of the infants were male and the mean (SD) gestational age was 38.38 (1.87) weeks. In the P-VLBW cohort, 55% were male and the mean (SD) gestational age was 26.87 (2.40) weeks. In the full cohort, preeclampsia was associated with an increased risk of all ROP (adjusted odds ratio [aOR], 2.46; 95% CI, 2.17-2.79; P prematurity, because prematurity is an outcome of preeclampsia.

  17. Premature Calcifications of Costal Cartilages: A New Perspective Premature Calcifications of Costal Cartilages: A New Perspective

    International Nuclear Information System (INIS)

    Rhomberg, W.; Schuster, A.

    2014-01-01

    Calcifications of the costal cartilages occur, as a rule, not until the age of 30 years. The knowledge of the clinical significance of early and extensive calcifications is still incomplete. Materials and Methods. A search was made to find patients below the age of 30 years who showed distinct calcifications of their lower costal cartilages by viewing 360 random samples of intravenous pyelograms and abdominal plain films. The histories, and clinical and laboratory findings of these patients were analyzed. Results. Nineteen patients fulfilled the criteria of premature calcifications of costal cartilages (CCCs). The patients had in common that they were frequently referred to a hospital and were treated by several medical disciplines. Nevertheless many complaints of the patients remained unsolved. Premature CCCs were often associated with rare endocrine disorders, inborn errors of metabolism, and abnormal hematologic findings. Among the metabolic disorders there were 2 proven porphyrias and 7 patients with a suspected porphyria but with inconclusive laboratory findings. Conclusion. Premature CCCs are unlikely to be a normal variant in skeletal radiology. The findings in this small group of patients call for more intensive studies, especially in regard to the putative role of a porphyria

  18. Large right ventricular sinusoids in an infant with aorta-left ventricular tunnel and proximal right coronary artery atresia.

    Science.gov (United States)

    Chen, Peter C; Spinner, Joseph A; Heinle, Jeffrey S

    2018-07-01

    We report a 1-month-old infant diagnosed with an aorta-left ventricular tunnel, ventricular septal defect, and right coronary atresia with right ventricular sinusoids. The patient's anatomy and physiology did not indicate right-ventricular-dependent coronary circulation, and therefore right ventricular decompression could be performed without compromising coronary perfusion during surgical correction. A detailed understanding of the coronary anatomy is critical in managing this defect when coronary anomalies are present.

  19. Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping.

    Science.gov (United States)

    Cameron, Daniel J; Bentley, Jocelyn; Grahn, Jessica A

    2015-01-01

    The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced by the culture of the participant and the culture of the rhythm. Specifically, we predicted that a participant's ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

  20. Extracting fetal heart beats from maternal abdominal recordings: selection of the optimal principal components

    International Nuclear Information System (INIS)

    Di Maria, Costanzo; Liu, Chengyu; Zheng, Dingchang; Murray, Alan; Langley, Philip

    2014-01-01

    This study presents a systematic comparison of different approaches to the automated selection of the principal components (PC) which optimise the detection of maternal and fetal heart beats from non-invasive maternal abdominal recordings. A public database of 75 4-channel non-invasive maternal abdominal recordings was used for training the algorithm. Four methods were developed and assessed to determine the optimal PC: (1) power spectral distribution, (2) root mean square, (3) sample entropy, and (4) QRS template. The sensitivity of the performance of the algorithm to large-amplitude noise removal (by wavelet de-noising) and maternal beat cancellation methods were also assessed. The accuracy of maternal and fetal beat detection was assessed against reference annotations and quantified using the detection accuracy score F1 [2*PPV*Se / (PPV + Se)], sensitivity (Se), and positive predictive value (PPV). The best performing implementation was assessed on a test dataset of 100 recordings and the agreement between the computed and the reference fetal heart rate (fHR) and fetal RR (fRR) time series quantified. The best performance for detecting maternal beats (F1 99.3%, Se 99.0%, PPV 99.7%) was obtained when using the QRS template method to select the optimal maternal PC and applying wavelet de-noising. The best performance for detecting fetal beats (F1 89.8%, Se 89.3%, PPV 90.5%) was obtained when the optimal fetal PC was selected using the sample entropy method and utilising a fixed-length time window for the cancellation of the maternal beats. The performance on the test dataset was 142.7 beats 2 /min 2 for fHR and 19.9 ms for fRR, ranking respectively 14 and 17 (out of 29) when compared to the other algorithms presented at the Physionet Challenge 2013. (paper)

