Sample records for prolonged ventricular pauses

  1. Prolonging the postcomplex spike pause speeds eyeblink conditioning.

    Maiz, Jaione; Karakossian, Movses H; Pakaprot, Narawut; Robleto, Karla; Thompson, Richard F; Otis, Thomas S


    Climbing fiber input to the cerebellum is believed to serve as a teaching signal during associative, cerebellum-dependent forms of motor learning. However, it is not understood how this neural pathway coordinates changes in cerebellar circuitry during learning. Here, we use pharmacological manipulations to prolong the postcomplex spike pause, a component of the climbing fiber signal in Purkinje neurons, and show that these manipulations enhance the rate of learning in classical eyelid conditioning. Our findings elucidate an unappreciated aspect of the climbing fiber teaching signal, and are consistent with a model in which convergent postcomplex spike pauses drive learning-related plasticity in the deep cerebellar nucleus. They also suggest a physiological mechanism that could modulate motor learning rates.

  2. Pause

    Travis, Michael Andrew


    Pause is a necessity within the rhythm of life. There are pauses everywhere around us; we pause when we breathe, we pause when we speak, and we pause when we think. Pause is a crucial part in the most beautiful pieces of music, it is in between our bites of food and sips of coffee. Pause is what makes life beautiful; without it the world around us will consist of a meaningless cacophony. Architecture, much like other things in life must also contain pauses to be enjoyable. The most memora...

  3. Pre-shock chest compression pause effects on termination of ventricular fibrillation/tachycardia and return of organized rhythm within mechanical and manual cardiopulmonary resuscitation

    Olsen, J.A.; Brunborg, C.; Steinberg, M.; Persse, D.; Sterz, F.; Lozano, M., Jr.; Westfall, M.; Travis, D.T.; Lerner, E.B.; Brouwer, M.A.; Wik, L.


    BACKGROUND: Shorter manual chest compression pauses prior to defibrillation attempts is reported to improve the defibrillation success rate. Mechanical load-distributing band (LDB-) CPR enables shocks without compression pause. We studied pre-shock pause and termination of ventricular

  4. Left Ventricular Function After Prolonged Exercise in Equine Endurance Athletes

    Flethøj, M.; Schwarzwald, C. C.; Haugaard, M. M.;


    Background: Prolonged exercise in human athletes is associated with transient impairment of left ventricular (LV) function, known as cardiac fatigue. Cardiac effects of prolonged exercise in horses remain unknown. Objectives :To investigate the effects of prolonged exercise on LV systolic...

  5. QT interval prolongation after Premature Ventricular Contractions (PVCs

    Mohammed Haroon Rashid


    Full Text Available Long QT syndrome (LQTS is an inherited ion channelopathy resulting in abnormal ventricular repolarization and abnormal prolongation of QT interval on the ECG. Syncope, fainting, cardiac arrest, and sudden death are common manifestations of LQTS. We present a case report that describes a patient with prolonged QT interval after extrasystoles and a family history of sudden cardiac deaths.

  6. Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest.

    Brouwer, Tom F; Walker, Robert G; Chapman, Fred W; Koster, Rudolph W


    Minimizing pauses in chest compressions during cardiopulmonary resuscitation is a focus of current guidelines. Prior analyses found that prolonged pauses for defibrillation (perishock pauses) are associated with worse survival. We analyzed resuscitations to characterize the association between pauses for all reasons and both ventricular fibrillation termination and patient survival. In 319 patients with ventricular tachycardia/fibrillation out-of-hospital cardiac arrest, we analyzed recordings from all defibrillators used during resuscitation and measured durations of all cardiopulmonary resuscitation pauses. Median durations were 32 seconds (25th and 75th percentile, 22 and 52 seconds) for the longest pause for any reason, 23 seconds (25th and 75th percentile, 14 and 34 seconds) for the longest perishock pause, and 24 seconds (25th and 75th percentile, 11 and 38 seconds) for the longest nonshock pause. Multivariable regression models showed lower odds for survival per 5-second increase in the longest overall pause (odds ratio, 0.89; 95% confidence interval, 0.83-0.95), longest perishock pause (odds ratio, 0.85; 95% confidence interval, 0.77-0.93), and longest nonshock pause (odds ratio, 0.83; 95% confidence interval, 0.75-0.91). In 36% of cases, the longest pause was a nonshock pause; this subgroup had lower survival than the group in whom the longest pause was a perishock pause (27% versus 44%, respectively; P<0.01) despite a higher chest compression fraction. Preshock pauses were 8 seconds (25th and 75th percentile, 4 and 17 seconds) for shocks that terminated ventricular fibrillation and 7 seconds (25th and 75th percentile, 4 and 13 seconds) for shocks that did not (P=0.18). Prolonged pauses have a negative association with survival not explained by chest compression fraction or decreased ventricular fibrillation termination rate. Ventricular fibrillation termination was not the mechanism linking pause duration and survival. Strategies shortening the longest

  7. Prolonged sustained ventricular fibrillation without loss of consciousness in patients supported by a left ventricular assist device.

    Fasseas, Panayotis; Kutalek, Steven P; Kantharia, Bharat K


    Patients with cardiomyopathy of either ischemic or nonischemic origin are at increased risk for malignant ventricular arrhythmias. Normally sustained ventricular fibrillation (VF) leads to death very rapidly. We report two patients who remained in sustained VF, supported by a left ventricular assist device, for a prolonged period of time. Perfusion pressure through the device was sufficient to allow the patients to remain awake and responsive for several hours while in VF. The cases represent two of the longest reported episodes of sustained VF recorded in awake patients implanted with such devices.

  8. Ventricular ectopy and QTc-interval prolongation associated with dronedarone therapy.

    Gonzalez, Jaime E; Sauer, William H; Krantz, Mori J


    Amiodarone is an effective treatment for atrial and ventricular arrhythmias, but its use is limited by a toxic adverse-effect profile. Although dronedarone has been touted as an antiarrhythmic agent devoid of both solid organ toxicity and proarrhythmic properties, its potential for prolonging ventricular repolarization may augment triggered ectopy. We describe a 66-year-old man who began dronedarone 400 mg twice/day for new-onset paroxysmal atrial fibrillation; he had no left ventricular dysfunction or clinical heart failure. Three months after starting the drug, he complained of malaise, fatigue, and rare palpitations. Twenty four-hour Holter monitoring revealed increased premature ventricular complexes, and the rate-corrected QT (QTc) interval was prolonged (range 525-760 msec). Dronedarone was discontinued and the patient's symptoms gradually resolved over the next 3 weeks. Holter monitoring revealed a marked reduction in ventricular ectopy burden, and the QTc interval decreased to his baseline values. Even in the absence of documented symptomatic torsade de pointes, this case suggests that caution should be exercised when prescribing dronedarone and that serial QTc interval monitoring may be appropriate. In addition, clinicians should have a low threshold to perform Holter monitoring if symptoms develop during dronedarone therapy.

  9. Recurrent takotsubo with prolonged QT and torsade de pointes and left ventricular thrombus.

    Ahmed, Alaa Eldin K; Serafi, Abdulhalim; Sunni, Nadia S; Younes, Hussein; Hassan, Walid


    Takotsubo cardiomyopathy, also known as "takotsubo syndrome," refers to transient apical ballooning syndrome, stress cardiomyopathy, or broken heart syndrome and is a recently recognized syndrome typically characterized by transient and reversible left ventricular dysfunction that develops in the setting of acute severe emotional or physical stress. Increased catecholamine levels have been proposed to play a central role in the pathogenesis of the disease, although the specific pathophysiology of this condition remains to be fully determined. At present, there have been very few reports of recurrent takotsubo cardiomyopathy. In this case report, we present a patient with multiple recurrences of takotsubo syndrome triggered by severe emotional stress that presented with recurrent loss of consciousness, QT prolongation, and polymorphic ventricular tachycardia (torsade de pointes) and left ventricular apical thrombus.

  10. Ryanodine prolongs Ca-currents while suppressing contraction in rat ventricular muscle cells.

    Mitchell, M. R.; Powell, T; Terrar, D. A.; Twist, V. W.


    Ryanodine (1 microM) suppressed or abolished contraction in response to step depolarization in voltage-clamped cells isolated from adult rat ventricular myocardium. The step depolarizations evoked the second inward current, which is carried largely by Ca ions under these conditions, and there was little or no change in the amplitude of this current when contraction was reduced or abolished by ryanodine. The effects of ryanodine on contraction were, however, accompanied by a prolongation of th...

  11. Ventricular Cycle Length Characteristics Estimative of Prolonged RR Interval during Atrial Fibrillation



    Background When atrial fibrillation (AF) is incessant, imaging during a prolonged ventricular RR interval may improve image quality. It was hypothesized that long RR intervals could be predicted from preceding RR values. Methods From the PhysioNet database, electrocardiogram RR intervals were obtained from 74 persistent AF patients. An RR interval lengthened by at least 250 ms beyond the immediately preceding RR interval (termed T0 and T1, respectively) was considered prolonged. A two-parameter scatterplot was used to predict the occurrence of a prolonged interval T0. The scatterplot parameters were: (1) RR variability (RRv) estimated as the average second derivative from 10 previous pairs of RR differences, T13–T2, and (2) Tm–T1, the difference between Tm, the mean from T13 to T2, and T1. For each patient, scatterplots were constructed using preliminary data from the first hour. The ranges of parameters 1 and 2 were adjusted to maximize the proportion of prolonged RR intervals within range. These constraints were used for prediction of prolonged RR in test data collected during the second hour. Results The mean prolonged event was 1.0 seconds in duration. Actual prolonged events were identified with a mean positive predictive value (PPV) of 80% in the test set. PPV was >80% in 36 of 74 patients. An average of 10.8 prolonged RR intervals per 60 minutes was correctly identified. Conclusions A method was developed to predict prolonged RR intervals using two parameters and prior statistical sampling for each patient. This or similar methodology may help improve cardiac imaging in many longstanding persistent AF patients. PMID:23998759

  12. Comparison of QT dispersion during atrial fibrillation and sinus rhythm in the same patients, at normal and prolonged ventricular repolarization

    Houltz, B; Darpo, B; Swedberg, K; Blomstrom, P; Crijns, HJGM; Jensen, SM; Svernhage, E; Edvardsson, N

    Aims Drug-induced increase in QT dispersion has been associated with increased risk of ventricular proarrhythmia. The aim of the present study was to compare QT dispersion during atrial fibrillation and sinus rhythm in the same patients at normal and prolonged ventricular repolarization. Methods and

  13. Outcome of Prolonged Ventricular Fibrillation and CPR in a Rat Model of Chronic Ischemic Left Ventricular Dysfunction

    Xiangshao Fang


    Full Text Available Patients with chronic left ventricular (LV dysfunction are assumed to have a lower chance of successful CPR and lower likelihood of ultimate survival. However, these assumptions have rarely been documented. Therefore, we investigated the outcome of prolonged ventricular fibrillation (VF and CPR in a rat model of chronic LV dysfunction. Sprague-Dawley rats were randomized to (1 chronic LV dysfunction: animals underwent left coronary artery ligation; and (2 sham control. Echocardiography was used to measure cardiac performance before surgery and 4 weeks after surgery. Four weeks after surgical intervention, 8 min of VF was induced and defibrillation was delivered after 8 min of CPR. LV dilation and low ejection fraction were observed 4 weeks after coronary ligation. With optimal chest compressions, coronary perfusion pressure values during CPR were well maintained and indistinguishable between groups. There were no differences in resuscitability and numbers of shock required for successful resuscitation between groups. Despite the significantly decreased cardiac index in LV dysfunction animals before induction of VF, no differences in cardiac index were observed between groups following resuscitation, which was associated with the insignificant difference in postresuscitation survival. In conclusion, the outcomes of CPR were not compromised by the preexisting chronic LV dysfunction.

  14. Nifekalant hydrochloride terminating sustained ventricular tachycardia accompanied with QT dispersion prolongation

    WANG Jing; HUA Wei; ZHU Jun; YANG Yan-min; WANG Fang-zheng; PU Jie-lin; CHEN Ke-ping; ZHANG Shu


    Background Ventricular tachycardia (VT) and ventricular fibrillation are the main reasons causing sudden cardiac death.This study aimed to investigate the effects of nifekalant hydrochloride (NIF) on QT dispersion (QTd) in treating VT.Methods A total of 16 consecutive patients suffered sustained VT was included and then randomly divided into two groups according to the administration duration of NIF.In long-time group (group L), patients were injected with NIF continuously for at least 12 hours after a bolus dose.The patients in short-time group (group S) were injected with NIF just for 1 hour.Results There were 7 of all 10 episodes of VT which were terminated by NIF, including 4 episodes in group L were stopped over 1 hour after continuous infusion of NIF.One patient suffered from torsade de pointes.Electrocardiography analysis indicated that QTd was significantly decreased 12 hours after stopping of infusing NIF compared with that when VT stopped ((45.4±22.1) ms vs.(73.4±33.2) ms, P <0.01), and the corrected QTd (QTcd) decreased too ((47.8±22.9) ms vs.(78.3±36.5) ms, P <0.01 ).There was a positive correlation between the increase in QTd and dose of administrating NIF (P <0.01), so was QTcd (P <0.01).Conclusions More administration of NIF indicates higher terminating rate of VT and more QTd prolongation.However,the safety is acceptable if several important issues were noticed in using NIF, such as serum potassium concentration,stopping side-effect related agents, and carefully observing clinical responses.

  15. Prolonged corrected QT interval is predictive of future stroke events even in subjects without ECG-diagnosed left ventricular hypertrophy.

    Ishikawa, Joji; Ishikawa, Shizukiyo; Kario, Kazuomi


    We attempted to evaluate whether subjects who exhibit prolonged corrected QT (QTc) interval (≥440 ms in men and ≥460 ms in women) on ECG, with and without ECG-diagnosed left ventricular hypertrophy (ECG-LVH; Cornell product, ≥244 mV×ms), are at increased risk of stroke. Among the 10 643 subjects, there were a total of 375 stroke events during the follow-up period (128.7±28.1 months; 114 142 person-years). The subjects with prolonged QTc interval (hazard ratio, 2.13; 95% confidence interval, 1.22-3.73) had an increased risk of stroke even after adjustment for ECG-LVH (hazard ratio, 1.71; 95% confidence interval, 1.22-2.40). When we stratified the subjects into those with neither a prolonged QTc interval nor ECG-LVH, those with a prolonged QTc interval but without ECG-LVH, and those with ECG-LVH, multivariate-adjusted Cox proportional hazards analysis demonstrated that the subjects with prolonged QTc intervals but not ECG-LVH (1.2% of all subjects; incidence, 10.7%; hazard ratio, 2.70, 95% confidence interval, 1.48-4.94) and those with ECG-LVH (incidence, 7.9%; hazard ratio, 1.83; 95% confidence interval, 1.31-2.57) had an increased risk of stroke events, compared with those with neither a prolonged QTc interval nor ECG-LVH. In conclusion, prolonged QTc interval was associated with stroke risk even among patients without ECG-LVH in the general population.

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

    Balaji, Seshadri


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

  17. Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes.

    Wang, Honglan; Bonilla, Ingrid M; Huang, Xin; He, Quanhua; Kohr, Mark J; Carnes, Cynthia A; Ziolo, Mark T


    Ventricular myocytes deficient in endothelial nitric oxide synthase (NOS3(-/-)) exhibit prolonged action potential (AP) duration and enhanced spontaneous activity (early and delayed afterdepolarizations) during β-adrenergic (β-AR) stimulation. Studies have shown that nitric oxide is able to regulate various K(+) channels. Our objective was to examine if NOS3(-/-) myocytes had altered K(+) currents. APs, transient outward (I(to)), sustained (I(Ksus)), and inward rectifier (I(K1)) K(+) currents were measured in NOS3(-/-) and wild-type (WT) myocytes. During β-AR stimulation, AP duration (measured as 90% repolarization-APD(90)) was prolonged in NOS3(-/-) compared to WT myocytes. Nevertheless, we did not observe differences in I(to), I(Ksus), or I(K1) between WT and NOS3(-/-) myocytes. Our previous work showed that NOS3(-/-) myocytes had a greater Ca(2+) influx via L-type Ca(2+) channels with β-AR stimulation. Thus, we measured β-AR-stimulated SR Ca(2+) load and found a greater increase in NOS3(-/-) versus WT myocytes. Hence, our data suggest that the prolonged AP in NOS3(-/-) myocytes is not due to changes in I(to), I(Ksus), or I(K1). Furthermore, the increase in spontaneous activity in NOS3(-/-) myocytes may be due to a greater increase in SR Ca(2+) load. This may have important implications for heart failure patients, where arrhythmias are increased and NOS3 expression is decreased.

  18. International Conference on Harmonisation; guidance on S7B Nonclinical Evaluation of the Potential for Delayed Ventricular Repolarization (QT Interval Prolongation) by Human Pharmaceuticals; availability. Notice.


    The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "S7B Nonclinical Evaluation of the Potential for Delayed Ventricular Repolarization (QT Interval Prolongation) by Human Pharmaceuticals." The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance describes a nonclinical testing strategy for assessing the potential of a test substance to delay ventricular repolarization and includes information concerning nonclinical assays and an integrated risk assessment. The guidance is intended to facilitate the nonclinical assessment of the effects of pharmaceuticals on ventricular repolarization and proarrhythmic risk.

  19. Resuscitation from Prolonged Ventricular Fibrillation by Epinephrine Combined with Sodium-Hydrogen Exchanger Isoform-1 Inhibitor Cariporide

    易忠; Rual J GAZMURI; Iyad M AYOUB; Julieta D KOLAROVA


    Objective To test theresuscitative effects from prolonged ventricular fibrillation by epinephrine combined with sodium-hydrogen exchanger isoform-1 inhibitor Cariporide. Methods 16 rats were received a 3 mg/kg bolus of Cariporide or the same volume of 0.9 % NaCl solution (control) 15seconds before completion 12 minutes untreated VF.Chest compression (CC) was started for a total of 8minutes. Adjusted the depth of compressor so that the aortic diastolic pressure to 25~ 28 mmHg during the 2nd minute of CC. Fix the depth of the piston and this depth was used throughout the remaining 6 minutes of CC. 10 seconds before starting the 3rd minute of chest compression, injected epinephrine (30 μg/kg) .Recorded the time at which restoration of spontaneous circulation (ROSC) occurred in Cariporide-treated rats. Electrical defibrillation was timed in control group to match the time of spontaneous defibrillation in Cariporide-treated rats. To the rats, which can't be defibrillated spontaneously, received chest compression and rescues electrical shocks. Results compared with control group, with the same CC depth, Cariporide-treated rats received the higher and longer lasting coronary perfusion pressure (P < 0.05), higher resuscitative rate ( P < 0.05), less post resuscitative ventricular ectopic activities (P < 0. 001), better hemodynamic effects and longer survival time (P <0.05) Conclusion Epinephrine combined with sodium-hydrogen exchanger isoform-1 inhibitor Cariporide may represent a novel and remarkably effective intervention for resuscitation from prolonged VF.

  20. Prolonged Action Potential and After depolarizations Are Not due to Changes in Potassium Currents in NOS3 Knockout Ventricular Myocytes

    Honglan Wang


    Full Text Available Ventricular myocytes deficient in endothelial nitric oxide synthase (NOS3−/− exhibit prolonged action potential (AP duration and enhanced spontaneous activity (early and delayed afterdepolarizations during β-adrenergic (β-AR stimulation. Studies have shown that nitric oxide is able to regulate various K+ channels. Our objective was to examine if NOS3-/- myocytes had altered K+ currents. APs, transient outward (to, sustained (Ksus, and inward rectifier (K1 K+ currents were measured in NOS3-/- and wild-type (WT myocytes. During β-AR stimulation, AP duration (measured as 90% repolarization-APD90 was prolonged in NOS3−/− compared to WT myocytes. Nevertheless, we did not observe differences in to, Ksus, or K1 between WT and NOS3−/− myocytes. Our previous work showed that NOS3−/− myocytes had a greater Ca2+ influx via L-type Ca2+ channels with β-AR stimulation. Thus, we measured β-AR-stimulated SR Ca2+ load and found a greater increase in NOS3−/− versus WT myocytes. Hence, our data suggest that the prolonged AP in NOS3−/− myocytes is not due to changes in to, Ksus, or K1. Furthermore, the increase in spontaneous activity in NOS3−/− myocytes may be due to a greater increase in SR Ca2+ load. This may have important implications for heart failure patients, where arrhythmias are increased and NOS3 expression is decreased.

  1. ARRITMIAS VENTRICULARES Y NUEVO SÍNDROME CORONARIO AGUDO EN PACIENTES CON INFARTO Y DISPERSIÓN DEL INTERVALO QT PROLONGADO / Ventricular arrhythmias and new acute coronary syndrome in patients with infarction and prolonged QT dispersion

    Luis M. Reyes Hernández


    and Objectives: Myocardial ischemia increases QT dispersion in the electrocardiogram because, in these circumstances, the action potential duration decreases in the ischemic insult area by creating a dispersion of repolarization. The rapid succession of local metabolic and ionic alterations creates favorable situations in the genesis of ventricular arrhythmias during ischemia. The objective was to determine the association of the prolonged QTc dispersion, in the acute coronary syndrome, with ventricular arrhythmias and the recurrence of acute coronary disease. Method: A total of 194 patients with acute myocardial infarction were studied. The QT interval duration was measured in a 12-lead electrocardiogram and it was corrected for heart rate in each of these leads. The dispersion of the interval was also assessed. It was taken into account the electrocardiographic evolution of these patients in relation to the occurrence of ventricular arrhythmias and a new acute coronary syndrome in a 30-day follow-up. Results: Among the patients who had a prolonged QT dispersion, there was a prevalence of the deceased due to ventricular fibrillation (7 cases for 7.5%, and only 2 patients (2.2% who suffered from this arrhythmia were discharged alive. A new acute coronary syndrome was found in 17 patients with prolonged QT dispersion, versus 8 patients with normal QT dispersion. Conclusions: Ventricular extrasystoles was the most common arrhythmia in patients with normal QT dispersion, and ventricular fibrillation was the most common in patients with prolonged QT dispersion. Most patients who had a new acute coronary syndrome had a prolonged QTc.

  2. Common Variation in the NOS1AP Gene Is Associated With Drug-Induced QT Prolongation and Ventricular Arrhythmia

    Jamshidi, Yalda; Nolte, Ilja M.; Dalageorgou, Chrysoula; Zheng, Dongling; Johnson, Toby; Bastiaenen, Rachel; Ruddy, Suzanne; Talbott, Daniel; Norris, Kris J.; Snieder, Harold; George, Alfred L.; Marshall, Vanessa; Shakir, Saad; Kannankeril, Prince J.; Munroe, Patricia B.; Camm, A. John; Jeffery, Steve; Roden, Dan M.; Behr, Elijah R.


    Objectives This study sought to determine whether variations in NOS1AP affect drug-induced long QT syndrome (LQTS). Background Use of antiarrhythmic drugs is limited by the high incidence of serious adverse events including QT prolongation and torsades de pointes. NOS1AP gene variants play a role in

  3. Inverted Takotsubo-Like Left Ventricular Dysfunction with Pulmonary Oedema Developed after Caesarean Delivery Complicated by Massive Haemorrhage in a Severe Preeclamptic Parturient with a Prolonged Painful Labour

    Hyejin Jeong


    Full Text Available Inverted takotsubo cardiomyopathy (TTC, a variant of stress-induced cardiomyopathy, features transient myocardial dysfunction characterized by a hyperdynamic left ventricular apex and akinesia of the base. Herein, we describe a 38-year-old primigravida with severe preeclampsia who had active labour for 4 h followed by an emergency caesarean delivery. She developed postpartum haemorrhage due to uterine atony complicated by pulmonary oedema, which was managed with large-volume infusion and hysterectomy. Her haemodynamic instability was associated with cardiac biomarkers indicative of diffuse myocardial injury and echocardiographic findings of an “inverted” TTC. The patient was almost fully recovered one month later. Our case shows that a reversible inverted TTC may result from a prolonged painful labour. TTC should be listed in the differential diagnosis of the patient presenting with pulmonary oedema of unknown origin, especially in patients with severe preeclampsia.

  4. Thermodynamic and Kinetic Modeling of Transcriptional Pausing

    Vasisht R. Tadigotla; Dáibhid Ó. Maoiléidigh; Anirvan M. Sengupta; Vitaly Epshtein; Richard H. Ebright; Evgeny Nudler; Andrei E. Ruckenstein


    We present a statistical mechanics approach for the prediction of backtracked pauses in bacterial transcription elongation derived from structural models of the transcription elongation complex (EC...

  5. Back Channelling, Repair, Pausing, and Private Speech.

    White, Ron


    Focuses on differences in back channelling, repair, repetition, pausing, and private speech among Japanese and American study participants, based on sales negotiations. Findings indicate that differences in the deployment of such features as back channelling and pausing can result in pragma-linguistic breakdown, which is linked to culturally…

  6. Interruption and Pausing of Public Display Games

    Feuchtner, Tiare; Walter, Robert; Müller, Jörg

    We present a quantitative and qualitative analysis of interruptions of interaction with a public display game, and explore the use of a manual pause mode in this scenario. In previous public display installations we observed users frequently interrupting their interaction. To explore ways...... of supporting such behavior, we implemented a gesture controlled multiuser game with four pausing techniques. We evaluated them in a field study analyzing 704 users and found that our pausing techniques were eagerly explored, but rarely used with the intention to pause the game. Our study shows...... that interactions with public displays are considerably intermissive, and that users mostly interrupt interaction to socialize and mainly approach public displays in groups. We conclude that, as a typical characteristic of public display interaction, interruptions deserve consideration. However, manual pause modes...

  7. A universal transcription pause sequence is an element of initiation factor σ70-dependent pausing

    Bird, Jeremy G.; Strobel, Eric J.; Roberts, Jeffrey W.


    The Escherichia coli σ70 initiation factor is required for a post-initiation, promoter-proximal pause essential for regulation of lambdoid phage late gene expression; potentially, σ70 acts at other sites during transcription elongation as well. The pause is induced by σ70 binding to a repeat of the promoter −10 sequence. After σ70 binding, further RNA synthesis occurs as DNA is drawn (or ‘scrunched’) into the enzyme complex, presumably exactly as occurs during initial synthesis from the promoter; this synthesis then pauses at a defined site several nucleotides downstream from the active center position when σ70 first engages the −10 sequence repeat. We show that the actual pause site in the stabilized, scrunched complex is the ‘elemental pause sequence’ recognized from its frequent occurrence in the E. coli genome. σ70 binding and the elemental pause sequence together, but neither alone, produce a substantial transcription pause. PMID:27098041

  8. Transcriptional interference by RNA polymerase pausing and dislodgement of transcription factors.

    Palmer, Adam C; Egan, J Barry; Shearwin, Keith E


    Transcriptional interference is the in cis suppression of one transcriptional process by another. Mathematical modeling shows that promoter occlusion by elongating RNA polymerases cannot produce strong interference. Interference may instead be generated by (1) dislodgement of slow-to-assemble pre-initiation complexes and transcription factors and (2) prolonged occlusion by paused RNA polymerases.

  9. Interword and intraword pause threshold in writing

    Chenu, Florence; Pellegrino, François; Jisa, Harriet; Fayol, Michel


    Writing words in real life involves setting objectives, imagining a recipient, translating ideas into linguistic forms, managing grapho-motor gestures, etc. Understanding writing requires observation of the processes as they occur in real time. Analysis of pauses is one of the preferred methods for accessing the dynamics of writing and is based on the idea that pauses are behavioral correlates of cognitive processes. However, there is a need to clarify what we are observing when studying pause phenomena, as we will argue in the first section. This taken into account, the study of pause phenomena can be considered following two approaches. A first approach, driven by temporality, would define a threshold and observe where pauses, e.g., scriptural inactivity occurs. A second approach, linguistically driven, would define structural units and look for scriptural inactivity at the boundaries of these units or within these units. Taking a temporally driven approach, we present two methods which aim at the automatic identification of scriptural inactivity which is most likely not attributable to grapho-motor management in texts written by children and adolescents using digitizing tablets in association with Eye and Pen© (Chesnet and Alamargot, 2005). The first method is purely statistical and is based on the idea that the distribution of pauses exhibits different Gaussian components each of them corresponding to a different type of pause. After having reviewed the limits of this statistical method, we present a second method based on writing dynamics which attempts to identify breaking points in the writing dynamics rather than relying only on pause duration. This second method needs to be refined to overcome the fact that calculation is impossible when there is insufficient data which is often the case when working with young scriptors. PMID:24723896

  10. Thermodynamic and kinetic modeling of transcriptional pausing.

    Tadigotla, Vasisht R; O Maoiléidigh, Dáibhid; Sengupta, Anirvan M; Epshtein, Vitaly; Ebright, Richard H; Nudler, Evgeny; Ruckenstein, Andrei E


    We present a statistical mechanics approach for the prediction of backtracked pauses in bacterial transcription elongation derived from structural models of the transcription elongation complex (EC). Our algorithm is based on the thermodynamic stability of the EC along the DNA template calculated from the sequence-dependent free energy of DNA-DNA, DNA-RNA, and RNA-RNA base pairing associated with (i) the translocational and size fluctuations of the transcription bubble; (ii) changes in the associated DNA-RNA hybrid; and (iii) changes in the cotranscriptional RNA secondary structure upstream of the RNA exit channel. The calculations involve no adjustable parameters except for a cutoff used to discriminate paused from nonpaused complexes. When applied to 100 experimental pauses in transcription elongation by Escherichia coli RNA polymerase on 10 DNA templates, the approach produces statistically significant results. We also present a kinetic model for the rate of recovery of backtracked paused complexes. A crucial ingredient of our model is the incorporation of kinetic barriers to backtracking resulting from steric clashes of EC with the cotranscriptionally generated RNA secondary structure, an aspect not included explicitly in previous attempts at modeling the transcription elongation process.

  11. Interruption and Pausing of Public Display Games

    Feuchtner, Tiare; Walter, Robert; Müller, Jörg


    We present a quantitative and qualitative analysis of interruptions of interaction with a public display game, and explore the use of a manual pause mode in this scenario. In previous public display installations we observed users frequently interrupting their interaction. To explore ways of supp...

  12. Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction.

    Nelson, O Lynne; Rourke, Bryan C


    Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min(-1) to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was ~9.5 times longer, and the diastolic phase was 28× longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance of contraction and relaxation for regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal than during the active period, particularly systolic strain, which was 33% of active, compared with the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin

  13. Thermodynamic and kinetic modeling of transcriptional pausing

    Tadigotla, Vasisht R.; Maoiléidigh, Dáibhid Ó; Sengupta, Anirvan M.; Epshtein, Vitaly; Ebright, Richard H.; Nudler, Evgeny; Ruckenstein, Andrei E.


    We present a statistical mechanics approach for the prediction of backtracked pauses in bacterial transcription elongation derived from structural models of the transcription elongation complex (EC). Our algorithm is based on the thermodynamic stability of the EC along the DNA template calculated from the sequence-dependent free energy of DNA–DNA, DNA–RNA, and RNA–RNA base pairing associated with (i) the translocational and size fluctuations of the transcription bubble; (ii) changes in the as...

  14. Effects of transcriptional pausing on gene expression dynamics.

    Tiina Rajala


    Full Text Available Stochasticity in gene expression affects many cellular processes and is a source of phenotypic diversity between genetically identical individuals. Events in elongation, particularly RNA polymerase pausing, are a source of this noise. Since the rate and duration of pausing are sequence-dependent, this regulatory mechanism of transcriptional dynamics is evolvable. The dependency of pause propensity on regulatory molecules makes pausing a response mechanism to external stress. Using a delayed stochastic model of bacterial transcription at the single nucleotide level that includes the promoter open complex formation, pausing, arrest, misincorporation and editing, pyrophosphorolysis, and premature termination, we investigate how RNA polymerase pausing affects a gene's transcriptional dynamics and gene networks. We show that pauses' duration and rate of occurrence affect the bursting in RNA production, transcriptional and translational noise, and the transient to reach mean RNA and protein levels. In a genetic repressilator, increasing the pausing rate and the duration of pausing events increases the period length but does not affect the robustness of the periodicity. We conclude that RNA polymerase pausing might be an important evolvable feature of genetic networks.

  15. Phonetic Pause Unites Phonology and Semantics against Morphology and Syntax

    Sakarna, Ahmad Khalaf; Mobaideen, Adnan


    The present study investigates the phonological effect triggered by the different types of phonetic pause used in Quran on morphology, syntax, and semantics. It argues that Quranic pause provides interesting evidence about the close relation between phonology and semantics, from one side, and semantics, morphology, and syntax, from the other…

  16. Phonetic Pause Unites Phonology and Semantics against Morphology and Syntax

    Sakarna, Ahmad Khalaf; Mobaideen, Adnan


    The present study investigates the phonological effect triggered by the different types of phonetic pause used in Quran on morphology, syntax, and semantics. It argues that Quranic pause provides interesting evidence about the close relation between phonology and semantics, from one side, and semantics, morphology, and syntax, from the other…

  17. Using Habit Reversal to Decrease Filled Pauses in Public Speaking

    Mancuso, Carolyn; Miltenberger, Raymond G.


    This study evaluated the effectiveness of simplified habit reversal in reducing filled pauses that occur during public speaking. Filled pauses consist of "uh," "um," or "er"; clicking sounds; and misuse of the word "like." After baseline, participants received habit reversal training that consisted of…

  18. PBMA Pause and Learn Video Nuggets Transcript

    Rogers, Ed


    This document is a transcript for a video about a practice practiced at Goddard Space Flight Center called Pause and Learn (PaL). The PaL process is intended to, first of all, help the team learn. So, the team that was involved in the activity, the group that actually did the work, that handled the review, or ran the tests, or developed the piece of equipment, they sit down and actually say, "What did we learn from this exercise?" The idea is to create a learning environment at various key milestones in the execution of a process, rather than wait until the end of the given process, be it a launch or a mission.

  19. Leptin decreases heart rate associated with increased ventricular repolarization via its receptor.

    Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H; Hull, Robert; Davis, Mary; Yu, Han-Gang


    Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1-30 μg/kg) decreased resting heart rate; at high doses (150-300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03-0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias.

  20. Pause for thought: response perseveration and personality in gambling.

    Corr, Philip J; Thompson, Stephen J


    In a sample of normal volunteers, response perseveration (RP) on a computerised gambling task, the card perseveration task, was examined under two conditions: No pause (Standard task) and a 5-s pause (Pause task) following feedback from previous bet. Behavioural outcomes comprised number of cards played (and cash won/lost) and latency of response. Individual differences in these outcomes were conceptualised in terms of the reinforcement sensitivity theory of personality. Results showed that, on the Standard task only, sub-scales of the Carver and White (J Pers Social Psychol 67:319-333, 1994) Behavioural Approach System scale positively correlated with number of cards played and amount of money lost (indicative of impaired RP), but these associations were abolished with the imposition of a 5-s pause between feedback and the opportunity to make the next bet-this pause also had an overall main effect of improving RP and reducing losses. As related research shows that such a pause normalises the RP deficit seen in pathological gamblers, these findings hold potentially valuable implications for informing practice in the prevention and treatment of pathological gambling, and point to the role played by individual differences in approach motivation.

  1. QT Prolongation due to Graves’ Disease

    Zain Kulairi


    Full Text Available Hyperthyroidism is a highly prevalent disease affecting over 4 million people in the US. The disease is associated with many cardiac complications including atrial fibrillation and also less commonly with ventricular tachycardia and fibrillation. Many cardiac pathologies have been extensively studied; however, the relationship between hyperthyroidism and rate of ventricular repolarization manifesting as a prolonged QTc interval is not well known. Prolonged QTc interval regardless of thyroid status is a risk factor for cardiovascular mortality and life-threatening ventricular arrhythmia. The mechanism regarding the prolongation of the QT interval in a hyperthyroid patient has not been extensively investigated although its clinical implications are relevant. Herein, we describe a case of prolonged QTc in a patient who presented with signs of hyperthyroidism that was corrected with return to euthyroid status.

  2. QT Prolongation due to Graves' Disease

    Deol, Nisha; Tolly, Renee; Manocha, Rohan; Naseer, Maliha


    Hyperthyroidism is a highly prevalent disease affecting over 4 million people in the US. The disease is associated with many cardiac complications including atrial fibrillation and also less commonly with ventricular tachycardia and fibrillation. Many cardiac pathologies have been extensively studied; however, the relationship between hyperthyroidism and rate of ventricular repolarization manifesting as a prolonged QTc interval is not well known. Prolonged QTc interval regardless of thyroid status is a risk factor for cardiovascular mortality and life-threatening ventricular arrhythmia. The mechanism regarding the prolongation of the QT interval in a hyperthyroid patient has not been extensively investigated although its clinical implications are relevant. Herein, we describe a case of prolonged QTc in a patient who presented with signs of hyperthyroidism that was corrected with return to euthyroid status. PMID:28154763

  3. Global distribution of pauses observed with satellite measurements

    M Venkat Ratnam; P Kishore; Isabella Velicogna


    Several studies have been carried out on the tropopause, stratopause, and mesopause (collectively termed as ‘pauses’) independently; however, all the pauses have not been studied together. We present global distribution of altitudes and temperatures of these pauses observed with long-term space borne high resolution measurements of Global Positioning System (GPS) Radio Occultation (RO) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) aboard Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. Here we study the commonality and differences observed in the variability of all the pauses. We also examined how good other datasets will represent these features among (and in between) different satellite measurements, re-analysis, and model data. Hemispheric differences observed in all the pauses are also reported. In addition, we show that asymmetries between northern and southern hemispheres continue up to the mesopause. We analyze inter and intra-seasonal variations and long-term trends of these pauses at different latitudes. Finally, a new reference temperature profile is shown from the ground to 110 km for tropical, mid-latitudes, and polar latitudes for both northern and southern hemispheres.

  4. Detection of bursts and pauses in spike trains.

    Ko, D; Wilson, C J; Lobb, C J; Paladini, C A


    Midbrain dopaminergic neurons in vivo exhibit a wide range of firing patterns. They normally fire constantly at a low rate, and speed up, firing a phasic burst when reward exceeds prediction, or pause when an expected reward does not occur. Therefore, the detection of bursts and pauses from spike train data is a critical problem when studying the role of phasic dopamine (DA) in reward related learning, and other DA dependent behaviors. However, few statistical methods have been developed that can identify bursts and pauses simultaneously. We propose a new statistical method, the Robust Gaussian Surprise (RGS) method, which performs an exhaustive search of bursts and pauses in spike trains simultaneously. We found that the RGS method is adaptable to various patterns of spike trains recorded in vivo, and is not influenced by baseline firing rate, making it applicable to all in vivo spike trains where baseline firing rates vary over time. We compare the performance of the RGS method to other methods of detecting bursts, such as the Poisson Surprise (PS), Rank Surprise (RS), and Template methods. Analysis of data using the RGS method reveals potential mechanisms underlying how bursts and pauses are controlled in DA neurons.

  5. Profiles and Pauses: Two Practical Activities for the Writing Class

    Ernest Hall


    Full Text Available Abstract : This article describes two classroom activities, "Profiling" and "Pause Analysis", that can be successfully used in ESL writing classes. "Profiling" addresses such problems as poor development of ideas, simplistic ideas, and lack of coherence in written texts. "Pause Analysis" focusses on the thinking processes that students engage in while drafting text, processes such as searching for ideas, evaluat­ing ideas, and postponing ideas. Both activities enable the instructor to assume the role of intervener in the students' writing processes, rather than evaluator of the text produced. In drawing The attention of the student write to both product and process, "Profiling" and "Pause Analysis" help them develop an awareness of the relation-ship between ideas in English expository text and the thinking pro­cesses that writers engage in while drafting such text.

  6. Ventricular assist device

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  7. Prolonged chewing at lunch decreases later snack intake.

    Higgs, Suzanne; Jones, Alison


    Prolonged chewing of food can reduce meal intake. However, whether prolonged chewing influences intake at a subsequent eating occasion is unknown. We hypothesised that chewing each mouthful for 30s would reduce afternoon snack intake more than (a) an habitual chewing control condition, and (b) an habitual chewing condition with a pauses in between each mouthful to equate the meal durations. We further hypothesised that this effect may be related to effects of prolonged chewing on lunch memory. Forty three participants ate a fixed lunch of sandwiches in the laboratory. They were randomly allocated to one of the three experimental groups according to a between-subjects design. Appetite, mood and lunch enjoyment ratings were taken before and after lunch and before snacking. Snack intake of candies at a taste test 2h after lunch was measured as well as rated vividness of lunch memory. Participants in the prolonged chewing group ate significantly fewer candies than participants in the habitual chewing group. Snack intake by the pauses group did not differ from either the prolonged or habitual chewing groups. Participants in the prolonged chewing group were less happy and enjoyed their lunch significantly less than participants in other conditions. Appetite ratings were not different across groups. Rated vividness of lunch memory was negatively correlated with intake but there was no correlation with rated lunch enjoyment. Prolonged chewing of a meal can reduce later snack intake and further investigation of this technique for appetite control is warranted.

  8. eRNAs lure NELF from paused polymerases.

    Plosky, Brian S


    RNAs transcribed from enhancers (eRNAs) have been linked to enhancer function. In this issue of Molecular Cell, Schaukowitch et al. (2014) show that upon activation, eRNAs can bind NELF and are necessary for its transient removal from promoters to release paused RNA polymerase II and drive expression of immediate-early genes in neurons.

  9. Code-Switching and Pausing: An Interdisciplinary Study

    Gardner-Chloros, Penelope; McEntee-Atalianis, Lisa; Paraskeva, Marilena


    This study considers code-switching (CS) and pausing in two sociolinguistically distinct groups in London and Cyprus, bilingual in Greek-Cypriot Dialect (GCD) and English. The characteristics of their speech are examined both in monolingual and bilingual modes (Grosjean, 2001). It was hypothesised that in London Greek-Cypriots, where CS is a…

  10. Transient pauses of the bacterial flagellar motor at low load

    Nord, A. L.; Pedaci, F.; Berry, R. M.


    The bacterial flagellar motor (BFM) is the molecular machine responsible for the swimming and chemotaxis of many species of motile bacteria. The BFM is bidirectional, and changes in the rotation direction of the motor are essential for chemotaxis. It has previously been observed that many species of bacteria also demonstrate brief pauses in rotation, though the underlying cause of such events remains poorly understood. We examine the rotation of Escherichia coli under low mechanical load with high spatial and temporal resolution. We observe and characterize transient pauses in rotation in a strain which lacks a functional chemosensory network, showing that such events are a phenomenon separate from a change in rotational direction. Rotating at low load, the BFM of E. coli exhibits about 10 pauses s-1, lasting on average 5 ms, during which time the rotor diffuses with net forwards rotation. Replacing the wild type stators with Na+ chimera stators has no substantial effect on the pausing. We discuss possible causes of such events, which are likely a product of a transient change in either the stator complex or the rotor.

  11. Pause, Prompt, and Praise: The Need for More Research.

    Goyen, Judith D.; McClelland, David J.


    Finds that the effectiveness of the "Pause, Prompt, and Praise" procedure varied according to the method of analysis used: subjective interpretation of gain scores indicated that the procedure was the most effective treatment for both tutees and tutors; the ANOVA indicated that the tutoring experience was effective; whereas the more rigorous…

  12. Pause, Prompt, and Praise: The Need for More Research.

    Goyen, Judith D.; McClelland, David J.


    Finds that the effectiveness of the "Pause, Prompt, and Praise" procedure varied according to the method of analysis used: subjective interpretation of gain scores indicated that the procedure was the most effective treatment for both tutees and tutors; the ANOVA indicated that the tutoring experience was effective; whereas the more rigorous…

  13. Pauses in theatrical interpretation: delimitation of prosodic constituents

    Lourenço Chacon


    Full Text Available We intend to observe the function of a linguistic resource – the pause – in theatrical interpretation. Connected to the field of speech therapy, we search for theoretical support in the Linguistics field, mainly in prosodic phonology – specifically, we highlight intonational phrase and phonological utterance, prosodic constituents –, proposing a dialogue between these fields, regarding the work with actors. In speech therapy literature, the work with actors focuses, centrally, in organic issues involved in the vocal process, such as “misuse” or “voice abuse”. To a smaller extent, we find, in this literature, researches that emphasize issues regarding interpretation and expressive resources, besides a few emphasizing the importance of linguistic resources in interpretation. Differently, in linguistics literature, the pause is approached, to a larger extent, from the phonetic perspective, related to several language levels. In this research, we analyzed audio recordings of four actors from a same theatrical group, acting the theatrical text Brutas flores, focused on these aims: (1 detect the place where pauses happen in the interpretation of a single text by four actors; (2 survey physical characteristics of length of these pauses; (3 check to what extent the length of a pause is related to the place where it happens, regarding the prosodic limits of intonational phrases (I and phonological utterance (U. We could observe that, although the interpretation is characterized by the subjectivity of the actor, the interpretation is constructed based in the possibilities offered by the prosodic organization of the text itself, being more or less flexible.We were also able to confirm, by considering the length of VVs units containing pauses, the prosodic hierarchy proposed by Nespor & Vogel, once the length of these units in U's limits was significantly higher than the length in I's limits. Thus, our results reinforce the premise that a

  14. Responsible gambling tools: pop-up messages and pauses on video lottery terminals.

    Cloutier, Martin; Ladouceur, Robert; Sévigny, Serge


    The authors examined the effect of messages and pauses, presented on video lottery terminal screens, on erroneous beliefs and persistence to play. At posttest, the strength of erroneous beliefs was lower for participants who received messages conveying information about randomness in gambling as compared to those who received pauses. Pauses also diminished the strength of erroneous beliefs, and there was no difference between the effects of pauses and messages on the number of games played. The authors discuss these results in terms of the use of messages and pauses on video lottery terminals as a strategy for promoting responsible gambling.