  1. The effect of gamma-enhancing binaural beats on the control of feature bindings.

    Science.gov (United States)

    Colzato, Lorenza S; Steenbergen, Laura; Sellaro, Roberta

    2017-07-01

    Binaural beats represent the auditory experience of an oscillating sound that occurs when two sounds with neighboring frequencies are presented to one's left and right ear separately. Binaural beats have been shown to impact information processing via their putative role in increasing neural synchronization. Recent studies of feature-repetition effects demonstrated interactions between perceptual features and action-related features: repeating only some, but not all features of a perception-action episode hinders performance. These partial-repetition (or binding) costs point to the existence of temporary episodic bindings (event files) that are automatically retrieved by repeating at least one of their features. Given that neural synchronization in the gamma band has been associated with visual feature bindings, we investigated whether the impact of binaural beats extends to the top-down control of feature bindings. Healthy adults listened to gamma-frequency (40 Hz) binaural beats or to a constant tone of 340 Hz (control condition) for ten minutes before and during a feature-repetition task. While the size of visuomotor binding costs (indicating the binding of visual and action features) was unaffected by the binaural beats, the size of visual feature binding costs (which refer to the binding between the two visual features) was considerably smaller during gamma-frequency binaural beats exposure than during the control condition. Our results suggest that binaural beats enhance selectivity in updating episodic memory traces and further strengthen the hypothesis that neural activity in the gamma band is critically associated with the control of feature binding.

  2. Electrophysiological measurement of binaural beats: effects of primary tone frequency and observer age.

    Science.gov (United States)

    Grose, John H; Mamo, Sara K

    2012-01-01

    The purpose of this study was to determine the reliability of the electrophysiological binaural beat steady state response as a gauge of temporal fine structure coding, particularly as it relates to the aging auditory system. The hypothesis was that the response would be more robust in a lower, than in a higher, frequency region and in younger, than in older, adults. Two experiments were undertaken. The first measured the 40 Hz binaural beat steady state response elicited by tone pairs in two frequency regions: lower (390 and 430 Hz tone pair) and higher (810 and 850 Hz tone pair). Frequency following responses (FFRs) evoked by the tones were also recorded. Ten young adults with normal hearing participated. The second experiment measured the binaural beat and FFRs in older adults but only in the lower frequency region. Fourteen older adults with relatively normal hearing participated. Response metrics in both experiments included response component signal-to-noise ratio (F statistic) and magnitude-squared coherence. Experiment 1 showed that FFRs were elicited in both frequency regions but were more robust in the lower frequency region. Binaural beat responses elicited by the lower frequency pair of tones showed greater amplitude fluctuation within a participant than the respective FFRs. Experiment 2 showed that older adults exhibited similar FFRs to younger adults, but proportionally fewer older participants showed binaural beat responses. Age differences in onset responses were also observed. The lower prevalence of the binaural beat response in older adults, despite the presence of FFRs, provides tentative support for the sensitivity of this measure to age-related deficits in temporal processing. However, the lability of the binaural beat response advocates caution in its use as an objective measure of fine structure coding.

  3. Binaural beat technology in humans: a pilot study to assess psychologic and physiologic effects.

    Science.gov (United States)

    Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather

    2007-01-01

    Binaural beat technology (BBT) products are sold internationally as personal development and health improvement tools. Producers suggest benefit from regular listening to binaural beats including reduced stress and anxiety, and increased focus, concentration, motivation, confidence, and depth in meditation. Binaural beats are auditory brainstem responses that originate in the superior olivary nucleus as a result of different frequency auditory stimuli provided to each ear. Listeners to binaural beat "hear" a beat at a frequency equal to the difference between the frequencies of the applied tones. The objectives of this pilot study were to gather preliminary data on psychologic and physiologic effects of 60 days daily use of BBT for hypothesis generation and to assess compliance, feasibility, and safety for future studies. Uncontrolled pilot study. Eight healthy adults participated in the study. Participants listened to a CD with delta (0-4 Hz) binaural beat frequencies daily for 60 days. Psychologic and physiological data were collected before and after a 60-day intervention. PSYCHOLOGIC: Depression (Beck Depression Inventory-2), anxiety (State-Trait Anxiety Inventory), mood (Profile of Mood States), absorption (Tellegen Absorption Scale) and quality of Life (World Health Organization-Quality of Life Inventory). PHYSIOLOGICAL: Cortisol, dehydroepiandrosterone, melatonin, insulin-like growth factor-1, serotonin, dopamine, epinephrine, norepinephrine, weight, blood pressure, high sensitivity C-reactive protein. There was a decrease in trait anxiety (p = 0.004), an increase in quality of life (p = 0.03), and a decrease in insulin-like growth factor-1 (p = 0.01) and dopamine (p = 0.02) observed between pre- and postintervention measurements. Binaural beat technology may exhibit positive effect on self-reported psychologic measures, especially anxiety. Further research is warranted to explore the effects on anxiety using a larger, randomized and controlled trial.