  15. A positioned +1 nucleosome enhances promoter-proximal pausing.

    Jimeno-González, Silvia; Ceballos-Chávez, María; Reyes, José C


    Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in transcription is not fully understood. Here we show in vivo that the +1 nucleosome plays a role in modulating RNA polymerase II (RNAPII) promoter-proximal pausing. When a +1 nucleosome is strongly positioned, elongating RNAPII has a tendency to stall at the promoter-proximal region, recruits more negative elongation factor (NELF) and produces less mRNA. The nucleosome-induced pause favors pre-mRNA quality control by promoting the addition of the cap to the nascent RNA. Moreover, the uncapped RNAs produced in the absence of a positioned nucleosome are degraded by the 5'-3' exonuclease XRN2. Interestingly, reducing the levels of the chromatin remodeler ISWI factor SNF2H decreases +1 nucleosome positioning and increases RNAPII pause release. This work demonstrates a function for +1 nucleosome in regulation of transcription elongation, pre-mRNA processing and gene expression.

  16. Run-and-pause dynamics of cytoskeletal motor proteins

    Hafner, Anne E.; Santen, Ludger; Rieger, Heiko; Shaebani, M. Reza


    Cytoskeletal motor proteins are involved in major intracellular transport processes which are vital for maintaining appropriate cellular function. When attached to cytoskeletal filaments, the motor exhibits distinct states of motility: active motion along the filaments, and pause phase in which it remains stationary for a finite time interval. The transition probabilities between motion and pause phases are asymmetric in general, and considerably affected by changes in environmental conditions which influences the efficiency of cargo delivery to specific targets. By considering the motion of individual non-interacting molecular motors on a single filament as well as a dynamic filamentous network, we present an analytical model for the dynamics of self-propelled particles which undergo frequent pause phases. The interplay between motor processivity, structural properties of filamentous network, and transition probabilities between the two states of motility drastically changes the dynamics: multiple transitions between different types of anomalous diffusive dynamics occur and the crossover time to the asymptotic diffusive or ballistic motion varies by several orders of magnitude. We map out the phase diagrams in the space of transition probabilities, and address the role of initial conditions of motion on the resulting dynamics.

  17. Analysis of Pause Occurrence in Three Kinds of Modified Speech: Public Address, Caretaker Talk, and Foreigner Talk.

    Osada, Nobuko


    Analyzes the occurrence of silent pauses n monologues, especially in modified speech, such as in public address, caretaker talk, and foreigner talk. Discusses speech rate, articulation rate, pause unit length, individual pause length, and pause percentage to overall speech time. (Author/VWL)

  18. Management of ventricular fibrillation or unstable ventricular tachycardia in patients with congenital long-QT syndrome: a suggested modification to ACLS guidelines.

    Homme, Jason H; White, Roger D; Ackerman, Michael J


    Prolongation of the QT interval is a known risk factor for syncope, seizures and sudden cardiac death. Most patients with QT prolongation have an acquired cause, but congenital forms of QT prolongation are being increasingly recognized. However, existing advanced cardiac life support (ACLS) treatment algorithms for prolonged QT mediated ventricular fibrillation pertains to acquired long-QT syndrome (LQTS). Here, a young patient with out-of-hospital cardiac arrest secondary to congenital LQTS illustrates critical exceptions to the current ACLS treatment algorithms for ventricular fibrillation and unstable ventricular tachycardia when QT prolongation is congenital in origin. A clarified ACLS algorithm is proposed.

  19. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses.

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik


    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.

  20. The Effect of Compressor-Administered Defibrillation on Peri-shock Pauses in a Simulated Cardiac Arrest Scenario

    Joshua Glick


    Full Text Available Introduction: Coordination of the tasks of performing chest compressions and defibrillation can lead to communication challenges that may prolong time spent off the chest. The purpose of this study was to determine whether defibrillation provided by the provider performing chest compressions led to a decrease in peri-shock pauses as compared to defibrillation administered by a second provider, in a simulated cardiac arrest scenario. Methods: This was a randomized, controlled study measuring pauses in chest compressions for defibrillation in a simulated cardiac arrest model. We approached hospital providers with current CPR certification for participation between July, 2011 and October, 2011. Volunteers were randomized to control (facilitator-administered defibrillation or experimental (compressor-administered defibrillation groups. All participants completed one minute of chest compressions on a mannequin in a shockable rhythm prior to administration of defibrillation. We measured and compared pauses for defibrillation in both groups. Results: Out of 200 total participants, we analyzed data from 197 defibrillations. Compressor-initiated defibrillation resulted in a significantly lower pre-shock hands-off time (0.57 s; 95% CI: 0.47-0.67 compared to facilitator-initiated defibrillation (1.49 s; 95% CI: 1.35-1.64. Furthermore, compressor-initiated defibrillation resulted in a significantly lower peri-shock hands-off time (2.77 s; 95% CI: 2.58-2.95 compared to facilitator-initiated defibrillation (4.25 s; 95% CI: 4.08-4.43. Conclusion: Assigning the responsibility for shock delivery to the provider performing compressions encourages continuous compressions throughout the charging period and decreases total time spent off the chest. However, as this was a simulation-based study, clinical implementation is necessary to further evaluate these potential benefits. [West J Emerg Med. 2014;15(2:246–250.

  1. Barack Obama’s pauses and gestures in humorous speeches

    Navarretta, Costanza


    and they emphasise the speech segment which they follow or precede. We also found a highly significant correlation between Obama’s speech pauses and audience response. Obama produces numerous head movements, facial expressions and hand gestures and their functions are related to both discourse content and structure....... Characteristics for these speeches is that Obama points to individuals in the audience and often smiles and laughs. Audience response is equally frequent in the two events, and there are no significant changes in speech rate and frequency of head movements and facial expressions in the two speeches while Obama...

  2. Kinetic modeling of molecular motors: pause model and parameter determination from single-molecule experiments

    Morin, José A.; Ibarra, Borja; Cao, Francisco J.


    Single-molecule manipulation experiments of molecular motors provide essential information about the rate and conformational changes of the steps of the reaction located along the manipulation coordinate. This information is not always sufficient to define a particular kinetic cycle. Recent single-molecule experiments with optical tweezers showed that the DNA unwinding activity of a Phi29 DNA polymerase mutant presents a complex pause behavior, which includes short and long pauses. Here we show that different kinetic models, considering different connections between the active and the pause states, can explain the experimental pause behavior. Both the two independent pause model and the two connected pause model are able to describe the pause behavior of a mutated Phi29 DNA polymerase observed in an optical tweezers single-molecule experiment. For the two independent pause model all parameters are fixed by the observed data, while for the more general two connected pause model there is a range of values of the parameters compatible with the observed data (which can be expressed in terms of two of the rates and their force dependencies). This general model includes models with indirect entry and exit to the long-pause state, and also models with cycling in both directions. Additionally, assuming that detailed balance is verified, which forbids cycling, this reduces the ranges of the values of the parameters (which can then be expressed in terms of one rate and its force dependency). The resulting model interpolates between the independent pause model and the indirect entry and exit to the long-pause state model

  3. Comparison of pausing behavior in children who stutter and children who have Asperger syndrome.

    Beltrame, Jessica Monique; Viera, Renata Alves Torello; Tamanaha, Ana Carina; Arcuri, Cláudia Fassin; Osborn, Ellen; Perissinoto, Jacy; Schiefer, Ana Maria


    The objective of this research was to compare the number and types of grammatical and non-grammatical silent pauses presented by stutterers and subjects with Asperger syndrome in their narratives. Ten children who stutter and four participants with Asperger syndrome (mean ages of both groups 10 years) were assessed at the Speech and Language Disorders Department of the Universidade Federal de São Paulo/Brasil. They narrated a story based on a pre-selected sequence of pictures. They were filmed and their productions were analyzed using version 5.0.47 of Praat ( Silent intervals in the speech that ranged from 0.25 to 4s were considered pauses. The pauses were classified as grammatical and non-grammatical, depending on the words that preceded and followed them. Both groups presented grammatical and non-grammatical pauses and the former predominated. The children with Asperger syndrome produced a greater number of pauses than the stutterers. The reader will be able to: (1) characterize the use of pauses in the oral narrative; (2) distinguish a grammatical pause from a non-grammatical pause regarding the use and function; (3) recognize the pattern of pause found in the two populations. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Promoter-proximal pausing of RNA polymerase II: emerging roles in metazoans

    Adelman, Karen; Lis, John T.


    Recent years have witnessed a sea change in our understanding of transcription regulation: whereas traditional models focused solely on the events that brought RNA polymerase II (Pol II) to a gene promoter to initiate RNA synthesis, emerging evidence points to the pausing of Pol II during early elongation as a widespread regulatory mechanism in higher eukaryotes. Current data indicate that pausing is particularly enriched at genes in signal-responsive pathways. Here the evidence for pausing of Pol II from recent high-throughput studies will be discussed, as well as the potential interconnected functions of promoter-proximally paused Pol II. PMID:22986266

  5. Model of the pathway of −1 frameshifting: Long pausing

    Ping Xie


    Full Text Available It has been characterized that the programmed ribosomal −1 frameshifting often occurs at the slippery sequence on the presence of a downstream mRNA pseudoknot. In some prokaryotic cases such as the dnaX gene of Escherichia coli, an additional stimulatory signal—an upstream, internal Shine–Dalgarno (SD sequence—is also necessary to stimulate the efficient −1 frameshifting. However, the molecular and physical mechanism of the −1 frameshifting is poorly understood. Here, we propose a model of the pathway of the −1 translational frameshifting during ribosome translation of the dnaX −1 frameshift mRNA. With the model, the single-molecule fluorescence data (Chen et al. (2014 [29] on the dynamics of the shunt either to long pausing or to normal translation, the tRNA transit and sampling dynamics in the long-paused rotated state, the EF-G sampling dynamics, the mean rotated-state lifetimes, etc., are explained quantitatively. Moreover, the model is also consistent with the experimental data (Yan et al. (2015 [30] on translocation excursions and broad branching of frameshifting pathways. In addition, we present some predicted results, which can be easily tested by future optical trapping experiments.

  6. Ventricular fibrillation via torsade des pointes of cardiac sarcoidosis with preserved left ventricular ejection fraction.

    Sekihara, Takayuki; Nakane, Eisaku; Nakasone, Kazutaka; Inoko, Moriaki


    Generally, low left ventricular ejection fraction (LVEF) is a risk for ventricular arrhythmia in patients with cardiac sarcoidosis. We present a case of cardiac sarcoidosis with preserved LVEF that evoked ventricular fibrillation (VF). A 73-year-old woman with VF presented to our emergency department. She had a history of ocular sarcoidosis, with gradual thinning of the basal intraventricular septum. LVEF was 62% on the most recent echocardiography. The electrocardiogram after defibrillation showed complete atrioventricular block (CAVB) with QT segment prolongation and frequent ventricular premature beats. VF via torsade des pointes (TdP) was suspected, and temporary intravenous ventricular pacing and magnesium sulfate infusion suppressed her VF. Cardiac sarcoidosis was diagnosed, and an implantable cardioverter defibrillator was implanted. Patients with cardiac sarcoidosis with CAVB are at risk of evoking VF via TdP regardless of LVEF. If cardiac sarcoidosis is suspected, early diagnosis and risk stratification of ventricular arrhythmia are important. 2016 BMJ Publishing Group Ltd.

  7. Safety information on QT-interval prolongation

    Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H;


    Prolongation of the QT interval can predispose to fatal ventricular arrhythmias. Differences in QT-labeling language can result in miscommunication and suboptimal risk mitigation. We systematically compared the phraseology used to communicate on QT-prolonging properties of 144 drugs newly approve......) was moderate (kappa 0.434). However, the agreement in expected clinical decisions based on the product labels was much higher (kappa 0.673). The US drug label tends to be more explicit, especially when it considers absence of QT effects....

  8. Reducing Vocalized Pauses in Public Speaking Situations Using the VP Card

    Ramos Salazar, Leslie


    This article describes a speaking problem very common in today's world--"vocalized pauses" (VP). Vocalized pauses are defined as utterances such as "uh," "like," and "um" that occur between words in oral sentences. This practice of everyday speech can affect how a speaker's intentions are…

  9. Progress in Written Language Bursts, Pauses, Transcription, and Written Composition across Schooling

    Alves, Rui A.; Limpo, Teresa


    Research on adult writers has shown that writing proceeds through bursts of transcription activity interspersed by long pauses. Yet few studies have examined how these writing behaviors unfold during early and middle childhood. This study traces the progress of bursts, pauses, transcription, and written composition in Portuguese students from…

  10. What 50 Years of Research Tell Us about Pausing under Ratio Schedules of Reinforcement

    Schlinger, H. D.; Derenne, A.; Baron, A.


    Textbooks in learning and behavior commonly describe performance on fixed-ratio schedules as "break and run," indicating that after reinforcement subjects typically pause and then respond quickly to the next reinforcement. Performance on variable-ratio schedules, on the other hand, is described as steady and fast, with few long pauses. Beginning…

  11. Absence of Non-histone Protein Complexes at Natural Chromosomal Pause Sites Results in Reduced Replication Pausing in Aging Yeast Cells

    Marleny Cabral


    Full Text Available There is substantial evidence that genomic instability increases during aging. Replication pausing (and stalling at difficult-to-replicate chromosomal sites may induce genomic instability. Interestingly, in aging yeast cells, we observed reduced replication pausing at various natural replication pause sites (RPSs in ribosomal DNA (rDNA and non-rDNA locations (e.g., silent replication origins and tRNA genes. The reduced pausing occurs independent of the DNA helicase Rrm3p, which facilitates replication past these non-histone protein-complex-bound RPSs, and is independent of the deacetylase Sir2p. Conditions of caloric restriction (CR, which extend life span, also cause reduced replication pausing at the 5S rDNA and at tRNA genes. In aged and CR cells, the RPSs are less occupied by their specific non-histone protein complexes (e.g., the preinitiation complex TFIIIC, likely because members of these complexes have primarily cytosolic localization. These conditions may lead to reduced replication pausing and may lower replication stress at these sites during aging.

  12. Contextual Interaction Design: The Case of Pause Buddy

    Keyson, David V.; Doff-Ottens, Hannah J.

    This paper describes a range of design techniques which have been elaborated upon by Industrial Designers to create novel interactive products in which context and social interaction play a central role in the user experience. The techniques described here can be broadly grouped under Context Mapping and Research through Design. The methods are presented as part of a design process, from "fuzzy front end" to a working field prototype. To illustrate how the methods can be applied, the design of a prototype product that was developed to reduce office stress by stimulating short breaks and social interaction pauses is described. The results of a field study are reported following by a reflection on the value of applied design methods.

  13. Transcriptional pausing at the translation start site operates as a critical checkpoint for riboswitch regulation

    Chauvier, Adrien; Picard-Jean, Frédéric; Berger-Dancause, Jean-Christophe; Bastet, Laurène; Naghdi, Mohammad Reza; Dubé, Audrey; Turcotte, Pierre; Perreault, Jonathan; Lafontaine, Daniel A.


    On the basis of nascent transcript sequencing, it has been postulated but never demonstrated that transcriptional pausing at translation start sites is important for gene regulation. Here we show that the Escherichia coli thiamin pyrophosphate (TPP) thiC riboswitch contains a regulatory pause site in the translation initiation region that acts as a checkpoint for thiC expression. By biochemically probing nascent transcription complexes halted at defined positions, we find a narrow transcriptional window for metabolite binding, in which the downstream boundary is delimited by the checkpoint. We show that transcription complexes at the regulatory pause site favour the formation of a riboswitch intramolecular lock that strongly prevents TPP binding. In contrast, cotranscriptional metabolite binding increases RNA polymerase pausing and induces Rho-dependent transcription termination at the checkpoint. Early transcriptional pausing may provide a general mechanism, whereby transient transcriptional windows directly coordinate the sensing of environmental cues and bacterial mRNA regulation. PMID:28071751

  14. Predicting pauses in L1 and L2 speech: the effects of utterance boundaries and word frequency

    de Jong, N.H.


    This paper compares the distribution of silent and filled pauses in first (L1) and second language (L2) speech. The occurrence of pauses of 52 L2 and 18 L1 Dutch speakers was evaluated with respect to utterance boundaries and word frequency. We found that L2 speakers paused more often than L1

  15. Predicting pauses in L1 and L2 speech: the effects of utterance boundaries and word frequency

    de Jong, N.H.


    This paper compares the distribution of silent and filled pauses in first (L1) and second language (L2) speech. The occurrence of pauses of 52 L2 and 18 L1 Dutch speakers was evaluated with respect to utterance boundaries and word frequency. We found that L2 speakers paused more often than L1 speake

  16. Experimental pain leads to reorganisation of trapezius electromyography during computer work with active and passive pauses

    Samani, Afshin; Holtermann, Andreas; Søgaard, Karen


    in one day, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 40 s without and with presence of experimental pain. Surface EMG signals were recorded from four parts of the trapezius. The centroid of exposure variation analysis along the time axis......The aim of this laboratory study was to investigate acute effects of experimental muscle pain on spatial electromyographic (EMG) activity of the trapezius muscle during computer work with active and passive pauses. Twelve healthy male subjects performed four sessions of computer work for 2 min...... was lower during computer work with active pauses when compared with passive one in all muscle parts (P

  17. Effects of eccentric exercise on trapezius electromyography during computer work with active and passive pauses

    Samani, Afshin; Holtermann, Andreas; Søgaard, Karen


    BACKGROUND: The aim of this laboratory study was to investigate the effects of eccentric exercises on the trapezius muscle spatial electromyographic (EMG) activity during computer work with active and passive pauses. METHODS: Twelve healthy male subjects performed computer work with passive (relax......) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 40s over 2 days, before, immediately and 24h after eccentric exercise. Surface EMG signals were recorded from four parts of the trapezius during computer work. FINDINGS: EMG amplitude during computer work decreased...... immediately after exercise (Pactive pauses compared with passive ones (P

  18. Active pauses induce more variable electromyographic pattern of the trapezius muscle activity during computer work

    Samani, Afshin; Holtermann, Andreas; Søgaard, Karen


    , with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 2 min at two different work paces (low/high). Bipolar SEMG from four parts of the trapezius muscle was recorded. The relative rest time was higher for the lower parts compared with the upper......The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day...... of the trapezius (pactive pause compared with passive one (p

  19. Premature Ventricular Contractions (PVCs)

    Diseases and Conditions Premature ventricular contractions (PVCs) By Mayo Clinic Staff Premature ventricular contractions (PVCs) are extra, abnormal heartbeats that begin in one of your heart's two ...

  20. Pol II Docking and Pausing at Growth and Stress Genes in C. elegans

    Colin S. Maxwell; William S. Kruesi; Leighton J. Core; Nicole Kurhanewicz; Colin T. Waters; Caitlin L. Lewarch; Igor Antoshechkin; John T. Lis; Barbara J. Meyer; L. Ryan Baugh


    Fluctuations in nutrient availability profoundly impact gene expression. Previous work revealed postrecruitment regulation of RNA polymerase II (Pol II) during starvation and recovery in Caenorhabditis elegans, suggesting that promoter-proximal pausing promotes rapid response to feeding. To test this hypothesis, we measured Pol II elongation genome wide by two complementary approaches and analyzed elongation in conjunction with Pol II binding and expression. We confirmed bona fide pausing dur...

  1. Pausing Behavior of End -Users in Online Searching - A Case Study of National Taiwan University

    Mu-hsuan Huang


    Full Text Available This article analyzes the pausing behavior of end-users. The subjects are real end-users from National Taiwan University. This article uses the Dialog command language as its searching tool. It attempts to investigate the characteristics of pausing behavior. In addition, it tries to compare the behavior difference between the Chinese and American end-users. [Article content in Chinese

  2. An investigation into the correlation of cue phrases, unfilled pauses and the structuring of spoken discourse

    Cahn, J E


    Expectations about the correlation of cue phrases, the duration of unfilled pauses and the structuring of spoken discourse are framed in light of Grosz and Sidner's theory of discourse and are tested for a directions-giving dialogue. The results suggest that cue phrase and discourse structuring tasks may align, and show a correlation for pause length and some of the modifications that speakers can make to discourse structure.

  3. Detecting sequence dependent transcriptional pauses from RNA and protein number time series

    Emmert-Streib Frank


    Full Text Available Abstract Background Evidence suggests that in prokaryotes sequence-dependent transcriptional pauses affect the dynamics of transcription and translation, as well as of small genetic circuits. So far, a few pause-prone sequences have been identified from in vitro measurements of transcription elongation kinetics. Results Using a stochastic model of gene expression at the nucleotide and codon levels with realistic parameter values, we investigate three different but related questions and present statistical methods for their analysis. First, we show that information from in vivo RNA and protein temporal numbers is sufficient to discriminate between models with and without a pause site in their coding sequence. Second, we demonstrate that it is possible to separate a large variety of models from each other with pauses of various durations and locations in the template by means of a hierarchical clustering and a random forest classifier. Third, we introduce an approximate likelihood function that allows to estimate the location of a pause site. Conclusions This method can aid in detecting unknown pause-prone sequences from temporal measurements of RNA and protein numbers at a genome-wide scale and thus elucidate possible roles that these sequences play in the dynamics of genetic networks and phenotype.

  4. Detecting sequence dependent transcriptional pauses from RNA and protein number time series.

    Emmert-Streib, Frank; Häkkinen, Antti; Ribeiro, Andre S


    Evidence suggests that in prokaryotes sequence-dependent transcriptional pauses affect the dynamics of transcription and translation, as well as of small genetic circuits. So far, a few pause-prone sequences have been identified from in vitro measurements of transcription elongation kinetics. Using a stochastic model of gene expression at the nucleotide and codon levels with realistic parameter values, we investigate three different but related questions and present statistical methods for their analysis. First, we show that information from in vivo RNA and protein temporal numbers is sufficient to discriminate between models with and without a pause site in their coding sequence. Second, we demonstrate that it is possible to separate a large variety of models from each other with pauses of various durations and locations in the template by means of a hierarchical clustering and a random forest classifier. Third, we introduce an approximate likelihood function that allows to estimate the location of a pause site. This method can aid in detecting unknown pause-prone sequences from temporal measurements of RNA and protein numbers at a genome-wide scale and thus elucidate possible roles that these sequences play in the dynamics of genetic networks and phenotype.

  5. Replication pauses of the wild-type and mutant mitochondrial DNA polymerase gamma: a simulation study.

    Zhuo Song


    Full Text Available The activity of polymerase γ is complicated, involving both correct and incorrect DNA polymerization events, exonuclease activity, and the disassociation of the polymerase:DNA complex. Pausing of pol-γ might increase the chance of deletion and depletion of mitochondrial DNA. We have developed a stochastic simulation of pol-γ that models its activities on the level of individual nucleotides for the replication of mtDNA. This method gives us insights into the pausing of two pol-γ variants: the A467T substitution that causes PEO and Alpers syndrome, and the exonuclease deficient pol-γ (exo(- in premature aging mouse models. To measure the pausing, we analyzed simulation results for the longest time for the polymerase to move forward one nucleotide along the DNA strand. Our model of the exo(- polymerase had extremely long pauses, with a 30 to 300-fold increase in the time required for the longest single forward step compared to the wild-type, while the naturally occurring A467T variant showed at most a doubling in the length of the pauses compared to the wild-type. We identified the cause of these differences in the polymerase pausing time to be the number of disassociations occurring in each forward step of the polymerase.

  6. Replication pauses of the wild-type and mutant mitochondrial DNA polymerase gamma: a simulation study.

    Song, Zhuo; Cao, Yang; Samuels, David C


    The activity of polymerase γ is complicated, involving both correct and incorrect DNA polymerization events, exonuclease activity, and the disassociation of the polymerase:DNA complex. Pausing of pol-γ might increase the chance of deletion and depletion of mitochondrial DNA. We have developed a stochastic simulation of pol-γ that models its activities on the level of individual nucleotides for the replication of mtDNA. This method gives us insights into the pausing of two pol-γ variants: the A467T substitution that causes PEO and Alpers syndrome, and the exonuclease deficient pol-γ (exo(-)) in premature aging mouse models. To measure the pausing, we analyzed simulation results for the longest time for the polymerase to move forward one nucleotide along the DNA strand. Our model of the exo(-) polymerase had extremely long pauses, with a 30 to 300-fold increase in the time required for the longest single forward step compared to the wild-type, while the naturally occurring A467T variant showed at most a doubling in the length of the pauses compared to the wild-type. We identified the cause of these differences in the polymerase pausing time to be the number of disassociations occurring in each forward step of the polymerase.

  7. The carotid baroreflex is reset following prolonged exercise in humans

    Hart, E. C.; Rasmussen, P.; Secher, N. H.


    Alterations in the carotid baroreflex (CBR) control of arterial pressure may explain the reduction in arterial pressure and left ventricular (LV) function after prolonged exercise. We examined the CBR control of heart rate (HR) and mean arterial pressure (MAP), in addition to changes in LV function......, pre- to post-exercise....

  8. [Dopplerometry at prolonged pregnancy].

    Salii-Prenichi, L; Milchev, N; Markova, D; Apiosjan, Zh


    Prolonged pregnancy, associated with low amniotic fluid is a reason for the increase of fetal mortality and morbidity. There is no a define test at prolonged pregnancy which can determine which pregnancy are at a risk for adverse outcome and complications. Dopplerometry as a noninvasive method for examination of blood circulation, and especially a. cerebri media and a. umbilicalis can be used for the prediction of the outcome of prolonged pregnancy.

  9. [Competitive pacing in a patient with DDD pacemaker and bigeminal ventricular extrasystoles].

    Carbone, Vincenzo; Candelmo, Fiore; Todaro, Chiara; Oreto, Giuseppe


    The ECG recorded from a patient with DDD pacemaker showed variable responses of the pacing system to bigeminal ventricular extrasystoles, dependent on the coupling interval of premature beats. For relatively short coupling intervals, the premature spontaneous event was detected by the pacemaker, inhibiting both atrial and ventricular output, and resulting in a relatively long pacing pause. In slightly less premature end-diastolic extrasystoles, in contrast, the pacing system delivered an atrial spike that was superimposed upon the spontaneous premature QRS complex (pseudo-pseudofusion); under these circumstances, the atrial spike was followed, at the end of the programmed atrioventricular interval, by a ventricular spike falling on the extrasystolic T wave apex (competitive ventricular pacing). This phenomenon, however, did not express a sensing malfunction, but was due to post-atrial ventricular blanking (PAVB), a short period initiated by the atrial spike during which ventricular sensing is temporarily disabled, so that no signal can be detected. Finally, whenever premature end-diastolic impulses occurred after PAVB, during the brief interval defined ventricular safety pacing, the spontaneous event was sensed, being followed by an earlier-than-expected ventricular spike, whose prematurity was aimed at avoiding the occurrence of an artificial impulse upon the T wave of extrasystole. In conclusion, despite several not sensed ventricular extrasystoles and competitive pacing, no sensing malfunction was present. This case demonstrates how complex can be the electrocardiographic analysis of a DDD pacemaker, owing to the many complicating phenomena related to this pacing mechanism.

  10. A case of delayed cardiac perforation of active ventricular lead

    Hangyuan Guo


    Full Text Available A 65-year-old man was admitted as for one month of repetitive dizziness and one episode of syncope. Electrocardiogram showed sinus bradycardia and his Holter monitoring also showed sinus bradycardia with sinus arrest, sino-atrial block and a longest pause of 4.3 s. Then sick sinus syndrome and Adam-Stokes syndrome were diagnosed. Then a dual chamber pacemaker (Medtronic SDR303 was implanted and the parameters were normal by detection. The patient was discharged 1 week later with suture removed. Then 1.5 month late the patient was presented to hospital once again for sudden onset of chest pain with exacerbation after taking deep breath. Pacemaker programming showed both pacing and sensing abnormality with threshold of?5.0V and resistance of 1200?. Lead perforation was revealed by chest X-ray and confirmed by echocardiogram. Considering the fact that there was high risk to remove ventricular lead, spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to the septum. Previous ventricular lead was maintained. As we know that the complications of lead perforation in the clinic was rare. Here we discuss the clinical management and the possible reasons for cardiac perforation of active ventricular lead.

  11. Left Ventricular Function After Prolonged Exercise in Equine Endurance Athletes

    Flethøj, M.; Schwarzwald, C. C.; Haugaard, M. M.


    Doppler imaging, and two-dimensional speckle tracking. Correlation between echocardiographic variables and cardiac troponin I was evaluated. Results: Early diastolic myocardial velocities decreased significantly in longitudinal (baseline: −17.4 ± 2.4cm/s; end of ride: −15.8 ± 3.2cm/s (P = .013); morning...

  12. How long is too long? How pause features after requests affect the perceived willingness of affirmative answers

    Kohtz, Lea Susan; Niebuhr, Oliver


    A perception experiment involving 28 German listeners is presented. It investigates – for sequences of request, pause, and affirmative answer – the effect of pause duration on the answerer's perceived willingness to comply with the request. Replicating earlier results on American English, perceiv......) on perceived willingness judgments. The overall results picture is discussed with respect to the origin of the "tolerance threshold", the status of breathing in speech, and the function of pauses in communication....

  13. Ventricular torsional relation to ventricular fiber arrangement

    Ranjbar, Saeed; Meybodi, Mahmood Emami


    Left ventricular torsion from helically oriented myofibers is a key parameter of cardiac performance. Physicians observing heart motion on echocardiograms, during cardiac catheterization, or in the operating room, are impressed by the twisting or rotary motion of the left ventricle during systole. Conceptually, the heart has been treated as a pressure chamber. The rotary or torsional deformation has been poorly understood by basic scientists and has lacked clinical relevance. The aim of this paper attempts to discuss about this question: Is ventricular twisting related to ventricular fiber arrangement? That is dependent to an assumed model of the left ventricular structure.

  14. Transcriptional pausing coordinates folding of the aptamer domain and the expression platform of a riboswitch.

    Perdrizet, George A; Artsimovitch, Irina; Furman, Ran; Sosnick, Tobin R; Pan, Tao


    Riboswitches are cis-acting elements that regulate gene expression by affecting transcriptional termination or translational initiation in response to binding of a metabolite. A typical riboswitch is made of an upstream aptamer domain and a downstream expression platform. Both domains participate in the folding and structural rearrangement in the absence or presence of its cognate metabolite. RNA polymerase pausing is a fundamental property of transcription that can influence RNA folding. Here we show that pausing plays an important role in the folding and conformational rearrangement of the Escherichia coli btuB riboswitch during transcription by the E. coli RNA polymerase. This riboswitch consists of an approximately 200 nucleotide, coenzyme B12 binding aptamer domain and an approximately 40 nucleotide expression platform that controls the ribosome access for translational initiation. We found that transcriptional pauses at strategic locations facilitate folding and structural rearrangement of the full-length riboswitch, but have minimal effect on the folding of the isolated aptamer domain. Pausing at these regulatory sites blocks the formation of alternate structures and plays a chaperoning role that couples folding of the aptamer domain and the expression platform. Pausing at strategic locations may be a general mechanism for coordinated folding and conformational rearrangements of riboswitch structures that underlie their response to environmental cues.


    MIKA J.


    Full Text Available The paused warming since ca. 2002 (maybe, 1998 is not satisfactorily reflected by the IPCC WGI (2013 Report. The aim of the present study is to collect, present and discuss the key arguments of the issue, selected strictly from this valuable Report. Our study tackles three aspects: (i Symptoms of pausing, including atmospheric changes, near-surface oceans, cryosphere and geographical differences. (ii Possible reasons of the paused warming, including external forcing factors, playing rather minor role, and the enhanced ocean heat uptake. Though missing warming is 0.2 K/decade compared to the model expectations, the whole climate system integrates continuously increasing amount of heat, 95 % of which is locked in the oceans. (iii Consequences of the pausing for the three main branches of the IPCC activity. For climate science, correct simulation of the enhanced heat uptake is a challenge. Since characteristic time scale of most adaptation measures is 1-2 decades, or shorter, near-term projections may not drive adaptation until climate models become able meet this challenge. On the other hand, pausing warming does not question the need for mitigation, since it is physically unlikely, that oceans can uptake endless amount of heat. Vertical temperature gradients of the upper ocean layers already show stagnation.

  16. The history of research on the filled pause as evidence of the written language bias in linguistics (Linell, 1982).

    O'Connell, Daniel C; Kowal, Sabine


    Erard's (2004) publication in the New York Times of a journalistic history of the filled pause serves as the occasion for this critical review of the past half-century of research on the filled pause. Historically, the various phonetic realizations or instantiations of the filled pause have been presented with an odd recurrent admixture of the interjection ah. In addition, the filled pause has been consistently associated with both hesitation and disfluency. The present authors hold that such a mandatory association of the filled pause with disfluency is the product of The written language bias in linguistics [Linell, 1982] and disregards much cogent evidence to the contrary. The implicit prescriptivism of well formedness--a demand derived from literacy--must be rejected; literate well formedness is not a necessary or even typical property of spontaneous spoken discourse; its structures and functions--including those of the filled pause--are very different from those of written language The recent work of Clark and Fox Tree (2002) holds promise for moving the status of the filled pause not only toward that of a conventional word, but also toward its status as an interjection. This latter development is also being fostered by lexicographers. Nonetheless, in view of ongoing research regarding the disparate privileges of occurrence and functions of filled pauses in comparison with interjections, the present authors are reluctant to categorize the filled pause as an interjection.

  17. Ventricular septal defect (image)

    Ventricular septal defect is a congenital defect of the heart, that occurs as an abnormal opening in ... wall that separates the right and left ventricles. Ventricular septal defect may also be associated with other ...

  18. Pausing of RNA polymerase II regulates mammalian developmental potential through control of signaling networks.

    Williams, Lucy H; Fromm, George; Gokey, Nolan G; Henriques, Telmo; Muse, Ginger W; Burkholder, Adam; Fargo, David C; Hu, Guang; Adelman, Karen


    The remarkable capacity for pluripotency and self-renewal in embryonic stem cells (ESCs) requires a finely tuned transcriptional circuitry wherein the pathways and genes that initiate differentiation are suppressed, but poised to respond rapidly to developmental signals. To elucidate transcriptional control in mouse ESCs in the naive, ground state, we defined the distribution of engaged RNA polymerase II (Pol II) at high resolution. We find that promoter-proximal pausing of Pol II is most enriched at genes regulating cell cycle and signal transduction and not, as expected, at developmental or bivalent genes. Accordingly, ablation of the primary pause-inducing factor NELF does not increase expression of lineage markers, but instead causes proliferation defects, embryonic lethality, and dysregulation of ESC signaling pathways. Indeed, ESCs lacking NELF have dramatically attenuated FGF/ERK activity, rendering them resistant to differentiation. This work thus uncovers a key role for NELF-mediated pausing in establishing the responsiveness of stem cells to developmental cues.

  19. Pol II Docking and Pausing at Growth and Stress Genes in C. elegans

    Colin S. Maxwell


    Full Text Available Fluctuations in nutrient availability profoundly impact gene expression. Previous work revealed postrecruitment regulation of RNA polymerase II (Pol II during starvation and recovery in Caenorhabditis elegans, suggesting that promoter-proximal pausing promotes rapid response to feeding. To test this hypothesis, we measured Pol II elongation genome wide by two complementary approaches and analyzed elongation in conjunction with Pol II binding and expression. We confirmed bona fide pausing during starvation and also discovered Pol II docking. Pausing occurs at active stress-response genes that become downregulated in response to feeding. In contrast, “docked” Pol II accumulates without initiating upstream of inactive growth genes that become rapidly upregulated upon feeding. Beyond differences in function and expression, these two sets of genes have different core promoter motifs, suggesting alternative transcriptional machinery. Our work suggests that growth and stress genes are both regulated postrecruitment during starvation but at initiation and elongation, respectively, coordinating gene expression with nutrient availability.

  20. Cold Water and Pauses in Illumination Reduces Pain During Photodynamic Therapy: A Randomized Clinical Study

    Wiegell, S.R.; Haedersdal, M.; Wulf, H.C.


    symmetrical areas and cooled with either cold-water-spray or cold-water-pack (Coo]Pack). Treatment areas were cooled during either the first or second period of illumination, which were separated by a 3-min pause in illumination. Pain intensity was scored from 0 to 10. Water-spray reduced the mean pain score...... by 1.2 points (p=0.030) and CoolPack by 1.3 points (p=0.007) during the first half of the illumination. Pain intensity decreased during the pause by 3.7 points in water-spray patients (p

  1. An Investigation of the Effects of Different Types of Activities during Pauses in a Segmented Instructional Animation

    Cheon, Jongpil; Chung, Sungwon; Crooks, Steven M.; Song, Jaeki; Kim, Jeakyeong


    Since the complex and transient information in instructional animations requires more cognitive resources, the segmenting principle has been proposed to reduce cognitive overload by providing smaller chunks with pauses between segments. This study examined the effects of different types of activities during pauses in a segmented animation. Four…

  2. An Investigation of the Effects of Different Types of Activities during Pauses in a Segmented Instructional Animation

    Cheon, Jongpil; Chung, Sungwon; Crooks, Steven M.; Song, Jaeki; Kim, Jeakyeong


    Since the complex and transient information in instructional animations requires more cognitive resources, the segmenting principle has been proposed to reduce cognitive overload by providing smaller chunks with pauses between segments. This study examined the effects of different types of activities during pauses in a segmented animation. Four…

  3. Adverse ventricular-ventricular interactions in right ventricular pressure load: Insights from pediatric pulmonary hypertension versus pulmonary stenosis.

    Driessen, Mieke M P; Hui, Wei; Bijnens, Bart H; Dragulescu, Andreea; Mertens, Luc; Meijboom, Folkert J; Friedberg, Mark K


    Right ventricular (RV) pressure overload has a vastly different clinical course in children with idiopathic pulmonary arterial hypertension (iPAH) than in children with pulmonary stenosis (PS). While RV function is well recognized as a key prognostic factor in iPAH, adverse ventricular-ventricular interactions and LV dysfunction are less well characterized and the pathophysiology is incompletely understood. We compared ventricular-ventricular interactions as hypothesized drivers of biventricular dysfunction in pediatric iPAH versus PS Eighteen iPAH, 16 PS patients and 18 age- and size-matched controls were retrospectively studied. Cardiac cycle events were measured by M-mode and Doppler echocardiography. Measurements were compared between groups using ANOVA with post hoc Dunnet's or ANCOVA including RV systolic pressure (RVSP; iPAH 96.8 ± 25.4 mmHg vs. PS 75.4 ± 18.9 mmHg; P = 0.011) as a covariate. RV-free wall thickening was prolonged in iPAH versus PS, extending beyond pulmonary valve closure (638 ± 76 msec vs. 562 ± 76 msec vs. 473 ± 59 msec controls). LV and RV isovolumetric relaxation were prolonged in iPAH (P < 0.001; LV 102.8 ± 24.1 msec vs. 63.1 ± 13.7 msec; RV 95 [61-165] vs. 28 [0-43]), associated with adverse septal kinetics; characterized by rightward displacement in early systole and leftward displacement in late RV systole (i.e., early LV diastole). Early LV diastolic filling was decreased in iPAH (73 ± 15.9 vs. PS 87.4 ± 14.4 vs. controls 95.8 ± 12.5 cm/sec; P = 0.004). Prolonged RVFW thickening, prolonged RVFW isovolumetric times, and profound septal dyskinesia are associated with interventricular mechanical discoordination and decreased early LV filling in pediatric iPAH much more than PS These adverse mechanics affect systolic and diastolic biventricular efficiency in iPAH and may form the basis for worse clinical outcomes. We used clinically derived data to study the pathophysiology of ventricular-ventricular

  4. The pause on avian H5N1 influenza virus transmission research should be ended

    R.A.M. Fouchier (Ron); A. García-Sastre (Adolfo); Y. Kawaoka (Yoshihiro)


    textabstractA voluntary 60-day pause on avian H5N1 influenza virus transmission research was announced in January 2012 by the international community of influenza scientists engaged in this work to provide time to explain the benefits of such work and the risk mitigation measures in place. Subsequen

  5. Pause Time Patterns in Writing Narrative and Expository Texts by Children and Adults

    Hell, J.G. van; Verhoeven, L.T.W.; Beijsterveldt, E.M. van


    How do beginning and skilled writers compose a text in the course of time? To gain insight into the temporal aspects of planning and translating activities during writing, this article examined writing in real time and analyzed pause time patterns in writing in relation to linguistic characteristics

  6. Pause and Utterance Duration in Child-Directed Speech in Relation to Child Vocabulary Size

    Marklund, Ulrika; Marklund, Ellen; Lacerda, Francisco; Schwarz, Iris-Corinna


    This study compares parental pause and utterance duration in conversations with Swedish speaking children at age 1;6 who have either a large, typical, or small expressive vocabulary, as measured by the Swedish version of the McArthur-Bates CDI. The adjustments that parents do when they speak to children are similar across all three vocabulary…

  7. Computer work duration and its dependence on the used pause definition.

    Richter, Janneke M; Slijper, Harm P; Over, Eelco A B; Frens, Maarten A


    Several ergonomic studies have estimated computer work duration using registration software. In these studies, an arbitrary pause definition (Pd; the minimal time between two computer events to constitute a pause) is chosen and the resulting duration of computer work is estimated. In order to uncover the relationship between the used pause definition and the computer work duration (PWT), we used registration software to record usage patterns of 571 computer users across almost 60,000 working days. For a large range of Pds (1-120 s), we found a shallow, log-linear relationship between PWT and Pds. For keyboard and mouse use, a second-order function fitted the data best. We found that these relationships were dependent on the amount of computer work and subject characteristics. Comparison of exposure duration from studies using different pause definitions should take this into account, since it could lead to misclassification. Software manufacturers and ergonomists assessing computer work duration could use the found relationships for software design and study comparison.

  8. Pause and Utterance Duration in Child-Directed Speech in Relation to Child Vocabulary Size

    Marklund, Ulrika; Marklund, Ellen; Lacerda, Francisco; Schwarz, Iris-Corinna


    This study compares parental pause and utterance duration in conversations with Swedish speaking children at age 1;6 who have either a large, typical, or small expressive vocabulary, as measured by the Swedish version of the McArthur-Bates CDI. The adjustments that parents do when they speak to children are similar across all three vocabulary…

  9. Writing profiles: the effect of the writing mode on pausing and revision patterns of experienced writers

    Van Waes, Luuk; Schellens, Peter Jan


    We investigated how writing processes are affected by physical aspects of the task environment, specifically the use of a word processor, with respect to patterns of pausing and revision. Consistent with the tradition of cognitive writing research, the writing processes of experienced writers were e

  10. An Exploratory Study of Pauses in Computer-Assisted EFL Writing

    Xu, Cuiqin; Ding, Yanren


    The advance of computer input log and screen-recording programs over the last two decades has greatly facilitated research into the writing process in real time. Using Inputlog 4.0 and Camtasia 6.0 to record the writing process of 24 Chinese EFL writers in an argumentative task, this study explored L2 writers' pausing patterns in…

  11. Modified pause schemes and working days for more volume flexibility in manufactering

    Rhijn, G.; Looze, M. de; Bosch, T.


    The effects of two measures to increase the volume flexibility, namely the introduction of an alternating pause scheme and the elongation of the working day, were evaluated in two manufacturing companies. Both measures led to an increase in volume output of about 16% at relatively low costs. The

  12. Comparison of Pausing Behavior in Children Who Stutter and Children Who Have Asperger Syndrome

    Beltrame, Jessica Monique; Viera, Renata Alves Torello; Tamanaha, Ana Carina; Arcuri, Claudia Fassin; Osborn, Ellen; Perissinoto, Jacy; Schiefer, Ana Maria


    Purpose: The objective of this research was to compare the number and types of grammatical and non-grammatical silent pauses presented by stutterers and subjects with Asperger syndrome in their narratives. Method: Ten children who stutter and four participants with Asperger syndrome (mean ages of both groups 10 years) were assessed at the Speech…

  13. Cues-Pause-Point Language Training: Teaching Echolalics Functional Use of Their Verbal Labeling Repertoires.

    McMorrow, Martin J.; And Others


    A cues-pause-point procedure was used to train two severely retarded females to remain quiet before, during, and briefly after the presentation of questions and then to verbalize on the basis of environmental cues whose labels represented the correct responses. Echolalia was rapidly replaced by correct responding on the trained stimuli. (Author/JW)

  14. Impact of Typical Aging and Parkinson's Disease on the Relationship among Breath Pausing, Syntax, and Punctuation

    Huber, Jessica E.; Darling, Meghan; Francis, Elaine J.; Zhang, Dabao


    Purpose: The present study examines the impact of typical aging and Parkinson's disease (PD) on the relationship among breath pausing, syntax, and punctuation. Method: Thirty young adults, 25 typically aging older adults, and 15 individuals with PD participated. Fifteen participants were age- and sex-matched to the individuals with PD.…

  15. High frequency of pauses during intermittent locomotion of small South American gymnophthalmid lizards (Squamata, Gymnophthalmidae

    Elizabeth Höfling


    Full Text Available We studied the locomotor behavior of two closely-related species of Gymnophthalmini lizards, Vanzosaura rubricauda and Procellosaurinus tetradactylus, that was imaged under laboratory conditions at a rate of 250 frames/s with a high-speed video camera (MotionScope PCI 1000 on four different substrates with increasing degrees of roughness (smooth perspex, cardboard, glued sand, and glued gravel. Vanzosaura rubricauda and P. tetradactylus are both characterized by intermittent locomotion, with pauses occurring with high frequency and having a short duration (from 1/10 to 1/3 s, and taking place in rhythmic locomotion in an organized fashion during all types ofgaits and on different substrates. The observed variations in duration and frequency of pauses suggest that in V. rubricauda mean pause duration is shorter and pause frequency is higher than in P. tetradactylus. The intermittent locomotion observed in V.rubricauda and P. tetradactylus imaging at 250 frames/s is probably of interest for neurobiologists. In the review of possible determinants, the phylogenetic relationships among the species of the tribe Gymnophthalmini are focused. Keywords: .