  4. Cardiac arrhythmia beat classification using DOST and PSO tuned SVM.

    Science.gov (United States)

    Raj, Sandeep; Ray, Kailash Chandra; Shankar, Om

    2016-11-01

    -based assessment scheme respectively to the state-of-art diagnosis. The results reported are further compared to the existing methodologies in literature. The proposed feature representation of cardiac signals based on symmetrical features along with PSO based optimization technique for the SVM classifier reported an improved classification accuracy in both the assessment schemes evaluated on the benchmark MIT-BIH arrhythmia database and hence can be utilized for automated computer-aided diagnosis of cardiac arrhythmia beats. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Sildenafil and retinopathy of prematurity risk in very low birth weight infants

    NARCIS (Netherlands)

    S. Samiee-Zafarghandy; J.N. van den Anker (John); M. Laughon (Matthew); R.H. Clark; P.B. Smith; C.P. Hornik

    2016-01-01

    textabstractObjective: To examine the effect of sildenafil therapy on development of severe retinopathy of prematurity (ROP) requiring surgical intervention in premature infants. Study Design: We identified premature infants who were discharged from Pediatrix Medical Group neonatal intensive care

  6. An empirical investigation of attitudes towards wife-beating among men and women in seven sub-Saharan African countries.

    Science.gov (United States)

    Rani, Manju; Bonu, Sekhar; Diop-Sidibe, Nafissatou

    2004-12-01

    This study used data from the demographic and health surveys (DHS) conducted between 1999 and 2001 in Benin, Ethiopia, Malawi, Mali, Rwanda, Uganda and Zimbabwe, to examine the magnitude and correlates of conditional acceptance of wife-beating among both men and women. Multivariate logistic regression models were fitted to investigate the independent association between different socio-demographic characteristics and acceptance of wife-beating. The acceptance of wife-beating for transgressing certain gender roles was widespread in all the countries. Men were consistently less likely to justify wife-beating than women. Household wealth and education emerged as strongest and most consistent negative predictors of acceptance of wife-beating among both men and women. Older men and women were less likely to justify wife-beating. Men and women in the polygamous union were more likely to accept wife-beating, though the association was not always significant. With the exception of Uganda, women working for pay were more likely to justify wife-beating than non-working women were. The results indicate that dominant social and cultural norms create images of "ideal" women among both men and women that include definition and widespread acceptance of gender roles as well as sanction use of force to enforce these gender roles. The State and its different institutions may fail to mitigate wife-beating, as sensitivity to objectively address wife-beating may be tellingly lacking. Though education, economic growth, etc, can reduce acceptance of wife-beating, the process may be too slow and too late to make a substantial difference in the near future. Proactive measures may be required to change attitudes towards wife-beating among both men and women.

  7. Stress induced right ventricular dysfunction: An indication of reversible right ventricular ischaemia

    International Nuclear Information System (INIS)

    Underwood, S.R.; Walton, S.; Emanuel, R.W.; Swanton, R.H.; Campos Costa, D.; Laming, P.J.; Ell, P.J.

    1987-01-01

    Stress induced changes in left ventricular ejection fraction are widely used in the detection and assessment of coronary artery disease. This study demonstrates that right ventricular dysfunction may also occur, and assesses its significance in terms of coronary artery anatomy. This study involved 14 normal subjects and 26 with coronary artery disease investigated by equilibrium radionuclide ventriculography, at rest and during maximal dynamic exercise. Mean normal resting right ventricular ejection fraction (RVEF) was 0.40 (SD 0.118), and all normal subjects increased RVEF with stress (mean ΔRVEF+0.13 SD 0.099). Mean ΔRVEF in the subjects with coronary artery disease was significantly lower at 0.00 (SD 0.080), but there was overlap between the two groups. The largest falls in RVEF were seen if the right coronary artery was occluded without retrograde filling. In this subgroup with the most severely compromised right ventricular perfusion (nine subjects), RVEF always fell with stress, and mean ΔRVEF was -0.08 (SD 0.050). There was no significant correlation between ΔLVEF and ΔRVEF, implying that the right ventricular dysfunction was due to right ventricular ischaemia, rather than secondary to left ventricular dysfunction. Stress induced right ventricular ischaemia can therefore be detected readily by radionuclide ventriculography. (orig.)