  16. Exhaustion from prolonged gambling

    Fatimah Lateef


    Full Text Available Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities. Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion. Recently, three patients were seen at the Department of Emergency Medicine, presenting with exhaustion from prolonged involvement in gambling activities. The cases serve to highlight some of the physical consequences of prolonged gambling.

  17. Exhaustion from prolonged gambling

    Fatimah Lateef


    Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities.Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion.Recently, three patients were seen at theDepartment ofEmergencyMedicine, presenting with exhaustion from prolonged involvement in gambling activities.The cases serve to highlight some of the physical consequences of prolonged gambling.

  18. Deciding about treatments that prolong life

    Palliative care - treatments that prolong life; Palliative care - life support; End-of-life-treatments that prolong life; Ventilator - treatments that prolong life; Respirator - treatments that prolong life; ...

  19. Execution and pauses in writing narratives: processing time, cognitive effort and typing skill.

    Alves, Rui Alexandre; Castro, São Luís; Olive, Thierry


    At the behavioural level, the activity of a writer can be described as periods of typing separated by pauses. Although some studies have been concerned with the functions of pauses, few have investigated motor execution periods. Precise estimates of the distribution of writing processes, and their cognitive demands, across periods of typing and pauses are lacking. Furthermore, it is uncertain how typing skill affects these aspects of writing. We addressed these issues, selecting writers of low and high typing skill who performed dictation and composition tasks. The occurrences of writing processes were assessed through directed verbalization, and their cognitive demands were measured through interference in reaction times (IRT). Before writing a narrative, 34 undergraduates learned to categorize examples of introspective thoughts as different types of activities related to writing (planning, translating, or revising). Then, while writing, they responded to random auditory probes, and reported their ongoing activity according to the learned categories. Convergent with previous findings, translating was most often reported, and revising and planning had fewer occurrences. Translating was mostly activated during motor execution, whereas revising and planning were mainly activated during pauses. However, none of the writing processes can be characterized as being typical of pauses, since translating was activated to a similar extent as the other two processes. Regarding cognitive demands, revising is likely to be the most demanding process in narrative writing. Typing skill had an impact on IRTs of motor execution. The demands of execution were greater in the low than in the high typing skill group, but these greater demands did not affect the strategy of writing processes activation. Nevertheless, low typing skill had a detrimental impact on text quality.

  20. Profiling Speech and Pausing in Amyotrophic Lateral Sclerosis (ALS and Frontotemporal Dementia (FTD.

    Yana Yunusova

    Full Text Available This study examines reading aloud in patients with amyotrophic lateral sclerosis (ALS and those with frontotemporal dementia (FTD in order to determine whether differences in patterns of speaking and pausing exist between patients with primary motor vs. primary cognitive-linguistic deficits, and in contrast to healthy controls.136 participants were included in the study: 33 controls, 85 patients with ALS, and 18 patients with either the behavioural variant of FTD (FTD-BV or progressive nonfluent aphasia (FTD-PNFA. Participants with ALS were further divided into 4 non-overlapping subgroups--mild, respiratory, bulbar (with oral-motor deficit and bulbar-respiratory--based on the presence and severity of motor bulbar or respiratory signs. All participants read a passage aloud. Custom-made software was used to perform speech and pause analyses, and this provided measures of speaking and articulatory rates, duration of speech, and number and duration of pauses. These measures were statistically compared in different subgroups of patients.The results revealed clear differences between patient groups and healthy controls on the passage reading task. A speech-based motor function measure (i.e., articulatory rate was able to distinguish patients with bulbar ALS or FTD-PNFA from those with respiratory ALS or FTD-BV. Distinguishing the disordered groups proved challenging based on the pausing measures.This study demonstrated the use of speech measures in the identification of those with an oral-motor deficit, and showed the usefulness of performing a relatively simple reading test to assess speech versus pause behaviors across the ALS-FTD disease continuum. The findings also suggest that motor speech assessment should be performed as part of the diagnostic workup for patients with FTD.

  1. Profiling Speech and Pausing in Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD)

    Yunusova, Yana; Graham, Naida L.; Shellikeri, Sanjana; Phuong, Kent; Kulkarni, Madhura; Rochon, Elizabeth; Tang-Wai, David F.; Chow, Tiffany W.; Black, Sandra E.; Zinman, Lorne H.; Green, Jordan R.


    Objective This study examines reading aloud in patients with amyotrophic lateral sclerosis (ALS) and those with frontotemporal dementia (FTD) in order to determine whether differences in patterns of speaking and pausing exist between patients with primary motor vs. primary cognitive-linguistic deficits, and in contrast to healthy controls. Design 136 participants were included in the study: 33 controls, 85 patients with ALS, and 18 patients with either the behavioural variant of FTD (FTD-BV) or progressive nonfluent aphasia (FTD-PNFA). Participants with ALS were further divided into 4 non-overlapping subgroups—mild, respiratory, bulbar (with oral-motor deficit) and bulbar-respiratory—based on the presence and severity of motor bulbar or respiratory signs. All participants read a passage aloud. Custom-made software was used to perform speech and pause analyses, and this provided measures of speaking and articulatory rates, duration of speech, and number and duration of pauses. These measures were statistically compared in different subgroups of patients. Results The results revealed clear differences between patient groups and healthy controls on the passage reading task. A speech-based motor function measure (i.e., articulatory rate) was able to distinguish patients with bulbar ALS or FTD-PNFA from those with respiratory ALS or FTD-BV. Distinguishing the disordered groups proved challenging based on the pausing measures. Conclusions and Relevance This study demonstrated the use of speech measures in the identification of those with an oral-motor deficit, and showed the usefulness of performing a relatively simple reading test to assess speech versus pause behaviors across the ALS—FTD disease continuum. The findings also suggest that motor speech assessment should be performed as part of the diagnostic workup for patients with FTD. PMID:26789001

  2. The effect of pause time upon the communicative interactions of young people who use augmentative and alternative communication.

    Mathis, Hilary; Sutherland, Dean; McAuliffe, Megan


    This study investigated the effect of variation in partner-initiated pause time on the expressive communication of young people who use Augmentative and Alternative Communication (AAC). Eight participants aged 8;11-20;08 years (mean 16;02 years) participated in the study. Three pause time conditions (2, 10, and 45 seconds) were trialled during a scripted shared storybook reading task. A total of 27 turn opportunities were provided for participants during the task. Participant interactions were analysed for the percentage of responses made to a turn opportunity, mean length of utterance in words (MLU), percentage of assertive conversational acts made, and the modes of communication used. Findings indicated that participants were more likely to respond to a turn opportunity when their communication partner provided a longer pause time. Additionally, a longer pause time resulted in longer MLUs. Participants did not use more assertive conversational acts and continued to use a variety of communication modes when provided with a longer pause time. Results indicate that increasing pause time is an effective strategy to support the development of expressive communication for young people who use AAC. This suggests the need for professionals providing AAC services to encourage communication partners to provide extended pauses during interactions.

  3. Torsade de Pointes: Risk prediction and role of ventricular activation

    Stams, T.R.G.


    Torsade de Pointes (TdP) is a ventricular tachycardia that can result in sudden death. Risk factors include the congenital long QT syndrome, but also acquired factors including drugs that prolong the repolarization (QT interval). If concerns exist about the cardiac safety of (novel) drug, an animal

  4. Prolonged labour : women's experiences

    Nystedt, Astrid


    Aim: The overall aim of this thesis was to illuminate, describe, and promote understanding of women’s experiences of prolonged labour. The thesis compromises four studies. Methods: Paper I describes a case-referent study that recruited women (n = 255) giving singleton live birth to their first child by spontaneous labour after more than 37 completed weeks’ pregnancy. Participants completed a questionnaire that investigated childbirth experiences, previous family relationships, and childhood e...

  5. Effects of Breath Training Pattern "End-Inspiratory Pause" on Respiratory Mechanics and Arterial Blood Gas of Patients with COPD

    梁永杰; 蔡映云


    Objective:In order to explore the mechanism of Chinese traditional breath training, theeffects of end-inspiratory pause breathing (EIPB) on the respiratory mechanics and arterial blood gas werestudied in patients with chronic obstructive pulmonary disease (COPD). Methods: Ten patients in steadystage participating in the study had a breath training of regulating the respiration rhythm as to having apause between the deep and slow inspiration and the slow expiration. Effect of the training was observed byvisual feedback from the screen of the respiratory inductive plethysmograph. The dynamic change of par-tial pressure of oxygen saturation in blood (SpO2) was recorded with sphygmo-oximeter, the pulmonarymechanics and EIPB were determined with spirometer, and the data of arterial blood gases in tranquilizedbreathing and EIPB were analysed. Results: After EIPB training, SpO2 increased progressively, PaO2 in-creased and PaCO2 decreased, and the PaO2 increment was greater than the PaCO2 decrement. Further-more, the tidal volume increased and the frequency of respiration decreased significantly, both inspirationtime and expiration time were prolonged. There was no significant change in both mean inspiration flowrate (VT/Ti) and expiration flow rate (VT/Te). The baselines in spirogram during EIPB training had noraise. Conclusion: EIPB could decrease the ratio of the dead space and tidal volume (VD/VT), cause in-crease of PaO2 more than the decrease of PaCO2, suggesting that this training could improve both the func-tion of ventilation and gaseous exchange in the lung. EIPB training might be a breathing training patternfor rehabilitation of patients with COPD.

  6. Ventricular Assist Device Support

    Fasseas, Panayotis; Kutalek, Steven P.; Samuels, Fania L.; Holmes, Elena C.; Samuels, Louis E.


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias. (Tex Heart Inst J 2002;29:33–6) PMID:11995847

  7. Ventricular tachycardia in acromegaly.

    Arias, Miguel A; Pachón, Marta; Rodríguez-Padial, Luis


    Cases of sudden cardiac death have been reported in patients with acromegaly. Malignant ventricular arrhythmias may play an important role in this fatal complication, but the exact mechanisms are not well understood. We report on an acromegalic patient presenting with documented recurrent syncopal ventricular tachycardia.

  8. Translational pauses during the synthesis of proteins and mRNA structure.

    Zama, M


    Translational pauses are observed during a spider fibroin synthesis (1,2). The spider major ampullate (dragline) silk of the spider Nephila clavipes is composed of multiple proteins. The amino acid sequences of the partial cDNA clones for the two major dragline silk fibroin components (Spidroin 1 and 2) exhibit repetitive motifs (3,4). Our detailed inspection of the nucleotide sequences of the repetitive motifs revealed highly selective site-specific codon usage patterns within a motif, suggesting that the secondary structure of the spider fibroin mRNA is optimized by the nucleotide sequence of the fibroin gene. The results, combined with our preceding results on silk fibroin from Bombyx mori (5) suggest that translational pauses of spider silk are interpreted in terms of the mRNA secondary structure.

  9. Calcium Imaging Reveals Coordinated Simple Spike Pauses in Populations of Cerebellar Purkinje Cells

    Jorge E. Ramirez


    Full Text Available The brain’s control of movement is thought to involve coordinated activity between cerebellar Purkinje cells. The results reported here demonstrate that somatic Ca2+ imaging is a faithful reporter of Na+-dependent “simple spike” pauses and enables us to optically record changes in firing rates in populations of Purkinje cells in brain slices and in vivo. This simultaneous calcium imaging of populations of Purkinje cells reveals a striking spatial organization of pauses in Purkinje cell activity between neighboring cells. The source of this organization is shown to be the presynaptic gamma-Aminobutyric acid producing (GABAergic network, and blocking ionotropic gamma-Aminobutyric acid receptor (GABAARs abolishes the synchrony. These data suggest that presynaptic interneurons synchronize (inactivity between neighboring Purkinje cells, and thereby maximize their effect on downstream targets in the deep cerebellar nuclei.

  10. RNA polymerase II pausing downstream of core histone genes is different from genes producing polyadenylated transcripts.

    Krishanpal Anamika

    Full Text Available Recent genome-wide chromatin immunoprecipitation coupled high throughput sequencing (ChIP-seq analyses performed in various eukaryotic organisms, analysed RNA Polymerase II (Pol II pausing around the transcription start sites of genes. In this study we have further investigated genome-wide binding of Pol II downstream of the 3' end of the annotated genes (EAGs by ChIP-seq in human cells. At almost all expressed genes we observed Pol II occupancy downstream of the EAGs suggesting that Pol II pausing 3' from the transcription units is a rather common phenomenon. Downstream of EAGs Pol II transcripts can also be detected by global run-on and sequencing, suggesting the presence of functionally active Pol II. Based on Pol II occupancy downstream of EAGs we could distinguish distinct clusters of Pol II pause patterns. On core histone genes, coding for non-polyadenylated transcripts, Pol II occupancy is quickly dropping after the EAG. In contrast, on genes, whose transcripts undergo polyA tail addition [poly(A(+], Pol II occupancy downstream of the EAGs can be detected up to 4-6 kb. Inhibition of polyadenylation significantly increased Pol II occupancy downstream of EAGs at poly(A(+ genes, but not at the EAGs of core histone genes. The differential genome-wide Pol II occupancy profiles 3' of the EAGs have also been confirmed in mouse embryonic stem (mES cells, indicating that Pol II pauses genome-wide downstream of the EAGs in mammalian cells. Moreover, in mES cells the sharp drop of Pol II signal at the EAG of core histone genes seems to be independent of the phosphorylation status of the C-terminal domain of the large subunit of Pol II. Thus, our study uncovers a potential link between different mRNA 3' end processing mechanisms and consequent Pol II transcription termination processes.

  11. Computer mouse use predicts acute pain but not prolonged or chronic pain in the neck and shoulder

    Andersen, JH; Harhoff, M.; Grimstrup, S.


    BACKGROUND: Computer use may have an adverse effect on musculoskeletal outcomes. This study assessed the risk of neck and shoulder pain associated with objectively recorded professional computer use. METHODS: A computer programme was used to collect data on mouse and keyboard usage and weekly...... quartile increase in weekly mouse usage time. Mouse and keyboard usage time did not predict the onset of prolonged or chronic pain in the neck or shoulder. Women had higher risks for neck and shoulder pain. Number of keystrokes and mouse clicks, length of the average activity period, and micro-pauses did...... not influence reports of acute or prolonged pain. A few psychosocial factors predicted the risk of prolonged pain. CONCLUSIONS: Most computer workers have no or minor neck and shoulder pain, few experience prolonged pain, and even fewer, chronic neck and shoulder pain. Moreover, there seems...

  12. Scalability Performance of MANET Routing Protocols with Reference to Variable Pause Time

    Asha Ambhaikar


    Full Text Available As mobile networking continues to experience increasing popularity, the need to connect large numbers of wireless devices will become more prevalent. Many recent proposals for ad hoc routing have certain characteristics. A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks does play important role in civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is possible. It is a crucial part in the performance evaluation of MANET to select suitable mobility model and routing protocols. Therefore, a number of routing protocols as well as mobility models have been proposed for ad hoc wireless networks based on different scenarios. In this paper, we study and compare the performance of the two reactive routing protocols AODV and DSR with reference to varying Pause Time. For experimental purposes, we have considered increasing Pause Time from 5 sec to 40 sec and illustrate the performance of the routing protocol across Packet Delivery Ratio parameter. Our simulation result shows that both AODV & DSR is performing equally good until the Pause Time cross a certain limit.

  13. Balloon Dilatation of Pediatric Subglottic Laryngeal Stenosis during the Artificial Apneic Pause: Experience in 5 Children

    J. Lisý


    Full Text Available Introduction. Balloon dilatation is a method of choice for treatment of laryngeal stenosis in children. The aim of procedure in apneic pause is to avoid new insertion of tracheostomy cannula. Patients and Methods. The authors performed balloon dilatation of subglottic laryngeal strictures (SGS in 5 children (3 girls and 2 boys without tracheotomy. Two of them with traumatic and inflammatory SGS had a tracheal cannula removed in the past. The other 3 children with postintubation SGS had never had a tracheostomy before. The need for tracheostomy due to worsening stridor was imminent for all of them. Results. The total of seven laryngeal dilatations by balloon esophagoplasty catheter in apneic pause was performed in the 5 children. The procedure averted the need for tracheostomy placement in 4 of them (80%. Failure of dilatation in girl with traumatic stenosis and concomitant severe obstructive lung disease led to repeated tracheostomy. Conclusion. Balloon dilatation of laryngeal stricture could be done in the absence of tracheostomy in apneic pause. Dilatation averted threatening tracheostomy in all except one case. Early complication after the procedure seems to be a negative prognostic factor for the outcome of balloon dilatation.

  14. Putting a Pause in Pain, A personal journey for this teen | NIH MedlinePlus the Magazine

    ... please turn JavaScript on. Feature: Pain Management Putting a Pause in Pain, A personal journey for this teen Winter 2017 Table ... Northern Kentucky with an extra confidence and bounce. A fan of Chilean poet Pablo Neruda, she's working ...

  15. Use of right ventricular support with a centrifugal pump in post-valve surgery right ventricular failure: a case series.

    Moulodi, Abdol Rasoul; Sheibat Zadeh, Gholam Reza; Sabzi, Feridoun


    The optimal treatment method for right ventricular failure after valve surgery complicated by a low cardiac output has not been determined, although several case reports have been published on patients with ventricular failure and arrhythmia who were bridged to cardiac transplantation using biventricular or left ventricular assist devices. This case series illustrates successful circulatory support of 4 patients with prolonged low cardiac outputs and right ventricular failure and arrhythmias after valvular heart surgery with or without severe pulmonary hypertension. In-hospital death occurred in one patient and 3 patients were discharged from the hospital with good general condition. At two years' follow-up, 2 patients were in functional class one but another patient underwent laparotomy for multiple splenic abscesses and died from multiple organ failure.

  16. "Pause-2-Play": a pilot schoolbased obesity prevention program "Pause-2-Play": um programa piloto escolar de prevenção de obesidade

    Gregory Killough


    Full Text Available OBJECTIVES: "Pause-2-Play" is an obesity prevention program targeting screen-related sedentary behaviours and increasing physical activity among elementary school students. The program consisted of a Behavioural Modification Curriculum and a Health Promoting Afterschool Program. This pilot study reports program feasibility, practicability, and impact. METHODS: the 12-week pilot program was implemented with 32 grade five and six students. Program feasibility and practicability were assessed using a qualitative approach. Intervention effects were assessed by comparing pre-post changes in BMI, body composition, fitness scores, screen time, and cognitive variables related to screening viewing behaviours. RESULTS: "Pause-2-Play" was perceived as a useful, fun program with numerous benefits including: children trying new snacks, feeling fitter and better about one's own body shape, and becoming more aware of a healthy lifestyle. The intervention resulted in a statistically significant reduction in percent body fat and an increase in fat-free mass index in overweight children; a decrease in waist circumference and an increase in fat-free mass index were observed in normal weight children. The intervention also statistically improved fitness scores in both normal weight and overweight children. CONCLUSIONS: "Pause-2-Play" was feasible, practical, and favourably changed body composition and fitness level.OBJETIVOS: "Pause-2-Play" é um programa de prevenção da obesidade direcionado aos comportamentos sedentários relacionados ao uso de monitores de computador e televisores, visando promover a atividade física entre estudantes de escolas de educação básica. O programa trata-se de um currículo de modificação comportamental e um programa extracurricular de promoção de saúde. Este estudo-piloto relata sobre a viabilidade, praticidade e impacto do programa. MÉTODOS: o programa de doze semanas foi implementado com 32 alunos escolares do quinto e

  17. Right ventricular dysfunction affects survival after surgical left ventricular restoration.

    Couperus, Lotte E; Delgado, Victoria; Palmen, Meindert; van Vessem, Marieke E; Braun, Jerry; Fiocco, Marta; Tops, Laurens F; Verwey, Harriëtte F; Klautz, Robert J M; Schalij, Martin J; Beeres, Saskia L M A


    Several clinical and left ventricular parameters have been associated with prognosis after surgical left ventricular restoration in patients with ischemic heart failure. The aim of this study was to determine the prognostic value of right ventricular function. A total of 139 patients with ischemic heart failure (62 ± 10 years; 79% were male; left ventricular ejection fraction 27% ± 7%) underwent surgical left ventricular restoration. Biventricular function was assessed with echocardiography before surgery. The independent association between all-cause mortality and right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain was assessed. The additive effect of multiple impaired right ventricular parameters on mortality also was assessed. Baseline right ventricular fractional area change was 42% ± 9%, tricuspid annular plane systolic excursion was 18 ± 3 mm, and right ventricular longitudinal peak systolic strain was -24% ± 7%. Within 30 days after surgery, 15 patients died. Right ventricular fractional area change (hazard ratio, 0.93; 95% confidence interval, 0.88-0.98; P right ventricular longitudinal peak systolic strain (hazard ratio, 1.15; 95% confidence interval, 1.05-1.26; P Right ventricular function was impaired in 21%, 20%, and 27% of patients on the basis of right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain, respectively. Any echocardiographic parameter of right ventricular dysfunction was present in 39% of patients. The coexistence of several impaired right ventricular parameters per patient was independently associated with increased 30-day mortality (hazard ratio, 2.83; 95% confidence interval, 1.64-4.87, P right ventricular systolic dysfunction is independently associated with increased mortality in patients with ischemic heart failure undergoing surgical left

  18. Left Ventricular Hypertrophy

    ... the chamber itself also increases. The enlarged heart muscle loses elasticity and eventually may fail to pump with as much force as needed. Left ventricular hypertrophy is more common in people who have uncontrolled ...

  19. Transcriptional regulation: effects of promoter proximal pausing on speed, synchrony and reliability.

    Alistair N Boettiger


    Full Text Available Recent whole genome polymerase binding assays in the Drosophila embryo have shown that a substantial proportion of uninduced genes have pre-assembled RNA polymerase-II transcription initiation complex (PIC bound to their promoters. These constitute a subset of promoter proximally paused genes for which mRNA elongation instead of promoter access is regulated. This difference can be described as a rearrangement of the regulatory topology to control the downstream transcriptional process of elongation rather than the upstream transcriptional initiation event. It has been shown experimentally that genes with the former mode of regulation tend to induce faster and more synchronously, and that promoter-proximal pausing is observed mainly in metazoans, in accord with a posited impact on synchrony. However, it has not been shown whether or not it is the change in the regulated step per se that is causal. We investigate this question by proposing and analyzing a continuous-time Markov chain model of PIC assembly regulated at one of two steps: initial polymerase association with DNA, or release from a paused, transcribing state. Our analysis demonstrates that, over a wide range of physical parameters, increased speed and synchrony are functional consequences of elongation control. Further, we make new predictions about the effect of elongation regulation on the consistent control of total transcript number between cells. We also identify which elements in the transcription induction pathway are most sensitive to molecular noise and thus possibly the most evolutionarily constrained. Our methods produce symbolic expressions for quantities of interest with reasonable computational effort and they can be used to explore the interplay between interaction topology and molecular noise in a broader class of biochemical networks. We provide general-purpose code implementing these methods.

  20. Comparison of Ventricular Electrophysiological Effects of Amiodarone in Canine Models With Congestive Heart Failure and Normal Dogs

    Shuxian Zhou; Yuling Zhang; Juan Lei; Wei Wu; Xuming Zhang


    Objectives This study compared the effects of amiodarone on ventricular electrophysiological properties in normal dogs and CHF dogs.Methods Dogs(n=44) were randomized into four groups:Group 1(n=10)was the control.Group 2(n=10) was given amiodarone orally 300 mg·d-1 for4 to 5 weeks.Group 3(n=12)was the congestive heart failure(CHF)models induced by right ventricular rapid pacing(240 pulses·rain-1 for 4 to 5 weeks).Group 4 (n=12) was the CHF models given amiodarone orally 300 mg·d-1 for 4 to 5 weeks.The ventricular electrophysiological variables were evaluated by standard electric stimulation and monophasic action potential(MAP)recording.Results Amiodarone prolonged sinus cycle length(SCL),intra-ventricular conduction time(IVCT),MAP duration(MAPD90),ventricular effective period(VERP),ventricular activation time(VAT)and ventficular recovery time(VRT)without significant effects on the ratio of VERP to MAPD90 (VERP/MAPD90),ventricular fibrillation threshold(VFT),the dispersion of VRT(VRTD),and ventricular late repolarization duration(VLRD)in normal dogs.However,amiodarone did not further prolong the prolonged SCL,MAPD90,VERP,VAT and VRT,but further prolonged IVCT in CHF dogs.Amiodarone normalized the abnormal ventficular electrophysiological properties in CHF dogs as manifested by increasing the decreased VERP/MAPD90 and VFT,shortening the prolonged VLRD,and decreasing the increased VRTD.Amiodarone did not worsen the hemodynamic parameters in normal and CHF dogs.Conclusions Amiodarone had different effects on ventricular electrophysiological properties in normal and CHF dogs.The favorable effects of amiodarone in normalizing some abnormal cardiac electrophysiological properties in CHF models may have potential value on the prevention and treatment of ventricular arrhythmias and sudden cardiac death in CHF.


    ZENG Qing; OUYANG Xing-biao; LI Man; LIU Xiao-chun; GUAN Xin-min


    Objective:To investigate the effect of electroacupuncture (EA) on aconitine-induced ventricular tachyarrhythmia. Methods: Twenty SD rats ate (300 mg/kg, I.p.) were evenly and anesthetized with chloral hydrrandomly divided into control and EA groups. Ventricular arrhythmia was induced by intravenous infusion of 0.001% aconitine (I.v., 3.5 mg/kg, 0.4 mL/min). EA (4~16 Hz, 1~3 V) was applied to "Neiguan"(内关 PC 6) and "Jianshi"(间使 PC 5) for 30 min. ECG was recorded andanalyzed to determine ventricular premature beat (VPB), ventricular tachycardia (VT) and ventricular fibrillation (VF). Results: EA elevated the dose threshold of aconitine-induced VF (P<0.05), delayed the occurrence of VT and VF (P<0.01), prolonged the survival time and reduced the mortality of rats treated with aconitine (P<0.01). Conclusion: EA can suppress aconitine-induced ventricular tachyarrhythmia.

  2. Ventricular repolarization in a rat model of global heart failure.

    Krandycheva, Valeria; Kharin, Sergey; Strelkova, Marina; Shumikhin, Konstantin; Sobolev, Aleksey; Shmakov, Dmitry


    Isoproterenol in high doses induces infarction-like myocardial damage and structural and functional remodelling of the ventricular myocardium. The purpose of the present study was to investigate ventricular repolarization in a rat model of isoproterenol-induced heart failure. Isoproterenol was administered twice to female Wistar rats (170 mg/kg, s.c., 24 h apart). Four weeks after the injections, cardiac output was measured and unipolar epicardial ventricular electrograms were recorded in situ. Activation-recovery intervals were calculated to assess repolarization. Histological examination of the heart ventricles was also performed. Heart failure in rats treated with isoproterenol was indicated by myocardial histopathological damage and reduced cardiac output. In rats with heart failure, the regional differences in activation-recovery interval prolongation over the ventricular epicardium resulted in increasing heterogeneity in the activation-recovery interval distribution and increasing repolarization heterogeneity of the ventricular subepicardium. Myocardial damage and haemodynamic changes in heart failure induced by isoproterenol were accompanied by significant changes in ventricular repolarization, which were not associated with myocardial hypertrophy.

  3. Effects of active pause pattern of surface electromyographic activity among subjects performing monotonous tasks: A systematic review.

    Januario, Leticia Bergamin; Moreira, Roberta de Fátima Carreira; Cid, Marina Machado; Samani, Afshin; Madeleine, Pascal; Oliveira, Ana Beatriz


    Active pauses have shown potentially beneficial effects to increase the variability of the electrical activation pattern of muscles. However, there is a lack of consensus as to how to design and implement those pauses and the processing methods of surface electromyography (EMG) data when evaluating low-level monotonous tasks. The aim of this systematic review was to synthesize the evidences regarding the way which active pauses have been applied, and the methods used to investigate the related EMG changes. PubMed-MEDLINE, Embase, Web of Science, Lilacs, Ebsco, and Scopus databases were searched. Two authors independently extracted data from the primary studies. The methodological quality was assessed using a list from van der Windt et al. (2000), and the level of evidence was synthesized through GRADE. The ISEK guideline for reporting EMG data was also applied as a checklist. Fifteen studies were included - 14 with high methodological quality. In general, active pauses were able to change the level of EMG activity in monotonous tasks. The level of evidence through GRADE was very low for all EMG processing methods, except RMS which was low. A vast heterogeneity concerning the methods applied to analyze EMG data contributed to decrease the quality of evidence synthesis, and the findings need to be carefully considered. The GRADE approach and the ISEK guideline contributed to identify important flaws in the literature. Future studies investigating active pauses in longitudinal studies and following the standard for recording and reporting EMG data care are warranted.

  4. Vulnerability to ventricular fibrillation

    Janse, Michiel J.


    One of the factors that favors the development of ventricular fibrillation is an increase in the dispersion of refractoriness. Experiments will be described in which an increase in dispersion in the recovery of excitability was determined during brief episodes of enhanced sympathetic nerve activity, known to increase the risk of fibrillation. Whereas in the normal heart ventricular fibrillation can be induced by a strong electrical shock, a premature stimulus of moderate intensity only induces fibrillation in the presence of regional ischemia, which greatly increases the dispersion of refractoriness. One factor that is of importance for the transition of reentrant ventricular tachycardia to ventricular fibrillation during acute regional ischemia is the subendocardial Purkinje system. After selective destruction of the Purkinje network by lugol, reentrant tachycardias still develop in the ischemic region, but they do not degenerate into fibrillation. Finally, attempts were made to determine the minimal mass of thin ventricular myocardium required to sustain fibrillation induced by burst pacing. This was done by freezing of subendocardial and midmural layers. The rim of surviving epicardial muscle had to be larger than 20 g. Extracellular electrograms during fibrillation in both the intact and the "frozen" left ventricle were indistinguishable, but activation patterns were markedly different. In the intact ventricle epicardial activation was compatible with multiple wavelet reentry, in the "frozen" heart a single, or at most two wandering reentrant waves were seen.

  5. Analog self-powered harvester achieving switching pause control to increase harvested energy

    Makihara, Kanjuro; Asahina, Kei


    In this paper, we propose a self-powered analog controller circuit to increase the efficiency of electrical energy harvesting from vibrational energy using piezoelectric materials. Although the existing synchronized switch harvesting on inductor (SSHI) method is designed to produce efficient harvesting, its switching operation generates a vibration-suppression effect that reduces the harvested levels of electrical energy. To solve this problem, the authors proposed—in a previous paper—a switching method that takes this vibration-suppression effect into account. This method temporarily pauses the switching operation, allowing the recovery of the mechanical displacement and, therefore, of the piezoelectric voltage. In this paper, we propose a self-powered analog circuit to implement this switching control method. Self-powered vibration harvesting is achieved in this study by attaching a newly designed circuit to an existing analog controller for SSHI. This circuit aims to effectively implement the aforementioned new switching control strategy, where switching is paused in some vibration peaks, in order to allow motion recovery and a consequent increase in the harvested energy. Harvesting experiments performed using the proposed circuit reveal that the proposed method can increase the energy stored in the storage capacitor by a factor of 8.5 relative to the conventional SSHI circuit. This proposed technique is useful to increase the harvested energy especially for piezoelectric systems having large coupling factor.

  6. A Pause-then-Cancel model of stopping: evidence from basal ganglia neurophysiology.

    Schmidt, Robert; Berke, Joshua D


    Many studies have implicated the basal ganglia in the suppression of action impulses ('stopping'). Here, we discuss recent neurophysiological evidence that distinct hypothesized processes involved in action preparation and cancellation can be mapped onto distinct basal ganglia cell types and pathways. We examine how movement-related activity in the striatum is related to a 'Go' process and how going may be modulated by brief epochs of beta oscillations. We then describe how, rather than a unitary 'Stop' process, there appear to be separate, complementary 'Pause' and 'Cancel' mechanisms. We discuss the implications of these stopping subprocesses for the interpretation of the stop-signal reaction time-in particular, some activity that seems too slow to causally contribute to stopping when assuming a single Stop processes may actually be fast enough under a Pause-then-Cancel model. Finally, we suggest that combining complementary neural mechanisms that emphasize speed or accuracy respectively may serve more generally to optimize speed-accuracy trade-offs.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'.

  7. Manipulation of KLF4 Expression Generates iPSCs Paused at Successive Stages of Reprogramming

    Ken Nishimura


    Full Text Available The detailed mechanism of reprogramming somatic cells into induced pluripotent stem cells (iPSCs remains largely unknown. Partially reprogrammed iPSCs are informative and useful for understanding the mechanism of reprogramming but remain technically difficult to generate in a predictable and reproducible manner. Using replication-defective and persistent Sendai virus (SeVdp vectors, we analyzed the effect of decreasing the expression levels of OCT4, SOX2, KLF4, and c-MYC and found that low KLF4 expression reproducibly gives rise to a homogeneous population of partially reprogrammed iPSCs. Upregulation of KLF4 allows these cells to resume reprogramming, indicating that they are paused iPSCs that remain on the path toward pluripotency. Paused iPSCs with different KLF4 expression levels remain at distinct intermediate stages of reprogramming. This SeVdp-based stage-specific reprogramming system (3S reprogramming system is applicable for both mouse and human somatic cells and will facilitate the mechanistic analysis of reprogramming.

  8. Elongation Factor P Interactions with the Ribosome Are Independent of Pausing.

    Tollerson, Rodney; Witzky, Anne; Ibba, Michael


    Bacterial elongation factor P (EF-P) plays a pivotal role in the translation of polyproline motifs. To stimulate peptide bond formation, EF-P must enter the ribosome via an empty E-site. Using fluorescence-based single-molecule tracking, Mohapatra et al. (S. Mohapatra, H. Choi, X. Ge, S. Sanyal, and J. C. Weisshaar, mBio 8:e00300-17, 2017, monitored the cellular distribution of EF-P and quantified the frequency of association between EF-P and the ribosome under various conditions. Findings from the study showed that EF-P has a localization pattern that is strikingly similar to that of ribosomes. Intriguingly, EF-P was seen to bind ribosomes more frequently than the estimated number of pausing events, indicating that E-site vacancies occur even when ribosomes are not paused. The study provides new insights into the mechanism of EF-P-dependent peptide bond formation and the intricacies of translation elongation. Copyright © 2017 Tollerson et al.

  9. Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake

    Keenan, Trevor F.; Prentice, I. Colin; Canadell, Josep G.; Williams, Christopher A.; Wang, Han; Raupach, Michael; Collatz, G. James


    Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions. The terrestrial carbon sink is increasing, yet the mechanisms responsible for its enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple global vegetation models, we report a recent pause in the growth rate of atmospheric CO2, and a decline in the fraction of anthropogenic emissions that remain in the atmosphere, despite increasing anthropogenic emissions. We attribute the observed decline to increases in the terrestrial sink during the past decade, associated with the effects of rising atmospheric CO2 on vegetation and the slowdown in the rate of warming on global respiration. The pause in the atmospheric CO2 growth rate provides further evidence of the roles of CO2 fertilization and warming-induced respiration, and highlights the need to protect both existing carbon stocks and regions, where the sink is growing rapidly.

  10. Left ventricular apical diseases.

    Cisneros, Silvia; Duarte, Ricardo; Fernandez-Perez, Gabriel C; Castellon, Daniel; Calatayud, Julia; Lecumberri, Iñigo; Larrazabal, Eneritz; Ruiz, Berta Irene


    There are many disorders that may involve the left ventricular (LV) apex; however, they are sometimes difficult to differentiate. In this setting cardiac imaging methods can provide the clue to obtaining the diagnosis. The purpose of this review is to illustrate the spectrum of diseases that most frequently affect the apex of the LV including Tako-Tsubo cardiomyopathy, LV aneurysms and pseudoaneurysms, apical diverticula, apical ventricular remodelling, apical hypertrophic cardiomyopathy, LV non-compaction, arrhythmogenic right ventricular dysplasia with LV involvement and LV false tendons, with an emphasis on the diagnostic criteria and imaging features. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13244-011-0091-6) contains supplementary material, which is available to authorized users.

  11. Using mechanical force to probe the mechanism of pausing and arrest during continuous elongation by Escherichia coli RNA polymerase

    Forde, Nancy R.; Izhaky, David; Woodcock, Glenna R.; Wuite, Gijs J. L.; Bustamante, Carlos


    Escherichia coli RNA polymerase translocates along the DNA discontinuously during the elongation phase of transcription, spending proportionally more time at some template positions, known as pause and arrest sites, than at others. Current models of elongation suggest that the enzyme backtracks at these locations, but the dynamics are unresolved. Here, we study the role of lateral displacement in pausing and arrest by applying force to individually transcribing molecules. We find that an assisting mechanical force does not alter the translocation rate of the enzyme, but does reduce the efficiency of both pausing and arrest. Moreover, arrested molecules cannot be rescued by force, suggesting that arrest occurs by a bipartite mechanism: the enzyme backtracks along the DNA followed by a conformational change of the ternary complex (RNA polymerase, DNA and transcript), which cannot be reversed mechanically.

  12. [Drug-induced QT interval prolongation: do we know the risks?].

    Villamañán, Elena; Armada, Eduardo; Ruano, Margarita


    Sudden cardiac death is an important cause of mortality in developed countries, most of them being consequence of acute ventricular arrhythmias. These arrhythmias, in some cases, owe to QT interval prolongation. A major risk factor for this condition is the use of drugs that prolong the QT interval. In fact, in recent years, one of the most common reasons for drug withdrawal or usage restrictions has been drug induced QT interval prolongation that involves both cardiovascular and non-cardiovascular drugs. Taking into account the severity that the occurrence of such an event may have, it is important for clinicians to know the risks of these drugs in certain patients. In this review we analyze the drugs that prolong the QT interval, the risk factors that can enhance QT prolongation and the drug interactions that can increase these risks. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  13. Ventricular Standstill Following Intravenous Erythromycin and Borderline Hypokalemia

    Saad A Khan


    Full Text Available Ventricular standstill (VS is a potentially fatal arrhythmia that is usually associated with syncope, if prolonged and is rarely asymptomatic[1]. Its mechanism involves either a lack of supraventricular impulse or an interruption in the transmission of these signals from the atria to the ventricles, resulting in a sudden loss of cardiac output[2]. Although rare, ventricular arrhythmias have been associated with intravenous (IV erythromycin. However, to our knowledge, VS has not been reported following the administration of IV erythromycin. The Authors  describe a rare case of asymptomatic VS and subsequent third-degree atrioventricular block, following the administration of IV erythromycin in a 49-year-old woman with borderline hypokalemia. Through this case, the Authors highlight the importance of cardiac monitoring and electrolyte replacement when administering IV erythromycin, as well as discuss several other mechanisms that contribute to ventricular arrhythmias.

  14. Disseminated Streptococcus pneumoniae infection involving a ventricular assist device.

    Reeves, J S; Rajagopalan, N; Huaman, M A


    We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation.

  15. Ventricular arrhythmias in patients of atrial fibrillation treated with Flecainide: A case report

    Barman M, Djamel B


    Full Text Available Purpose: Flecainide is a class 1C antiarrhythmic drug, especially used for the management of supraventricular arrhythmia. Flecainide also has a recognized proarrhythmic effect in all age groups of adult patients treated for ventricular tachycardia. It is used to treat a variety of cardiac arrhythmias including paroxysmal fibrillation, Paroxysmal Supraventricular tachycardia and ventricular tachycardia. Flecainide works by regulating the flow of sodium in the heart, causing prolongation of the cardiac action potential. The proarrhythmic effects however noted are not widely reported. Case report: We report a case of paroxysmal atrial fibrillation with structurally normal heart who was treated with oral Flecainide. Despite subjective improvement and no adverse events [QTc prolongation] a repeat holter detected him to have multiple short non sustained ventricular arrhythmias. Results: Development of ventricular arrhythmias, salvos &non sustained ventricular tachycardia after a month of initiation of oral Flecainide detected by 24 hours ECG holter lead to discontinuation of Flecainide and subsequent early electro physiological studies and successful ablation. Conclusion: Initiation of oral Flecainide in a case of atrial fibrillation with subjective improvement and regular ECG monitoring, no QTc prolongation can still lead to development of dangerous ventricular arrhythmias. A cautious approach and thorough investigations and follow up are recommended.

  16. Effects of hypokalemia on transmural dispersion of ventricular repolarization in left ventricular myocardium

    Jiang-Hua Zhong; Shi-Juan Lu; Mo-Shui Chen; Zi-Bin Chen; Liu Wang; Ping-Sheng Wu


    Objective: To observe effects of hypokalemia on transmural heterogeneity of ventricular repolarization in left ventricular myocardium of rabbit, and explore the role of hypokalemia in malignant ventricular arrhythmia (MVA). Methods: A total of 20 rabbits were randomly divided into control group and hypokalemic group. Isolated hearts in the control group were simply perfused with modified Tyrode's solution, and were perfused with hypokalemic Tyrode's solution in hypokalemic group. Ventricular fibrillation threshold (VFT), 90% monophasic action potential repolarization duration (APD90) of subepicardial, midmyocardial and subendocardial myocardium, transmural dispersion of repolarization (TDR) and Cx43 protein expression in three layers of myocardium were measured in both groups. Results: VFT in the control group and the hypokalemic group were (13.40±2.95) V, and (7.00±1.49) V, respectively. There was a significant difference between two groups (P<0.01). APD90 of three myocardial layers in the hypokalemic group were significantly prolonged than those in the control group (P<0.01). APD90 in the hypokalemic group and the control group were (38.10±10.29) ms and (23.70±5.68) ms, and TDR were (52.90±14.55) ms and (36.10±12.44) ms, respectively. APD90 and TDR in the hypokalemic group were significantly higher than those in the control group (P<0.05), and the increase in APD90 of midmyocardium was more significant in the hypokalemic group. Cx43 protein expression of all three myocardial layers were decreased significantly in the hypokalemic group (P<0.01), and Cx43 was significantly increased (P<0.05). Reduction of Cx43 protein expression was more significant in the midmyocardium. Conclusions: Hypokalemic can increase transmural heterogeneity of Cx43 expression and repolarization in left ventricular myocardium of rabbit, and decrease VFT and can induce MVA more easily.

  17. Abnormal atrial activation is common in patients with arrhythmogenic right ventricular cardiomyopathy

    Platonov, Pyotr G; Christensen, Alex H; Holmqvist, Fredrik;


    INTRODUCTION: Structural right atrial abnormalities have been described in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, little is known about electrocardiographic signs of atrial involvement in ARVC because no systematic studies have been conducted. METHODS: P......%, whereas 15 patients (37%) had atypical P-wave positive in all 3 leads (P right ventricular abnormality. CONCLUSIONS: Patients with ARVC commonly demonstrate deteriorated...... atrial activation expressed either as prolonged P-wave duration or abnormal P-wave morphology. The P-wave abnormalities were not secondary to right ventricular dilatation. These findings show that atrial involvement is common in ARVC and may represent yet another manifestation of the disease...

  18. Active myocyte shortening during the 'isovolumetric relaxation' phase of diastole is responsible for ventricular suction; 'systolic ventricular filling'.

    Buckberg, Gerald D; Castellá, Manuel; Gharib, Morteza; Saleh, Saleh


    To study the 'isovolumetric relaxation' phase of rapid ventricular filling by analysis of the shortening of cardiac muscle in the endocardial and epicardial segments of the left ventricle in the dual helical model of the ventricular band, described by Torrent-Guasp. In 10 pigs (27-82 kg), temporal shortening by sonomicrometer crystals was recorded while recording ECG, and measuring intraventricular pressure and dP/dt with Millar pressure transducers. The following sequence was observed; shortening began in descending or endocardial segment, and 82+/-23 ms later it was initiated in the epicardial or ascending segment of the band. The descending segment stops shortening during the rapid filling phase of fast descent of ventricular pressure, but the ascending segment shortening continues for 92+/-33 ms, so that active shortening continues during the period of isovolumetric relaxation. During the rapid filling phase, dopamine decreased the interval between completion of endocardial and termination of epicardial contraction from 92+/-20 to 33+/-8 ms. Conversely propranolol delayed the start of epicardial shortening from 82+/-23 to 121+/-20 ms, and prolonged the duration of endocardial contraction, causing a closer (21+/-5 ms vs 92+/-20 ms) interval between termination of contraction of endocardial and epicardial fibers. The resultant slope of the rapid descent of the left ventricular pressure curve became prolonged. These time sequences show that ongoing unopposed ascending segment shortening occurs during the phase of rapid fall of ventricular pressure. These active shortening phases respond to positive and negative inotropic stimulation, and indicate the classic concept of 'isovolumetric relaxation', IVR, must be reconsidered, and the new term 'isovolumetric contraction', IVC, or systolic ventricular filing may be used.