  8. Action potential conduction between a ventricular cell model and an isolated ventricular cell

    NARCIS (Netherlands)

    Wilders, R.; Kumar, R.; Joyner, R. W.; Jongsma, H. J.; Verheijck, E. E.; Golod, D.; van Ginneken, A. C.; Goolsby, W. N.

    1996-01-01

    We used the Luo and Rudy (LR) mathematical model of the guinea pig ventricular cell coupled to experimentally recorded guinea pig ventricular cells to investigate the effects of geometrical asymmetry on action potential propagation. The overall correspondence of the LR cell model with the recorded

  9. Right ventricular failure after implantation of a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Cordtz, Johan Joakim; Nilsson, Jens C; Hansen, Peter B

    2014-01-01

    Right ventricular failure (RVF) is a significant complication after implantation of a left ventricular assist device. We aimed to identify haemodynamic changes in the early postoperative phase that predicted subsequent development of RVF in a cohort of HeartMate II (HMII) implanted patients....

  10. Reversion of left ventricular systolic dysfunction and abnormal stress test: by catheter ablation, in a patient with Wolff-Parkinson-White syndrome from Para-Hisian Kent bundle.

    Science.gov (United States)

    Tu, Chung-Ming; Chu, Kai-Ming; Cheng, Cheng-Chung; Cheng, Shu-Mung; Lin, Wei-Shiang

    2010-01-01

    The diagnosis of Wolff-Parkinson-White syndrome is typically reserved for patients who experience ventricular pre-excitation and symptoms that are related to paroxysmal supraventricular tachycardia, such as chest pain, dyspnea, dizziness, palpitations, or syncope. Herein, we report the case of a 38-year-old woman who presented at our outpatient department because of exercise intolerance. Cardiac auscultation revealed a grade 2/6 pansystolic murmur over the left lower sternal border. Twelve-lead electrocardiography showed sinus rhythm at a rate of 76 beats/min, with a significant delta wave. Transthoracic echocardiography revealed abnormal left ventricular systolic function. The results of a thallium stress test were also abnormal. Coronary artery disease was suspected; however, coronary angiography yielded normal results. Electrophysiologic study revealed a para-Hisian Kent bundle and a dual atrioventricular nodal pathway. After radiofrequency catheter ablation was performed, the patient's left ventricular function improved and her symptoms disappeared. In Wolff-Parkinson-White syndrome, left ventricular systolic dyssynchrony can yield abnormal findings on echocardiography and thallium scanning--even in persons who have no cardiovascular risk factors. Physicians who are armed with this knowledge can avoid performing coronary angiography unnecessarily. Catheter ablation can reverse the dyssynchrony of the ventricle and improve the patient's symptoms.

  11. The Beats as Cultural Others/Exotics in Recent Memoirs by Exile Poets

    DEFF Research Database (Denmark)

    Sørensen, Bent

    Poets who have come to the USA during the 1950s and 60s as expatriates or exiles from central European countries dominated by Communist regimes have often looked to Beat Generation writers as role models and inspirational figures. This is no doubt due to the spirit of individuality, non-conformis......Poets who have come to the USA during the 1950s and 60s as expatriates or exiles from central European countries dominated by Communist regimes have often looked to Beat Generation writers as role models and inspirational figures. This is no doubt due to the spirit of individuality, non......-conformism and jubilant celebration of difference and otherness which permeates the writings of poets such as Allen Ginsberg, and which resonated with dissident poets often oppressed by totalitarian regimes. Authors such as Andrei Codrescu and Charles Simic have published memoirs and poems detailing their fascination...... with figures associated with the Beat Generation. This paper examines the representation of Beat writers such as Ginsberg and Jack Kerouac in Codrescu and Simic's texts, and argues that the exile poets overlay the well-known figures of the Beat writers with yet another dimension of otherness and exoticism...

  12. Beating of Aharonov-Bohm oscillations in a closed-loop interferometer

    International Nuclear Information System (INIS)

    Jo, Sanghyun; Chang, Dong-In; Lee, Hu-Jong; Khym, Gyong Luck; Kang, Kicheon; Chung, Yunchul; Mahalu, Diana; Umansky, Vladimir

    2007-01-01

    One of the points at issue with closed-loop-type interferometers is beating in the Aharonov-Bohm (AB) oscillations. Recent observations suggest the possibility that the beating results from the Berry-phase pickup by the conducting electrons in materials with the strong spin-orbit interaction (SOI). In this study, we also observed beats in the AB oscillations in a gate-defined closed-loop interferometer fabricated on a GaAs/Al 0.3 Ga 0.7 As two-dimensional electron-gas heterostructure. Since this heterostructure has very small SOI, the picture of the Berry-phase pickup is ruled out. The observation of beats in this study, with the controllability of forming a single transverse subband mode in both arms of our gate-defined interferometer, also rules out the often-claimed multiple transverse subband effect. It is observed that nodes of the beats with an h/2e period exhibit a parabolic distribution for varying the side gate. These results are shown to be well interpreted, without resorting to the SOI effect, by the existence of two-dimensional multiple longitudinal modes in a single transverse subband. The Fourier spectrum of measured conductance, despite showing multiple h/e peaks with the magnetic-field dependence that are very similar to that from strong-SOI materials, can also be interpreted as the two-dimensional multiple-longitudinal-modes effect

  13. Effects of adriamycin and irradiation on beating of rat heart muscle cells in culture

    International Nuclear Information System (INIS)

    Petrovic, D.; Brown, S.M.; Yatvin, M.B.

    1977-01-01

    In an attempt to elucidate the mechanisms involved in Adriamycin (ADM) induced cardiotoxicity as well as determining the possible potentiating effect that irradiation has when it is combined with the drug, heart cells from newborn rats were isolated, cultured and treated with Adriamycin. The actions of these two agents separately or in combination on the survival of beating activity and beating frequency are measured. Beating activity could be decreased temporarily either by exposing the cells to 50 krad of γ-irradiation or 0.1 μg of Adriamycin. Following 100 krad of γ-radiation or 1.0 μg Adriamycin, an irreversible cessation of beating occurred. In the case of Adriamycin, cessation was preceded by a temporary sharp increase in beating frequency. Doses of radiation up to 10 krad in combination with Adriamycin were not potentiating. The results indicate that Adriamycin produces its cardiotoxic effects, at least in part, by a direct action on heart muscle cells. It is less likely, however, that damage which occurs in the heart following therapeutic doses of irradiation is the result of such direct action

  14. Global beta-beating compensation of the ALS W16 wiggler

    International Nuclear Information System (INIS)

    Robin, D.; Decking, W.; Nishimura, H.

    1997-05-01

    The W16 wiggler is the first wiggler and highest field insertion device to be installed in the ALS storage ring. When the gaps of the W16 wiggler are closed, the vertical tune increases by 0.065 and the vertical beta function is distorted by up to ±37%. There are 48 quadrupoles in the ring whose fields can be adjusted individually to restore the tunes and partially compensate the beta-beating. In order to adjust the quadrupole field strengths to accurately compensate the focusing, it is necessary to have a method to precisely determine the beta-beating. In this paper we compare measurements of the induced beta-beating using two methods: measuring the tune dependence on quadrupole field strength and fitting a lattice model with measured response matrices. The fitted model also allows us to predict quadrupole field strengths that will best compensate the beta beating. These quadrupole field strengths are then applied and the resultant beta-beating is measured

  15. 4D ultrasound and 3D MRI registration of beating heart

    International Nuclear Information System (INIS)

    Herlambang, N.; Matsumiya, K.; Masamune, K.; Dohi, T.; Liao, H.; Tsukihara, H.; Takamoto, S.

    2007-01-01

    To realize intra-cardiac surgery without cardio-pulmonary bypass, a medical imaging technique with both high image quality and data acquisition rate that is fast enough to follow heart beat movements is required. In this research, we proposed a method that utilized the image quality of MRI and the speed of ultrasound. We developed a 4D image reconstruction method using image registration of 3D MRI and 4D ultrasound images. The registration method consists of rigid registration between 3D MRI and 3D ultrasound with the same heart beat phase, and non-rigid registration between 3D ultrasound images from different heart beat phases. Non-rigid registration was performed with B-spline based registration using variable spring model. In phantom experiment using balloon phantom, registration accuracy was less than 2 mm for total heart volume variation range of 10%. We applied our registration method on 3D MRI and 4D ultrasound images of a volunteer's beating heart data and confirmed through visual observation that heart beat pattern was well reproduced. (orig.)