  19. The effect of filled pauses on the processing of the surface form and the establishment of causal connections during the comprehension of spoken expository discourse.

    Cevasco, Jazmín; van den Broek, Paul


    The purpose of this study was to examine the effect of filled pauses (uh) on the verification of words and the establishment of causal connections during the comprehension of spoken expository discourse. With this aim, we asked Spanish-speaking students to listen to excerpts of interviews with writers, and to perform a word-verification task and a question-answering task on causal connectivity. There were two versions of the excerpts: filled pause present and filled pause absent. Results indicated that filled pauses increased verification times for words that preceded them, but did not make a difference on response times to questions on causal connectivity. The results suggest that, as signals of delay, filled pauses create a break with surface information, but they do not have the same effect on the establishment of meaningful connections.

  20. Ventral tegmental area GABA projections pause accumbal cholinergic interneurons to enhance associative learning.

    Brown, Matthew T C; Tan, Kelly R; O'Connor, Eoin C; Nikonenko, Irina; Muller, Dominique; Lüscher, Christian


    The ventral tegmental area (VTA) and nucleus accumbens (NAc) are essential for learning about environmental stimuli associated with motivationally relevant outcomes. The task of signalling such events, both rewarding and aversive, from the VTA to the NAc has largely been ascribed to dopamine neurons. The VTA also contains GABA (γ-aminobutyric acid)-releasing neurons, which provide local inhibition and also project to the NAc. However, the cellular targets and functional importance of this long-range inhibitory projection have not been ascertained. Here we show that GABA-releasing neurons of the VTA that project to the NAc (VTA GABA projection neurons) inhibit accumbal cholinergic interneurons (CINs) to enhance stimulus-outcome learning. Combining optogenetics with structural imaging and electrophysiology, we found that VTA GABA projection neurons selectively target NAc CINs, forming multiple symmetrical synaptic contacts that generated inhibitory postsynaptic currents. This is remarkable considering that CINs represent a very small population of all accumbal neurons, and provide the primary source of cholinergic tone in the NAc. Brief activation of this projection was sufficient to halt the spontaneous activity of NAc CINs, resembling the pause recorded in animals learning stimulus-outcome associations. Indeed, we found that forcing CINs to pause in behaving mice enhanced discrimination of a motivationally important stimulus that had been associated with an aversive outcome. Our results demonstrate that VTA GABA projection neurons, through their selective targeting of accumbal CINs, provide a novel route through which the VTA communicates saliency to the NAc. VTA GABA projection neurons thus emerge as orchestrators of dopaminergic and cholinergic modulation in the NAc.

  1. An Investigation of Read Speech of Arabic Students Learning Turkish as a Second Language in Terms of Stress and Pause

    Derman, Serdar; Bardakçi, Mehmet; Öztürk, Mustafa Serkan


    Suprasegmental features are essential in conveying meaning; however, they are one of the neglected topics in teaching Turkish as a foreign/second language. This paper aims to examine read speech by Arabic students learning Turkish as a second language and describe their read speech in terms of stress and pause. Within this framework, 34 Syrian…

  2. A Diagnostic Marker to Discriminate Childhood Apraxia of Speech from Speech Delay: IV. the Pause Marker Index

    Shriberg, Lawrence D.; Strand, Edythe A.; Fourakis, Marios; Jakielski, Kathy J.; Hall, Sheryl D.; Karlsson, Heather B.; Mabie, Heather L.; McSweeny, Jane L.; Tilkens, Christie M.; Wilson, David L.


    Purpose: Three previous articles provided rationale, methods, and several forms of validity support for a diagnostic marker of childhood apraxia of speech (CAS), termed the pause marker (PM). Goals of the present article were to assess the validity and stability of the PM Index (PMI) to scale CAS severity. Method: PM scores and speech, prosody,…

  3. Interventions for Echolalic Behaviour for Children with Autism: A Review of Verbal Prompts and the Cues Pause Point Procedure.

    Kavon, Nicole M.; McLaughlin, T. F.


    This paper examines behavior interventions for echolalic behavior in children with autism, including verbal prompting (focusing on the echolalic behavior itself) and the cues-pause-point procedure (which employs the child's prerequisite skills to teach correct verbal responses). A review of the literature indicated that both techniques were…

  4. Speech and Pause Characteristics Associated with Voluntary Rate Reduction in Parkinson’s disease and Multiple Sclerosis

    Tjaden, Kris; Wilding, Greg


    The primary purpose of this study was to investigate how speakers with Parkinson’s disease (PD) and Multiple Sclerosis (MS) accomplish voluntary reductions in speech rate. A group of talkers with no history of neurological disease was included for comparison. This study was motivated by the idea that knowledge of how speakers with dysarthria voluntarily accomplish a reduced speech rate would contribute toward a descriptive model of speaking rate change in dysarthria. Such a model has the potential to assist in identifying rate control strategies to receive focus in clinical treatment programs and also would advance understanding of global speech timing in dysarthria. All speakers read a passage in Habitual and Slow conditions. Speech rate, articulation rate, pause duration, and pause frequency were measured. All speaker groups adjusted articulation time as well as pause time to reduce overall speech rate. Group differences in how voluntary rate reduction was accomplished were primarily one of quantity or degree. Overall, a slower-than-normal rate was associated with a reduced articulation rate, shorter speech runs that included fewer syllables, and longer more frequent pauses. Taken together, these results suggest that existing skills or strategies used by patients should be emphasized in dysarthria training programs focusing on rate reduction. Results further suggest that a model of voluntary speech rate reduction based on neurologically normal speech shows promise as being applicable for mild to moderate dysarthria. PMID:21767851

  5. Case report: paradoxical ventricular septal motion in the setting of primary right ventricular myocardial failure.

    Maslow, Andrew; Schwartz, Carl; Mahmood, Feroze; Singh, Arun; Heerdt, Paul M


    In this report, a case of right ventricular (RV) failure, hemodynamic instability, and systemic organ failure is described to highlight how paradoxical ventricular systolic septal motion (PVSM), or a rightward systolic displacement of the interventricular septum, may contribute to RV ejection. Multiple inotropic medications and vasopressors were administered to treat right heart failure and systemic hypotension in a patient following combined aortic and mitral valve replacement. In the early postoperative period, echocardiographic evaluation revealed adequate left ventricular systolic function, akinesis of the RV myocardial tissues, and PVSM. In the presence of PVSM, RV fractional area of contraction was > or =35% despite akinesis of the primary RV myocardial walls. The PVSM appeared to contribute toward RV ejection. As a result, the need for multiple inotropes was re-evaluated, in considering that end-organ dysfunction was the result of systemic hypotension and prolonged vasopressor administration. After discontinuation of phosphodiesterase inhibitors, native vascular tone returned and the need for vasopressors declined. This was followed by recovery of systemic organ function. Echocardiographic re-evaluation two years later, revealed persistent akinesis of the RV myocardial tissues and PVSM, the latter appearing to contribute toward RV ejection. This case highlights the importance of left to RV interactions, and how PVSM may mediate these hemodynamic interactions.

  6. Ventricular Assist Device Support: for Management of Sustained Ventricular Arrhythmias


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the s...

  7. Post-extrasystolic potentiation without a compensatory pause in normal and diseased hearts

    Kuijer, P.J.P.; Werf, T. van der; Meijler, F.L.


    Variables derived from left ventricular volume were used to study post-extrasystolic potentiation. Left ventriculograms were obtained from 11 healthy individuals and 49 patients with coronary heart disease (30 with a previous myocardial infarction and 19 without any signs of myocardial damage). Post

  8. Acidosis slows electrical conduction through the atrio-ventricular node

    Ashley Muir Nisbet


    Full Text Available Acidosis affects the mechanical and electrical activity of mammalian hearts but comparatively little is known about its effects on the function of the atrio-ventricular node (AVN. In this study, the electrical activity of the epicardial surface of the left ventricle of isolated Langendorff-perfused rabbit hearts was examined using optical methods. Perfusion with hypercapnic Tyrode’s solution (20% CO2, pH 6.7 increased the time of earliest activation (Tact from 100.5+7.9 to 166.1+7.2ms (n=8 at a pacing cycle length (PCL of 300ms (37oC. Tact increased at shorter PCL, and the hypercapnic solution prolonged Tact further: at 150ms PCL, Tact was prolonged from 131.0+5.2 to 174.9+16.3ms. 2:1 AVN block was common at shorter cycle lengths. Atrial and ventricular conduction times were not significantly affected by the hypercapnic solution suggesting that the increased delay originated in the AVN. Isolated right atrial preparations were superfused with Tyrode’s solutions at pH 7.4 (control, 6.8 and 6.3. Low pH prolonged the atrial-Hisian (AH interval, the effective and functional refractory periods and Wenckebach cycle length significantly. Complete AVN block occurred in 6 out of 9 preparations. Optical imaging of conduction at the AV junction revealed increased conduction delay in the region of the AVN, with less marked effects in atrial and ventricular tissue. Thus acidosis can dramatically prolong the AVN delay, and in combination with short cycle lengths, this can cause partial or complete AVN block and is therefore implicated in the development of brady-arrhythmias in conditions of local or systemic acidosis.

  9. Quinidine elicits proarrhythmic changes in ventricular repolarization and refractoriness in guinea-pig.

    Osadchii, Oleg E


    Quinidine is a class Ia Na(+) channel blocker that prolongs cardiac repolarization owing to the inhibition of I(Kr), the rapid component of the delayed rectifier current. Although quinidine may induce proarrhythmia, the contributing mechanisms remain incompletely understood. This study examined whether quinidine may set proarrhythmic substrate by inducing spatiotemporal abnormalities in repolarization and refractoriness. The monophasic action potential duration (APD), effective refractory periods (ERPs), and volume-conducted electrocardiograms (ECGs) were assessed in perfused guinea-pig hearts. Quinidine was found to produce the reverse rate-dependent prolongation of ventricular repolarization, which contributed to increased steepness of APD restitution. Throughout the epicardium, quinidine elicited a greater APD increase in the left ventricular chamber compared with the right ventricle, thereby enhancing spatial repolarization heterogeneities. Quinidine prolonged APD to a greater extent than ERP, thus extending the vulnerable window for ventricular re-excitation. This change was attributed to increased triangulation of epicardial action potential because of greater APD lengthening at 90% repolarization than at 30% repolarization. Over the transmural plane, quinidine evoked a greater ERP prolongation at endocardium than epicardium and increased dispersion of refractoriness. Premature ectopic beats and monomorphic ventricular tachycardia were observed in 50% of quinidine-treated heart preparations. In summary, abnormal changes in repolarization and refractoriness contribute greatly to proarrhythmic substrate upon quinidine infusion.

  10. Ventricular dysfunction in a family with long QT syndrome type 3

    Hummel, Yoran M.; Wilde, Arthur A. M.; Voors, Adriaan A.; Bugatti, Silvia; Hillege, Hans L.; van den Berg, Maarten P.


    Long QT syndrome (LQTS) type 3 is characterized by prolonged ventricular repolarization due to persistent sodium inward current secondary to a mutation in SCN5a, the gene encoding for the -subunit of the sodium channel. We speculated that by disrupting calcium homeostasis the persistent inward sodiu

  11. Prolonged unexplained fatigue in paediatrics

    Bakker, R.J.


    Prolonged Unexplained Fatigue in Paediatrics. Fatigue, as the result of mental or physical exertion, will disappear after rest, drinks and food. Fatigue as a symptom of illness will recover with the recovering of the illness. But when fatigue is ongoing for a long time, and not the result of exertio

  12. Prolongation structures for supersymmetric equations

    Roelofs, G.H.M.; Hijligenberg, van den N.W.


    The well known prolongation technique of Wahlquist and Estabrook (1975) for nonlinear evolution equations is generalized for supersymmetric equations and applied to the supersymmetric extension of the KdV equation of Manin-Radul. Using the theory of Kac-Moody Lie superalgebras, the explicit form of

  13. Ventricular assist device support for management of sustained ventricular arrhythmias.

    Fasseas, Panayotis; Kutalek, Steven P; Samuels, Fania L; Holmes, Elena C; Samuels, Louis E


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias.

  14. Postpartal right ventricular thrombosis.

    Velicki, Lazar; Milosavljević, Aleksandar; Majin, Marijan; Vujin, Bojan; Kovacević, Pavle


    The discovery of an intracardial mass in patients presents a serious diagnostic dilemma. The differential diagnosis of this condition may seem abundant, but myxomas and intracardial thrombosis are the most frequent diagnoses. A connection between pregnancy and the presence of thrombosis has been documented frequently. Normal pregnancy leads to changes of the coagulative and fibrinolytic status toward a hypercoagulable condition which has its own physiological justification (the risk of blood loss decreases during labor). The case of a patient suffering from postpartal right ventricular thrombosis, which was successfully resolved by surgery as described in this contribution, demonstrates the value of a multidisciplinary approach.

  15. Ethnic classification in primary dental care and dental health services research: time to pause for thought.

    Buck, D J; Malik, S; Murphy, N; Patel, V; Singh, S; Syed, B; Vora, N


    'Ethnicity' is an important concept in dental health services research and in enabling general dental practitioners to gain insight into their patients values and expectations. Since more health services research is being undertaken in primary dental care settings it is becoming an important issue for dental professionals and researchers in primary care to be aware of. Ethnicity is thought to be related to dental health inequalities and access and is often used as a stratifying variable in many dental studies. The meaning and use of the term however differs among researchers and among the public. It is clear that researchers and professionals need to pause for thought when considering what this often bandied about term actually means and the impact of different definitions. This is illustrated using examples from the authors' own research and published papers in the medical and dental literature. There is also much debate about whether ethnicity--however defined--is an important predictor of differences in dental health in itself or is merely a marker for other factors such as social deprivation or the impact of 'place' on dental health. While the jury on this debate is out we suggest guidelines on the reporting of ethnicity should be outlined in the dental literature--perhaps updating those published in 1996 in the British Medical Journal.

  16. Clues cue the smooze: rhyme, pausing and prediction help children learn new words from storybooks

    Kirsten eRead


    Full Text Available Rhyme, which is ubiquitous in the language experiences of young children, may be especially facilitative to vocabulary learning because of how it can support active predictions about upcoming words. In two experiments, we tested whether rhyme, when used to help children anticipate new words would make those words easier to learn. Two- to 4-year-old children heard rhyming stanzas naming novel monsters under three conditions: A non-rhyme condition in which novel monster names appeared as unrhymed elements within a rhymed stanza, a non-predictive rhyme condition in which the novel names were the rhymed element in the first line of a stanza, and a predictive rhyme condition in which the monster name came as the rhymed element in the last line of the stanza after a description of the features that distinguished him. In tests of retention and identification children showed greatest novel name learning in the predictive rhyme condition in both between-subjects (Experiment 1 and within-subjects (Experiment 2 comparisons. Additionally, when parents acted as the storybook readers in Experiment 2, many of them distinctly paused before target words in the predictive rhyme condition and for their children a stronger predictive rhyme advantage surfaced. Thus rhyme is not only facilitative for learning, but when the novel vocabulary is specifically in a position where it is predictable from the rhymes, it is most accessible.

  17. Getting from how to why: a pause for reflection on professional life.

    McEntyre, M C


    In the course of institutional life, many may lose their sense of purpose. The daily demands of both medicine and teaching--small defeats, time pressures, bureaucratic obstacles, and chronic overload--can erode the sense of purpose and clarity of desire that infuse work with spirit and energy. One antidote for this drained state is time for renewal--not long periods of rest and relaxation, valuable though these may be, but rather a "particular kind of stopping . . . the pause for a poem." The author describes how stopping in the middle of the day to read and reflect on a poem can defamiliarize the familiar, giving the reader a fresh outlook on the ordinary day. She describes how poetry also can awaken a sense of play, a childlike openness and sense of curiosity, and a renewed awareness of feelings. To honor feeling can provide a needed corrective to the conventionalized response that has become thoughtless or bloodless or tired. The kind of play poems engage readers in can also provide a connection to the sacred, restoring the wider vision and deeper purposes without which the practice of medicine might diminish to something less lifegiving for both patient and physician than it ought to be. In her discussion of the restorative power of poetry, the author quotes several poems in full and invites readers to consider the fresh perspectives they offer.

  18. Filled pause refinement based on the pronunciation probability for lecture speech.

    Long, Yan-Hua; Ye, Hong


    Nowadays, although automatic speech recognition has become quite proficient in recognizing or transcribing well-prepared fluent speech, the transcription of speech that contains many disfluencies remains problematic, such as spontaneous conversational and lecture speech. Filled pauses (FPs) are the most frequently occurring disfluencies in this type of speech. Most recent studies have shown that FPs are widely believed to increase the error rates for state-of-the-art speech transcription, primarily because most FPs are not well annotated or provided in training data transcriptions and because of the similarities in acoustic characteristics between FPs and some common non-content words. To enhance the speech transcription system, we propose a new automatic refinement approach to detect FPs in British English lecture speech transcription. This approach combines the pronunciation probabilities for each word in the dictionary and acoustic language model scores for FP refinement through a modified speech recognition forced-alignment framework. We evaluate the proposed approach on the Reith Lectures speech transcription task, in which only imperfect training transcriptions are available. Successful results are achieved for both the development and evaluation datasets. Acoustic models trained on different styles of speech genres have been investigated with respect to FP refinement. To further validate the effectiveness of the proposed approach, speech transcription performance has also been examined using systems built on training data transcriptions with and without FP refinement.

  19. Genome-wide chromatin occupancy analysis reveals a role for ASH2 in transcriptional pausing.

    Pérez-Lluch, Sílvia; Blanco, Enrique; Carbonell, Albert; Raha, Debasish; Snyder, Michael; Serras, Florenci; Corominas, Montserrat


    An important mechanism for gene regulation involves chromatin changes via histone modification. One such modification is histone H3 lysine 4 trimethylation (H3K4me3), which requires histone methyltranferase complexes (HMT) containing the trithorax-group (trxG) protein ASH2. Mutations in ash2 cause a variety of pattern formation defects in the Drosophila wing. We have identified genome-wide binding of ASH2 in wing imaginal discs using chromatin immunoprecipitation combined with sequencing (ChIP-Seq). Our results show that genes with functions in development and transcriptional regulation are activated by ASH2 via H3K4 trimethylation in nearby nucleosomes. We have characterized the occupancy of phosphorylated forms of RNA Polymerase II and histone marks associated with activation and repression of transcription. ASH2 occupancy correlates with phosphorylated forms of RNA Polymerase II and histone activating marks in expressed genes. Additionally, RNA Polymerase II phosphorylation on serine 5 and H3K4me3 are reduced in ash2 mutants in comparison to wild-type flies. Finally, we have identified specific motifs associated with ASH2 binding in genes that are differentially expressed in ash2 mutants. Our data suggest that recruitment of the ASH2-containing HMT complexes is context specific and points to a function of ASH2 and H3K4me3 in transcriptional pausing control.

  20. Performance Evaluation of Aodv&DSR with Varying Pause Time & Node Density Over TCP&CBR Connections in Vanet

    Paul, Bijan; Bikas, Md Abu Naser


    Vehicular ad hoc network is formed by cars which are called nodes; allow them to communicate with one another without using any fixed road side unit. It has some unique characteristics which make it different from other ad hoc network as well as difficult to define any exact mobility model and routing protocols because of their high mobility and changing mobility pattern. Hence performance of routing protocols can vary with the various parameters such as speed, pause time, node density and traffic scenarios. In this research paper, the performance of two on-demand routing protocols AODV & DSR has been analyzed by means of packet delivery ratio, loss packet ratio & average end-to-end delay with varying pause time and node density under TCP & CBR connection.

  1. Performance Evaluation of AODV & DSR with Varying Pause Time & Speed Time Over TCP & CBR Connections in VANET

    Paul, Bijan; Bikas, Md Abu Naser


    VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Vehicular ad hoc network is formed by cars which are called nodes; allow them to communicate with one another without using any fixed road side unit. It has some unique characteristics which make it different from other ad hoc network as well as difficult to define any exact mobility model and routing protocols because of their high mobility and changing mobility pattern. Hence performance of routing protocols can vary with the various parameters such as speed, pause time, node density and traffic scenarios. In this research paper, the performance of two on-demand routing protocols AODV & DSR has been analyzed by means of packet delivery ratio, loss packet ratio & average end-to-end delay with varying pause time, speed time and node density under TCP & CBR connection.

  2. Pausing and activating thread state upon pin assertion by external logic monitoring polling loop exit time condition

    Chen, Dong; Giampapa, Mark; Heidelberger, Philip; Ohmacht, Martin; Satterfield, David L; Steinmacher-Burow, Burkhard; Sugavanam, Krishnan


    A system and method for enhancing performance of a computer which includes a computer system including a data storage device. The computer system includes a program stored in the data storage device and steps of the program are executed by a processer. The processor processes instructions from the program. A wait state in the processor waits for receiving specified data. A thread in the processor has a pause state wherein the processor waits for specified data. A pin in the processor initiates a return to an active state from the pause state for the thread. A logic circuit is external to the processor, and the logic circuit is configured to detect a specified condition. The pin initiates a return to the active state of the thread when the specified condition is detected using the logic circuit.

  3. Adolescent girls in Denmark use oral contraceptives at an increasingly young age, and with more pauses and shifts

    Løkkegaard, Ellen; Nielsen, Anne Kristine


    , adolescent girls have more pauses and shifts between types of hormonal contraceptives. Since 2010 there has been a shift toward use of second generation oral contraceptives away from third and fourth generation contraceptives. CONCLUSION: Adolescent girls tend to initiate their use of oral contraceptives...... at a younger age than the older cohorts do. Furthermore, they have more pauses and shift between products more frequently than older cohorts. The type of oral contraceptive used has shifted since 2010 towards older products with second generation progestins. FUNDING: The study was funded by salaries from North......INTRODUCTION: Use of hormonal contraceptives for birth control is commonplace in the Western World. In Europe, there is considerable variety in the frequency of use of hormonal contraceptives and in the age at which these contraceptives are initiated. The purpose of the present study...

  4. Performance Evaluation of AODV and DSR with Varying Pause Time and Speed Time Over TCP and CBR Connections in VANET

    Bijan Paul


    Full Text Available VANET (Vehicular Ad-hoc Network is a new technology which has taken enormous attention in the recent years. Vehicular ad hoc network is formed by cars which are called nodes; allow them to communicate with one another without using any fixed road side unit. It has some unique characteristics which make it different from other ad-hoc network as well as difficult to define any exact mobility model and routing protocols because of their high mobility and changing mobility pattern. Hence performance of routing protocols can vary with the various parameters such as speed, pause time, node density and traffic scenarios. In this research paper, the performance of two on-demand routing protocols AODV and DSR has been analyzed by means of packet delivery ratio, loss packet ratio average end-to-end delay with varying pause time, speed time and node density under TCP and CBR connection.

  5. Guanosine tetraphosphate as a global regulator of bacterial RNA synthesis: a model involving RNA polymerase pausing and queuing.

    Bremer, H; Ehrenberg, M


    A recently reported comparison of stable RNA (rRNA, tRNA) and mRNA synthesis rates in ppGpp-synthesizing and ppGpp-deficient (delta relA delta spoT) bacteria has suggested that ppGpp inhibits transcription initiation from stable RNA promoters, as well as synthesis of (bulk) mRNA. Inhibition of stable RNA synthesis occurs mainly during slow growth of bacteria when cytoplasmic levels of ppGpp are high. In contrast, inhibition of mRNA occurs mainly during fast growth when ppGpp levels are low, and it is associated with a partial inactivation of RNA polymerase. To explain these observations it has been proposed that ppGpp causes transcriptional pausing and queuing during the synthesis of mRNA. Polymerase queuing requires high rates of transcription initiation in addition to polymerase pausing, and therefore high concentrations of free RNA polymerase. These conditions are found in fast growing bacteria. Furthermore, the RNA polymerase queues lead to a promoter blocking when RNA polymerase molecules stack up from the pause site back to the (mRNA) promoter. This occurs most frequently at pause sites close to the promoter. Blocking of mRNA promoters diverts RNA polymerase to stable RNA promoters. In this manner ppGpp could indirectly stimulate synthesis of stable RNA at high growth rates. In the present work a mathematical analysis, based on the theory of queuing, is presented and applied to the global control of transcription in bacteria. This model predicts the in vivo distribution of RNA polymerase over stable RNA and mRNA genes for both ppGpp-synthesizing and ppGpp-deficient bacteria in response to different environmental conditions. It also shows how small changes in basal ppGpp concentrations can produce large changes in the rate of stable RNA synthesis.

  6. Right ventricular metastasis of leiomyosarcoma

    Stagmo Martin


    Full Text Available Abstract Metastatic presentation of leiomyosarcoma in the heart is very rare. We present transthoracic echocardiography and combined PET/CT images of a case with a large right ventricular metastasis of leiomyosarcoma. The patient was placed on cytostatic drugs for palliative purposes, but passed away one month later because of an untreatable ventricular tackycardia.

  7. Mitochondria and left ventricular hypertrophy

    Haiyan Zhu; Shiwen Wang


    @@ Introduction Left ventricular hypertrophy (LVH) is one of the vicious organ damages of essential hypertension.It contributes a lot to high mortality of essential hypertension due to sudden cardiac death,ventricular arrhythmia and heart failure.Many factors involve in the pathogenesis of hypertension-induced LVH including inherited variants as well as environmental factors.

  8. Divertículo ventricular congênito associado à taquicardia ventricular Congenital ventricular diverticulum associated with ventricular tachycardia

    Ranieli Pitol


    Full Text Available Divertículos ventriculares congênitos são raros. Clinicamente, podem ser assintomáticos ou causa de embolização sistêmica, insuficiência cardíaca, insuficiência valvar, ruptura ventricular, arritmia ventricular ou morte súbita. Apresentamos caso de uma mulher de 56 anos com taquicardia ventricular sustentada, na qual, durante a investigação, foi diagnosticada a presença de um divertículo na posição ínfero-basal do ventrículo esquerdo. Comentam-se as características clínicas e o tratamento desta doença infreqüente.Congenital ventricular diverticula are rare. Clinically, they may be asymptomatic or cause systemic embolization, heart failure, valvular regurgitation, ventricular rupture, ventricular arrhythmia, or sudden death. We report the case of a 56-year-old woman with sustained ventricular tachycardia, who, during investigation, was diagnosed with a diverticulum in the inferobasal portion of the left ventricle. The clinical characteristics and treatment of this rare disease are discussed.

  9. Mitral valve prolapse and electrolyte abnormality: a dangerous combination for ventricular arrhythmias.

    Rajani, Ali Raza; Murugesan, Vagishwari; Baslaib, Fahad Omar; Rafiq, Muhammad Anwer


    A 27-year-old woman with a history of bileaflet mitral valve prolapse and moderate mitral regurgitation presented to our emergency with untractable polymorphic wide complex tachycardia and unstable haemodynamics. After cardiopulmonary resuscitation, return of spontaneous circulation was achieved 30 min later. Her post-resuscitation ECG showed a prolonged QT interval which progressively normalised over the same day. Her laboratory investigations revealed hypocalcaemia while other electrolytes were within normal limits. A diagnosis of ventricular arrhythmia secondary to structural heart disease further precipitated by hypocalcaemia was made. Further hospital stay did not reveal a recurrence of prolonged QT interval or other arrhythmias except for an episode of non-sustained ventricular tachycardia. However, the patient suffered diffuse hypoxic brain encephalopathy secondary to prolonged cardiopulmonary resuscitation.

  10. The road to right ventricular septal pacing: techniques and tools.

    Mond, Harry G


    Prolonged right ventricular (RV) apical pacing is associated with progressive left ventricular dysfunction due to dysynchronous ventricular activation and contraction. RV septal pacing allows a narrower QRS compared to RV apical pacing, which might reflect a more physiological and synchronous ventricular activation. Previous clinical studies, which did not consistently achieve RV septal pacing, were not confirmatory and need to be repeated. This review summarizes the anatomy of the RV septum, the radiographic appearances of pacing leads in the RV, the electrocardiograph correlates of RV septal lead positioning, and the techniques and tools required for implantation of an active-fixation lead onto the RV septum. Using the described techniques and tools, conventional active-fixation leads can now be reliably secured to either the RV outflow tract septum or mid-RV septum with very low complication rates and good long-term performance. Even though physiologic and hemodynamic studies on true RV septal pacing have not been completed, the detrimental effects of long-term RV apical pacing are significant enough to suggest that it is now time to leave the RV apex and secure all RV leads onto the septum.

  11. Dwell-Time Distribution, Long Pausing and Arrest of Single-Ribosome Translation through the mRNA Duplex

    Ping Xie


    Full Text Available Proteins in the cell are synthesized by a ribosome translating the genetic information encoded on the single-stranded messenger RNA (mRNA. It has been shown that the ribosome can also translate through the duplex region of the mRNA by unwinding the duplex. Here, based on our proposed model of the ribosome translation through the mRNA duplex we study theoretically the distribution of dwell times of the ribosome translation through the mRNA duplex under the effect of a pulling force externally applied to the ends of the mRNA to unzip the duplex. We provide quantitative explanations of the available single molecule experimental data on the distribution of dwell times with both short and long durations, on rescuing of the long paused ribosomes by raising the pulling force to unzip the duplex, on translational arrests induced by the mRNA duplex and Shine-Dalgarno(SD-like sequence in the mRNA. The functional consequences of the pauses or arrests caused by the mRNA duplex and the SD sequence are discussed and compared with those obtained from other types of pausing, such as those induced by “hungry” codons or interactions of specific sequences in the nascent chain with the ribosomal exit tunnel.

  12. Prolonged fever after Infliximab infusion

    Jennifer; Katz; Michael; Frank


    Pharmacologic management for ulcerative colitis (UC) has recently been expanded to include antitumor necrosis factor (TNF) therapy for severe disease. Infliximab, a chimeric monoclonal antibody directed again TNF α was first tested in patients with Crohn’s disease. In addition to serious infections, malignancy, drug induced lupus and other autoimmune diseases, serum sickness-like reactions, neurological disease, and infusion reactions further complicate the use of Infliximab. We report a case of prolonged fever after Infliximab infusion to treat steroid refractory UC.

  13. Recurrent Ventricular Tachycardia in Sheehan’s Syndrome

    Bashir Ahmad Laway


    Full Text Available Sheehan’s syndrome is one of the common causes of hypopituitarism in developing countries. Electrocardiographic (ECG abnormalities in Sheehan’s syndrome are not well documented. However, in hypopituitarism due to other causes, ECG findings include low-voltage QRS complex, ST segment depression, T-wave inversion and prolonged QT interval. We hereby describe a 45-year-old female who presented with a history of recurrent syncope for last three years. Electrocardiography revealed ventricular tachycardia, which reverted back with hormone replacement therapy. Since it is a common problem in our community, clinicians should consider Sheehan’s syndrome as an etiology of metabolic disturbances leading to ventricular tachycardia in women.

  14. Symbolic dynamics of ventricular tachycardia and ventricular fibrillation

    Wang, Jun; Chen, Jie


    In this paper, the symbolic dynamics analysis was used to analyze the complexity of normal heartbeat signal (NSR), Ventricular tachycardia (VT) and ventricular fibrillation (VF) signals. By calculating the information entropy value of symbolic sequences, the complexities were quantified. Based on different information entropy values, NSR, VT and VF signals were distinguished with satisfactory results. The study showed that a sudden drop of symbolic sequence’s entropy value indicated that the patients most likely entered the episode of ventricular tachycardia and this was a crucial episode for the clinical treatment of patients. It had important clinical significance for the automatic diagnosis.

  15. Prolonged QT interval in a man with anorexia nervosa

    Macías-Robles, María Dolores; Perez-Clemente, Ana María; Maciá-Bobes, Carmen; Alvarez-Rueda, María Asunción; Pozo-Nuevo, Sergio


    Anorexia nervosa is an eating disorder characterized by the avoidance of food intake, which usually leads to a weight loss. Cardiac co-morbility is common and we can find sometimes a mass loss from the left ventricle, which can be seen by echocardiography. But the commonest complications are rhythm variations, typically bradycardia with a prolonged QT interval in up to a 40% of the cases, which altogether elevates ventricular tachycardia and sudden death risk. We present the case of a male who was diagnosed with anorexia nervosa and developed asthenia, a long QT interval and also a severe both hypokalaemia and hypomagnesaemia. We intend to discuss the pathogenic paths as well as prophylactic and therapeutic measures to this potentially-lethal pathology. PMID:19646241

  16. TbRGG2 facilitates kinetoplastid RNA editing initiation and progression past intrinsic pause sites.

    Ammerman, Michelle L; Presnyak, Vladimir; Fisk, John C; Foda, Bardees M; Read, Laurie K


    TbRGG2 is an essential kinetoplastid RNA editing accessory factor that acts specifically on pan-edited RNAs. To understand the mechanism of TbRGG2 action, we undertook an in-depth analysis of edited RNA populations in TbRGG2 knockdown cells and an in vitro examination of the biochemical activities of the protein. We demonstrate that TbRGG2 down-regulation more severely impacts editing at the 5' ends of pan-edited RNAs than at their 3' ends. The initiation of editing is reduced to some extent in TbRGG2 knockdown cells. In addition, TbRGG2 plays a post-initiation role as editing becomes stalled in TbRGG2-depleted cells, resulting in an overall decrease in the 3' to 5' progression of editing. Detailed analyses of edited RNAs from wild-type and TbRGG2-depleted cells reveal that TbRGG2 facilitates progression of editing past intrinsic pause sites that often correspond to the 3' ends of cognate guide RNAs (gRNAs). In addition, noncanonically edited junction regions are either absent or significantly shortened in TbRGG2-depleted cells, consistent with impaired gRNA transitions. Sequence analysis further suggests that TbRGG2 facilitates complete utilization of certain gRNAs. In vitro RNA annealing and in vivo RNA unwinding assays demonstrate that TbRGG2 can modulate RNA-RNA interactions. Collectively, these data are consistent with a model in which TbRGG2 facilitates initiation and 3' to 5' progression of editing through its ability to affect gRNA utilization, both during the transition between specific gRNAs and during usage of certain gRNAs.

  17. Cesium-induced QT-interval prolongation in an adolescent.

    O'Brien, Catherine E; Harik, Nada; James, Laura P; Seib, Paul M; Stowe, Cindy D


    Alternative medicine is becoming increasingly popular, especially with terminally ill patients. Most alternative remedies have not been adequately studied or proven effective for the diseases for which they are promoted. In the worst cases, these therapies are harmful. We describe a 16-year-old girl with metastatic hepatocellular carcinoma who experienced cesium-induced QT-interval prolongation after the start of a cesium chloride-based alternative treatment regimen. She had received seven courses of chemotherapy, with a cumulative doxorubicin dose of 500 mg/m(2) over 5 months, resulting in minimal tumor regression. Against the advice of her oncologist, she abandoned traditional therapy and started an alternative regimen that included cesium chloride supplements. Two weeks later, the patient went to a local emergency department after experiencing two brief syncopal episodes. An electrocardiogram revealed occasional premature ventricular contractions, a QTc interval of 683 msec (normal range for females 450-460 msec), and R on T phenomenon. She was admitted to the hospital and later experienced monomorphic ventricular tachycardia, which resolved spontaneously. Lidocaine therapy was started, and the patient was transferred to a cardiac intensive care unit at our hospital. Her plasma cesium level was 2400 microg/dl (normal cesium level was 1800 microg/dl, and her QTc interval was 494 msec. According to the Naranjo adverse drug reaction probability scale, cesium was the probable cause of the patient's arrhythmia. In animal models, cesium chloride has induced cardiac arrhythmias, including torsade de pointes. It inhibits delayed rectifier potassium channels in the myocardium, causing delayed repolarization and QT-interval prolongation. Patients with cancer should be aware that alternative remedies may be harmful and ineffective. Because patients may be unlikely to self-report alternative remedies, health care providers should specifically ask their patients about any

  18. Ventricular fibrillation following autologous intramyocardial cell therapy for inherited cardiomyopathy.

    Pytel, Peter; Husain, Aliya; Moskowitz, Ivan; Raman, Jai; MacLeod, Heather; Anderson, Allen S; Burke, Martin; McNally, Elizabeth M


    A 41-year-old male with cardiomyopathy from an inherited beta myosin heavy-chain mutation underwent treatment for heart failure with intramyocardial cell transplantation. He received direct injections into his heart of autologous precursor cells isolated from his blood. He immediately suffered ventricular fibrillation. Although he was resuscitated, he experienced a prolonged downward course that prohibited his undergoing transplantation. His autopsy revealed marked fibrosis throughout the myocardium with areas of mononuclear cell infiltrate. This case highlights the potential adverse effects associated with intramyocardial therapy in the cardiomyopathic heart.

  19. Ventricular fibrillation following autologous intramyocardial cell therapy for inherited cardiomyopathy

    Pytel, Peter; Husain, Aliya; Moskowitz, Ivan; Raman, Jai; MacLeod, Heather; Anderson, Allen S.; Burke, Martin; McNally, Elizabeth M.


    A 41 year old male with cardiomyopathy from an inherited β myosin heavy chain mutation underwent treatment for heart failure with intramyocardial cell transplantation. He received direct injections into his heart of autologous precursor cells isolated from his blood. He immediately suffered ventricular fibrillation. Although he was resuscitated, he experienced a prolonged downward course that prohibited his undergoing transplantation. His autopsy revealed marked fibrosis throughout the myocardium with areas of mononuclear cell infiltrate. This case highlights the potential adverse effects associated with intramyocardial therapy in the cardiomyopathic heart. PMID:19026577

  20. Subacute gastric perforation caused by a left ventricular assist device

    Demetris Yannopoulos


    This case report describes a rare complication of a left ventricular assist device (LVAD). A patient with ischemic cardiomyopathy had an LVAD placed due to intractable congestive heart failure following a large anterior myocardial infarction. The patient developed chronic bacteremia and multiple septic episodes. A gastric endoscopy revealed perforation of the anterior wall of the stomach by the LVAD. Gastric acid related erosions were present on the metallic surface suggesting prolonged exposure. This is the second case report of this rare complication and the first case report of a subacute course.

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

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


    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 dilatatio...

  2. Effects of Na+ channel blockers on extrasystolic stimulation-evoked changes in ventricular conduction and repolarization.

    Osadchii, Oleg E


    Antiarrhythmic agents which belong to class Ia (quinidine) and Ic (flecainide) reportedly increase propensity to ventricular tachyarrhythmia, whereas class Ib agents (lidocaine and mexiletine) are recognized as safe antiarrhythmics. Clinically, tachyarrhythmia is often initiated by a premature ectopic beat, which increases spatial nonuniformities in ventricular conduction and repolarization thus facilitating reentry. This study examined if electrical derangements evoked by premature excitation may be accentuated by flecainide and quinidine, but unchanged by lidocaine and mexiletine, which would explain the difference in their safety profile. In perfused guinea pig hearts, a premature excitation evoked over late repolarization phase was associated with prolonged epicardial activation time, reduced monophasic action potential duration (APD), and increased transepicardial dispersion of the activation time and APD. Flecainide and quinidine increased conduction slowing evoked by extrasystolic stimulation, prolonged APD, and accentuated spatial heterogeneities in ventricular conduction and repolarization associated with premature excitation. Spontaneous episodes of nonsustained monomorphic ventricular tachycardia were observed in 50% of heart preparations exposed to drug infusion. In contrast, lidocaine and mexiletine had no effect on extrasystolic stimulation-evoked changes in ventricular conduction and repolarization or arrhythmic susceptibility. These findings suggest that flecainide and quinidine may promote arrhythmia by exaggerating electrophysiological abnormalities evoked by ectopic beats.

  3. Docosahexaenoic acid has influence on action potentials and transient outward potassium currents of ventricular myocytes

    Yang Zhen-Yu


    Full Text Available Abstract Background There are many reports about the anti-arrhythmic effects of ω-3 polyunsaturated fatty acids, however, the mechanisms are still not completely delineated. The purpose of this study was to investigate the characteristics of action potentials and transient outward potassium currents (Ito of Sprague-Dawley rat ventricular myocytes and the effects of docosahexaenoic acid (DHA on action potentials and Ito. Methods The calcium-tolerant rat ventricular myocytes were isolated by enzyme digestion. Action potentials and Ito of epicardial, mid-cardial and endocardial ventricular myocytes were recorded by whole-cell patch clamp technique. Results 1. Action potential durations (APDs were prolonged from epicardial to endocardial ventricular myocytes (P 2. Ito current densities were decreased from epicardial to endocardial ventricular myocytes, which were 59.50 ± 15.99 pA/pF, 29.15 ± 5.53 pA/pF, and 12.29 ± 3.62 pA/pF, respectively at +70 mV test potential (P 3. APDs were gradually prolonged with the increase of DHA concentrations from 1 μmol/L to 100 μmol/L, however, APDs changes were not significant as DHA concentrations were in the range of 0 μmol/L to 1 μmol/L. 4. Ito currents were gradually reduced with the increase of DHA concentrations from 1 μmol/L to 100 μmol/L, and its half-inhibited concentration was 5.3 μmol/L. The results showed that there were regional differences in the distribution of action potentials and Ito in rat epicardial, mid-cardial and endocardial ventricular myocytes. APDs were prolonged and Ito current densities were gradually reduced with the increase of DHA concentrations. Conclusion The anti-arrhythmia mechanisms of DHA are complex, however, the effects of DHA on action potentials and Ito may be one of the important causes.

  4. The effects of sotalol on ventricular repolarization during exercise

    LI Jian; WANG Jia-nan


    Objective: Although after pacing animal and human studies have demonstrated a rate-dependent effect of sotalol on ventricular repolarization, there is little information on the effects of sotalol on ventricular repolarization during exercise. This study attempted to show the effects of sotalol on ventricular repolarization during physiological exercise. Methods: Thirty-one healthy volunteers (18 males, 13 females) were enrolled in the study. Each performed a maximal treadmill exercise test according to the Bruce protocol after random treatment with sotalol, propranolol and placebo. Results: Sotalol significantly prolonged QTc(corrected QT) and JTc (corrected JT) intervals at rest compared with propranolol (QTc 324.86 ms vs 305.21 ms, P<0.001; JTc245.04 ms vs 224.17 ms, P<0.001) and placebo (QTc 324.86 ms vs 314.06 ms, P<0.01; JTc 245.04 ms vs. 232.69 ms, P<0.001).The JTc percent reduction increased progressively with each stage of exercise and correlated positively with exercise heart rate(r=0.148, P<0.01). The JTc percent reduction correlation with exercise heart rate did not exist with either propranolol or placebo.Conclusions: These results imply that with sotalol ventricular repolarization is progressively shortened after exercise. Thus the specific class Ⅲ antiarrhythmic activity of sotalol, present as delay of ventricular repolarization, may be attenuated during exercise.Such findings may imply the need to consider other antiarrythmic therapy during periods of stress-induced tachycardia.

  5. Ventricular arrhythmias in Chagas disease

    Marco Paulo Tomaz Barbosa


    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.

  6. Survival without sequelae after prolonged cardiopulmonary resuscitation after electric shock.

    Motawea, Mohamad; Al-Kenany, Al-Sayed; Hosny, Mostafa; Aglan, Omar; Samy, Mohamad; Al-Abd, Mohamed


    "Electrical shock is the physiological reaction or injury caused by electric current passing through the human body. It occurs upon contact of a human body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair causing undesirable effects ranging from simple burns to death." Ventricular fibrillation is believed to be the most common cause of death after electrical shock. "The ideal duration of cardiac resuscitation is unknown. Typically prolonged cardiopulmonary resuscitation is associated with poor neurologic outcomes and reduced long term survival. No consensus statement has been made and traditionally efforts are usually terminated after 15-30 minutes." The case under discussion seems worthy of the somewhat detailed description given. It is for a young man who survived after 65 minutes after electrical shock (ES) after prolonged high-quality cardiopulmonary resuscitation (CPR), multiple defibrillations, and artificial ventilation without any sequelae. Early start of adequate chest compressions and close adherence to advanced cardiac life support protocols played a vital role in successful CPR.

  7. Calcium-activated potassium current modulates ventricular repolarization in chronic heart failure.

    Ingrid M Bonilla

    Full Text Available The role of I(KCa in cardiac repolarization remains controversial and varies across species. The relevance of the current as a therapeutic target is therefore undefined. We examined the cellular electrophysiologic effects of I(KCa blockade in controls, chronic heart failure (HF and HF with sustained atrial fibrillation. We used perforated patch action potential recordings to maintain intrinsic calcium cycling. The I(KCa blocker (apamin 100 nM was used to examine the role of the current in atrial and ventricular myocytes. A canine tachypacing induced model of HF (1 and 4 months, n = 5 per group was used, and compared to a group of 4 month HF with 6 weeks of superimposed atrial fibrillation (n = 7. A group of age-matched canine controls were used (n = 8. Human atrial and ventricular myocytes were isolated from explanted end-stage failing hearts which were obtained from transplant recipients, and studied in parallel. Atrial myocyte action potentials were unchanged by I(KCa blockade in all of the groups studied. I(KCa blockade did not affect ventricular myocyte repolarization in controls. HF caused prolongation of ventricular myocyte action potential repolarization. I(KCa blockade caused further prolongation of ventricular repolarization in HF and also caused repolarization instability and early afterdepolarizations. SK2 and SK3 expression in the atria and SK3 in the ventricle were increased in canine heart failure. We conclude that during HF, I(KCa blockade in ventricular myocytes results in cellular arrhythmias. Furthermore, our data suggest an important role for I(KCa in the maintenance of ventricular repolarization stability during chronic heart failure. Our findings suggest that novel antiarrhythmic therapies should have safety and efficacy evaluated in both atria and ventricles.

  8. Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation.

    Takatsuki, S; Mitamura, H; Ogawa, S


    A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.

  9. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement.

    Sung, June Min; Hong, Sung Jin; Chung, In Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo


    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture.

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

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


    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...... remodeling but very low mortality. Isokalemic and hyperkalemic responses indicate downregulation of functional IKs. Increased short-term variability during hypokalemia unmasks a reduced repolarization reserve....

  11. Aliskiren ameliorates sympathetic nerve sprouting and suppresses the inducibility of ventricular tachyarrhythmia in postinfarcted rat heart

    JIA Yin-yu; BAO Zhi-wei; WEI Mei-fang; ZHU Jian-hua; GUI Le


    Background Aliskiren is an oral renin inhibitor,which inhibits the first rate limiting step in the renin angiotensin aldosterone system.In this study,sympathetic nerve sprouting and the inducibility of ventricular fibrillation after aliskiren treatment in myocardial infarction were investigated.Methods Male Sprague Dawley rats after coronary artery ligation were randomly allocated to four groups:angiotensin converting enzyme inhibitor enalapril,angiotensin receptor blocker valsartan,β adrenergic receptor blocker carvedilol and rennin inhibitor aliskiren treatment for six weeks.Electrophysiological study,histological examination and Western blotting were performed.Results The plasma norepinephrine level and sympathetic nerve innervation significantly increased in treated infarcted rats compared to untreated rats.Aliskiren treatment reduced the sympathetic nerve innervations after myocardial infarction.There is no significant difference in sympathetic nerve innervations after myocardial infarction among the enalapril,valsartan,carvediloand or aliskiren treated groups.Programmed electrical stimulation study showed that inducible ventricular arrhythmia was reduced,ventricular fibrillation threshold was increased and ventricular effective refractory period was prolonged in enalapril,valsartan,carvedilol and aliskiren treated infarcted rats compared to untreated infarcted rats.Cardiomyocytic apoptosis in infarcted region was significantly decreased in enalapril,valsartan,carvedilol and aliskiren treated infarcted rats.Conclusions Aliskiren ameliorated cardiomyocytic apoptosis,attenuated the sympathetic nerve innervations and reduced the vulnerability of ventricular arrhythmias after myocardial infarction.Enalapril,valsartan and carvedilol have similar effects as aliskiren on cardiomyocytic apoptosis,sympathetic nerve innervations and vulnerability of ventricular arrhythmias after myocardial infarction.

  12. Mutational Pressure in Zika Virus: Local ADAR-Editing Areas Associated with Pauses in Translation and Replication

    Khrustalev, Vladislav V.; Khrustaleva, Tatyana A.; Sharma, Nitin; Giri, Rajanish


    Zika virus (ZIKV) spread led to the recent medical health emergency of international concern. Understanding the variations in virus system is of utmost need. Using available complete sequences of ZIKV we estimated directions of mutational pressure along the length of consensus sequences of three lineages of the virus. Results showed that guanine usage is growing in ZIKV RNA plus strand due to adenine to guanine transitions, while adenine usage is growing due to cytosine to adenine transversions. Especially high levels of guanine have been found in two-fold degenerated sites of certain areas of RNA plus strand with high amount of secondary structure. The usage of cytosine in two-fold degenerated sites shows direct dependence on the amount of secondary structure in 52% (consensus sequence of East African ZIKV lineage)—32% (consensus sequence of epidemic strains) of the length of RNA minus strand. These facts are the evidences of ADAR-editing of both strands of ZIKV genome during pauses in replication. RNA plus strand can also be edited by ADAR during pauses in translation caused by the appearance of groups of rare codons. According to our results, RNA minus strand of epidemic ZIKV strain has lower number of points in which polymerase can be stalled (allowing ADAR-editing) compared to other strains. The data on preferable directions of mutational pressure in epidemic ZIKV strain is useful for future vaccine development and understanding the evolution of new strains. PMID:28275585

  13. The Effects of Computer-assisted Pronunciation Readings on ESL Learners’ Use of Pausing, Stress, Intonation, and Overall Comprehensibility

    Mark Tanner


    Full Text Available With research showing the benefits of pronunciation instruction aimed at suprasegmentals (Derwing, Munro, & Wiebe, 1997, 1998; Derwing & Rossiter, 2003; Hahn, 2004; McNerney and Mendelsohn, 1992, more materials are needed to provide learners opportunities for self-directed practice. A 13-week experimental study was performed with 75 ESL learners divided into control and treatment groups. The treatment group was exposed to 11 weeks of self-directed computer-assisted practice using Cued Pronunciation Readings (CPRs. In the quasi-experimental pre-test/post-test design, speech perception and production samples were collected at Time 1 (week one of the study and Time 2 (week 13. Researchers analyzed the treatment’s effect on the learners’ perception and production of key suprasegmental features (pausing, word stress, and sentence-final intonation, and the learners’ level of perceived comprehensibility. Results from the statistical tests revealed that the treatment had a significant effect on learners’ perception of pausing and word stress and controlled production of stress, even with limited time spent practicing CPRs in a self-directed environment.

  14. Prolonged QT interval in Rett syndrome


    Rett syndrome is a severe neurodevelopmental disorder of unknown aetiology. A prolonged QT interval has been described previously in patients with Rett syndrome. To investigate QT prolongation and the presence of cardiac tachyarrhythmias in Rett syndrome electrocardiography and 24 hour Holter monitoring were performed prospectively in a cohort of 34 girls with Rett syndrome. The corrected QT value was prolonged in nine patients. Compared with a group of healthy controls of a...

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

    Ali Aydin

    Full Text Available BACKGROUND: Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation. METHODS AND RESULTS: 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. CONCLUSIONS: 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.

  16. Genetics Home Reference: arrhythmogenic right ventricular cardiomyopathy

    ... Twitter Home Health Conditions ARVC arrhythmogenic right ventricular cardiomyopathy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description Arrhythmogenic right ventricular cardiomyopathy ( ARVC ) is a form of heart disease that ...

  17. Flecainide attenuates rate adaptation of ventricular repolarization in guinea-pig heart

    Osadchii, Oleg E.


    OBJECTIVES: Flecainide is class Ic antiarrhythmic agent that was found to increase the risk of sudden cardiac death. Arrhythmic responses to flecainide could be precipitated by exercise, suggesting a role played by inappropriate rate adaptation of ventricular repolarization. This study therefore...... examined flecainide effect on adaptation of the QT interval and ventricular action potential duration (APD) to abrupt reductions of the cardiac cycle length. DESIGN: ECG and ventricular epicardial and endocardial monophasic APD were recorded in isolated, perfused guinea-pig heart preparations upon...... a sustained cardiac acceleration (rapid pacing for 30 s), and following a single perturbation of the cycle length evoked by extrasystolic stimulation. RESULTS: Sustained increase in heart rate was associated with progressive bi-exponential shortening of the QT interval and APD. Flecainide prolonged...

  18. Salade malade: malignant ventricular arrhythmias due to an accidental intoxication with Aconitum napellus

    Weijters, B.J.; Verbunt, R.J.A.M.; Hoogsteen, J.; Visser, R.F.


    Intoxication with Aconitum napellus is rare in our regions. Aconite alkaloids can cause ventricular arrhythmia by a prolonged activation of sodium channels. Because the margin of safety is low between the analgesic and toxic dose, intoxication is not rare when Aconite is used in herbal medicine. We present a case in which a 39-year-old male was accidentally intoxicated with Aconite. Even though no antidote or adequate therapy is available he was successfully resuscitated. (Neth Heart J 2008;1...

  19. Pharmacological inhibition of I-K1 by PA-6 in isolated rat hearts affects ventricular repolarization and refractoriness

    Skarsfeldt, Mark A.; Carstensen, Helena; Skibsbye, Lasse;


    .1 14.7 msec, 67%, P ventricular fibrillation was observed in two of six hearts. Neither atrial ERP nor duration of atrial fibrillation was altered following PA-6 application. The results show that pharmacological inhibition...... cycle length, and ventricular effective refractory period were determined following 200 nmol/L PA-6 perfusion. 200 nmol/L PA-6 resulted in a significant timelatency in drug effect on the IK1 current expressed in HEK-293 cells, giving rise to a maximal effect at 20 min. In the Langendorff-perfused heart...... experiments, PA-6 prolonged the ventricular action potential duration at 90% repolarization (from 41.8 6.5 msec to 72.6 21.1 msec, 74% compared to baseline, P ventricular effective refractory period compared to baseline (from 34.8 4.6 msec to 58...

  20. Catheter ablation of a polymorphic ventricular tachycardia inducing monofocal premature ventricular complex.

    Uemura, Takashi; Yamabe, Hiroshige; Tanaka, Yasuaki; Morihisa, Kenji; Kawano, Hiroaki; Kaikita, Koichi; Sumida, Hitoshi; Sugiyama, Seigo; Ogawa, Hisao


    Ventricular tachycardia originating from the right ventricular outflow tract (RVOT) is considered benign, but sometimes it causes polymorphic ventricular tachycardia and ventricular fibrillation, resulting in sudden cardiac death. A 58-year-old woman without structural heart disease was admitted for evaluation of recurrent episodes of syncope. Surface ECG showed frequent repetitive premature ventricular contraction (PVC) of RVOT origin. Polymorphic ventricular tachycardia triggered by the same PVC was documented by Holter ECG during an episode of syncope. Radiofrequency catheter ablation was performed to eradicate this PVC. No polymorphic ventricular tachycardia has developed after the procedure, and the patient has had no recurrence of syncope.

  1. Low-dose carvedilol reduces transmural heterogeneity of ventricular repolarization in congestive heart failure

    Jiang-hua ZHONG; Xiao-pan CHEN; Mei-ling YUN; Wei-jing LI; Yan-fang CHEN; Zhen YAO


    Aim: To study the effects of carvedilol on the transmural heterogeneity of ven-tricular repolarization in rabbits with congestive heart failure (CHF). Methods:Rabbits were randomly divided into 3 groups: control, CHF and carvedilol treated CHF group. Monophasic action potential duration (MAPD) in the 3 myocardial layers was simultaneously recorded. Results: All the rabbits in the CHF group had signs of severe CHF. Compared with the control group, the mean blood pressure and cardiac output were significantly decreased, while peripheral resis-tance was significantly increased in the CHF group. This proved that the CHF model was successful created with adriamycin in this study. Compared to the control group, the ventricular fibrillation threshold (VFT) was remarkably decreased and all MAPD of the 3 myocardial layers were extended in rabbits with CHF. However, the extension of MAPD in the midmyocardium was more obvious. The transmural dispersion of repolarization (TDR) was significantly increased in CHF.Low-dose carvedilol (0.25 mg/kg, twice daily) had no effects on ventricular remodeling. Treatment with low-dose carvedilol significantly increased VFT. Al-though the MAPD of the 3 myocardial layers were further prolonged in the carvedilol treated CHF group, the prolongation of MAPD in the midmyocardium was shorter than those in the epicardium and endocardium. Treatment with low-dose carvedilol significantly decreased TDR in CHF. Conclusion: In the present study, the trans-mural heterogeneity of ventricular repolarization increased in the rabbits with CHF. Low-dose carvedilol decreased the transmural heterogeneity of ventricular repolarization in CHF, which may be related to its direct electrophysiological pro-perty rather than its effect on ventricular remodeling.

  2. 21 CFR 882.4060 - Ventricular cannula.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular cannula. 882.4060 Section 882.4060...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4060 Ventricular cannula. (a) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  3. 21 CFR 882.4100 - Ventricular catheter.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular catheter. 882.4100 Section 882.4100...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4100 Ventricular catheter. (a) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for...

  4. Prolonged Pregnancy: Methods, Causal Determinants and Outcome

    Olesen, Annette Wind

    Summary Prolonged pregnancy, defined as a pregnancy with a gestational length of 294 days or more, is a frequent condition. It is associated with an increased risk of fetal and maternal complications. Little is known about the aetiology of prolonged pregnancy. The aims of the thesis were 1...

  5. Prenatal risk indicators of a prolonged pregnancy

    Olesen, Annette Wind; Westergaard, Jes Grabow; Olsen, Jørn


    BACKGROUND: Few prenatal risk factors of prolonged pregnancy, a pregnancy of 42 weeks or more, are known. The objective was to examine whether sociodemographic, reproductive, toxicologic, or medical health conditions were associated with the risk of prolonged pregnancy. METHODS: Data from the Dan...

  6. Facts about Ventricular Septal Defect

    ... Living With Heart Defects Data & Statistics Tracking & Research Articles & Key Findings Free Materials Multimedia and Tools Links to Other Websites Information For... Media Policy Makers Facts about Ventricular Septal Defect Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir ...

  7. Modulation of ventricular fibrillation in isolated perfused heart by dofetilide.

    Amitzur, Giora; Shenkar, Nitza; Leor, Jonathan; Novikov, Ilia; Eldar, Michael


    The authors studied the involvement of IKr potassium current in ventricular fibrillation during perfusion. Electrophysiologic parameters were measured before and after dofetilide administration (2.5, 7.5, and 12.5 x 10-7 M, n = 8) in isolated perfused feline hearts. During pacing, these parameters included epicardial conduction time, refractoriness, and the fastest rate for 1:1 pacing/response capture. During 8 minutes of electrically induced tachyarrhythmias, they included heart rate and normalized entropy reflecting the degree of organization. In all groups, arrhythmia rate was slower in the right ventricle than in the left ventricle. Dofetilide decreased the arrhythmia rate more than it increased organization, reduced its maintenance, or increased difficulty in initiation. Refractoriness was prolonged in a reverse use-dependent way which was less than 1:1 pacing/response capture. Unexpectedly, a moderate prolongation of conduction time was observed. Inverse correlation was found between the arrhythmia rate and changes in refractoriness and conduction time and between the degree of organization and refractoriness (both ventricles) and conduction time (right ventricle). Dofetilide, which intensively blocks IKr current and unexpectedly suppressed conduction, has different quantitative effects on fibrillation features. These changes in fibrillation suggest that these effects are mainly associated with refractoriness prolongation and do not seem to be attenuated by conduction suppression.

  8. Ethical challenges with the left ventricular assist device as a destination therapy

    Rady Mohamed Y


    Full Text Available Abstract The left ventricular assist device was originally designed to be surgically implanted as a bridge to transplantation for patients with chronic end-stage heart failure. On the basis of the REMATCH trial, the US Food and Drug Administration and the US Centers for Medicare & Medicaid Services approved permanent implantation of the left ventricular assist device as a destination therapy in Medicare beneficiaries who are not candidates for heart transplantation. The use of the left ventricular assist device as a destination therapy raises certain ethical challenges. Left ventricular assist devices can prolong the survival of average recipients compared with optimal medical management of chronic end-stage heart failure. However, the overall quality of life can be adversely affected in some recipients because of serious infections, neurologic complications, and device malfunction. Left ventricular assist devices alter end-of-life trajectories. The caregivers of recipients may experience significant burden (e.g., poor physical health, depression, anxiety, and posttraumatic stress disorder from destination therapy with left ventricular assist devices. There are also social and financial ramifications for recipients and their families. We advocate early utilization of a palliative care approach and outline prerequisite conditions so that consenting for the use of a left ventricular assist device as a destination therapy is a well informed process. These conditions include: (1 direct participation of a multidisciplinary care team, including palliative care specialists, (2 a concise plan of care for anticipated device-related complications, (3 careful surveillance and counseling for caregiver burden, (4 advance-care planning for anticipated end-of-life trajectories and timing of device deactivation, and (5 a plan to address the long-term financial burden on patients, families, and caregivers. Short-term mechanical circulatory devices (e

  9. The assessment of potential for QT interval prolongation with new pharmaceuticals: impact on drug development.

    Gralinski, M R


    Few examinations of a single physiological variable can end the development of a putative new pharmaceutical. Prolongation of the electrocardiographic QT interval is one of these tests. Recognizing the removal of several approved and widely used medicines, worldwide regulatory authorities have raised a heightened awareness on the submission of data surrounding the ventricular repolarization process. This review will discuss the anatomy and physiology surrounding the generation of the electrocardiographic QT interval and the consequences of its alteration. In addition, relevant models of preclinical safety and general guidelines for clinical examination in this area are discussed along with the impact of incorporating these assays into the drug development process.

  10. Structural basis of transcription: mismatch-specific fidelity mechanisms and paused RNA polymerase II with frayed RNA.

    Sydow, Jasmin F; Brueckner, Florian; Cheung, Alan C M; Damsma, Gerke E; Dengl, Stefan; Lehmann, Elisabeth; Vassylyev, Dmitry; Cramer, Patrick


    We show that RNA polymerase (Pol) II prevents erroneous transcription in vitro with different strategies that depend on the type of DNARNA base mismatch. Certain mismatches are efficiently formed but impair RNA extension. Other mismatches allow for RNA extension but are inefficiently formed and efficiently proofread by RNA cleavage. X-ray analysis reveals that a TU mismatch impairs RNA extension by forming a wobble base pair at the Pol II active center that dissociates the catalytic metal ion and misaligns the RNA 3' end. The mismatch can also stabilize a paused state of Pol II with a frayed RNA 3' nucleotide. The frayed nucleotide binds in the Pol II pore either parallel or perpendicular to the DNA-RNA hybrid axis (fraying sites I and II, respectively) and overlaps the nucleoside triphosphate (NTP) site, explaining how it halts transcription during proofreading, before backtracking and RNA cleavage.

  11. GSK3β is involved in the relief of mitochondria pausing in a Tau-dependent manner.

    María Llorens-Martín

    Full Text Available Mitochondrial trafficking deficits have been implicated in the pathogenesis of several neurological diseases, including Alzheimer's disease (AD. The Ser/Thre kinase GSK3β is believed to play a fundamental role in AD pathogenesis. Given that GSK3β substrates include Tau protein, here we studied the impact of GSK3β on mitochondrial trafficking and its dependence on Tau protein. Overexpression of GSK3β in neurons resulted in an increase in motile mitochondria, whereas a decrease in the activity of this kinase produced an increase in mitochondria pausing. These effects were dependent on Tau proteins, as Tau (-/- neurons did not respond to distinct GSK3β levels. Furthermore, differences in GSK3β expression did not affect other parameters like mitochondria velocity or mitochondria run length. We conclude that GSK3B activity regulates mitochondrial axonal trafficking largely in a Tau-dependent manner.

  12. The Impact of Promoting Transcription on Early Text Production: Effects on Bursts and Pauses, Levels of Written Language, and Writing Performance

    Alves, Rui A.; Limpo, Teresa; Fidalgo, Raquel; Carvalhais, Lénia; Pereira, Luísa Álvares; Castro, São Luís


    Writing development seems heavily dependent upon the automatization of transcription. This study aimed to further investigate the link between transcription and writing by examining the effects of promoting handwriting and spelling skills on a comprehensive set of writing measures (viz., bursts and pauses, levels of written language, and writing…

  13. A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: III. Theoretical Coherence of the Pause Marker with Speech Processing Deficits in Childhood Apraxia of Speech.

    Shriberg, Lawrence D; Strand, Edythe A; Fourakis, Marios; Jakielski, Kathy J; Hall, Sheryl D; Karlsson, Heather B; Mabie, Heather L; McSweeny, Jane L; Tilkens, Christie M; Wilson, David L


    Previous articles in this supplement described rationale for and development of the pause marker (PM), a diagnostic marker of childhood apraxia of speech (CAS), and studies supporting its validity and reliability. The present article assesses the theoretical coherence of the PM with speech processing deficits in CAS. PM and other scores were obtained for 264 participants in 6 groups: CAS in idiopathic, neurogenetic, and complex neurodevelopmental disorders; adult-onset apraxia of speech (AAS) consequent to stroke and primary progressive apraxia of speech; and idiopathic speech delay. Participants with CAS and AAS had significantly lower scores than typically speaking reference participants and speech delay controls on measures posited to assess representational and transcoding processes. Representational deficits differed between CAS and AAS groups, with support for both underspecified linguistic representations and memory/access deficits in CAS, but for only the latter in AAS. CAS-AAS similarities in the age-sex standardized percentages of occurrence of the most frequent type of inappropriate pauses (abrupt) and significant differences in the standardized occurrence of appropriate pauses were consistent with speech processing findings. Results support the hypotheses of core representational and transcoding speech processing deficits in CAS and theoretical coherence of the PM's pause-speech elements with these deficits.

  14. Postreinforcement Pause Duration Varies within a Session and with a Variable Response Requirement but Not as a Function of Prior Revolutions

    Belke, Terry W.


    The current study examined the variables that influence postreinforcement pause (PRP) duration in rats when wheel running serves as the reinforcing consequence. The relationship between revolutions and PRP duration when revolutions were manipulated within a session and the effect of changing the response requirement from fixed to variable on PRP…

  15. Lysophosphatidic acid increases the electrophysiological instability of adult rabbit ventricular myocardium by augmenting L-type calcium current.

    Yong Wei

    Full Text Available Lysophosphatidic acid (LPA has diverse actions on the cardiovascular system and is widely reported to modulate multiple ion currents in some cell types. However, little is known about its electrophysiological effects on cardiac myocytes. This study investigated whether LPA has electrophysiological effects on isolated rabbit myocardial preparations. The results indicate that LPA prolongs action potential duration at 90% repolarization (APD(90 in a concentration- and frequency-dependent manner in isolated rabbit ventricular myocytes. The application of extracellular LPA significantly increases the coefficient of APD(90 variability. LPA increased L-type calcium current (I(Ca,L density without altering its activation or deactivation properties. In contrast, LPA has no effect on two other ventricular repolarizing currents, the transient outward potassium current (I(to and the delayed rectifier potassium current (I(K. In arterially perfused rabbit left ventricular wedge preparations, the monophasic action potential duration, QT interval, and Tpeak-end are prolonged by LPA. LPA treatment also significantly increases the incidence of ventricular tachycardia induced by S(1S(2 stimulation. Notably, the effects of LPA on action potentials and I(Ca,L are PTX-sensitive, suggesting LPA action requires a G(i-type G protein. In conclusion, LPA prolongs APD and increases electrophysiological instability in isolated rabbit myocardial preparations by increasing I(Ca,L in a G(i protein-dependent manner.

  16. Structured prediction for differentiating between normal rhythms, ventricular tachycardia, and ventricular fibrillation in the ECG.

    Alwan, Yaqub; Cvetkovic, Zoran; Curtis, Michael


    Recent studies have been performed on feature selection for diagnostics between non-ventricular rhythms and ventricular arrhythmias, or between non-ventricular fibrillation and ventricular fibrillation. However they did not assess classification directly between non-ventricular rhythms, ventricular tachycardia and ventricular fibrillation, which is important in both a clinical setting and preclinical drug discovery. In this study it is shown that in a direct multiclass setting, the selected features from these studies are not capable at differentiating between ventricular tachycardia and ventricular fibrillation. A high dimensional feature space, Fourier magnitude spectra, is proposed for classification, in combination with the structured prediction method conditional random fields. An improvement in overall accuracy, and sensitivity of every category under investigation is achieved.

  17. Atrial – Ventricular Septal Defect

    T Panagiotopoulos


    Full Text Available Atrial and ventricular septal defect constitute the most common congenital heart disease.Aim: Τhe aim of the present retrospective study was to record data and factors that affect atrial and ventricular septal defect.Method and material: The sample study included patients of both sexes who were hospitalized with diagnosis atrial and ventricular septal defect in a Cardiac Surgery hospital of Athens. A specially constructed printed form was used for data collection, where were recorded the demographic and personal variables, the pathological, surgical, cardiology and obstetric history, the habits of adults, as well as the personal characteristics of mothers. Analysis of data was performed by descriptive statistical analysis.Results: The sample study consisted of 101 individuals with diagnosis atrial or ventricular Septal Defect, of which 40% were boys and 60% girls. The 70% of the sample study suffered from atrial Septal Defect and the 30% suffered from ventricular Septal Defect. Regarding age, 12% of the sample study was 0-1 years old, 35% was >1 years old, 8% was >12-18 years old and 45% over than 18 years old. Regarding educational status of the adult participants, 9% was of 0-6 years education, 22%>6 -12 years, 13%>12 years. 14% of the adult paticipants smoked, 4% consumed alcohol and 5% smoked in conjunction with alcohol. In terms of the obstetric history of the sample studied, 32% of the cases had normal birth, 4% had a twin birth and 1% had a triplet one. According to the variables related to mothers, the mean age of the mother was 30 years and 3 months, 10% were smokers at pregnancy and 3% used chemical substance and mainly hair color. Also, the results of the present study showed that individuals of 12-18 and >18 years old did not suffer from ventricular Septal Defect, whereas the infants 0-1 years old did not suffer from Atrial Septal Defect. The mean value of age at the admission in intensive care unit was 7 months (12% for the infants




    To study prognostic factors in patients with sustained ventricular tachycardias (VT) or ventricular fibrillation (VF) complicated by left ventricular dysfunction, we evaluated the predictive value of demographic, clinical, and hemodynamic parameters for cardiac mortality and sudden cardiac death in

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

    Corrado, Domenico


    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.

  20. Uremic retention solute indoxyl sulfate level is associated with prolonged QTc interval in early CKD patients.

    Tang, Wei-Hua; Wang, Chao-Ping; Chung, Fu-Mei; Huang, Lynn L H; Yu, Teng-Hung; Hung, Wei-Chin; Lu, Li-Fen; Chen, Po-Yuan; Luo, Ching-Hsing; Lee, Kun-Tai; Lee, Yau-Jiunn; Lai, Wen-Ter


    Total mortality and sudden cardiac death is highly prevalent in patients with chronic kidney disease (CKD). In CKD patients, the protein-bound uremic retention solute indoxyl sulfate (IS) is independently associated with cardiovascular disease. However, the underlying mechanisms of this association have yet to be elucidated. The relationship between IS and cardiac electrocardiographic parameters was investigated in a prospective observational study among early CKD patients. IS arrhythmogenic effect was evaluated by in vitro cardiomyocyte electrophysiological study and mathematical computer simulation. In a cohort of 100 early CKD patients, patients with corrected QT (QTc) prolongation had higher IS levels. Furthermore, serum IS level was independently associated with prolonged QTc interval. In vitro, the delay rectifier potassium current (IK) was found to be significantly decreased after the treatment of IS in a dose-dependent manner. The modulation of IS to the IK was through the regulation of the major potassium ion channel protein Kv 2.1 phosphorylation. In a computer simulation, the decrease of IK by IS could prolong the action potential duration (APD) and induce early afterdepolarization, which is known to be a trigger mechanism of lethal ventricular arrhythmias. In conclusion, serum IS level is independently associated with the prolonged QTc interval in early CKD patients. IS down-regulated IK channel protein phosphorylation and the IK current activity that in turn increased the cardiomyocyte APD and QTc interval in vitro and in the computer ORd model. These findings suggest that IS may play a role in the development of arrhythmogenesis in CKD patients.

  1. Hippocampal Abnormalities in Prolonged Febrile Seizures

    J Gordon Millichap


    Full Text Available Apparent diffusion coefficient (ADC measurements were used to characterize hippocampal edema within 5 days of a prolonged febrile seizure (PFS in a study at Great Ormond Street Hospital, London, UK.

  2. MRI Abnormalities After Prolonged Febrile Seizures

    J Gordon Millichap


    Full Text Available The clinical, radiologic, and laboratory findings of 17 Asian patients with encephalopathy following a prolonged febrile seizure were reviewed retrospectively at Kameda Medical Center, and other centers in Japan and San Francisco, USA.

  3. Ventricular hypertrophy--physiological mechanisms.

    Vaughan Williams, E M


    Adult cardiac myocytes are incapable of mitosis. Dead cells are replaced by connective tissue so that after myocardial infarction (MI), function can only be restored by compensatory hypertrophy of the surviving myocardium. In physiological hypertrophy in response to exercise, high altitude, or mild hypertension, additional myoplasm expands cell diameter in an orderly fashion; Z-lines are in register and the normal ratio of volume densities of contractile elements, mitochondria, and capillaries is conserved. In hypertrophy induced by aortic or pulmonary artery banding or by experimental or congenital hypertension, the borderline between physiological and pathological hypertrophy may be crossed, causing disorganization of fibers and an unfavourable contractile element to capillary ratio. There was, therefore, a need for a graded model of hypertrophy, which involves simulating an altitude of 6,000 m at sea level by supplying rabbits with appropriate nitrogen/oxygen mixtures. In this environment, 50% right ventricular hypertrophy can be achieved without alteration of left ventricular weight or hematocrit. Longer exposures produced 100% right ventricular hypertrophy, with only moderate increases in hematocrit and left ventricular weight. It is well known that adrenergic stimulation causes cardiac hypertrophy, and it has been suggested that release of a trophic factor from sympathetic nerves, either noradrenaline or a protein, might be a necessary stimulus for growth. If so, long-term treatment of post-MI patients with beta-adrenergic blocking agents could inhibit a desirable compensatory hypertrophy of the surviving myocardium. In the above model it has been found, however, that neither beta-blockade nor chemical sympathectomy with guanethidine or 6-hydroxydopamine had any effect on the hypertrophy, nor did treatment with verapamil or nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Increase in action potential duration and inhibition of the delayed rectifier outward current IK by berberine in cat ventricular myocytes.

    Sánchez-Chapula, J.


    1. In the present work, the effects of the antiarrhythmic drug, berberine, on action potential and ionic currents of cat ventricular myocytes were studied. 2. Berberine prolonged action potential duration in cat ventricular myocytes without altering other variables of the action potential. 3. The drug at concentrations of 0.3-30 microM blocked only the delayed rectifier (IK) current with an IC50 = 4.1 microM. Berberine produced a tonic block and a phasic block that was increased with the dura...

  5. Modeling and visualization of the activation wavefront propagation to improve understanding the QRS complex changes indicating left ventricular hypertrophy.

    Svehlikova, Jana; Zelinka, Jan; Bacharova, Ljuba; Tysler, Milan


    Activation wavefront propagation was computed and visualized in a geometrical heart model for pathological cases of reduced velocity of propagation, left ventricular hypertrophy and their combination. Selected parameters of a multiple dipole equivalent heart generator were computed and compared for three heart geometries and several degrees and extents of reduction of propagation velocity. First, the influence of geometrical changes modeling the left ventricular hypertrophy at reference propagation velocity was compared with reduction of the propagation velocity in the reference heart geometry. Reduced propagation velocity yielded similar or greater changes of the magnitude of the (electrical) heart vector representing the activation wavefront than the geometrical changes. Observations of the wavefront propagation with reduced velocity revealed longer presence of a large extent of the wavefront during depolarization which resulted in increased magnitude of the heart vector. The duration of depolarization was significantly prolonged only when the propagation velocity was decreased to 25% of its normal value. Changes of the direction of the maximal heart vector were dependent on the position of the region where the propagation velocity was reduced. Then the combination of the left ventricular hypertrophy and reduced propagation velocity was studied. Such combination enhanced the enlargement of the electrical heart vector and significantly prolonged the duration of depolarization. The influence of reduced activation velocity on the observed parameters was greater than the effect of the enlargement of the left ventricular mass. The presented study showed that intramyocardial conduction disturbances might cause increase of the actual surface area of propagation wavefront leading to changes of the amplitudes of ECG signals comparable with the changes resulting from the left ventricular hypertrophy. Intramyocardial conduction disturbances, as well as the modeled 50

  6. pH-dependent inhibition of K2P3.1 prolongs atrial refractoriness in whole hearts

    Skarsfeldt, Mark A; Jepps, Thomas A; Bomholtz, Sofia H


    displayed a more uniform expression of KCNK3 between atria and ventricle. In voltage-clamp experiments, ML365 and A293 were found to be potent and selective inhibitors of K2P3.1, but at pH 7.4, they failed to prolong atrial APD and refractory period (effective refractory period (ERP)) in isolated perfused...... rat and guinea pig hearts. At pH 7.8, which augments K2P3.1 currents, pharmacological channel inhibition produced a significant prolongation of atrial ERP (11.6 %, p = 0.004) without prolonging ventricular APD but did not display a significant antiarrhythmic effect in our guinea pig AF model (3...

  7. Premature ventricular contractions associated with isotretinoin use.

    Alan, Sevil; Ünal, Betül; Yildirim, Aytül


    Isotretinoin has been considered a unique drug for acne treatment. However, it is associated with numerous adverse effects. Isotretinoin can trigger premature ventricular contractions. This report describes a 33-year-old-woman who presented with palpitations for 1 week while undergoing 1-month isotretinoin treatment for mild-moderate facial acne. An electrocardiogram and Holter monitoring showed premature ventricular contractions during isotretinoin (Roaccutane, Roche) treatment. Isotretinoin-related premature ventricular contractions were strongly suggested in this case due to the existence of documented premature ventricular contractions on electrocardiograms and the disappearance of these premature ventricular contractions two weeks after termination of the treatment To the authors' knowledge, there has been 1 reported case of premature ventricular contractions linked to isotretinoin use; this report describes a second such case.

  8. Premature ventricular contractions associated with isotretinoin use*

    Alan, Sevil; Ünal, Betül; Yildirim, Aytül


    Isotretinoin has been considered a unique drug for acne treatment. However, it is associated with numerous adverse effects. Isotretinoin can trigger premature ventricular contractions. This report describes a 33-year-old-woman who presented with palpitations for 1 week while undergoing 1-month isotretinoin treatment for mild-moderate facial acne. An electrocardiogram and Holter monitoring showed premature ventricular contractions during isotretinoin (Roaccutane, Roche) treatment. Isotretinoin-related premature ventricular contractions were strongly suggested in this case due to the existence of documented premature ventricular contractions on electrocardiograms and the disappearance of these premature ventricular contractions two weeks after termination of the treatment To the authors' knowledge, there has been 1 reported case of premature ventricular contractions linked to isotretinoin use; this report describes a second such case. PMID:28099609

  9. [Heart failure with preserved left ventricular ejection fraction].

    Maeder, Micha T; Rickli, Hans


    Heart failure with preserved left ventricular ejection fraction (LVEF; HFpEF) is a common type of heart failure in the elderly, and it typically represents advanced hypertensive heart disease. The left ventricle in patients with HFpEF is characterized by concentric remodeling, normal LVEF, but reduced left longitudinal shortening, and importantly diastolic dysfunction. Dyspnoe and fatigue in patients with HFpEF are due to impaired left ventricular filling with a rapid increase in filling pressures and the lack of an increase in stroke volume during exercise. The diagnosis of HFpEF requires the careful exclusion of non-cardiac causes of dyspnoe as well as cardiac causes of dyspnoe associated with preserved LVEF other than HFpEF, primarily coronary artery disease and valve disease. Then, the following findings are required to make a diagnosis of HFpEF: a non-dilated left ventricle with an LVEF >50% and the presence of a significant diastolic impairment, which can be assessed using invasive haemodynamics, echocardiography, natriuretic peptides, or a combination of these tools. In contrast to patients with heart failure and reduced LVEF there is still no established treatment for patients with HFpEF, which prolongs survival or reduces the rate of hospitalizations for heart failure. There is currently however intense research going on in this field, and results from large trials evaluating the effects of various interventions on clinical endpoints are expected within the next years.

  10. Quality of drug label information on QT interval prolongation

    Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H;


    characteristics (SPC) of recently approved medicinal products. METHODS: Drug labels of products centrally approved in Europe between 2006 and 2012 were screened. Of drugs including the term 'QT' in the SPC, the message on QT-prolongation ('no prolongation'/'unclear drug-QT association'/'possibly QT......-prolongation'/'QT-prolongation') and the advice on cautionary measures pertaining to QT-prolongation in the label were examined, as well as their association. RESULTS: Of the 175 screened products, 44 contained information on QT in the SPC ('no QT-prolongation': 23%, 'unclear drug-QT association': 43%, 'possibly QT-prolongation': 16%, 'QT......-prolongation': 18%). 62% contained advices to act with caution in patients with additional risk factors for QT-prolongation. Products that more likely to have QT-prolonging properties according to the SPC provided more information on QT-prolongation in the SPC ('no prolongation': 10% and for the category 'QT...

  11. Urocortin2 prolongs action potential duration and modulates potassium currents in guinea pig myocytes and HEK293 cells.

    Yang, Li-Zhen; Zhu, Yi-Chun


    We previously reported that activation of corticotropin releasing factor receptor type 2 by urocortin2 up-regulates both L-type Ca(2+) channels and intracellular Ca(2+) concentration in ventricular myocytes and plays an important role in cardiac contractility and arrhythmogenesis. This study goal was to further test the hypothesis that urocortin2 may modulate action potentials as well as rapidly and slowly activating delayed rectifier potassium currents. With whole cell patch-clamp techniques, action potentials and slowly activating delayed rectifier potassium currents were recorded in isolated guinea pig ventricular myocytes, respectively. And rapidly activating delayed rectifier potassium currents were tested in hERG-HEK293 cells. Urocortin2 produced a time- and concentration-dependent prolongation of action potential duration. The EC50 values of action potential duration and action potential duration at 90% of repolarization were 14.73 and 24.3nM respectively. The prolongation of action potential duration of urocortin2 was almost completely or partly abolished by H-89 (protein kinase A inhibitor) or KB-R7943 (Na(+)/Ca(2+) exchange inhibitor) pretreatment respectively. And urocortin2 caused reduction of rapidly activating delayed rectifier potassium currents in hERG-HEK293 cells. In addition, urocortin2 slowed the rate of slowly activating delayed rectifier potassium channel activation, and rightward shifted the threshold of slowly activating delayed rectifier potassium currents to more positive potentials. Urocortin2 prolonged action potential duration via activation of protein kinase A and Na(+)/ Ca(2+) exchange in isolated guinea pig ventricular myocytes in a time- and concentration- dependent manner. In hERG-HEK293 cells, urocortin2 reduced rapidly activating delayed rectifier potassium current density which may contribute to action potential duration prolongation.

  12. Procainamide and lidocaine produce dissimilar changes in ventricular repolarization and arrhythmogenicity in guinea-pig.

    Osadchii, Oleg E


    Procainamide is class Ia Na(+) channel blocker that may prolong ventricular repolarization secondary to inhibition of IK r , the rapid component of the delayed rectifier K(+) current. In contrast to selective IN a blockers such as lidocaine, procainamide was shown to produce arrhythmogenic effects in the clinical setting. This study examined whether pro-arrhythmic responses to procainamide may be accounted for by drug-induced repolarization abnormalities including impaired electrical restitution kinetics, spatial gradients in action potential duration (APD), and activation-to-repolarization coupling. In perfused guinea-pig hearts, procainamide was found to prolong the QT interval on ECG and left ventricular (LV) epicardial monophasic APD, increased the maximum slope of electrical restitution, enhanced transepicardial APD variability, and eliminated the inverse correlation between the local APD and activation time values determined at distinct epicardial recording sites prior to drug infusion. In contrast, lidocaine had no effect on electrical restitution, the degree of transepicardial repolarization heterogeneities, and activation-to-repolarization coupling. Spontaneous episodes of monomorphic ventricular tachycardia were observed in 57% of procainamide-treated heart preparations. No arrhythmia was induced by lidocaine. In summary, this study suggests that abnormal changes in repolarization may contribute to pro-arrhythmic effects of procainamide.

  13. Speech and pause characteristics in multiple sclerosis: A preliminary study of speakers with high and low neuropsychological test performance



    This preliminary study investigated how cognitive-linguistic status in multiple sclerosis (MS) is reflected in two speech tasks (i.e. oral reading, narrative) that differ in cognitive-linguistic demand. Twenty individuals with MS were selected to comprise High and Low performance groups based on clinical tests of executive function and information processing speed and efficiency. Ten healthy controls were included for comparison. Speech samples were audio-recorded and measures of global speech timing were obtained. Results indicated predicted differences in global speech timing (i.e. speech rate and pause characteristics) for speech tasks differing in cognitive-linguistic demand, but the magnitude of these task-related differences was similar for all speaker groups. Findings suggest that assumptions concerning the cognitive-linguistic demands of reading aloud as compared to spontaneous speech may need to be re-considered for individuals with cognitive impairment. Qualitative trends suggest that additional studies investigating the association between cognitive-linguistic and speech motor variables in MS are warranted. PMID:23294227

  14. Replication fork progression is paused in two large chromosomal zones flanking the DNA replication origin in Escherichia coli.

    Akiyama, Masahiro Tatsumi; Oshima, Taku; Chumsakul, Onuma; Ishikawa, Shu; Maki, Hisaji


    Although the speed of nascent DNA synthesis at individual replication forks is relatively uniform in bacterial cells, the dynamics of replication fork progression on the chromosome are hampered by a variety of natural impediments. Genome replication dynamics can be directly measured from an exponentially growing cell population by sequencing newly synthesized DNA strands that were specifically pulse-labeled with the thymidine analogue 5-bromo-2'-deoxyuridine (BrdU). However, a short pulse labeling with BrdU is impracticable for bacteria because of poor incorporation of BrdU into the cells, and thus, the genomewide dynamics of bacterial DNA replication remain undetermined. Using a new thymidine-requiring Escherichia coli strain, eCOMB, and high-throughput sequencing, we succeeded in determining the genomewide replication profile in bacterial cells. We also found that fork progression is paused in two ~200-kb chromosomal zones that flank the replication origin in the growing cells. This origin-proximal obstruction to fork progression was overcome by an increased thymidine concentration in the culture medium and enhanced by inhibition of transcription. These indicate that DNA replication near the origin is sensitive to the impediments to fork progression, namely a scarcity of the DNA precursor deoxythymidine triphosphate and probable conflicts between replication and transcription machineries.

  15. Prolonged acute hepatitis A mimicking autoimmune hepatitis

    Rintaro Mikata; Osamu Yokosuka; Fumio Imazeki; Kenichi Fukai; Tatsuo Kanda; Hiromitsu Saisho


    AIM: We report a case with a prolonged course of hepatitisA, with alanine aminotransferase (ALT) higher than 500 IU/Lfor more than 2 mo.METHODS: A middle-aged woman had an elevated IgG level of more than 2 000 mg/dL, positive arti-nudear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), but no evidence of persistent hepatitis A virus (HAV) infection. Liver biopsy findings were compatible with prolonged acute hepatitis, although acute onset of autoimmune hepatitis could not be ruled out.RESULTS: It was assumed that she developed a course of hepatitis similar to autoimmune hepatitis triggered by HAV infection. Ursodeoxycholic acid (UDCA) treatment was initiated and a favorable outcome was obtained. CONCLUSION: We describe a case of a middle-aged woman who showed a prolonged course of acute hepatitis A mimicking autoimmune hepatitis. Treatment with UDCAproved to be effective.

  16. Acquired long QT syndrome and monomorphic ventricular tachycardia after alternative treatment with cesium chloride for brain cancer.

    Dalal, Anuj K; Harding, John D; Verdino, Ralph J


    Individuals searching for symptomatic relief or a potential cure are increasingly seeking and using nontraditional therapies for their various diseases. Little is known about the potential adverse effects that patients may encounter while undergoing these alternative treatments. Cesium chloride is an unregulated agent that has been reported to have antineoplastic properties. Cesium chloride is advertised as an alternative agent for many different types of cancers and can be purchased easily on the Internet. Recently, QT prolongation and polymorphic ventricular tachycardia were reported in several patients taking cesium chloride as alternative treatment for cancer. We report acquired QT prolongation and sustained monomorphic ventricular tachycardia in a patient who self-initiated and completed a course of cesium chloride as adjunctive treatment for brain cancer.

  17. Assessment of myocardial adrenergic innervation in patients with sick sinus syndrome: effect of asynchronous ventricular activation from ventricular apical stimulation

    Marketou, M E; Simantirakis, E N; Prassopoulos, V K; Chrysostomakis, S I; Velidaki, A A; Karkavitsas, N S; Vardas, P.E.


    Objective: To investigate ventricular sympathetic innervation in patients with sick sinus syndrome and to detect regional deterioration of adrenergic innervation caused by asynchronous ventricular activation from right ventricular pacing.

  18. Impact of the permanent ventricular pacing site on left ventricular function in children: A retrospective multicentre survey

    I.E. van Geldorp (Irene); T. Delhaas (Tammo); R.A. Gebauer (Roman); P. Frias (Patrick); M. Tomaske (Maren); M.K. Friedberg (Mark); S. Tisma-Dupanovic (Svjetlana); J. Elders (Jan); A. Früh (Andreas); F. Gabbarini (Fulvio); P. Kubuš (Petr); V. Illikova (Viera); E.C. Tsao (Elisa); A.C. Blank (Andreas Christian); A. Hiippala (Anita); T. Sluysmans (Thierry); P. Karpawich (Peter); S.A. Clur (Sally-Ann); X. Ganame (Xavier); K.K. Collins (Kathryn); G.C. Dann (Greg); J.-B. Thambo (Jean-Benoît); C. Trigo (Conceição); B. Nagel (Bert); J. Papagiannis (John); A. Rackowitz (Annette); J. Marek (Josef); J.-H. Nürnberg (Jan-Hendrik); W.Y. Vanagt (Ward); F.W. Prinzen (Frits); J. Janousek (Jan)


    textabstractBackground: Chronic right ventricular (RV) pacing is associated with deleterious effects on cardiac function. Objective In an observational multicentre study in children with isolated atrioventricular (AV) block receiving chronic ventricular pacing, the importance of the ventricular paci

  19. Impact of the permanent ventricular pacing site on left ventricular function in children : a retrospective multicentre survey

    van Geldorp, Irene E.; Delhaas, Tammo; Gebauer, Roman A.; Frias, Patrick; Tomaske, Maren; Friedberg, Mark K.; Tisma-Dupanovic, Svjetlana; Elders, Jan; Fruh, Andreas; Gabbarini, Fulvio; Kubus, Petr; Illikova, Viera; Tsao, Sabrina; Blank, Andreas Christian; Hiippala, Anita; Sluysmans, Thierry; Karpawich, Peter; Clur, Sally-Ann; Ganame, Xavier; Collins, Kathryn K.; Dann, Gisela; Thambo, Jean-Benoit; Trigo, Conceicao; Nagel, Bert; Papagiannis, John; Rackowitz, Annette; Marek, Jan; Nuernberg, Jan-Hendrik; Vanagt, Ward Y.; Prinzen, Frits W.; Janousek, Jan


    Background Chronic right ventricular (RV) pacing is associated with deleterious effects on cardiac function. Objective In an observational multicentre study in children with isolated atrioventricular (AV) block receiving chronic ventricular pacing, the importance of the ventricular pacing site on le

  20. Technical note: Electrocardiogram electrode repositioning for 320-row coronary CT angiography in patients with regular and recurrent premature ventricular contractions.

    Kondo, Takeshi; Matsutani, Hideyuki; Groarke, John; Takamura, Kazuhisa; Fujimoto, Shinichiro; Rybicki, Frank J; Kumamaru, Kanako K


    Arrhythmias can compromise image quality and increase radiation exposure during coronary CT angiography (CTA). However, premature ventricular contractions (PVCs) can occur in a predictable recurrent and regular pattern (ie, bigeminy, trigeminy, quadrigeminy) with post-PVC compensatory pauses. Electrocardiographic (ECG) electrode repositioning can achieve relative amplification of the R waves of PVCs compared with R waves of sinus beats. This technical note describes how simple ECG electrode repositioning, combined with an absolute-delay strategy, facilitated selective R waves of PVC ECG triggering of image acquisition in 6 patients with PVC bigeminy or quadrigeminy at the time of 320-row coronary CTA. All 6 studies were single heartbeat acquisition scans with excellent image quality and a median effective radiation dose of 2.9 mSv (interquartile range, 2.1-3.8 mSv). Standard ECG electrode positions used for 2 patients with PVC bigeminy undergoing coronary CTA were associated with an acquisition over 2 heartbeats and effective radiation doses of 6.8 and 10.3 mSv, respectively. In conclusion, ECG electrode repositioning combined with an absolute-delay strategy for regularly recurring PVCs, such as ventricular bigeminy, facilitates high image quality and lower radiation dose during coronary CTA. This simple and straightforward technique can be considered for all patients with regular and recurrent PVCs undergoing coronary CTA.

  1. Thoracic Epidural Anesthesia Reduces Right Ventricular Systolic Function With Maintained Ventricular-Pulmonary Coupling.

    Wink, Jeroen; de Wilde, Rob B P; Wouters, Patrick F; van Dorp, Eveline L A; Veering, Bernadette Th; Versteegh, Michel I M; Aarts, Leon P H J; Steendijk, Paul


    Blockade of cardiac sympathetic fibers by thoracic epidural anesthesia may affect right ventricular function and interfere with the coupling between right ventricular function and right ventricular afterload. Our main objectives were to study the effects of thoracic epidural anesthesia on right ventricular function and ventricular-pulmonary coupling. In 10 patients scheduled for lung resection, right ventricular function and its response to increased afterload, induced by temporary, unilateral clamping of the pulmonary artery, was tested before and after induction of thoracic epidural anesthesia using combined pressure-conductance catheters. Thoracic epidural anesthesia resulted in a significant decrease in right ventricular contractility (ΔESV25: +25.5 mL, P=0.0003; ΔEes: -0.025 mm Hg/mL, P=0.04). Stroke work, dP/dtMAX, and ejection fraction showed a similar decrease in systolic function (all Pright ventricular contractility increased (ΔESV25: -26.6 mL, P=0.0002; ΔEes: +0.034 mm Hg/mL, P=0.008), but ventricular-pulmonary coupling decreased (Δ(Ees/Ea) = -0.153, Pright ventricular contractility but does not inhibit the native positive inotropic response of the right ventricle to increased afterload. Right ventricular-pulmonary arterial coupling was decreased with increased afterload but not affected by the induction of thoracic epidural anesthesia. URL: Unique identifier: NTR2844. © 2016 American Heart Association, Inc.

  2. The pathophysiologic aspects and clinical implications of electrocardiographic parameters of ventricular conduction delay in repaired tetralogy of Fallot.

    Udink ten Cate, Floris E A; Sreeram, Narayanswami; Brockmeier, Konrad


    The 12-lead surface electrocardiogram is a valuable and feasible clinical tool in the management of patients following tetralogy of Fallot (TOF) repair. The importance of QRS duration in TOF patients has long been acknowledged. A prolonged QRS complex has been associated with increased risk for subsequent life-threatening ventricular arrhythmia and sudden cardiac death. Our current ability to risk-stratify TOF patients for malignant arrhythmogenic events primarily on the basis of QRS duration is rather limited. Nevertheless, increasing evidence suggests that QRS morphology and duration may be useful as surrogate markers of infundibular and regional right ventricular myocardial disease. The aim of this review is to provide a critical appraisal of the clinical implications of established and new electrocardiographic markers of ventricular conduction delay in TOF patients following surgical correction with a particular focus on QRS duration, lengthening, and fragmentation. In addition, the pathophysiological background of these parameters is addressed.

  3. Demonstration of Purkinje potential during idiopathic left ventricular tachycardia: a marker for ablation site by transient entrainment.

    Nishizaki, M; Arita, M; Sakurada, H; Ashikaga, T; Yamawake, N; Numano, F; Hiraoka, M


    During VT of QRS morphology with right bundle branch block and left axis deviation in a patient without obvious structural heart disease, entrainment by pacing from the right ventricular outflow tract and high right atrium was demonstrated. During entrainment of VT, a Purkinje potential preceding the QRS and recorded at the left ventricular mid-septum was activated by orthodromic impulses in the reentry circuit. The interval between the Purkinje potential and the earliest left ventricular activation was decrementally prolonged with shortening of pacing cycle length. Radiofrequency energy was applied to this site, resulting in successful elimination of VT. Therefore, the Purkinje potential represented activation by an orthodromic wavefront in the reentry circuit, while the orthodromically distal site to this potential showed an area of slow conduction with decremental property.

  4. Ventricular-Fold Dynamics in Human Phonation

    Bailly, Lucie; Bernardoni, Nathalie Henrich; Müller, Frank; Rohlfs, Anna-Katharina; Hess, Markus


    Purpose: In this study, the authors aimed (a) to provide a classification of the ventricular-fold dynamics during voicing, (b) to study the aerodynamic impact of these motions on vocal-fold vibrations, and (c) to assess whether ventricular-fold oscillations could be sustained by aerodynamic coupling with the vocal folds. Method: A 72-sample…

  5. Ventricular candidiasis in stone curlews (Burhinus oedicnemus).

    Caliendo, Valentina; Bull, Andrew


    Ventricular candidiasis is consistently one of the most prominent pathologic conditions diagnosed in stone curlews (Burhinus oedicnemus) in the United Arab Emirates, predominately affecting the captive population. Predisposing factors are a humid environment, stress, immunosuppression, inadequate nutrition, and an extended use of oral antibiotics. In this report, we describe the clinical signs, diagnosis, and pathologic result in stone curlews with ventricular candidiasis.

  6. Differences of promethazine and terfenadine on ion channels in guinea pig ventricular myocytes

    LI Xue-wen; NIU Shuan-cheng; ZHANG Xuan-ping; L(U) Ji-yuan; BAI Feng; ZHANG Ling; WU Bo-wei


    @@ Promethazine, a first generation antihistamine,has an antiarrhythmic effect on ischemia-reperfusion inducing arrhythmias1 and experimental arrhythmias.2 However, terfenadine as a second generation of antihistamine, has been reported to elicit hypotension, bradycardia, prolongation of the QTc interval and torsades de pointes (TdP) like ventricular arrhythmia.3 This may be due to the blockage on rectifier postassium current (Ik) of terfenadine, resulting in the prolongation of the action potential duration (APD) and dispersion of the repolarization duration, which might provoke a specific form of polymorphic ventricular tachydysrhythmia, i.e. TdP.4 In clinical practice,however, the class Ⅲ antiarrhythmic agents, which target on the Ik and prolong the action potential duration and QTc interval, rarely lead to arrhythmias.Other actions must be considered to underlie the arrhythmogenic tendency of terfenadine besides its inhibition on Ik. Though both promethazine and terfenadine block the H1 receptor, there must be a different pharmacology profile between the two compounds on ion channels of cardiac myocytes.Whole-cell patch clamp technique was used to investigate the effects of these two antagonists of the H1 receptor on the main ion currents in cardiac electrical activities.

  7. [Ventricular tachyarrhythmias in patients with cardiomyopathy

    Henningsen, K.; Christensen, A.H.; Svendsen, Jesper Hastrup


    of patients discharged with the diagnostic codes ventricular tachycardia, ventricular fibrillation or premature ventricular contractions with cardiomyopathy as the presumed aetiology. Patients discharged during a period of 6 years and 5 months were included in the study. The patients were characterized......INTRODUCTION: The purpose of this study was to determine the number and distribution of cardiomyopathies as the aetiology of ventricular tachyarrhythmias among patients discharged from the Department of Cardiology, Rigshospitalet. MATERIALS AND METHODS: The study was a retrospective review......), 57 (45%) patients had arrhythmogenic right ventricular cardiomyopathy (ARVC) and 13 (10%) had hypertrophic cardiomyopathy (HCM). The average age was 44 years for HCM, 41 years for ARVC and 58 years for DCM. The majority of the patients were male. ICD treatment was used in 95% of the patients...

  8. Giant and thrombosed left ventricular aneurysm

    Jose; Alberto; de; Agustin; Jose; Juan; Gomez; de; Diego; Pedro; Marcos-Alberca; Jose; Luis; Rodrigo; Carlos; Almeria; Patricia; Mahia; Maria; Luaces; Miguel; Angel; Garcia-Fernandez; Carlos; Macaya; Leopoldo; Perez; de; Isla


    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur,including heart failure,thromboembolism,or tachyarrhythmias. We report the case of a 78-yearold male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded,and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm,causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.

  9. Giant and thrombosed left ventricular aneurysm.

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez


    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded, and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm, causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.


    Suzanne Schneider


    Full Text Available Prolonged exercise may compromise immunity through a reduction of salivary antimicrobial proteins (AMPs. Salivary IgA (IgA has been extensively studied, but little is known about the effect of acute, prolonged exercise on AMPs including lysozyme (Lys and lactoferrin (Lac. Objective: To determine the effect of a 50-km trail race on salivary cortisol (Cort, IgA, Lys, and Lac. Methods: 14 subjects: (6 females, 8 males completed a 50km ultramarathon. Saliva was collected pre, immediately after (post and 1.5 hrs post race ( 1.5. Results: Lac concentration was higher at 1.5 hrs post race compared to post exercise (p0.05. IgA concentration, secretion rate, and IgA/Osm were lower 1.5 hrs post compared to pre race (p<0.05. Cort concentration was higher at post compared to 1.5 (p<0.05, but was unaltered from pre race levels. Subjects finished in 7.81 ± 1.2 hrs. Saliva flow rate did not differ between time points. Saliva Osm increased at post (p<0.05 compared to pre race. Conclusions: The intensity could have been too low to alter Lys and Lac secretion rates and thus, may not be as sensitive as IgA to changes in response to prolonged running. Results expand our understanding of the mucosal immune system and may have implications for predicting illness after prolonged running.

  11. Increased release of brain serotonin reduces vulnerability to ventricular fibrillation in the cat

    Lehnert, Hendrik; Lombardi, Federico; Raeder, Ernst A.; Lorenzo, Antonio V.; Verrier, Richard L.; Lown, Bernard; Wurtman, Richard J.


    The effect of administering the serotonin precursor 5-l-hydroxytryptophan, in conjunction with a monamine oxidase inhibitor phenelzine and a l-amino acid decarboxylase inhibitor carbidopa, on neurochemical changes in the concentrations of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid of the cat were investigated. Results showed that this drug regimen led to increases of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in the cerebrospinal fluid by 330 and 830 percent, respectively. Concomitantly, the threshold of ventricular fibrillation was found to be elevated by 42 percent and the effective refractory period was prolonged by 7 percent; the efferent sympathetic neural activity was suppressed in the normal heart. The results indicate that the enhancement of central serotoninergic neurotransmission can reduce the susceptibility of the heart to ventricular fibrillation mediated through a decline in sympathetic neural traffic to the heart.

  12. The Impact of Ventricular Assist Device Prior to Transplantation on Morphological Parameters in Cardiac Allografts

    Wassilew, Katharina


    Due to the shortage of donor organs, mechanical circulatory support systems (MCS) are now widely used as a treatment option to bridge the failing heart to transplantation. There are limited data, suggesting that prolonged use of ventricular assist device (VAD) therapy may result in cardiac...... of the level of macrophages on the degree of IF in right ventricular endomyocardial biopsies (EMBs) of cardiac allografts. Methods: We evaluated all consecutive EMBs of cardiac allografts from 254 patients taken between 01/2011 and 12/2012.With regard to pre-transplant MCS treatment, patients were divided....... The Cochran-Mantel-Haenzsel test was applied to assess significance of the differences in interactions between groups. To evaluate the impact of bridge- to- transplant mechanical circulatory support on development on transplant vasculopathy in cardiac allografts, the intramyocardial terminal arterial network...

  13. Ventricular tachycardia associated with lacosamide co-medication in drug-resistant epilepsy.

    DeGiorgio, Andrew C; Desso, Tamara E; Lee, Lance; DeGiorgio, Christopher M


    We report a case of sustained ventricular tachycardia following the initiation of lacosamide as adjunctive epilepsy treatment. A 49-year-old male with intractable frontal lobe seizures experienced severe ventricular tachycardia following the addition of 400 mg lacosamide to his existing regimen of carbamazepine, lamotrigine, clonazepam, and valproate. The tachycardia occurred during a cardiac stress test; stress tests prior to initiation of lacosamide were normal. Conduction defects, including QRS prolongation, persisted during hospitalization until lacosamide was discontinued. The patient had no prior history of cardiac arrhythmia but did possess cardiac risk factors, including hypertension, hypercholesterolemia, and low heart rate variability. This case represents one part of a growing body of literature suggesting a link between arrhythmia and use of lacosamide, which enhances slow inactivation of sodium channels in both the brain and the heart. We believe further study may be necessary to assess the safety of lacosamide in epilepsy patients with cardiac risk factors.

  14. The Impact of Ventricular Assist Device Prior to Transplantation on Morphological Parameters in Cardiac Allografts

    Wassilew, Katharina


    Due to the shortage of donor organs, mechanical circulatory support systems (MCS) are now widely used as a treatment option to bridge the failing heart to transplantation. There are limited data, suggesting that prolonged use of ventricular assist device (VAD) therapy may result in cardiac...... of the level of macrophages on the degree of IF in right ventricular endomyocardial biopsies (EMBs) of cardiac allografts. Methods: We evaluated all consecutive EMBs of cardiac allografts from 254 patients taken between 01/2011 and 12/2012.With regard to pre-transplant MCS treatment, patients were divided...... into two groups (MCS group n=82 patients, non-MCS group n=138 patients). The MCS patients were subdivided into groups regarding the device used (HeartMate II, HeartWare, Novacor, Incor, Excor). Patients were excluded from the analysis if they had an MCS system that was used in fewer than five of the study...


    Silvana de Araújo SILVA


    Full Text Available The identification of predictors for the progression of chronic Chagas cardiomyopathy (CCC is essential to ensure adequate patient management. This study looked into a non-concurrent cohort of 165 CCC patients between 1985 and 2010 for independent predictors for CCC progression. The outcomes were worsening of the CCC scores and the onset of left ventricular dysfunction assessed by means of echo-Doppler cardiography. Patients were analyzed for social, demographic, epidemiologic, clinical and workup-related variables. A descriptive analysis was conducted, followed by survival curves based on univariate (Kaplan-Meier and Cox’s univariate model and multivariate (Cox regression model analysis. Patients were followed from two to 20 years (mean: 8.2. Their mean age was 44.8 years (20-77. Comparing both iterations of the study, in the second there was a statistically significant increase in the PR interval and in the QRS duration, despite a reduction in heart rates (Wilcoxon < 0.01. The predictors for CCC progression in the final regression model were male gender (HR = 2.81, Holter monitoring showing pauses equal to or greater than two seconds (HR = 3.02 increased cardiothoracic ratio (HR = 7.87 and time of use of digitalis (HR = 1.41. Patients with multiple predictive factors require stricter follow-up and treatment.

  16. Carotid Baroreflex Function During Prolonged Exercise

    Raven, P. B.


    Astronauts are often required to work (exercise) at moderate to high intensities for extended periods while performing extra-vehicular activities (EVA). Although the physiologic responses associated with prolonged exercise have been documented, the mechanisms involved in blood pressure regulation under these conditions have not yet been fully elucidated. An understanding of this issue is pertinent to the ability of humans to perform work in microgravity and complies with the emphasis of NASA's Space Physiology and Countermeasures Program. Prolonged exercise at a constant workload is know to result in a progressive decrease in mean arterial pressure (MAP) concomitant with a decrease in stroke volume and a compensatory increase in heart rate. The continuous decrease in MAP during the exercise, which is related to the thermoregulatory redistribution of circulating blood volume to the cutaneous circulation, raises the question as to whether there is a loss of baroreflex regulation of arterial blood pressure. We propose that with prolongation of the exercise to 60 minutes, progressive increases on central command reflect a progressive upward resetting of the carotid baroreflex (CBR) such that the operating point of the CBR is shifted to a pressure below the threshold of the reflex rendering it ineffectual in correcting the downward drift in MAP. In order to test this hypothesis, experiments have been designed to uncouple the global hemodynamic response to prolonged exercise from the central command mediated response via: (1) continuous maintenance of cardiac filling volume by intravenous infusion of a dextran solution; and (2) whole body surface cooling to counteract thermoregulatory cutaneous vasodialation. As the type of work (exercise) performed by astronauts is inherently arm and upper body dependent, we will also examine the physiologic responses to prolonged leg cycling and arm ergometry exercise in the supine positions with and without level lower body negative

  17. Risk prediction of ventricular arrhythmias and myocardial function in Lamin A/C mutation positive subjects.

    Hasselberg, Nina E; Edvardsen, Thor; Petri, Helle; Berge, Knut E; Leren, Trond P; Bundgaard, Henning; Haugaa, Kristina H


    Mutations in the Lamin A/C gene may cause atrioventricular block, supraventricular arrhythmias, ventricular arrhythmias (VA), and dilated cardiomyopathy. We aimed to explore the predictors and the mechanisms of VA in Lamin A/C mutation-positive subjects. We included 41 Lamin A/C mutation-positive subjects. PR-interval and occurrence of VA were recorded. Left ventricular (LV) myocardial function was assessed as ejection fraction and speckle tracking longitudinal strain by echocardiography. Magnetic resonance imaging was performed to assess fibrosis in a selection of subjects. Ventricular arrhythmias were documented in 21 patients (51%). Prolonged PR-interval was the best predictor of VA (P function by strain was reduced in the interventricular septum compared with the rest of the LV segments (-16.7% vs. -18.7%, P = 0.001) and correlated to PR-interval (R = 0.41, P = 0.03). Myocardial fibrosis was found exclusively in the interventricular septum and only in patients with VA (P = 0.007). PR-interval was longer in patients with septal fibrosis compared with those without (320 ± 66 vs. 177 ± 40 ms, P PR-interval was the best predictor of VA in Lamin A/C mutation-positive subjects. Electrical, mechanical, and structural cardiac properties were related in these subjects. Myocardial function was most reduced in the interventricular septum and correlated to prolonged PR-interval. Myocardial septal fibrosis was associated with prolonged PR-interval and VA. Localized fibrosis in the interventricular septum may be the mechanism behind reduced septal function, atrioventricular block and VA in Lamin A/C mutation-positive subjects.

  18. Automated left ventricular capture management.

    Crossley, George H; Mead, Hardwin; Kleckner, Karen; Sheldon, Todd; Davenport, Lynn; Harsch, Manya R; Parikh, Purvee; Ramza, Brian; Fishel, Robert; Bailey, J Russell


    The stimulation thresholds of left ventricular (LV) leads tend to be less reliable than conventional leads. Cardiac resynchronization therapy (CRT) requires continuous capture of both ventricles. The purpose of this study is to evaluate a novel algorithm for the automatic measurement of the stimulation threshold of LV leads in cardiac resynchronization systems. We enrolled 134 patients from 18 centers who had existing CRT-D systems. Software capable of automatically executing LV threshold measurements was downloaded into the random access memory (RAM) of the device. The threshold was measured by pacing in the left ventricle and analyzing the interventricular conduction sensed in the right ventricle. Automatic LV threshold measurements were collected and compared with manual LV threshold tests at each follow-up visit and using a Holter monitor system that recorded both the surface electrocardiograph (ECG) and continuous telemetry from the device. The proportion of Left Ventricular Capture Management (LVCM) in-office threshold tests within one programming step of the manual threshold test was 99.7% (306/307) with a two-sided 95% confidence interval of (98.2%, 100.0%). The algorithm measured the threshold successfully in 96% and 97% of patients after 1 and 3 months respectively. Holter monitor analysis in a subset of patients revealed accurate performance of the algorithm. This study demonstrated that the LVCM algorithm is safe, accurate, and highly reliable. LVCM worked with different types of leads and different lead locations. LVCM was demonstrated to be clinically equivalent to the manual LV threshold test. LVCM offers automatic measurement, output adaptation, and trends of the LV threshold and should result in improved ability to maintain LV capture without sacrificing device longevity.

  19. Salade malade: malignant ventricular arrhythmias due to an accidental intoxication with Aconitum napellus.

    Weijters, B J; Verbunt, R J A M; Hoogsteen, J; Visser, R F


    Intoxication with Aconitum napellus is rare in our regions. Aconite alkaloids can cause ventricular arrhythmia by a prolonged activation of sodium channels. Because the margin of safety is low between the analgesic and toxic dose, intoxication is not rare when Aconite is used in herbal medicine. We present a case in which a 39-year-old male was accidentally intoxicated with Aconite. Even though no antidote or adequate therapy is available he was successfully resuscitated. (Neth Heart J 2008;16:96-9.).

  20. Remodelado ventricular y cirugía

    Ignacio Moriones


    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.

  1. Severe bradycardia and prolonged hypotension in ciguatera.

    Chan, Thomas Yan Keung


    Ciguatera results when ciguatoxin-contaminated coral reef fish from tropical or subtropical waters are consumed. The clinical features that present in affected persons are mainly gastrointestinal, neurological, general, and much less commonly, cardiovascular. We report the case of a 50-year-old man who developed the characteristic combination of acute gastrointestinal and neurological symptoms after the consumption of an unidentified coral reef fish head. In addition to those symptoms, he developed dizziness, severe bradycardia (46 bpm) and prolonged hypotension, which required the administration of intravenous atropine and over three days of intravenous fluid replacement with dopamine infusion. Patients with ciguatera can develop severe bradycardia and prolonged hypotension. Physicians should recognise the possible cardiovascular complications of ciguatera and promptly initiate treatment with intravenous atropine, intravenous fluid replacement and inotropic therapy if such complications are observed.

  2. [Prolonged pain in neonates: retrospective analysis].

    Lilla, Michèle; Stadelman-Diaw, Corinne; Ramelet, Anne-Sylvie


    Infants hospitalised in neonatology are inevitably exposed to pain repeatedly. Premature infants are particularly vulnerable, because they are hypersensitive to pain and demonstrate diminished behavioural responses to pain. They are therefore at risk of developing short and long-term complications if pain remains untreated. Compared to acute pain, there is limited evidence in the literature on prolonged pain in infants. However, the prevalence is reported between 20 and 40 %. This single case study aimed to identify the bio-contextual characteristics of neonates who experienced prolonged pain. This study was carried out in the neonatal unit of a tertiary referral centre in Western Switzerland. A retrospective data analysis of seven infants' profile, who experienced prolonged pain ,was performed using five different data sources. The mean gestational age of the seven infants was 32weeks. The main diagnosis included prematurity and respiratory distress syndrome. The total observations (N=55) showed that the participants had in average 21.8 (SD 6.9) painful procedures that were estimated to be of moderate to severe intensity each day. Out of the 164 recorded pain scores (2.9 pain assessment/day/infant), 14.6 % confirmed acute pain. Out of those experiencing acute pain, analgesia was given in 16.6 % of them and 79.1 % received no analgesia. This study highlighted the difficulty in managing pain in neonates who are exposed to numerous painful procedures. Pain in this population remains underevaluated and as a result undertreated.Results of this study showed that nursing documentation related to pain assessment is not systematic.Regular assessment and documentation of acute and prolonged pain are recommended. This could be achieved with clear guidelines on the Assessment Intervention Reassessment (AIR) cyclewith validated measures adapted to neonates. The adequacy of pain assessment is a pre-requisite for appropriate pain relief in neonates.

  3. Napping and Human Functioning during Prolonged Work


    alternative to napping is prolonged wakefulness. Polyphasic sleep , with frequent naps rather than a single sleep period per 24 hours, is natural for both the...very young and for the aged. It is not practiced by most adults, perhaps because of societal demands. Possibly a polyphasic sleep schedule could be...Functioning 1.2 Scope of this Chapter 2. REVIEW OF LITERATURE 2.1 Partial Sleep Deprivation Studies 2.2 Nap Studies: Four Nap Factors Affecting Performance

  4. Prolonged grief: setting the research agenda

    Rita Rosner


    Full Text Available Background: Prolonged grief disorder is proposed for the International Classification of Diseases (ICD-11, though it was rejected as a diagnosis for DSM-5. Objective: This review outlines findings and defines important areas for future research viewed from a lifespan perspective. Results: The development and psychometric evaluation of measures for the new diagnosis is paramount, specifically for children and adolescents. Treatments need to be adapted for specific subgroups and research findings have to be disseminated into various professional settings.

  5. Unilateral ventricular reflux and asymmetric ventricular distribution of intrathecally introduced contrast medium or tracer

    Deisenhammer, E.; Hammer, B.

    Fourteen cases of totally or predominantly unilateral ventricular reflux and stasis of intrathecally injected radioisotope or contrast medium were demonstrated by scintigraphy or computed tomographic cisternography. All showed asymmetric enlargement of the lateral ventricles and nine had ipsilateral brain lesions. Four case reports are presented. The pathophysiologic mechanism of communicating hydrocephalus and possible causes of unilateral ventricular reflux are discussed, as well as indications for ventricular shunt installation.

  6. Ventricular fibrillation induced by a radiofrequency energy delivery for idiopathic premature ventricular contractions arising from the left ventricular anterior papillary muscle.

    Yamada, Takumi; McElderry, H Thomas; Allred, James D; Doppalapudi, Harish; Kay, G Neal


    A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs.

  7. Prolonged ulcerative laryngitis: a new disease entity.

    Hsiao, Tzu-Yu


    Over the last decade, a new disease entity, prolonged ulcerative laryngitis (PUL), with unique clinical presentation and prolonged disease course, has been recognized. Until now, very few studies dealing with this disease have been reported in the literature. From 1999 to 2008, we analyzed clinical data from a series of 39 PUL patients who were treated with an observational approach without implementing specific treatments. This disease affects adults, predominantly females. The age of patients in our series ranged from 26 to 76 years with a median of 49.5 years. This disease is characterized by ulcers and signs of acute inflammation on the membranous portion of the vocal folds with a prolonged clinical course. The recovery times of patients ranged from 4 to 20 weeks with an average of 9.4 weeks. The data in this study may reflect a natural history of this disease. PUL seems to be a self-limited disease, but the etiology of this disease is unknown. Specific infections or systemic inflammatory processes involving the larynx must be ruled out before diagnosis, and conservative treatments are suggested.

  8. Clarithromycine-Induced Ventricular Tachycardia in a Geriatric Patient Using Multiple Drugs

    Gulsah Karaoren


    Full Text Available Long QT syndrome is a cardiac repolarization disorder, which can be either idiopathic or congenital, and cause sudden cardiac death. The iatrogenic form is generally associated with drugs or electrolyte imbalance. Although prolonged QT interval is frequently seen due to antiarrhythmic agents, it can also be seen with antibiotics or anti-epileptics. Adverse drug interaction can manifest in several clinicopathological forms in elder individuals. In such cases, potential adverse effects of drugs used should be taken into consideration before prescribing additional drugs. Here, we present a case of clarithromycine-induced ventricular arrhythmia accompanied by QT prolongation on the third day of therapy, and the subsequent therapeutic approach, in a 91-year-old man. The patient was taking multiple drugs due to comorbid conditions and was prescribed clarithromycine therapy in the intensive care unit.

  9. Acute left ventricular dysfunction secondary to right ventricular septal pacing in a woman with initial preserved contractility: a case report

    Gribaa Rim


    Full Text Available Abstract Introduction Right ventricular apical pacing-related heart failure is reported in some patients after long-term pacing. The exact mechanism is not yet clear but may be related to left ventricular dyssynchrony induced by right ventricular apical pacing. Right ventricular septal pacing is thought to deteriorate left ventricular function less frequently because of a more normal left ventricular activation pattern. Case presentation We report the case of a 55-year-old Tunisian woman with preserved ventricular function, implanted with a dual-chamber pacemaker for complete atrioventricular block. Right ventricular septal pacing induced a major ventricular dyssynchrony, severe left ventricular ejection fraction deterioration and symptoms of congestive heart failure. Upgrading to a biventricular device was associated with a decrease in the symptoms and the ventricular dyssynchrony, and an increase of left ventricular ejection fraction. Conclusion Right ventricular septal pacing can induce reversible left ventricular dysfunction and heart failure secondary to left ventricular dyssynchrony. This complication remains an unpredictable complication of right ventricular septal pacing.

  10. Uremic retention solute indoxyl sulfate level is associated with prolonged QTc interval in early CKD patients.

    Wei-Hua Tang

    Full Text Available Total mortality and sudden cardiac death is highly prevalent in patients with chronic kidney disease (CKD. In CKD patients, the protein-bound uremic retention solute indoxyl sulfate (IS is independently associated with cardiovascular disease. However, the underlying mechanisms of this association have yet to be elucidated. The relationship between IS and cardiac electrocardiographic parameters was investigated in a prospective observational study among early CKD patients. IS arrhythmogenic effect was evaluated by in vitro cardiomyocyte electrophysiological study and mathematical computer simulation. In a cohort of 100 early CKD patients, patients with corrected QT (QTc prolongation had higher IS levels. Furthermore, serum IS level was independently associated with prolonged QTc interval. In vitro, the delay rectifier potassium current (IK was found to be significantly decreased after the treatment of IS in a dose-dependent manner. The modulation of IS to the IK was through the regulation of the major potassium ion channel protein Kv 2.1 phosphorylation. In a computer simulation, the decrease of IK by IS could prolong the action potential duration (APD and induce early afterdepolarization, which is known to be a trigger mechanism of lethal ventricular arrhythmias. In conclusion, serum IS level is independently associated with the prolonged QTc interval in early CKD patients. IS down-regulated IK channel protein phosphorylation and the IK current activity that in turn increased the cardiomyocyte APD and QTc interval in vitro and in the computer ORd model. These findings suggest that IS may play a role in the development of arrhythmogenesis in CKD patients.

  11. Premature Ventricular Complexes and Premature Ventricular Complex Induced Cardiomyopathy.

    Latchamsetty, Rakesh; Bogun, Frank


    Presentation, prognosis, and management of premature ventricular complexes (PVCs) vary significantly among patients and depend on PVC characteristics as well as patient comorbidities. Presentation can range from incidental discovery in an asymptomatic patient to debilitating heart failure. Prognosis depends on, among other factors, the presence or absence of structural heart disease, PVC burden and other factors detailed in this review. Our understanding of the clinical significance of frequent PVCs, particularly as it relates to development of cardiomyopathy, has advanced greatly in the past decade. In this article, we explore the mechanisms governing PVC initiation and discuss prevalence and frequency of PVCs in the general population. We also explore prognostic implications based on PVC frequency as well as the presence or absence of underlying heart disease. We then take a focused look at PVC-induced cardiomyopathy and identify predictors for developing cardiomyopathy. Finally, we discuss clinical evaluation and management of patients presenting with frequent PVCs. Management can include clinical observation, addressing reversible causes, lifestyle modification, pharmacotherapy, or catheter ablation.

  12. Arrhythmogenic right ventricular dysplasia: A case report

    Tessa Negrín Valdés


    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.

  13. Ventricular repolarization measures for arrhythmic risk stratification

    Francesco Monitillo; Marta Leone; Caterina Rizzo; Andrea Passantino; Massimo Iacoviello


    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.

  14. Cardiac sarcoidosis mimicking right ventricular dysplasia.

    Shiraishi, Jun; Tatsumi, Tetsuya; Shimoo, Kazutoshi; Katsume, Asako; Mani, Hiroki; Kobara, Miyuki; Shirayama, Takeshi; Azuma, Akihiro; Nakagawa, Masao


    A 59-year-old woman with skin sarcoidosis was admitted to hospital for assessment of complete atrioventricular block. Cross-sectional echocardiography showed that the apical free wall of the right ventricle was thin and dyskinetic with dilation of the right ventricle. Thallium-201 myocardial imaging revealed a normal distribution. Both gallium-67 and technetium-99m pyrophosphate scintigraphy revealed no abnormal uptake in the myocardium. Right ventriculography showed chamber dilation and dyskinesis of the apical free wall, whereas left ventriculography showed normokinesis, mimicking right ventricular dysplasia. Cardiac sarcoidosis was diagnosed on examination of an endomyocardial biopsy specimen from the right ventricle. A permanent pacemaker was implanted to manage the complete atrioventricular block. After steroid treatment, electrocardiography showed first-degree atrioventricular block and echocardiography revealed an improvement in the right ventricular chamber dilation. Reports of cardiac sarcoidosis mimicking right ventricular dysplasia are extremely rare and as this case shows, right ventricular involvement may be one of its manifestations.

  15. A case with catecholaminergic polymorphic ventricular tachycardia

    Ahmet Ünalır


    Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a rare type of polymorphic ventricular tachycardias in individuals without structural cardiac abnormalities. It typically has been induced by exercise or emotional stres. It generally is seen in childhood and adolescent period but rarely is seen in elderly. It usually ends by spontaneus, but rarely cause hemodynamic collapse. In here, we present a case with CPVT of successful treatment with a beta blocker therapy. J Clin Exp Invest 2011;2(2:232-4

  16. Case series: Congenital left ventricular diverticulum

    Shah Dharita


    Full Text Available Congenital left ventricular diverticulum is a rare cardiac malformation characterized by a localized outpouching from the cardiac chamber. The patient is usually asymptomatic. However, complications like embolism, infective endocarditis, arrhythmia and, rarely, rupture can be the initial presentation. Diagnosis can be established by USG, echocardiography, CT angiography, and MRI. We report here two neonates with congenital left ventricular apical diverticulum associated with epigastric hernia.

  17. Ventricular tachycardia induced by weight loss pills

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


    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-susta......-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....

  18. Ventricular Septal Defect from Takotsubo Syndrome

    Caplow, Julie; Quatromoni, Neha


    Takotsubo Syndrome is a transient condition characterized by left ventricular systolic dysfunction with apical akinesis/dyskinesis and ballooning. Although the prognosis with medical management is excellent in most cases, rare cases of serious complications can occur. We present here a case of a 71-year-old woman presenting with acute decompensated heart failure with initial findings consistent with a myocardial infarction, who was found instead to have an acute ventricular septal defect as a complication of Takotsubo Syndrome. PMID:27563471

  19. Ventricular Septal Defect from Takotsubo Syndrome

    Daniel Y. Lu


    Full Text Available Takotsubo Syndrome is a transient condition characterized by left ventricular systolic dysfunction with apical akinesis/dyskinesis and ballooning. Although the prognosis with medical management is excellent in most cases, rare cases of serious complications can occur. We present here a case of a 71-year-old woman presenting with acute decompensated heart failure with initial findings consistent with a myocardial infarction, who was found instead to have an acute ventricular septal defect as a complication of Takotsubo Syndrome.

  20. [The treatment of recent myocardial infarction by prolonged infusion of trinitrin (author's transl)].

    Chiche, P; Derrida, J P; Baligadoo, S; Sal, R


    Seventy four clinically comparable cases of myocardial infarction, admitted on average at the 10th hour were divided at random in two groups: thirty nine were treated with a prolonged intravenous infusion of trinitrin lasting for 24 hours in 12 cases and during 5 at 7 days in 27 cases: 35 served as controls. The results showed the following: a) the good tolerance of the drug used in this way; b) on the basis of precordial cartography, a reduction of 56.2 +/- 14.5% to 30 +/- 7.3% in the index of secondary extension of necrosis; c) clinical signs of left ventricular failure developed in 60% of the controls as compared with 45.8% of the treated group; d) the prevalence of rhythm disturbances was also lower in those treated; e) overall mortality during the first 4 weeks was 8 amongst the 35 controls and 2 of the treated patients (p less than 0.05).

  1. P-TEFb, the super elongation complex and mediator regulate a subset of non-paused genes during early Drosophila embryo development.

    Olle Dahlberg


    Full Text Available Positive Transcription Elongation Factor b (P-TEFb is a kinase consisting of Cdk9 and Cyclin T that releases RNA Polymerase II (Pol II into active elongation. It can assemble into a larger Super Elongation Complex (SEC consisting of additional elongation factors. Here, we use a miRNA-based approach to knock down the maternal contribution of P-TEFb and SEC components in early Drosophila embryos. P-TEFb or SEC depletion results in loss of cells from the embryo posterior and in cellularization defects. Interestingly, the expression of many patterning genes containing promoter-proximal paused Pol II is relatively normal in P-TEFb embryos. Instead, P-TEFb and SEC are required for expression of some non-paused, rapidly transcribed genes in pre-cellular embryos, including the cellularization gene Serendipity-α. We also demonstrate that another P-TEFb regulated gene, terminus, has an essential function in embryo development. Similar morphological and gene expression phenotypes were observed upon knock down of Mediator subunits, providing in vivo evidence that P-TEFb, the SEC and Mediator collaborate in transcription control. Surprisingly, P-TEFb depletion does not affect the ratio of Pol II at the promoter versus the 3' end, despite affecting global Pol II Ser2 phosphorylation levels. Instead, Pol II occupancy is reduced at P-TEFb down-regulated genes. We conclude that a subset of non-paused, pre-cellular genes are among the most susceptible to reduced P-TEFb, SEC and Mediator levels in Drosophila embryos.

  2. On the Rhythm of Chinese Poetry of the Syllable Pause System%论音顿体系的汉语诗歌节奏



    Given that the rhythm of some Chinese new metrical poems is not so beautiful, this paper traces back to the origin of western music rhythm and meter system and finds that Chinese poetry has a typical syllable-pause system rhythm rather than a sound foot system rhythm. However, "the theory of neat pauses”and“the theory of foot symmetry“of Chinese new poetry are influenced by the Western foot theory, because of which, the beauty of the rhythm of some poems is not so obvious. Chinese poetry must revert to syllable-pause system, in order to per⁃fectly realize the beautiful rhythm of Chinese poetry. The creation of poems in Chinese syllable-pause system forms a specific pattern, which can serve as a reference for writers.%  鉴于部分格律体新诗作品节奏美并不强的现实,本文追溯了西方音顿体系节奏和音步体系节奏的本源,发现汉语诗歌是典型的音顿体系节奏而不是音步体系节奏,而我国新诗格律的“顿数整齐论”和“音步对称论”是受西方音步理论影响而形成的,因而导致了部分作品节奏美不强;汉语诗歌必须回归音顿体系的正轨,才能完备地实现汉语诗歌节奏美。汉语音顿体系诗歌在创作中形成了具体形式法度,可供创作者借鉴。

  3. Tachy-Brady Arrhythmias: The Critical Role of Adenosine-induced Sino-Atrial Conduction Block in Post-Tachycardia Pauses

    Lou, Qing; Glukhov, Alexey V.; Hansen, Brian; Hage, Lori; Vargas-Pinto, Pedro; Billman, George E.; Carnes, Cynthia A.; Fedorov, Vadim V.


    Background In patients with sinoatrial nodal (SAN) dysfunction, atrial pauses lasting several seconds may follow rapid atrial pacing or paroxysmal tachycardia (tachy-brady arrhythmias). Clinical studies suggest that adenosine may play an important role in SAN dysfunction, but the mechanism remains unclear. Objective To define the mechanism of SAN dysfunction induced by the combination of adenosine and tachycardia. Methods We studied the mechanism of SAN dysfunction produced by a combination of adenosine and rapid atrial pacing in isolated coronary-perfused canine atrial preparations using high-resolution optical mapping (n=9). Sinus cycle length (SCL) and sinoatrial conduction time (SACT) were measured during adenosine (1–100μM) and 1μM DPCPX (A1 receptor antagonist, n=7) perfusion. Sinoatrial node recovery time was measured after one minute of “slow” pacing (3.3Hz) or tachypacing (7–9Hz). Results Adenosine significantly increased SCL (477±62 vs. 778±114 ms, p<0.01), and SACT during sinus rhythm (41±11 vs. 86±16 ms, p<0.01) dose-dependently. Adenosine dramatically affected SACT of the first SAN beat after tachypacing (41±5 vs. 221±98ms, p<0.01). Moreover, at high concentrations of adenosine (10–100μM), termination of tachypacing or atrial flutter/fibrillation produced atrial pauses of 4.2±3.4 seconds (n=5) due to conduction block between the SAN and atria, despite a stable SAN intrinsic rate. Conduction block was preferentially related to depressed excitability in SAN conduction pathways. Adenosine-induced changes were reversible upon washout or DPCPX treatment. Conclusions These data directly demonstrate that adenosine contributes to post-tachycardia atrial pauses through SAN exit block rather than slowed pacemaker automaticity. Thus, these data suggest an important modulatory role of adenosine in tachy-brady syndrome. PMID:22985657

  4. Right ventricular mass estimation by angioechocardiography.

    Arcilla, R A; Mathew, R; Sodt, P; Lester, L; Cahill, N; Thilenius, O G


    A combined angiocardiographic-echocardiographic method for estimating right ventricular wall mass is described. Biplane cineangiocardiograms are analyzed for ventricular volume in end-diastole, and wall thickness is determined from echocardiograms obtained with a high frequency transducer and strip chart recorder, The intracavitary and the external surface volumes of the ventricle are derived, and the difference multiplied by 1.050, the specific gravity of myocardium. Excellent correlation was observed between right ventricular wall mass and body surface area in normal children (r = 0.93). The mean right ventricular mass was 44.5 g/M2 as compared to 78.1 g/M2 for the left ventricle, corresponding mass/EDV values were 0.48 g/cm3 and 1.26 g/cm3, respectively. In isolated right ventricular pressure overload, the increase in right ventricular mass is chiefly due to the increase in wall thickness; in volume overload, it is due mostly to the increase in chamber volume,

  5. Selective left ventricular sensing lead implantation to overcome undersensing of ventricular fibrillation during implantable cardioverter defibrillator implantation.

    Steinberg, Christian; Philippon, François; O'Hara, Gilles; Molin, Franck


    Accurate sensing of malignant arrhythmia is critical for the appropriate delivery of therapy from implantable cardioverter defibrillators, and undersensing of ventricular tachyarrhythmias can have catastrophic consequences. Here, we present an unusual case of ventricular fibrillation undersensing from the right ventricular lead at multiple different implantation sites because of very low amplitude voltage signals during induced ventricular fibrillation. A left ventricular sensing electrode was implanted to allow correct sensing and therapy delivery.

  6. Effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony

    支力大; 华伟; 张澍; 史蓉芳; 王方正; 陈新


    Background Right ventricular apical pacing has been reported to reduce cardiac performance. But there are few reports on the effects of dual chamber (DDD) pacing on cardiac function compared to sinus rhythm. In this study, we evaluated the effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony using equilibrium radionuclide angiography.Methods Ten patients implanted with a right atrial and ventricular DDD pacemaker underwent equilibrium radionuclide angiography. The scintigraphic data were obtained during sinus rhythm and pacing rhythm. Cardiac function parameters were obtained semimanually. Phase analysis was used to study the ventricular activation sequence and ventricular synchrony.Results The left ventricular 1/3 ejection fraction decreased significantly during pacing compared with that during sinus rhythm[(23.4 ±6.1)% vs(27.7 ±4.5)%, P =0.01]. Regional ejection fraction also decreased during pacing, although the difference was not statistically significant. Phase analysis showed that the right ventricle was activated earlier than the left ventricle during pacing, and that the phase shift was significantly greater during pacing than that during sinus rhythm[64.13°±16.80° vs 52.88°± 9.26°, P =0.007]. The activation of both ventricles occurred simultaneously during sinus rhythm, with the activation sequence from proximal septum or base of left ventricle to apex. The earliest activation during pacing occurred at the right ventricular apex, and subsequently spread to the base and left ventricle.Conclusion Right atrial and ventricular DDD pacing impairs left ventricular systolic function and ventricular synchrony.

  7. Electrohydraulic ventricular assist device development.

    Diegel, P D; Mussivand, T; Holfert, J W; Juretich, J T; Miller, J A; Maclean, G K; Szurmak, Z; Santerre, J P; Rajagopalan, K; Dew, P A


    An electrohydraulic ventricular assist device has been developed. An axial flow pump driven by a brushless DC motor provides actuation. Energy is supplied by internal Ni/Cd batteries and by external Ag/Zn batteries, both rechargeable. Electromagnetic induction is used to pass energy through the skin with a transcutaneous energy transfer (TET) system. Physiologic control, battery management, motor commutation, and communication functions are performed by a surface mount internal controller. An infrared data link within the TET coils provides bidirectional communication between the external and internal controllers. A computer model was developed to predict system performance. The dimensions are 180 mm x 116 mm x 40 mm. An in vitro system pumped 5.7 L/min at 10 mmHg inflow and 100 mmHg outflow pressure. The internal battery can provide the projected energy requirements for 40 min after 540 charge/discharge cycles, and the external battery is capable of 4 hr of operation after 150 cycles. The TET system can deliver 60 W of power and exceeds 80% efficiency between 15 and 30 W. The device configuration is based on human cadaver and intraoperative fit trials. The device is being modified for calf implantation by redirecting the blood ports, increasing the output, and incorporating the internal controller in the unified device base.

  8. Prolonged labour as indication for emergency caesarean section

    Maaløe, Nanna; Sorensen, B L; Onesmo, R


    To audit the quality of obstetric management preceding emergency caesarean sections for prolonged labour.......To audit the quality of obstetric management preceding emergency caesarean sections for prolonged labour....

  9. Factors associated with prolonged hospitalization, readmission, and death in elderly heart failure patients in western Romania

    Gyalai-Korpos I


    Full Text Available Istvan Gyalai-Korpos,1,2 Oana Ancusa,1,2 Tiberiu Dragomir,1,2 Mirela Cleopatra Tomescu,1,2 Iosif Marincu1,3 1University of Medicine and Pharmacy, 2Cardiology Department, City Hospital, 3Department of Epidemiology and Infectious Diseases, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania Purpose: The purpose of this prospective study was to identify factors associated with prolonged hospitalization, readmission, and death in elderly patients presenting heart failure with reduced ejection fraction.Patients and methods: All consecutive patients aged ≥65 years discharged with a diagnosis of acute new-onset heart failure and a left ventricular ejection fraction (LVEF ≤45% were included and followed up for 1 year. The variables associated with outcomes were analyzed in univariate and multivariate logistic regression. For the independent predictors identified by multivariate analysis, receiver operating characteristic (ROC analysis was performed.Results: A total of 71 patients were included in the study. The patient mean age was 72.5 years, 50% were female, and the mean LVEF was 31.25%±5.76%. In all, 34 (48% patients experienced prolonged hospitalization, and this was independently associated with patients who were living in a rural area (P=0.005, those with a New York Heart Association functional class of 4 (P<0.001, the presence of comorbidities (P=0.023, chronic obstructive pulmonary disease (COPD infectious exacerbation (P<0.001, and chronic kidney disease (P=0.025. In the multivariate analysis, only COPD infectious exacerbation was independently associated with prolonged hospitalization (P=0.003. A total 19 patients (27% experienced readmissions during the 1-year follow up, of which 12 (17% had cardiovascular causes and seven (10% had noncardiovascular causes. The following independent variables associated with rehospitalizations were outlined in the univariate analysis: infections (P<0.020; COPD infectious exacerbation (P

  10. Arrhythmogenic right ventricular cardiomyopathy/dysplasia

    Basso Cristina


    Full Text Available Abstract Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D is a heart muscle disease clinically characterized by life-threatening ventricular arrhythmias. Its prevalence has been estimated to vary from 1:2,500 to 1:5,000. ARVC/D is a major cause of sudden death in the young and athletes. The pathology consists of a genetically determined dystrophy of the right ventricular myocardium with fibro-fatty replacement to such an extent that it leads to right ventricular aneurysms. The clinical picture may include: a subclinical phase without symptoms and with ventricular fibrillation being the first presentation; an electrical disorder with palpitations and syncope, due to tachyarrhythmias of right ventricular origin; right ventricular or biventricular pump failure, so severe as to require transplantation. The causative genes encode proteins of mechanical cell junctions (plakoglobin, plakophilin, desmoglein, desmocollin, desmoplakin and account for intercalated disk remodeling. Familiar occurrence with an autosomal dominant pattern of inheritance and variable penetrance has been proven. Recessive variants associated with palmoplantar keratoderma and woolly hair have been also reported. Clinical diagnosis may be achieved by demonstrating functional and structural alterations of the right ventricle, depolarization and repolarization abnormalities, arrhythmias with the left bundle branch block morphology and fibro-fatty replacement through endomyocardial biopsy. Two dimensional echo, angiography and magnetic resonance are the imaging tools for visualizing structural-functional abnormalities. Electroanatomic mapping is able to detect areas of low voltage corresponding to myocardial atrophy with fibro-fatty replacement. The main differential diagnoses are idiopathic right ventricular outflow tract tachycardia, myocarditis, dialted cardiomyopathy and sarcoidosis. Only palliative therapy is available and consists of antiarrhythmic drugs

  11. Laryngotracheal Injury following Prolonged Endotracheal Intubation

    J. Mehdizadeh


    Full Text Available Background: Prolonged endotracheal intubation is a growing method for supporting ventilation in patients who require intensive care. Despite considerable advancement in endotracheal intubation, this method still has some complications; the most important is laryngo-tracheal injuries. Methods: Over a 2-year period, this retrospective study was conducted on 57 patients with history of prolonged intubation who were referred to the ENT Department of Amir Alam Hospital. For each patient, a complete evaluation including history, physical examination, and direct laryngoscopy and bronchoscopy was done under general anesthesia. Results: Fifty-seven patients (44 male; mean age, 23.014.7 years were studied. Mean intubation period was 15.88 days. The most common presenting symptom was dyspnea (62%. Head trauma was responsible for most cases of intubation (72.4%. The most common types of tracheal and laryngeal lesions were tracheal (56.9% and subglottic (55.2% stenosis, respectively. Mean length of tracheal stenosis was 0.810.83 cm. There was a statistically significant relationship between length of tracheal stenosis and intubation period (P=0.0001 but no relation was observed between tracheal stenosis and age, sex, and etiology of intubation (All P=NS. Among the glottic lesions, inter- arytenoids adhesion was the most common lesion (25.9%. No statistically significant relation was found between glottic and subglottic lesions and age, sex and intubation period (all P=NS. Length of stenosis and intubation period was significantly greater in tracheal/ subglottic lesions than those in glottic/ supraglottic lesions (all P=NS. Conclusion: After prolonged endotracheal intubation, laryngo-tracheal lesions had no relation with patient’s age, sex, and cause of intubation.There was direct relation between length of tracheal stenosis and intubation period. Glottic lesions were more commonly observed in head trauma patients. Lesion length and intubation

  12. [Prolonged acute pancreatitis after bone marrow transplantation].

    De Singly, B; Simon, M; Bennani, J; Wittnebel, S; Zagadanski, A-M; Pacault, V; Gornet, J-M; Allez, M; Lémann, M


    Acute pancreatitis is not infrequent after allogenic marrow transplantation. Several causes can predispose to pancreatitis, including Graft-Versus-Host Disease (GVHD), a condition which is probably underestimated. In the literature, few description of pancreatic GVHD can be found. Pancreatic GVHD diagnosis can be difficult if pancreatic involvement occurs without other typical manifestations of GVHD. We report the case of a woman, 54 years old, suffering from prolonged, painful pancreatitis two months after allogenic bone marrow transplantation for acute myeloid leucemia. Pancreatic GVHD diagnosis was performed after five weeks on duodenal biopsies despite the absence of diarrheoa. The patient dramatically improved within few days on corticosteroids.

  13. Prolonged parenteral nutrition after neonatal gastrointestinal surgery

    Estmann, Anne; Qvist, Niels; Husby, Steffen


    INTRODUCTION: Long-term treatment with parenteral nutrition (PN) may be essential for survival in infants after neonatal gastrointestinal surgery. It seemed well indicated in a population-based study to estimate the need for long-term PN and to characterize the infants that received TPN with regard...... to diagnosis and clinical course. METHODOLOGY: This study reviews the clinical course of infants with gastrointestinal disease (gastroschisis, intestinal atresia, omphalocele, volvulus, Hirschsprung's disease and necrotizing enterocolitis) with a prolonged need for parenteral nutrition in the Western part...

  14. Survival of soil bacteria during prolonged desiccation.

    Chen, M.; Alexander, M.


    A determination was made of the kinds and numbers of bacteria surviving when two soils were maintained in the laboratory under dry conditions for more than half a year. Certain non-spore-forming bacteria were found to survive in the dry condition for long periods. A higher percentage of drought-tolerant than drought-sensitive bacteria was able to grow at low water activities. When they were grown in media with high salt concentrations, bacteria generally became more tolerant of prolonged drought and they persisted longer. The percent of cells in a bacterial population that remained viable when exposed to drought stress varied with the stage of growth.

  15. Prolonged parenteral nutrition after neonatal gastrointestinal surgery

    Estmann, Anne; Qvist, Niels; Husby, Steffen


    INTRODUCTION: Long-term treatment with parenteral nutrition (PN) may be essential for survival in infants after neonatal gastrointestinal surgery. It seemed well indicated in a population-based study to estimate the need for long-term PN and to characterize the infants that received TPN with regard...... to diagnosis and clinical course. METHODOLOGY: This study reviews the clinical course of infants with gastrointestinal disease (gastroschisis, intestinal atresia, omphalocele, volvulus, Hirschsprung's disease and necrotizing enterocolitis) with a prolonged need for parenteral nutrition in the Western part...

  16. Effect of right ventricular pacing on ventricular rhythm during atrial fibrillation

    Wittkampf, F.H.M.; Jongste, M.J.L. de; Lie, H.I.; Meijler, F.L.


    In 13 patients with atrial fibrillation, the effect of right ventricular pacing at various rates on spontaneous RR intervals was studied. Five hundred consecutive RR intervals were recorded and measured before and during varying right ventricular pacing rates. As anticipated, all RR intervals longer

  17. Radiofrequency ablation therapy of intractable ventricular tachycardia present with a left ventricular assist device

    Nielsen, Jan Møller; Kristiansen, Steen Buus; Gerdes, Christian;


    Ventricular tachycardia (VT) occurs in up to 59% of patients with left ventricular assist devices (LVAD). In some of these patients, the VT cannot be managed medically or by implantable cardioverter-defibrillator. In this case, a 66-year-old male was successfully treated with radiofrequency...

  18. Right ventricular failure after implantation of a continuous-flow left ventricular assist device

    Cordtz, Johan Joakim; Nilsson, Jens C; Hansen, Peter B;


    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....

  19. Outpatient evaluation and management of patients with ventricular premature beats or non-sustained ventricular tachycardia

    Svendsen, Jesper Hastrup; Goette, Andreas; Dobreanu, Dan


    In this survey, European physicians who deal with arrhythmia patients gave their opinions about diagnostic work up when they see patients with ventricular premature beats (VPBs) or non-sustained ventricular tachycardia (NSVT). In general, similar work-up regimens were used for these two arrhythmias...

  20. Giant left ventricular fibroma presenting as ventricular tachycardia in a child.

    Khan, Muhammad Arif; Saeedi, Abdul Raoof Al; Tayeab, Hyfeah Al; Momenah, Tarek


    We present a rare case of giant left ventricular apical fibroma presenting as recurrent ventricular tachycardia in a 14-month-old girl. The diagnosis was made by echocardiography and chest computed tomography, and confirmed by histopathology. The fibroma was resected surgically, and the patient followed up for 4 years.

  1. Postoperative normalization of left ventricular noncompaction and new echocardiographic signs in aorta to left ventricular tunnel.

    Malakan Rad, Elaheh; Zeinaloo, Ali Akbar


    We report postoperative normalization of left ventricular noncompaction in a neonate undergoing successful neonatal surgery for type II aorta to left ventricular tunnel (ALVT) associated with a large patent ductus arteriosus, floppy and extremely redundant anterior mitral leaflet, right coronary artery arising directly from the tunnel, and severe left ventricular noncompaction. We also described 2 novel echocardiographic findings in ALVT including "triple wavy line sign" on M-mode echocardiography which disappeared 1 month after operation and "abnormally increased left ventricular posterior wall motion" on M-mode of standard parasternal long-axis view on color tissue Doppler imaging (TDI) that also normalized postoperatively. We showed that proper definition of endocardial border is extremely important in strain and strain rate imaging in the context of left ventricular noncompaction. Preoperative longitudinal strain and strain rate were significantly decreased in comparison to radial strain and strain rate. Circumferential strain and strain rate were normal. © 2013, Wiley Periodicals, Inc.

  2. Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

    Rong BAI; Ruth KAM; Chi Keong CHING; Li Fern HSU; Wee Siong TEO


    Current permanent fight ventricular and fight atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asyno chronous electrical activation pattern, which results in asynchronous ventricular contraction and re-laxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold:0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

  3. Comparison of the Frequency-dependent Effects of Amiodarone on Ventricular Electrophysiology in Congestive Heart Failure Canine Models and Normal Dogs

    Zhou Shuxian; Zhang Yuling; Lei Juan; Wu Wei; Zhang Xuming


    Objectives To compare the frequency-dependent effects of amiodarone (Ami) on ventricular electrophysiology in right ventricular rapid pacing-induced congestive heart failure (CHF) canine models.Methods Thirty-two dogs were randomized into four groups: the control group, the Ami group in which the normal dogs were given Ami orally 300 mg a day for 4~5 weeks, the CHF group induced by right ventricular rapid pacing ( 240 pulses. min -1 for 4 ~ 5 weeks), and the group of CHF dogs fed with Ami orally 300 mg a day for 4 ~ 5 weeks. The techniques of electrical stimulation and monophasic action potential (MAP) recording were used in the electrophysiology studies. Results The effects of Ami on ventricular MAP duration(MAPD90) and effective refractory period (VERP)were not frequency-dependent in CHF dogs. There was also no frequency-dependent effect on the increase in the ratio of VERP to MAPD90 (VERP/MAPD90). The prolongation of ventricular conduction time was frequencydependent. Conclusions The frequency-dependent effects of Ami on ventricular electrophysiology in CHF dogs were similar to that in normal dogs.

  4. The Effects of Puerarin on Rat Ventricular Myocytes and the Potential Mechanism

    Xu, Hao; Zhao, Manxi; Liang, Shenghui; Huang, Quanshu; Xiao, Yunchuan; Ye, Liang; Wang, Qinyi; He, Longmei; Ma, Lanxiang; Zhang, Hua; Zhang, Li; Jiang, Hui; Ke, Xiao; Gu, Yuchun


    Puerarin, a known isoflavone, is commonly found as a Chinese herb medicine. It is widely used in China to treat cardiac diseases such as angina, cardiac infarction and arrhythmia. However, its cardioprotective mechanism remains unclear. In this study, puerarin significantly prolonged ventricular action potential duration (APD) with a dosage dependent manner in the micromolar range on isolated rat ventricular myocytes. However, submicromolar puerarin had no effect on resting membrane potential (RMP), action potential amplitude (APA) and maximal velocity of depolarization (Vmax) of action potential. Only above the concentration of 10 mM, puerarin exhibited more aggressive effect on action potential, and shifted RMP to the positive direction. Millimolar concentrations of puerarin significantly inhibited inward rectified K+ channels in a dosage dependent manner, and exhibited bigger effects upon Kir2.1 vs Kir2.3 in transfected HEK293 cells. As low as micromolar range concentrations of puerarin significantly inhibited Kv7.1 and IKs. These inhibitory effects may due to the direct inhibition of puerarin upon channels not via the PKA-dependent pathway. These results provided direct preclinical evidence that puerarin prolonged APD via its inhibitory effect upon Kv7.1 and IKs, contributing to a better understanding the mechanism of puerarin cardioprotection in the treatment of cardiovascular diseases. PMID:27762288

  5. Lifetime Prolonging Algorithms for Underwater Sensor Networks

    GUO Zhong-wen; LI Zhi-wei; YU Lei


    Underwater acoustic modem technology has attained a level of maturity to support underwater acoustic sensor networks (UASNs) which are generally formed by acoustically connected sensor nodes and a surface station providing a link to an on-shore control center. While many applications require long-term monitoring of the deployment area, the battery-powered network nodes limit the lifetime of UASNs. Therefore, designing a UASN that minimizes the power consumption while maximizing lifetime becomes a very difficult task. In this paper, a method is proposed to determine the optimum number of clusters through combining an application-specific protocol architecture and underwater acoustic communication model so as to reduce the energy dissipation of UASNs. Deploying more sensor nodes which work alternately is another way to prolong the lifetime of UASNs. An algorithm is presented for selecting sensor nodes and putting them into operation in each round, ensuring the monitoring to the whole given area. The present results show that the algorithm can help prolong system lifetime remarkably when it is applied to other conventional approaches for sensor networks under the condition that the sensor node density is high.

  6. Prolonged energy harvesting for ingestible devices.

    Nadeau, Phillip; El-Damak, Dina; Glettig, Dean; Kong, Yong Lin; Mo, Stacy; Cleveland, Cody; Booth, Lucas; Roxhed, Niclas; Langer, Robert; Chandrakasan, Anantha P; Traverso, Giovanni


    Ingestible electronics have revolutionized the standard of care for a variety of health conditions. Extending the capacity and safety of these devices, and reducing the costs of powering them, could enable broad deployment of prolonged monitoring systems for patients. Although prior biocompatible power harvesting systems for in vivo use have demonstrated short minute-long bursts of power from the stomach, not much is known about the capacity to power electronics in the longer term and throughout the gastrointestinal tract. Here, we report the design and operation of an energy-harvesting galvanic cell for continuous in vivo temperature sensing and wireless communication. The device delivered an average power of 0.23 μW per mm(2) of electrode area for an average of 6.1 days of temperature measurements in the gastrointestinal tract of pigs. This power-harvesting cell has the capacity to provide power for prolonged periods of time to the next generation of ingestible electronic devices located in the gastrointestinal tract.

  7. Left ventricular wall stress compendium.

    Zhong, L; Ghista, D N; Tan, R S


    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  8. Alterations in apoptotic markers and egg-specific protein gene expression in the chicken oviduct during pause in laying induced by tamoxifen.

    Socha, Joanna K; Hrabia, Anna


    The aim of this study was to examine the cell apoptosis, gene expression and activity of caspases 2, 3, 8 and 9, and the mRNA expression of selected egg-specific proteins in the chicken oviduct during pause in egg laying induced by tamoxifen (TMX) treatment. The experiment was carried out on Hy-Line Brown laying hens. The control birds were treated subcutaneously with vehicle (ethanol) and the experimental ones with TMX at a dose of 6 mg/kg of body weight. Hens were treated daily until a pause in egg laying occurred and sacrificed on Day 7 of the experiment. Within the oviductal wall, the highest number of apoptotic cells (TUNEL-positive) was found in the luminal epithelium and the lowest in the stroma. The administration of TMX increased the percentage of apoptotic cells in the magnum, isthmus, and shell gland as well as immunoreactivity for caspases 3 and 9. Real-time PCR analysis revealed the segment-dependent mRNA expression of caspases 2, 3, 8 and 9. Treatment of hens with TMX elevated the level of caspase-2 transcript in the infundibulum, caspases 2, 3 and 8 in the isthmus, and caspase-9 in the shell gland (P avidin and ovocleidin-116 mRNAs was decreased (P egg-specific proteins after TMX treatment suggest that there is a relationship between estrogen action and the expression of these genes. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Tethering sigma70 to RNA polymerase reveals high in vivo activity of sigma factors and sigma70-dependent pausing at promoter-distal locations.

    Mooney, Rachel Anne; Landick, Robert


    Bacterial sigma factors compete for binding to RNA polymerase (RNAP) to control promoter selection, and in some cases interact with RNAP to regulate at least the early stages of transcript elongation. However, the effective concentration of sigmas in vivo, and the extent to which sigma can regulate transcript elongation generally, are unknown. We report that tethering sigma70 to all RNAP molecules via genetic fusion of rpoD to rpoC (encoding sigma70 and RNAP's beta' subunit, respectively) yields viable Escherichia coli strains in which alternative sigma-factor function is not impaired. beta'::sigma70 RNAP transcribed DNA normally in vitro, but allowed sigma70-dependent pausing at extended -10-like sequences anywhere in a transcriptional unit. Based on measurement of the effective concentration of tethered sigma70, we conclude that the effective concentration of sigma70 in E. coli (i.e., its thermodynamic activity) is close to its bulk concentration. At this level, sigma70 would be a bona fide elongation factor able to direct transcriptional pausing even after its release from RNAP during promoter escape.

  10. High Altitude Pulmonary Edema Without Appropriate Action Progresses to Right Ventricular Strain: A Case Study.

    Mills, Logan; Harper, Chris; Rozwadowski, Sophie; Imray, Chris


    Mills, Logan, Chris Harper, Sophie Rozwadowski, and Chris Imray. High altitude pulmonary edema without appropriate action progresses to right ventricular strain: A case study. High Alt Med Biol. 17:228-232, 2016.-A 24-year-old male developed high altitude pulmonary edema (HAPE) after three ascents to 4061 m over 3 days, sleeping each night at 2735 m. He complained of exertional dyspnea, dry cough, chest pain, fever, nausea, vertigo, and a severe frontal headache. Inappropriate continuation of ascent despite symptoms led to functional impairment and forced a return to the valley, but dyspnea persisted in addition to new orthopnea. Hospital admission showed hypoxemia, resting tachycardia, and systemic hypertension. ECG revealed right ventricular strain and a chest X-ray revealed right lower zone infiltrates. This case demonstrates that HAPE can develop in previously unaffected individuals given certain precipitating factors, and that in the presence of HAPE, prolonged exposure to altitude with exercise (or exertion) does not confer acclimatization with protective adaptations and that rest and descent are the appropriate actions. The case additionally demonstrates well-characterized right ventricular involvement.

  11. Treatment of asymptomatic catecholaminergic polymorphic ventricular tachycardia.

    Obeyesekere, Manoj N; Sy, Raymond W; Leong-Sit, Peter; Gula, Lorne J; Yee, Raymond; Skanes, Allan C; Klein, George J; Krahn, Andrew D


    Catecholaminergic polymorphic ventricular tachycardia is a rare genetic disorder caused by mutations in genes involved in the intracellular calcium homeostasis of cardiac cells. Affected patients typically present with life-threatening ventricular arrhythmias precipitated by emotional/physical stress. The diagnosis is based on the demonstration of polymorphic or bidirectional ventricular tachycardia associated with adrenergic stress. Genetic testing can be confirmatory in some patients. Treatment for catecholaminergic polymorphic ventricular tachycardia includes medical and surgical efforts to suppress the effects of epinephrine at the myocardial level and/or modulation of calcium homeostasis. Mortality is high when untreated and sudden cardiac death may be the first manifestation of the disease. First-degree relatives of a proband should be offered genetic testing if the causal mutation is known. If the family mutation is not known, relatives should be clinically evaluated with provocative testing. In the absence of rigorous trials, prophylactic treatment of the asymptomatic catecholaminergic polymorphic ventricular tachycardia patient appears to reduce morbidity and mortality.

  12. Surgical Treatment of Left Ventricular Pseudoaneurysm

    Mujanovic, Emir; Bergsland, Jacob; Avdic, Sevleta; Stanimirovic-Mujanovic, Sanja; Kovacevic-Preradovic, Tamara; Kabil, Emir


    Introduction: Left ventricular pseudoaneurysm is a rare condition because in most instances ventricular free-wall rupture leads to fatal pericardial tamponade. Rupture of the free wall of the left ventricle is a cata­strophic complication of myocardial infarction, occurring in approximately 4% of pa­tients with infarcts, resulting in immediate collapse of the patient and electromechanical dissociation. In rare cases the rupture is contained by pericardial and fibrous tissue, and the result is a pseudoaneurysm. The left ventricular pseudoaneurysm contains only pericardial and fibrous elements in its wall-no myocardial tissue. Because such aneurysms have a strong tendency to rupture, this disorder may lead to death if it is left surgically untreated. Case report: In this case report, we present a patient who underwent successful repair of a left ventricular pseudoaneurysm, which followed a myocardial infarction that was caused by occlusion of the left circumflex coronary artery. Although repair of left ventricular pseudoaneurysm is still a surgical challenge, it can be performed with acceptable results in most patients. PMID:25568538

  13. Improved left ventricular function after growth hormone replacement in patients with hypopituitarism: assessment with radionuclide angiography

    Cuocolo, A. [Cattedra di Medicina Nucleare, Centro per la Medicina Nucleare del CNR, Universita Federico II, Napoli (Italy); Nicolai, E. [Cattedra di Medicina Nucleare, Centro per la Medicina Nucleare del CNR, Universita Federico II, Napoli (Italy); Colao, A. [Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Universita Federico II, Napoli (Italy); Longobardi, S. [Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Universita Federico II, Napoli (Italy); Cardei, S. [Cattedra di Medicina Nucleare, Centro per la Medicina Nucleare del CNR, Universita Federico II, Napoli (Italy); Fazio, S. [Medicina Interna, Universita Federico II, Napoli (Italy); Merola, B. [Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Universita Federico II, Napoli (Italy); Lombardi, G. [Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Universita Federico II, Napoli (Italy); Sacca, L. [Medicina Interna, Universita Federico II, Napoli (Italy); Salvatore, M. [Cattedra di Medicina Nucleare, Centro per la Medicina Nucleare del CNR, Universita Federico II, Napoli (Italy)


    Prolonged growth hormone deficiency (GHD) leads to marked cardiac dysfunction; however, whether reversal of this abnormality may be achieved after specific replacement therapy has not yet been completely clarified. Fourteen patients with childhood-onset GHD (nine men and five women, mean age 27{+-}4 years) and 12 normal control subjects underwent equilibrium radionuclide angiography under control conditions at rest. Patients with GHD were also studied 6 months after recombinant human (rh) GH treatment (0.05 IU/kg per day). Normal control subjects and patients with GHD did not differ with respect to age, gender and heart rate. In contrast, left ventricular ejection fraction (53%{+-}9% vs 66%{+-}6%, P <0.001), stroke volume index (41{+-}11 vs 51{+-}8 ml/m{sup 2}, P <0.01) and cardiac index (2.8{+-}0.6 vs 3.{+-}0.5 l/min/m{sup 2}, P <0.001) were significantly lower in GHD patients than in normal control subjects. None of the GHD patients showed adverse or side-effects during rhGH therapy; thus none required a reduction in GH dose during the treatment period. Heart rate and arterial blood pressure were not significantly modified by rhGH treatment. After 6 months of rhGH therapy a significant improvement in left ventricular ejection fraction (from 53%{+-}9% to 59%{+-}9%, P <0.01), stroke volume index (from 41{+-}11 to 47{+-}13 ml/m{sup 2}, P <0.05) and cardiac index (from 2.8{+-}0.6 to 3.3{+-}0.8 l/min/m{sup 2}, P <0.01) was observed in GHD patients. In conclusion, prolonged lack of GH leads to impaired left ventricular function at rest. Reversal of this abnormality may be observed after 6 months of specific replacement therapy in patients with childhood-onset GHD. (orig.). With 4 figs., 1 tab.

  14. Changes in Intracellular Na+ following Enhancement of Late Na+ Current in Virtual Human Ventricular Myocytes

    Giles, Wayne R.


    The slowly inactivating or late Na+ current, INa-L, can contribute to the initiation of both atrial and ventricular rhythm disturbances in the human heart. However, the cellular and molecular mechanisms that underlie these pro-arrhythmic influences are not fully understood. At present, the major working hypothesis is that the Na+ influx corresponding to INa-L significantly increases intracellular Na+, [Na+]i; and the resulting reduction in the electrochemical driving force for Na+ reduces and (may reverse) Na+/Ca2+ exchange. These changes increase intracellular Ca2+, [Ca2+]i; which may further enhance INa-L due to calmodulin-dependent phosphorylation of the Na+ channels. This paper is based on mathematical simulations using the O’Hara et al (2011) model of baseline or healthy human ventricular action potential waveforms(s) and its [Ca2+]i homeostasis mechanisms. Somewhat surprisingly, our results reveal only very small changes (≤ 1.5 mM) in [Na+]i even when INa-L is increased 5-fold and steady-state stimulation rate is approximately 2 times the normal human heart rate (i.e. 2 Hz). Previous work done using well-established models of the rabbit and human ventricular action potential in heart failure settings also reported little or no change in [Na+]i when INa-L was increased. Based on our simulations, the major short-term effect of markedly augmenting INa-L is a significant prolongation of the action potential and an associated increase in the likelihood of reactivation of the L-type Ca2+ current, ICa-L. Furthermore, this action potential prolongation does not contribute to [Na+]i increase. PMID:27875582

  15. Strong modulation of ectopic focus as a mechanism of repetitive interpolated ventricular bigeminy with heart rate doubling.

    Takayanagi, Kan; Nakahara, Shiro; Toratani, Noritaka; Chida, Ryuji; Kobayashi, Sayuki; Sakai, Yoshihiko; Takeuchi, Akihiro; Ikeda, Noriaki


    Repetitive interpolated ventricular bigeminy (RIVB) can introduce a doubling of the ventricular rate. To clarify the mechanism of RIVB, we hypothesized that it was introduced by a strong modulation of the ventricular automatic focus. RIVB, defined as more than 7 bigeminy events, was detected by instantaneous heart rate and bigeminy interval (BI) tachograms in 1450 successive patients with frequent ventricular premature contractions (≥3000 per day). Postextrasystolic interval bigeminy interval curves were plotted to determine the degree of modulation. Mean sinus cycle length bigeminy interval curves were plotted for selection. RIVB was simulated by using a computer-based parasystole model. RIVB was observed in 7 patients (age 60 ± 16 years; 2 men and 5 women) with a heart rate of 58.2 ± 6.5 beats/min during a rest period both during the day and at night. The tachograms disclosed the onset of the RIVB with a doubled ventricular rate to 112.3 ± 8.5 beats/min. On the postextrasystolic interval bigeminy interval curves, compensatory bigeminy and interpolated bigeminy constituted overlapping regression lines with slopes close to 1.00 and RIVB was located in the lower left portion. RIVB lasting for up to 3 hours was quickly detected by mean sinus cycle length bigeminy interval curve. The PQ interval immediately after RIVB was prolonged in comparison with baseline (0.18 ± 0.02 to 0.21 ± 0.02 seconds; P heart rate. Our findings support the hypothesis that RIVB was introduced by strongly modulated ventricular pacemaker accelerated by an intervening normal QRS. © 2013 Heart Rhythm Society. All rights reserved.

  16. Targeted inactivation of Cerberus like-2 leads to left ventricular cardiac hyperplasia and systolic dysfunction in the mouse.

    Ana Carolina Araújo

    Full Text Available Previous analysis of the Cerberus like 2 knockout (Cerl2-/- mouse revealed a significant mortality during the first day after birth, mostly due to cardiac defects apparently associated with randomization of the left-right axis. We have however, identified Cerl2-associated cardiac defects, particularly a large increase in the left ventricular myocardial wall in neonates that cannot be explained by laterality abnormalities. Therefore, in order to access the endogenous role of Cerl2 in cardiogenesis, we analyzed the embryonic and neonatal hearts of Cerl2 null mutants that did not display a laterality phenotype. Neonatal mutants obtained from the compound mouse line Cer2-/-::Mlc1v-nLacZ24+, in which the pulmonary ventricle is genetically marked, revealed a massive enlargement of the ventricular myocardium in animals without laterality defects. Echocardiography analysis in Cerl2-/- neonates showed a left ventricular systolic dysfunction that is incompatible with a long lifespan. We uncovered that the increased ventricular muscle observed in Cerl2-/- mice is caused by a high cardiomyocyte mitotic index in the compact myocardium which is mainly associated with increased Ccnd1 expression levels in the left ventricle at embryonic day (E 13. Interestingly, at this stage we found augmented left ventricular expression of Cerl2 levels when compared with the right ventricle, which may elucidate the regionalized contribution of Cerl2 to the left ventricular muscle formation. Importantly, we observed an increase of phosphorylated Smad2 (pSmad2 levels in embryonic (E13 and neonatal hearts indicating a prolonged TGFβs/Nodal-signaling activation. Concomitantly, we detected an increase of Baf60c levels, but only in Cerl2-/- embryonic hearts. These results indicate that independently of its well-known role in left-right axis establishment Cerl2 plays an important role during heart development in the mouse, mediating Baf60c levels by exerting an important control of

  17. Role of temporary pacing at the right ventricular outflow tract in anesthetic management of a patient with asymptomatic sick sinus syndrome.

    Nag, Kusha; Nagella, Amrutha Bindu; Kumar, V R Hemanth; Singh, Dewan Roshan; Ravishankar, M


    A 60-year-old woman posted for percutaneous nephrolithotomy with ureterolithotripsy was found to have a history of hypertension and ischemic heart disease from past 6 months on regular treatment. Pulse rate was irregularly irregular in a range of 56-60/min, unresponsive to atropine, with a sinus pause on the electrocardiogram. Although the patient was asymptomatic, anticipating unmasking of the sick sinus syndrome during general anesthesia in the prone position, a temporary pacemaker was implanted at right ventricular outflow tract (RVOT) septum before the scheduled surgery. A balanced anesthesia technique with endotracheal intubation was administered. There were several episodes of continuous pacing by the temporary pacemaker intraoperatively, which may be attributed to unmasking of the sinus node dysfunction due to general anesthesia. At the end of surgery, patient was extubated after adequate reversal from neuromuscular blockade. Postoperative period remained uneventful, and the pacemaker wires were removed on the 2(nd) postoperative day. With this case report, we highlight the importance of inserting a temporary pacemaker prior to anesthesia even in an asymptomatic patient if a sinus node dysfunction is suspected preoperatively and if intraoperative access to transvenous pacing is difficult such as in prone position. Pacing at RVOT septum minimizes ventricular dyssynchrony and improves hemodynamic parameters.

  18. Role of right ventricular three-dimensional electroanatomic voltage mapping for arrhythmic risk stratification of patients with corrected tetralogy of Fallot or other congenital heart disease involving the right ventricular outflow tract.

    Drago, Fabrizio; Pazzano, Vincenzo; Di Mambro, Corrado; Russo, Mario Salvatore; Palmieri, Rosalinda; Silvetti, Massimo Stefano; Giannico, Salvatore; Leonardi, Benedetta; Amodeo, Antonio; Di Ciommo, Vincenzo Maria


    The post-surgical history of repaired congenital heart disease (rCHD), in particular tetralogy of Fallot (TOF), is often complicated by sudden death. Electrical myocardial abnormalities could be a substrate for malignant ventricular arrhythmias. 146 patients with TOF or other rCHD involving a subpulmonary right ventricle, considered to be at high arrhythmic risk, underwent right ventricular (RV) electroanatomic voltage mapping (EVM). Maps showed endocardial scars (right ventricular systolic dysfunction [4.5% (±3.2) vs 2.8% (±2.3), p=0.016 and 3.5% (±3.0) vs 2.6% (±1.9), p=0.03, respectively], premature ventricular contractions (PVCs) [3.2% (±2.6) vs 2.2% (±1.8), pright ventricle show electrical scars with variable distribution, not necessarily matching with sites of surgical lesions. Scar extension correlates with some of the risk factors for life-threatening arrhythmias in CHD, such as prolonged QRS. Thus EVM could be considered an additional tool in the assessment of risk stratification in this particular population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. [Sideroblastic anemia after prolonged linezolid therapy].

    Kakimoto, Tsunayuki; Nakazato, Tomonori; Miura, Reiko; Kurai, Hanako; Yamashita, Daisuke; Sagara, Yuko; Ishida, Akaru


    Linezolid is an effective and well-tolerated antibiotic for the treatment of infections caused by Gram-positive pathogens. Some reports have shown that linezolid treatment for more than 2 weeks has been associated with reversible bone marrow suppression, especially thrombocytopenia and anemia. We encountered a case of sideroblastic anemia following prolonged linezolid therapy in a laryngeal cancer patient. He received linezolid therapy for multiple abscesses due to MRSA. Before treatment, the Hb level was 12.5 g/dl and then slowly decreased to 5.9 g/dl for 2 months during treatment. Ringed sideroblasts were detected in the bone marrow. Linezolid was discontinued and the Hb level was slowly increased. This case was considered to reflect a rare complication of linezolid therapy.

  20. Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy

    Michael Gysel


    Full Text Available A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP. She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM contributing to the development of a multifactorial acquired long QT syndrome (LQTS. The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM.

  1. Neurohumoral responses during prolonged exercise in humans

    Nybo, Lars; Nielsen, Bodil; Blomstrand, Eva


    in the hyperthermic trial, with a concomitant increase in perceived exertion (P brain had a small release of tryptophan (arteriovenous difference of -1.2 +/- 0.3 micromol/l), whereas a net balance was obtained during the two exercise trials. Both the arterial and jugular venous dopamine levels...... became elevated during the hyperthermic trial, but the net release from the brain was unchanged. During exercise, the O2/CHO was similar across trials, but, during recovery from the hyperthermic trial, the ratio decreased to 3.8 +/- 0.3 (P ...This study examined neurohumoral alterations during prolonged exercise with and without hyperthermia. The cerebral oxygen-to-carbohydrate uptake ratio (O2/CHO = arteriovenous oxygen difference divided by arteriovenous glucose difference plus one-half lactate), the cerebral balances of dopamine...

  2. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

    Tassi, Eduardo Marinho, E-mail: [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Continentino, Marcelo Abramoff [Hospital Frei Galvão, Guaratinguetá, SP (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia - UFRJ, Rio de Janeiro, RJ (Brazil); Pedrosa, Roberto Coury [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)


    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups.

  3. MRI assessment of right ventricular dysplasia

    Di Cesare, Ernesto [Department of Radiology, University of L' Aquila, via Vetoio 1, 67100, L' Aquila (Italy)


    Right ventricular dysplasia is a new entity of unknown origin in the classification of cardiomyopathies. Also known as arrhythmogenic right ventricular cardiomyopathy (ARVC) or arrhythmogenic right ventricular dysplasia, it is a disease of the heart muscle characterised by fibroadipose atrophy mainly involving the right ventricle and responsible for severe ventricular arrhythmias and sudden death also in young people. Magnetic resonance imaging provides evidence of ventricular dilatation at the outflow tract, thinning and thickening of the wall, diastolic bulging areas (especially located at the level of the right ventricle outflow tract) and fatty substitution of the myocardium mainly at the level of the right ventricle. Many radiologists erroneously consider the previously described fatty substitution as the main sign of ARVC, even though an evaluation of fat substitution alone may be a source of error for two reasons: firstly, because isolated areas of fatty replacement are not synonymous with ARVC since small non-transmural focal fatty areas of fat are also present in the normal patients; and secondly, because the MRI detection of fat may be overestimated due to partial-volume artefacts with normal subepicardial fat. Cardiac MRI can also be employed for the diagnosis of idiopathic right ventricular outflow tract tachycardia. Considering the evolutive nature of the disease, the non-invasiveness of MRI allows the follow-up of these patients and may be considered an excellent screening modality for the diagnosis of ARVC in family members. Finally, MRI can be employed in electrophysiological studies to locate the arrhythmogenic focus and reduce sampling errors. (orig.)

  4. Evaluation of right ventricular volumes measured by magnetic resonance imaging

    Møgelvang, J; Stubgaard, M; Thomsen, C


    Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular...... stroke volume was calculated as the difference between end-diastolic and end-systolic volume and compared to left ventricular stroke volume and to stroke volume determined simultaneously by a classical indicator dilution technique. There was good agreement between right ventricular stroke volume...... determined by MRI and by the indicator dilution method and between right and left ventricular stroke volume determined by MRI. Thus, MRI gives reliable values not only for left ventricular volumes, but also for right ventricular volumes. By MRI it is possible to obtain volumes from both ventricles...

  5. Endoventriculoplasty using autologous endocardium for anterior left ventricular aneurysms

    Grandjean, JG; Mariani, MA; D'Alfonso, A; Musazzi, A; Boonstra, PW

    Background: There is currently consensus that endoventriculoplasty is the treatment of choice for an anterior left ventricular aneurysm. We describe here a new technique of endoventriculoplasty using autologous endocardium for left ventricular anterior aneurysm. Method: From 1990 until 2003, 49

  6. Disruption of cardiac cholinergic neurons enhances susceptibility to ventricular arrhythmias

    Jungen, Christiane; Scherschel, Katharina; Eickholt, Christian; Kuklik, Pawel; Klatt, Niklas; Bork, Nadja; Salzbrunn, Tim; Alken, Fares; Angendohr, Stephan; Klene, Christiane; Mester, Janos; Klöcker, Nikolaj; Veldkamp, Marieke W.; Schumacher, Udo; Willems, Stephan; Nikolaev, Viacheslav O.; Meyer, Christian


    The parasympathetic nervous system plays an important role in the pathophysiology of atrial fibrillation. Catheter ablation, a minimally invasive procedure deactivating abnormal firing cardiac tissue, is increasingly becoming the therapy of choice for atrial fibrillation. This is inevitably associated with the obliteration of cardiac cholinergic neurons. However, the impact on ventricular electrophysiology is unclear. Here we show that cardiac cholinergic neurons modulate ventricular electrophysiology. Mechanical disruption or pharmacological blockade of parasympathetic innervation shortens ventricular refractory periods, increases the incidence of ventricular arrhythmia and decreases ventricular cAMP levels in murine hearts. Immunohistochemistry confirmed ventricular cholinergic innervation, revealing parasympathetic fibres running from the atria to the ventricles parallel to sympathetic fibres. In humans, catheter ablation of atrial fibrillation, which is accompanied by accidental parasympathetic and concomitant sympathetic denervation, raises the burden of premature ventricular complexes. In summary, our results demonstrate an influence of cardiac cholinergic neurons on the regulation of ventricular function and arrhythmogenesis. PMID:28128201

  7. New ECG Criteria in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

    M.G.P.J. Cox; J.J. van der Smagt; A.A.M. Wilde; A.C.P. Wiesfeld; D.E. Atsma; M.R. Nelen; L.M. Rodriguez; P. Loh; M.J. Cramer; P.A. Doevendans; J.P. van Tintelen; J.M.T. de Bakker; R.N.W. Hauer


    Background-Desmosomal changes, electric uncoupling, and surviving myocardial bundles in fibrofatty tissue characterize arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Resultant activation delay is pivotal for reentry and thereby ventricular tachycardia (VT). Current task force cr

  8. Dasatinib and Prednisolone Induction Therapy for a Case of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Dilated Cardiomyopathy Accompanied by Life-Threatening Ventricular Tachycardia

    Mitsutaka Nishimoto


    Full Text Available A 56-year-old man being treated for dilated cardiomyopathy presented with epigastralgia. He was diagnosed with ventricular tachycardia and Philadelphia chromosome-positive acute lymphoblastic leukemia. After treating incessant ventricular tachycardia, we commenced induction therapy for leukemia with dasatinib and prednisolone to minimize toxicity towards cardiomyocytes and the cardiac conduction system. Although dasatinib was temporarily withheld because of a recurrence of ventricular tachycardia, we rechallenged dasatinib while using bisoprolol and amiodarone and achieved a complete hematological response three weeks later. Although drug interactions between dasatinib and amiodarone were of concern, the blood concentration of each drug remained within the safe range after concomitant use, and there were no adverse cardiac effects such as QT prolongation after rechallenging dasatinib. Induction therapy with dasatinib and prednisolone may be an acceptable therapeutic option for Philadelphia chromosome-positive acute lymphoblastic leukemia with severe cardiac complications.

  9. Ventricular Tachycardia Induced by Weight Loss Pills

    Manan Pareek


    Full Text Available 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. Ventricular arrhythmias. Clinical recognition and management.

    Nestico, P F; DePace, N L; Morganroth, J


    The recognition that patients at high risk for sudden cardiac death can be identified raises our enthusiasm to eliminate some of these risk factors and thus our hope to prevent sudden cardiac death. Although this effect is yet to be shown in cooperative, well-controlled clinical trials, data exist to suggest that this result will be achieved. Thus, the use of antiarrhythmic agents in chronic ventricular ectopy, particularly in patients with left ventricular dysfunction, seems to be warranted, and new and more potent agents to be used for this end will be available in the future.

  11. Catecholaminergic polymorphic ventricular tachycardia in 2012

    Christian van der Werf


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

  12. Right ventricular cardiomyopathy meeting the arrhythmogenic right ventricular dysplasia revised criteria? Do not forget sarcoidosis

    Vasaturo, Sabina; Ploeg, David E.; Zeppenfeld, Katja; Veselic-Charvat, Maud [Leiden University Medical Center, Leiden (Netherlands); Buitrago, Guadalupe [Dept. of Radiology, Hospital General Universitario Gregorio Maranon, Madrid (Spain)


    A 53-year-old woman was referred for ventricular fibrillation with resuscitation. A CT-angiography showed signs of a right ventricular enlargement without obvious cause. A cardiac MRI demonstrated a dilated and hypokinetic right ventricle with extensive late gadolinium enhancement. Arrhythmogenic right ventricular dysplasia (ARVD) was suspected according to the {sup r}evised ARVD task force criteria{sup .} An endomyocardial biopsy was inconclusive. The patient developed purulent pericarditis after epicardial ablation therapy and died of toxic shock syndrome. The post-mortem pathologic examination demonstrated sarcoidosis involving the heart, lungs, and thyroid gland.

  13. Left ventricular cardiac fibroma in a child presenting with ventricular tachycardia.

    Stratemann, Stacy; Dzurik, Yvette; Fish, Frank; Parra, David


    Cardiac tumors in children are rare. Although most are histologically benign, they can be associated with life-threatening arrhythmias and sudden death. We report a 7-year-old boy, with a first episode of symptomatic tachycardia, who was found to have a left ventricular (LV) fibroma. He had a normal echocardiogram prior to an electrophysiology study, which revealed a sustained monomorphic ventricular tachycardia and a radio-opacity near the LV apex. These findings prompted a cardiac MRI, which demonstrated a discrete mass on his LV apex and free wall. Our case emphasizes that structural heart disease should be aggressively pursued in children presenting with ventricular tachycardia.

  14. Antipsychotic Drugs and the Risk of Ventricular Arrhythmia and/or Sudden Cardiac Death: A Nation‐wide Case‐Crossover Study


    Background Antipsychotics have been linked to prolongation of the QT interval. However, little is known about the risk of ventricular arrhythmia (VA) and/or sudden cardiac death (SCD) associated with individual antipsychotic drug use. This study was designed to investigate the association between specific antipsychotic drugs and the risk of VA and/or SCD. Methods and Results We conducted a case‐crossover study using a nation‐wide population‐based sample obtained from Taiwan's National Health ...

  15. The influence of progesterone alone and in combination with estradiol on ventricular action potential duration and triangulation in response to potassium channel inhibition.

    Tisdale, James E; Overholser, Brian R; Wroblewski, Heather A; Sowinski, Kevin M


    Females are at increased risk for torsades de pointes (TdP). Some evidence suggests that progesterone may protect against TdP, but few data exist regarding the effects of progesterone on cardiac repolarization. We determined the effects of progesterone alone and in combination with estradiol on ventricular action potential duration (APD) and triangulation in response to potassium channel inhibition. Female New Zealand white rabbits (n = 30) underwent ovariectomy and were implanted with 21-day sustained release pellets (each n = 6): progesterone; estradiol; progesterone; & estradiol combined; dihydrotestosterone (DHT); and placebo. After 20 days, hearts were excised, mounted, perfused with modified Krebs-Henseleit buffer, and paced at 150 bpm. After baseline measurements, hearts were perfused with quinidine 3 μmol/L. The degree of quinidine-associated prolongation of ventricular APD at 90% repolarization (APD(90) ) in the progesterone group was significantly less than that in the estradiol and the combined estradiol and progesterone groups, and not significantly different than in the DHT group. The degree of prolongation of action potential triangulation (APD(90) - APD(30) ) in hearts from progesterone-treated rabbits was significantly less than that in the estradiol group, and not significantly different from that in hearts from DHT-treated rabbits. There were no significant differences in quinidine effects on ventricular APD(90) or action potential triangulation between hearts exposed to estradiol alone or those exposed to both estradiol and progesterone. Progesterone protects against prolongation of APD(90) and triangulation associated with potassium channel inhibition. However, progesterone does not attenuate the effects of estradiol on prolongation of ventricular APD(90) associated with potassium channel inhibition. © 2010 Wiley Periodicals, Inc.

  16. A 2:1 AV rhythm: an adverse effect of a long AV delay during DDI pacing and its prevention by the ventricular intrinsic preference algorithm in DDD mode.

    Minamiguchi, Hitoshi; Oginosawa, Yasushi; Kohno, Ritsuko; Tamura, Masahito; Takeuchi, Masaaki; Otsuji, Yutaka; Abe, Haruhiko


    A 91-year-old woman received a dual-chamber pacemaker for sick sinus syndrome and intermittently abnormal atrioventricular (AV) conduction. The pacemaker was set in DDI mode with a 350-ms AV delay to preserve intrinsic ventricular activity. She complained of palpitation during AV sequential pacing. The electrocardiogram showed a 2:1 AV rhythm from 1:1 ventriculoatrial (VA) conduction during ventricular pacing in DDI mode with a long AV interval. After reprogramming of the pacemaker in DDD mode with a 250-ms AV interval and additional 100-ms prolongation of the AV interval by the ventricular intrinsic preference function, VA conduction disappeared and the patient's symptom were alleviated without increasing unnecessary right ventricular pacing.

  17. Methanolic Extract of Ceplukan Leaf (Physalis minima L.) Attenuates Ventricular Fibrosis through Inhibition of TNF-α in Ovariectomized Rats

    Lestari, Bayu; Permatasari, Nur; Rohman, Mohammad Saifur


    The increase of heart failure prevalence on menopausal women was correlated with the decrease of estrogen level. The aim of this study is to investigate the effects of ceplukan leaf (Physalis minima L.), which contains phytoestrogen physalin and withanolides, on ventricular TNF-α level and fibrosis in ovariectomized rats. Wistar rats were divided into six groups (control (—); OVX 5: 5-week ovariectomy (OVX); OVX 9: 9-week ovariectomy; treatments I, II, and III: 9-weeks OVX + 4-week ceplukan leaf's methanolic extract doses 500, 1500, and 2500 mg/kgBW, resp.). TNF-α levels were measured with ELISA. Fibrosis was counted as blue colored tissues percentage using Masson's Trichrome staining. This study showed that prolonged hypoestrogen increases ventricular fibrosis (p Physalis minima L. (p < 0.05) treatment. The reduction of fibrosis positively correlated with TNF-α level (p < 0.05, r = 0.873). Methanolic extract of ceplukan leaf decreases ventricular fibrosis through the inhibition of ventricular TNF-α level in ovariectomized rats. PMID:26941790

  18. Hypertrophic cardiomyopathy with mid-ventricular obstruction and apical aneurysm

    N.D. Oryshchyn


    Full Text Available A case report of apical left ventricular aneurysm in patient with hypertrophic cardiomyopathy with mid-ventricular obstruction (diagnosis and surgical treatment is presented. We revealed apical aneurysm and mid-ventricular obstruction during echocardiography and specified anatomical characteristics of aneurysm during computer tomography. There was no evidence of obstructive coronary artery disease during coronary angiography. Taking into consideration multiple cerebral infarcts, aneurysm resection and left ventricular plastics was performed. Electronic microscopy of myocardium confirmed the diagnosis of hypertrophic cardiomyopathy.

  19. Prolonged pain and disability are common after rib fractures.

    Fabricant, Loic; Ham, Bruce; Mullins, Richard; Mayberry, John


    The contribution of rib fractures to prolonged pain and disability may be underappreciated and undertreated. Clinicians are traditionally taught that the pain and disability of rib fractures resolves in 6 to 8 weeks. This study was a prospective observation of 203 patients with rib fractures at a level 1 trauma center. Chest wall pain was evaluated by the McGill Pain Questionnaire (MPQ) pain rating index (PRI) and present pain intensity (PPI). Prolonged pain was defined as a PRI of 8 or more at 2 months after injury. Prolonged disability was defined as a decrease in 1 or more levels of work or functional status at 2 months after injury. Predictors of prolonged pain and disability were determined by multivariate analysis. One hundred forty-five male patients and 58 female patients with a mean injury severity score (ISS) of 20 (range, 1 to 59) had a mean of 5.4 rib fractures (range, 1 to 29). Forty-four (22%) patients had bilateral fractures, 15 (7%) had flail chest, and 92 (45%) had associated injury. One hundred eighty-seven patients were followed 2 months or more. One hundred ten (59%) patients had prolonged chest wall pain and 142 (76%) had prolonged disability. Among 111 patients with isolated rib fractures, 67 (64%) had prolonged chest wall pain and 69 (66%) had prolonged disability. MPQ PPI was predictive of prolonged pain (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4 to 2.5), and prolonged disability (OR, 2.2; 95% CI, 1.5 to 3.4). The presence of significant associated injuries was predictive of prolonged disability (OR, 5.9; 95% CI, 1.4 to 29). Prolonged chest wall pain is common, and the contribution of rib fractures to disability is greater than traditionally expected. Further investigation into more effective therapies that prevent prolonged pain and disability after rib fractures is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Prolonged Tp-e Interval and Tp-e/QT Ratio in Children with Mitral Valve Prolapse.

    Demirol, Mustafa; Karadeniz, Cem; Ozdemir, Rahmi; Çoban, Şenay; Katipoğlu, Nagehan; Yozgat, Yılmaz; Meşe, Timur; Unal, Nurettin


    Although it is considered to be a benign condition, previous studies have shown that a subset of patients with mitral valve prolapse (MVP) may be at risk of ventricular arrhythmia and sudden cardiac death (SCD). Previous studies have suggested that the interval between the peak and the end of the T wave (Tp-e) can be used as a marker for the transmural dispersion of repolarization. Increased Tp-e interval and Tp-e/QT ratio are associated with ventricular arrhythmias and SCD. The aim of this study was to assess alterations in ventricular repolarization by using the Tp-e interval and Tp-e/QT ratio in children with MVP and to investigate their relationships with the degree of valvular regurgitation. This study prospectively investigated 110 children with MVP and 107 age- and sex-matched healthy control subjects. Tp-e interval, Tp-e/QT ratio, and QT and QTc dispersions were measured from a 12-lead electrocardiogram and compared between groups. QT and QTc dispersions, Tp-e interval, and Tp-e/QTc ratio were found to be significantly higher in patients with MVP. A positive correlation was found between Tp-e/QTc ratio and increase in the degree of mitral regurgitation (MR) (p e intervals; QT, QTc, or Tp-e dispersions; or Tp-e/QT ratio (all p values >0.05). Individuals with MVP may be more prone to ventricular arrhythmias due to prolonged QTd, QTcd, and Tp-e interval and increased Tp-e/QT and Tp-e/QTc ratios. Therefore, due to their longer life expectancy, children with MVP should be followed up on regarding life-threatening arrhythmias.

  1. Left Ventricular Involvement in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy Assessed by Echocardiography Predicts Adverse Clinical Outcome

    Mast, Thomas P.; Teske, Arco J.; van der Heijden, Jeroen F.; Groeneweg, Judith A.; Te Riele, Anneline S J M; Velthuis, Birgitta K.; Hauer, RNW; Doevendans, Pieter A.; Cramer, Maarten J.


    Background Among studies describing the phenotype of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), significant discrepancy exists regarding the extent and impact of left ventricular (LV) involvement. The capability of conventional and new quantitative echocardiographic techniqu

  2. 21 CFR 870.3545 - Ventricular bypass (assist) device.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device. 870.3545... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that...

  3. The relation between bradycardic dyssynchronous ventricular activation, remodeling and arrhythmogenesis

    Dunnink, A


    Sudden cardiac death (SCD) is a common cause of death and its incidence continues to rise. The occurrence of SCD is mainly due to development of malignant ventricular arrhythmias such as ventricular tachycardia or ventricular fibrillation. The underlying cause of SCD is almost always a complex

  4. The relation between bradycardic dyssynchronous ventricular activation, remodeling and arrhythmogenesis

    Dunnink, A


    Sudden cardiac death (SCD) is a common cause of death and its incidence continues to rise. The occurrence of SCD is mainly due to development of malignant ventricular arrhythmias such as ventricular tachycardia or ventricular fibrillation. The underlying cause of SCD is almost always a complex remod

  5. Increased persistent sodium current due to decreased PI3K signaling contributes to QT prolongation in the diabetic heart.

    Lu, Zhongju; Jiang, Ya-Ping; Wu, Chia-Yen C; Ballou, Lisa M; Liu, Shengnan; Carpenter, Eileen S; Rosen, Michael R; Cohen, Ira S; Lin, Richard Z


    Diabetes is an independent risk factor for sudden cardiac death and ventricular arrhythmia complications of acute coronary syndrome. Prolongation of the QT interval on the electrocardiogram is also a risk factor for arrhythmias and sudden death, and the increased prevalence of QT prolongation is an independent risk factor for cardiovascular death in diabetic patients. The pathophysiological mechanisms responsible for this lethal complication are poorly understood. Diabetes is associated with a reduction in phosphoinositide 3-kinase (PI3K) signaling, which regulates the action potential duration (APD) of individual myocytes and thus the QT interval by altering multiple ion currents, including the persistent sodium current INaP. Here, we report a mechanism for diabetes-induced QT prolongation that involves an increase in INaP caused by defective PI3K signaling. Cardiac myocytes of mice with type 1 or type 2 diabetes exhibited an increase in APD that was reversed by expression of constitutively active PI3K or intracellular infusion of phosphatidylinositol 3,4,5-trisphosphate (PIP3), the second messenger produced by PI3K. The diabetic myocytes also showed an increase in INaP that was reversed by activated PI3K or PIP3. The increases in APD and INaP in myocytes translated into QT interval prolongation for both types of diabetic mice. The long QT interval of type 1 diabetic hearts was shortened by insulin treatment ex vivo, and this effect was blocked by a PI3K inhibitor. Treatment of both types of diabetic mouse hearts with an INaP blocker also shortened the QT interval. These results indicate that downregulation of cardiac PI3K signaling in diabetes prolongs the QT interval at least in part by causing an increase in INaP. This mechanism may explain why the diabetic population has an increased risk of life-threatening arrhythmias.

  6. Lead reduces tension development and the myosin ATPase activity of the rat right ventricular myocardium

    D.V. Vassallo


    Full Text Available Lead (Pb2+ poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 µM to the bath. Changes in rate of stimulation (0.1-1.5 Hz, relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM, and the effect of isoproterenol (20 ng/mL were determined before and after the addition of 100 µM Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 µM. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 µM Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 µM Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 µM Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.

  7. Right Ventricular Imaging and Computer Simulation for Electromechanical Substrate Characterization in Arrhythmogenic Right Ventricular Cardiomyopathy

    Mast, TP; Teske, Arco J; Walmsley, John; van der Heijden, Jeroen F; van Es, René; Prinzen, Frits W; Delhaas, Tammo; van Veen, Toon A; Loh, KP; Doevendans, Pieter A; Cramer, Maarten J; Lumens, Joost


    BACKGROUND: Previous studies suggested that electrical abnormalities precede overt structural disease in arrhythmogenic right ventricular cardiomyopathy (ARVC). Abnormal RV deformation has been reported in early ARVC without structural abnormalities. The pathophysiological mechanisms underlying thes

  8. Diastolic Left Ventricular Dysfunction : A Clinical Appraisal

    Bronzwaer, J.G.F.


    Diastolic left ventricular (LV) distensibility is determined by the material properties of the LV wall and by LV geometry (i.e., LV shape, LV volume and LV wall thickness). These material properties are influenced both by the physical structure of the LV myocardium and by the dynamic process of myoc

  9. 3-Dimensional Right Ventricular Volume Assessment

    Jainandunsing, Jayant S.; Matyal, Robina; Shahul, Sajid S.; Wang, Angela; Woltersom, Bozena; Mahmood, Feroze

    Purpose: The purpose of this review was to evaluate new computer software available for 3-dimensional right ventricular (RV) volume estimation. Description: Based on 2-dimensional echocardiography, various algorithms have been used for RV volume estimation. These are complex, time-consuming

  10. Left ventricular hypertrophy : virtuous intentions, malign consequences

    Pokharel, S; Sharma, UC; Pinto, YM


    Left ventricular hypertrophy (LVH) is currently the focus of intense cardiovascular research, with the resultant rapid evolution of novel concepts relating to its exceedingly complex pathophysiology. In addition to the alterations in signal transduction and disturbances in Ca2+ homeostasis, there ar

  11. Catheter ablation of parahisian premature ventricular complex.

    Kim, Jun; Kim, Jeong Su; Park, Yong Hyun; Kim, June Hong; Chun, Kook Jin


    Catheter ablation is performed in selected patients with a symptomatic premature ventricular complex (PVC) or PVC-induced cardiomyopathy. Ablation of PVC from the His region has a high risk of inducing a complete atrioventricular block. Here we report successful catheter ablation of a parahisian PVC in a 63-year-old man.

  12. New test for arrhythmogenic right ventricular cardiomyopathy

    van Tintelen, J. Peter; Hauer, Richard N. W.

    Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is challenging to diagnose because of nonspecific findings, particularly in the early phases of the disease. clinical diagnosis is made on the basis of several criteria, but these lack sensitivity. Asimaki et al. suggest that

  13. Congestive cardiomyopathy and left ventricular thrombus.

    Gould, L; Gopalaswamy, C; Chandy, F; Kim, B S


    A left ventricular thrombus was detected by echocardiography in a 54-year-old man with congestive cardiomyopathy. With the use of anticoagulants, the thrombus completely disappeared. Patients with congestive cardiomyopathy who are at high risk for thrombus formation should be screened with two-dimensional echocardiography. If a thrombus is recognized, anticoagulation therapy can then be instituted.

  14. Diagnosis and management of ventricular dysphonia.

    Von Hake, C P; Ganzman, I P; Mauer, T P


    Ventricular phonation may develop on a functional level, or it may occur as an alternative voice for the patient who has an organic disease of the true vocal folds. Three cases that represent iatrogenic, traumatic, and neurologic forms of the disorder are reported. Diagnosis, treatment, and guidelines for follow-up speech therapy are discussed.

  15. Diastolic Left Ventricular Dysfunction : A Clinical Appraisal

    Bronzwaer, J.G.F.


    Diastolic left ventricular (LV) distensibility is determined by the material properties of the LV wall and by LV geometry (i.e., LV shape, LV volume and LV wall thickness). These material properties are influenced both by the physical structure of the LV myocardium and by the dynamic process of

  16. Ventricular tachycardia as a first manifestation of right ventricular myxoma--a case presentation.

    Badui, E; Cruz, H; Almazan, A; Enciso, R; Soberanis, N; Garcia, R


    The authors present a case of a thirty-nine-year-old white man in good health who developed episodes of ventricular tachycardia as a first manifestation of a right ventricular myxoma, which was diagnosed by two-dimensional echocardiogram and then resected with no complications and total disappearance of the cardiac arrhythmia. After reviewing the literature they consider the present case as a rare manifestation of an infrequent location of an uncommon disease.

  17. Effects of Long-term Right Ventricular Apical Pacing on Left Ventricular Remodeling and Cardiac Function


    Objective: To investigate the impacts of long-term right ventricular apical pacing on the ventricular remodeling and cardiac functions of patients with high-grade and third-degree atrioventricular blockage with normal heart structures and cardiac functions. In addition, we provide many evidences for choosing an optimal electrode implantation site.Methods: Study participants included patients who were admitted for pacemaker replacements and revisited for examinations of implanted pacemakers at outpatient. Pa...

  18. Angiographic left ventricular wall motion score to predict arrhythmia recurrence in patients with sustained ventricular tachycardia or fibrillation

    Wiesfeld, ACP; Crijns, HJGM; VandenBroek, SAJ; Landsman, MLJ; Hillege, HL; vanGilst, WH; Lie, KI


    Methods Sixty-nine patients with sustained ventricular tachyarrhythmias were followed up to evaluate the predictive value of functional capacity (i.e. New York Heart Association class and peak oxygen consumption) and resting left ventricular function (i.e. radionuclide left ventricular ejection frac

  19. Epicardial and endocardial mapping determine most successful site of ablation for ventricular tachyarrhythmias originating from left ventricular summit.

    Iijima, Kenichi; Chinushi, Masaomi; Furushima, Hiroshi; Aizawa, Yoshifusa


    A 34-year-old woman presented with idiopathic premature ventricular complex (PVC) and ventricular tachycardia (VT) originating from the area called the left ventricular summit. Radiofrequency (RF) application both through the coronary sinus and to the epicardial surface transiently suppressed the VT/PVC. Radiofrequency with sufficient energy was only applicable from the endocardial site, and the VT/PVC was successfully eliminated.

  20. Left ventricular remodeling during and after 60 days of sedentary head-down bed rest.

    Westby, Christian M; Martin, David S; Lee, Stuart M C; Stenger, Michael B; Platts, Steven H


    Short periods of weightlessness are associated with reduced stroke volume and left ventricular (LV) mass that appear rapidly and are thought to be largely dependent on plasma volume. The magnitude of these cardiac adaptations are even greater after prolonged periods of simulated weightlessness, but the time course during and the recovery from bed rest has not been previously described. We collected serial measures of plasma volume (PV, carbon monoxide rebreathing) and LV structure and function [tissue Doppler imaging, three-dimensional (3-D) and 2-D echocardiography] before, during, and up to 2 wk after 60 days of 6° head down tilt bed rest (HDTBR) in seven healthy subjects (four men, three women). By 60 days of HDTBR, PV was markedly reduced (2.7 ± 0.3 vs. 2.3 ± 0.3 liters,PResting measures of LV volume and mass were ∼15% (Prest values (P< 0.001). As previously reported, decreased PV and LV volume precede and likely contribute to cardiac atrophy during prolonged LV unloading. Although PV and LV volume recover rapidly after HDTBR, there is no concomitant normalization of LV mass. These results demonstrate that reduced LV mass in response to prolonged simulated weightlessness is not a simple effect of tissue dehydration, but rather true LV muscle atrophy that persists well into recovery.

  1. Cavopulmonary Anastomosis in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy With Severe Right Ventricular Dysfunction.

    Vaidyanathan, Swaminathan; Kothandam, Sivakumar; Kumar, Rajesh; Indrajith, Sujatha Desai; Agarwal, Ravi


    A 26-year-old lady presented with exertional dyspnea, palpitations, central cyanosis, and oxygen saturations of 80% in room air. Her electrocardiogram, echocardiogram, and cardiac magnetic resonance were diagnostic of arrhythmogenic right ventricular dysplasia. There was no documented ventricular arrhythmia or syncopal episodes and Holter recordings were repeatedly normal. Cardiac hemodynamics showed right to left shunt through atrial septal defect, low pulmonary blood flow, normal atrial pressures, and minimally elevated right ventricular end-diastolic pressures. Since her presenting symptoms and cyanosis were attributed to reduced pulmonary blood flow, she underwent off-pump cavopulmonary anastomosis between right superior vena cava and right pulmonary artery. As we intended to avoid the adverse effect of extracorporeal circulation on the myocardial function and pulmonary vasculature, we did not attempt to reduce the size of the atrial septal defect. Her postoperative period was uneventful; oxygen saturation improved to 89% with significant improvement in effort tolerance. At 18-month follow-up, there were no ventricular arrhythmias on surveillance. The clinical presentation of this disease may vary from serious arrhythmias warranting defibrillators and electrical ablations at one end to right ventricular pump failure warranting cardiomyoplasty or right ventricular exclusion procedures at the other end. However, when the presentation was unusual with severe cyanosis through a stretched foramen ovale leading to reduced pulmonary blood flows, Glenn shunt served as a good palliation and should be considered as one of the options in such patients.

  2. The requirement for pre-TCR during thymic differentiation enforces a developmental pause that is essential for V-DJβ rearrangement.

    Karen S Hathcock

    Full Text Available T cell development occurs in the thymus and is critically dependent on productive TCRβ rearrangement and pre-TCR expression in DN3 cells. The requirement for pre-TCR expression results in the arrest of thymocytes at the DN3 stage (β checkpoint, which is uniquely permissive for V-DJβ recombination; only cells expressing pre-TCR survive and develop beyond the DN3 stage. In addition, the requirement for TCRβ rearrangement and pre-TCR expression enforces suppression of TCRβ rearrangement on a second allele, allelic exclusion, thus ensuring that each T cell expresses only a single TCRβ product. However, it is not known whether pre-TCR expression is essential for allelic exclusion or alternatively if allelic exclusion is enforced by developmental changes that can occur in the absence of pre-TCR. We asked if thymocytes that were differentiated without pre-TCR expression, and therefore without pause at the β checkpoint, would suppress all V-DJβ rearrangement. We previously reported that premature CD28 signaling in murine CD4(-CD8(- (DN thymocytes supports differentiation of CD4(+CD8(+ (DP cells in the absence of pre-TCR expression. The present study uses this model to define requirements for TCRβ rearrangement and allelic exclusion. We demonstrate that if cells exit the DN3 developmental stage before TCRβ rearrangement occurs, V-DJβ rearrangement never occurs, even in DP cells that are permissive for D-Jβ and TCRα rearrangement. These results demonstrate that pre-TCR expression is not essential for thymic differentiation to DP cells or for V-DJβ suppression. However, the requirement for pre-TCR signals and the exclusion of alternative stimuli such as CD28 enforce a developmental "pause" in early DN3 cells that is essential for productive TCRβ rearrangement to occur.

  3. Prolonged cholestasis and ductopenia associated with tenoxicam.

    Trak-Smayra, Viviane; Cazals-Hatem, Dominique; Asselah, Tarik; Duchatelle, Veronique; Degott, Claude


    Cholestatic liver diseases leading to progressive destruction of intra-hepatic bile ducts and ductopenia encompass multiple etiologies. Pathophysiology and natural history of drug-induced cholangiopathies remain unclear. We report a case of prolonged ductopenia attributed to Tenoxicam (Tilcotil o--a non-steroidal anti-inflammatory drug of the oxicam family) ingested at therapeutic dose. A 36 year-old male patient was admitted for jaundice and Lyell syndrome starting 1 week after the ingestion of Tenoxicam. Liver biopsy showed cholestasis, non-suppurative cholangitis and polymorphous inflammatory infiltrate of the portal tracts (round cells, macrophages an eosinophils). Treatment with ursodesoxycholic acid and cholestyramine was instituted and the patient was asymptomatic 1 year after. Three years later mild biological cholestasis persisted and ductopenia was evidenced on liver biopsy. In this report we found that: (1) The toxicity of tenoxicam was probably mediated by an immunoallergic mechanism (Lyell syndrome and eosinophils on histology); (2) ductopenia was secondary to inflammatory cholangitis. Factors responsible for this chronic evolution are still unknown (genetic predisposition, vascular factors, etc.); and (3) the presence of ductopenia contrasted with the "clinical recovery" of the disease suggesting accessory bile drainage by cholangioles or partial reconstruction of the biliary tree.

  4. Prolonging sensor networks lifetime using convex clusters

    Payam Salehi


    Full Text Available Reducing the energy consumption of nodes in sensor networks and prolonging the network life time has been proposed as one of the most important challenges facing researchers in the field of sensor networks. Therefore, designing an energy-aware protocol to gather data from network level and transmitting it to sink is placed on the agenda at this paper. After presenting an analysis of the processes of clustering in sensory networks and investigating the effect of sending interval on the amount of energy consumption, We have shown that if the use of convex static casters be done such as all the communications within the cluster with the sending distance less than the optimal threshold, it Will help to increase the lifetime of nodes. also have shown that if we create a virtual backbone between cluster heads to transfer far cluster heads data from sink to sink , will has a significant impact on increasing the network lifetime. For this reason, a detailed discussion on how to determine the size of clusters and partitioning of the network environment to them is presented in Chapter 4.Simulation results show considerable improvement of the proposed algorithm.

  5. Persistent telomere cohesion triggers a prolonged anaphase.

    Kim, Mi Kyung; Smith, Susan


    Telomeres use distinct mechanisms (not used by arms or centromeres) to mediate cohesion between sister chromatids. However, the motivation for a specialized mechanism at telomeres is not well understood. Here we show, using fluorescence in situ hybridization and live-cell imaging, that persistent sister chromatid cohesion at telomeres triggers a prolonged anaphase in normal human cells and cancer cells. Excess cohesion at telomeres can be induced by inhibition of tankyrase 1, a poly(ADP-ribose) polymerase that is required for resolution of telomere cohesion, or by overexpression of proteins required to establish telomere cohesion, the shelterin subunit TIN2 and the cohesin subunit SA1. Regardless of the method of induction, excess cohesion at telomeres in mitosis prevents a robust and efficient anaphase. SA1- or TIN2-induced excess cohesion and anaphase delay can be rescued by overexpression of tankyrase 1. Moreover, we show that primary fibroblasts, which accumulate excess telomere cohesion at mitosis naturally during replicative aging, undergo a similar delay in anaphase progression that can also be rescued by overexpression of tankyrase 1. Our study demonstrates that there are opposing forces that regulate telomere cohesion. The observation that cells respond to unresolved telomere cohesion by delaying (but not completely disrupting) anaphase progression suggests a mechanism for tolerating excess cohesion and maintaining telomere integrity. This attempt to deal with telomere damage may be ultimately futile for aging fibroblasts but useful for cancer cells.

  6. [Prospective study of patients with prolonged fever].

    Calderón, E; Legorreta, J; Sztabinski, G; Hernández, M; Wilkins, A; Gómez, D; Dávila, A


    A prospective study was made in 283 patients who attended IMAN's Children's Hospital, with fever the main symptom. A clinical and paraclinical procedure was designed for the study of each patient. 112 patients were eliminated because they did not follow the established criteria. All patients had acute infectious diseases considered trivial; 85% were 3 weeks to 2 years of age. They all had an antibacterial treatment without precise diagnosis. It was considered that on admission the patients showed a normal course in the natural history of the basic disease. The study group included 171 patients 2 months to 13 years of age; 62.5% had fever due to infection, 12.2% to collagenopathies, 7% to neoplasias 5.2% to miscellaneous causes and 12.8% were not diagnosed. The most common infectious causes for prolonged fever were tuberculosis, upper respiratory infections, amoebic liver abscess, typhoid fever and malaria. Careful questioning and clinical examination were enough to enlighten diagnosis in more than 80% of the patients.


    Ah. Yusuf


    Full Text Available Introduction: Decision for cesarean section may lead to the stress for women in delivery. Stress response requires longer recovery time in post cesarean section patients. Most of patients who experience stress before and after surgical is associated with wound healing delay. When this condition continues, the wound will have a higher risk of infection. The objective of this study was to analyze correlation between stress and wound healing phase in post cesarean section patients. Method: A cross sectional design was used in this study. The population were women with cesarean section, both elective or emergency, in Delivery Room I RSU Dr. Soetomo Surabaya. Samples were recruited by using purposive sampling, with 28 samples who met to the inclusion criterias. The observed variables were stress and wound healing phase in post cesarean section patient. Stress data were collected by interview and wound healing measurement done by observation on the 3rd day post cesarean section. Result: The result showed that women with stress experience wound healing delay. The characteristic of wound healing delay was prolonged on inflammation phase, nevertheless there was presence of granulation tissue. Spearman’s rho correlation showed that correlation value r=0.675 with p=0.000. Discussion: It can be concluded that there was strong significant correlation between stress and wound healing phase in post cesarean section patients. It is important to give this information to the patients with cesarean section in order to prevent stress and delay in wound healing phase.

  8. Gluteal Compartment Syndrome After Prolonged Immobilisation

    H.L. Liu


    Full Text Available Muscles in the gluteal region are confined by distinct fascial attachments which can potentially result in compartment syndrome. A 74-year-old chronic drinker was admitted to the medical ward after being found drunk on the street. He noticed acute painful swelling of the right side of his buttock the following morning and recalled a slip and fall prior to his blackout. The whole right half of the buttock was tense with erythematous overlying skin. Examination revealed sciatic nerve palsy and myoglobinuria. Emergency fasciotomy and debridement were performed. Intra-operative pressure measurement confirmed a grossly elevated intra-compartmental pressure. Gluteal compartment syndrome is an extremely rare condition and has only been scantily documented previously in case reports. Early diagnosis is crucial but delay recognition is common from lack of knowledge of the condition and readily results in permanent sciatic nerve injury and acute renal shutdown from myoglobinuria. Awareness of the condition, early diagnosis and prompt exploration provide the only chance of avoiding these devastating consequences. Acute swelling diffusely affecting the whole or one side of the buttock, a history of trauma and prolonged local pressure impingement associated with pain out of proportion to the clinical signs should raise a suspicion of this rare condition.

  9. Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

    Zahra S Faritous


    Full Text Available Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG, 31 women needed prolonged mechanical ventilation (PMV, and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG.

  10. Arrhythmogenic right ventricular dysplasia: MRI findings

    Wall, E.E. van der; Bootsma, M.M.; Schalij, M.J. [Dept. of Cardiology, Leiden Univ. Medical Center, Leiden (Netherlands); Kayser, H.W.M.; Roos, A. de [Dept. of Radiology, Leiden Univ. Medical Center, Leiden (Netherlands)


    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.) [German] Die arrhythmogene rechtsventrikulaere Dysplasie (ARVD), eine Herzmuskelerkrankung unklarer Aetiologie, ist pathologisch durch fettige Degeneration des rechtsventrikulaeren Myokards gekennzeichnet. Die klinischen Symptome

  11. Encephalitis with Prolonged but Reversible Splenial Lesion

    Alena Meleková


    Full Text Available Introduction: The splenium of the corpus callosum has a specific structure of blood supply with a tendency towards blood-brain barrier breakdown, intramyelinic edema, and damage due to hypoxia or toxins. Signs and symptoms of reversible syndrome of the splenium of the corpus callosum typically include disorientation, confusion, impaired consciousness, and epileptic seizures. Case report: A previously healthy 32-year-old man suffered from weakness, headache, and fever. Subsequently, he developed apathy, ataxia, and inability to walk, and therefore was admitted to the hospital. Cerebrospinal fluid showed protein elevation (0.9 g/l and pleocytosis (232/1 ul. A brain MRI showed hyperintense lesions in the middle of the corpus callosum. The patient was treated with antibiotics, and subsequently, in combination with steroids. Two months later, the hyperintense lesions in the splenium and the basal ganglia had disappeared. Almost seven months since his hospitalization in the Department of Neurology, the patient has returned to his previous employment. He now does not exhibit any mental changes, an optic edema and urological problems have improved. In addition, he is now actively engaged in sports. Conclusion: We have described a case of a 32-year-old man with confusion, ataxia, and inability to stand and walk. The man developed a febrile meningeal syndrome and a hyperintense lesion of the splenium, which lasted for two months. Neurological changes, optic nerve edema, and urinary retention have resolved over the course of seven months. We think that the prolonged but transient lesion of the splenium may have been caused by encephalitis of viral origin.

  12. Diaphragmatic energetics during prolonged exhaustive exercise.

    Manohar, M; Hassan, A S


    The present study was carried out to examine diaphragmatic O2 extraction and lactate and ammonia production during prolonged exhaustive exercise. Experiments were performed on nine healthy exercise-conditioned ponies in which catheters had been implanted in the phrenic vein previously. Blood-gas variables and lactate and ammonia concentrations were determined on simultaneously obtained arterial and phrenic-venous blood samples at rest and during 30 min of exertion at 15 mph + 7% grade (heart rate, 200 beats/min; approximately 90% of maximum). Arterial O2 tension and saturation were maintained near resting value but CO2 tension decreased markedly with exercise, and because of increased hemoglobin concentration, arterial O2 content rose. Concomitantly, phrenic venous O2 tension, saturation and content decreased markedly (23.6 +/- 1 mm Hg, 24.5 +/- 2%, 5.2 +/- 0.3 ml/dl at 3 min of exertion) and significant fluctuations did not occur as exercise duration progressed to 30 min. Diaphragmatic arteriovenous O2 content difference and O2 extraction rose from 4 +/- 0.3 to 16 +/- 0.5 ml/dl and from 30 +/- 3 to 75 +/- 1% at 3 min of exercise, and significant deviations did not occur as exercise duration progressed. Arterial lactate and ammonia levels increased during exercise, indicating their release from working limb muscles. Phrenic-venous values of lactate and ammonia did not exceed arterial values. Ponies sweated profusely and were unable to keep up with the belt speed in the last 4 to 5 min of exercise. Constancy of phrenic arteriovenous O2 content difference in exercise indicated ability to adjust perfusion in diaphragm so as to adequately meet its O2 needs.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Exceptionally prolonged tooth formation in elasmosaurid plesiosaurians

    Kear, Benjamin P.; Larsson, Dennis; Lindgren, Johan; Kundrát, Martin


    Elasmosaurid plesiosaurians were globally prolific marine reptiles that dominated the Mesozoic seas for over 70 million years. Their iconic body-plan incorporated an exceedingly long neck and small skull equipped with prominent intermeshing ‘fangs’. How this bizarre dental apparatus was employed in feeding is uncertain, but fossilized gut contents indicate a diverse diet of small pelagic vertebrates, cephalopods and epifaunal benthos. Here we report the first plesiosaurian tooth formation rates as a mechanism for servicing the functional dentition. Multiple dentine thin sections were taken through isolated elasmosaurid teeth from the Upper Cretaceous of Sweden. These specimens revealed an average of 950 daily incremental lines of von Ebner, and infer a remarkably protracted tooth formation cycle of about 2–3 years–other polyphyodont amniotes normally take ~1–2 years to form their teeth. Such delayed odontogenesis might reflect differences in crown length and function within an originally uneven tooth array. Indeed, slower replacement periodicity has been found to distinguish larger caniniform teeth in macrophagous pliosaurid plesiosaurians. However, the archetypal sauropterygian dental replacement system likely also imposed constraints via segregation of the developing tooth germs within discrete bony crypts; these partly resorbed to allow maturation of the replacement teeth within the primary alveoli after displacement of the functional crowns. Prolonged dental formation has otherwise been linked to tooth robustness and adaption for vigorous food processing. Conversely, elasmosaurids possessed narrow crowns with an elongate profile that denotes structural fragility. Their apparent predilection for easily subdued prey could thus have minimized this potential for damage, and was perhaps coupled with selective feeding strategies that ecologically optimized elasmosaurids towards more delicate middle trophic level aquatic predation. PMID:28241059

  14. Fatigue associated with prolonged graded running.

    Giandolini, Marlene; Vernillo, Gianluca; Samozino, Pierre; Horvais, Nicolas; Edwards, W Brent; Morin, Jean-Benoît; Millet, Guillaume Y


    Scientific experiments on running mainly consider level running. However, the magnitude and etiology of fatigue depend on the exercise under consideration, particularly the predominant type of contraction, which differs between level, uphill, and downhill running. The purpose of this review is to comprehensively summarize the neurophysiological and biomechanical changes due to fatigue in graded running. When comparing prolonged hilly running (i.e., a combination of uphill and downhill running) to level running, it is found that (1) the general shape of the neuromuscular fatigue-exercise duration curve as well as the etiology of fatigue in knee extensor and plantar flexor muscles are similar and (2) the biomechanical consequences are also relatively comparable, suggesting that duration rather than elevation changes affects neuromuscular function and running patterns. However, 'pure' uphill or downhill running has several fatigue-related intrinsic features compared with the level running. Downhill running induces severe lower limb tissue damage, indirectly evidenced by massive increases in plasma creatine kinase/myoglobin concentration or inflammatory markers. In addition, low-frequency fatigue (i.e., excitation-contraction coupling failure) is systematically observed after downhill running, although it has also been found in high-intensity uphill running for different reasons. Indeed, low-frequency fatigue in downhill running is attributed to mechanical stress at the interface sarcoplasmic reticulum/T-tubule, while the inorganic phosphate accumulation probably plays a central role in intense uphill running. Other fatigue-related specificities of graded running such as strategies to minimize the deleterious effects of downhill running on muscle function, the difference of energy cost versus heat storage or muscle activity changes in downhill, level, and uphill running are also discussed.

  15. Stimulation of isolated ventricular myocytes within an open architecture microarray.

    Klauke, Norbert; Smith, Godfrey L; Cooper, Jonathan M


    This paper is concerned with the physiological responses of single heart cells within microfluidic chambers, in response to stimulation by integrated microelectrodes. To enable these investigations, which included the measurement of action potential duration, intracellular Ca2+ and cell shortening, a series of microfluidic chambers (50 microm wide, 180 microm long, 400 microm high, 500 microm pitch) and connecting channels (200 microm wide, 5000 microm long, 50 microm high, 500 microm pitch) were replica-moulded into the silicone elastomer, polydimethylsiloxane (PDMS). The structures were formed against a master of posts and lines, photolithograhically patterned into the high aspect ratio photoresist SU-8. The chambers within the slab of PDMS were aligned against pairs of stimulating gold microelectrodes (50 microm long, 20 microm wide, 0.1-10 microm thick, 180 microm apart) patterned on a microscope coverslip base, thus defining cavities of approximately 4 nL volume. The assembly was filled with physiological saline and single isolated rabbit ventricular myocytes were introduced by micropipetting, thus creating limited volumes of saline above individual myocytes that could be varied between 4 nL and > or = 4 microL. The application of transient current pulses to the cells via the electrodes caused transient contractions with constant amplitude (recorded as changes in sarcomere length), confirming that excitation contraction coupling (EC coupling) remained functional in these limited volumes. Continuous monitoring of the intracellular Ca2+ (using calcium sensitive dyes) showed, that in the absence of bath perfusion, the amplitude of the transients remained constant for approximately 3 min in the 4-nL volume and approximately 20 min for the 4 microL volume. Beyond this time, the cells became unexcitable until the bath was renewed. The action potential duration (APD) was recorded at stimulation frequencies of 1 Hz and 0.5 Hz using potential sensitive dyes and was

  16. Ventricular assist device in univentricular heart physiology.

    Brancaccio, Gianluca; Gandolfo, Fabrizio; Carotti, Adriano; Amodeo, Antonio


    The use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation (OHT) or to recovery for patients with congestive heart failure, however, the experience in single ventricle (SV) physiology is still limited. We report two cases of mechanical assistance in patients with SV physiology: a 2-year old male with hypoplastic left heart syndrome who underwent Norwood Stage I and II followed by HF and a 4-year old female with a univentricular heart who developed a severe right ventricular dysfunction 2 years after a cavopulmonary shunt. Mechanical support utilizing ventricular assist devices (VADs) is considered a valid tool to bridge patients with congestive heart failure to either OHT or to recovery. Increasing experience and improved outcomes utilizing this technology in children with biventricular hearts have led to considering employing these devices in failing SV treatment. We present 2 cases of terminally ill children with SV who were assisted with a VAD.

  17. Inherited cardiomyopathies mimicking arrhythmogenic right ventricular cardiomyopathy.

    Roberts, Jason D; Veinot, John P; Rutberg, Julie; Gollob, Michael H


    Arrhythmogenic right ventricular cardiomyopathy (ARVC) represents an inherited cardiomyopathy that manifests clinically with malignant ventricular arrhythmias, sudden cardiac death, and less commonly heart failure. The condition is characterized by replacement of the myocardium, primarily of the right ventricle, with fibrofatty tissue. Extensive fibrofatty replacement of the myocardium has been previously thought to be pathognomonic of ARVC; however, this report details two other forms of inherited cardiomyopathy, namely hypertrophic cardiomyopathy (HCM) and the PRKAG2 cardiac syndrome, that were found to have significant fibrofatty myocardial replacement at pathologic examination. This report represents the first documentation of inherited cardiomyopathies mimicking ARVC and highlights the concept that other cardiac conditions can be associated with fibrofatty replacement of the myocardium. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Right ventricular hydatid cyst ruptured to pericardium

    Feridoun Sabzi


    Full Text Available Cardiac hydatidosis is rare presentation of body hydatidosis. Incidence of cardiac involvements range from 5% to 5% of patients with hydatid disease. Most common site of hydatid cyst in heart is interventricular septum and left ventricular free wall. Right ventricular free wall involvement by cyst that ruptured to pericardial cavity is very rare presentation of hydatid cyst. Cardiac involvement may have serious consequences such as rupture to blood steam or pericardial cavity. Both the disease and its surgical treatment carry a high complication rate, including rupture leading to cardiac tamponade, anaphylaxis and also death. In the present report, a 43-year-old man with constrictive pericarditis secondary to a pericardial hydatid cyst is described.

  19. The Downside of Right Ventricular Apical Pacing

    Andrew Brenyo, MD


    Full Text Available The right ventricular (RV apex has been the standard pacing site since the development of implantable pacemaker technology. Although RV pacing was initially only utilized for the treatment of severe bradyarrhythmias usually due to complete heart block, today the indications for and implantation of RV pacing devices is dramatically larger. Recently, the adverse effects of chronic RV apical pacing have been described including an increased risk of heart failure and death. This review details the detrimental effects of RV apical pacing and their shared hemodynamic pathophysiology. In particular, the role of RV apical pacing induced ventricular dyssynchrony is highlighted with a specific focus on differential outcome based upon QRS morphology at implant.

  20. Right ventricular plasticity and functional imaging

    Brittain, Evan L.; Hemnes, Anna R.; Keebler, Mary; Lawson, Mark; Byrd, Benjamin F.; DiSalvo, Tom


    Right ventricular (RV) function is a strong independent predictor of outcome in a number of distinct cardiopulmonary diseases. The RV has a remarkable ability to sustain damage and recover function which may be related to unique anatomic, physiologic, and genetic factors that differentiate it from the left ventricle. This capacity has been described in patients with RV myocardial infarction, pulmonary arterial hypertension, and chronic thromboembolic disease as well as post-lung transplant and post-left ventricular assist device implantation. Various echocardiographic and magnetic resonance imaging parameters of RV function contribute to the clinical assessment and predict outcomes in these patients; however, limitations remain with these techniques. Early diagnosis of RV function and better insight into the mechanisms of RV recovery could improve patient outcomes. Further refinement of established and emerging imaging techniques is necessary to aid subclinical diagnosis and inform treatment decisions. PMID:23130100

  1. Late presentation of arrhythmogenic right ventricular cardiomyopathy: a case report

    Papaioannou Georgios I


    Full Text Available Abstract Introduction Arrhythmogenic right ventricular cardiomyopathy is an inherited myocardial disease affecting predominantly young people and manifests as sustained ventricular tachycardia with left bundle branch block morphology, sudden death or isolated right or biventricular heart failure. However, its first manifestation as sustained ventricular tachycardia in older patients without preceding symptoms of heart failure is infrequent. To our knowledge, our patient is among the oldest reported in the literature presenting with ventricular tachycardia because of arrhythmogenic right ventricular cardiomyopathy without preceding symptoms of heart failure. Case presentation We present an unusual case of a very late presentation of a right ventricular cardiomyopathy