  16. Beat Synchronization across the Lifespan: Intersection of Development and Musical Experience.

    Directory of Open Access Journals (Sweden)

    Elaine C Thompson

    Full Text Available Rhythmic entrainment, or beat synchronization, provides an opportunity to understand how multiple systems operate together to integrate sensory-motor information. Also, synchronization is an essential component of musical performance that may be enhanced through musical training. Investigations of rhythmic entrainment have revealed a developmental trajectory across the lifespan, showing synchronization improves with age and musical experience. Here, we explore the development and maintenance of synchronization in childhood through older adulthood in a large cohort of participants (N = 145, and also ask how it may be altered by musical experience. We employed a uniform assessment of beat synchronization for all participants and compared performance developmentally and between individuals with and without musical experience. We show that the ability to consistently tap along to a beat improves with age into adulthood, yet in older adulthood tapping performance becomes more variable. Also, from childhood into young adulthood, individuals are able to tap increasingly close to the beat (i.e., asynchronies decline with age, however, this trend reverses from younger into older adulthood. There is a positive association between proportion of life spent playing music and tapping performance, which suggests a link between musical experience and auditory-motor integration. These results are broadly consistent with previous investigations into the development of beat synchronization across the lifespan, and thus complement existing studies and present new insights offered by a different, large cross-sectional sample.

  17. Beat-wave excitation and current driven in tokamak plasma. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, B F [Plasma physics Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Wave heating current drive in tokamaks is a growing subject in the plasma physics literature. For current drive in tokamaks by electromagnetic waves, different methods have been proposed recently. One of the promising schemes for current drive remains the beat wave scheme. This technique employs two CO- or counterpropagating monochromatic laser beams (or microwaves) whose frequency difference matches the plasma frequency, while the wave number difference (or sum, in the case of counterpropagating) determine the wave number of the resulting plasma beat wave. In this work, the basic analysis of a beat wave current drive scheme in which collinear waves are used is discussed. by assuming a Gaussian profile for the amplitude of these pump waves, the amplitudes of the longitudinal and radial fields of the beat wave due to the nonlinear wave interactions have been calculated. Besides, the transfer of momentum flux that accompanies the transfer of wave action in beat-wave scattering will be used to drive the toroidal radial currents in tokamaks. self-generated magnetic fields due to those currents were also calculated. 1 fig.

  18. Reduced ischemia-reperfusion injury with isoproterenol in non-heart-beating donor lungs.

    Science.gov (United States)

    Jones, D R; Hoffmann, S C; Sellars, M; Egan, T M

    1997-05-01

    Transplantation of lungs retrieved from non-heart-beating donors could expand the donor pool. Recent studies suggest that the ischemia-reperfusion injury (IRI) to the lung can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, as measured by Kfc, in lungs retrieved from non-heart-beating donors and reperfused with or without isoproterenol (iso). Using an in situ isolated perfused lung model, lungs were retrieved from non-heart-beating donor rats ventilated with O2 or not at varying intervals after death. The lungs were reperfused with or without iso (10 microM). Kfc, lung viability, and pulmonary hemodynamics were measured, and tissue levels of adenine nucleotides and cAMP were measured by HPLC. Iso-reperfusion decreased Kfc significantly (P Kfc in non-iso-reperfused (r = 0.65) and iso-perfused (r = 0.84) lungs. cAMP levels increased significantly with iso-reperfusion. cAMP levels correlated with Kfc (r = 0.87) in iso-reperfused lungs. Iso-reperfusion of lungs retrieved from non-heart-beating donor rats results in decreased capillary permeability and increased lung tissue cAMP levels. Pharmacologic augmentation of tissue TAN and cAMP levels may further ameliorate the increased capillary permeability seen in lungs retrieved from non-heart-beating donors.

  19. Exercise thallium testing in ventricular preexcitation

    Energy Technology Data Exchange (ETDEWEB)

    Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

    1987-05-01

    Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation.

  20. Exercise thallium testing in ventricular preexcitation

    International Nuclear Information System (INIS)

    Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

    1987-01-01

    Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation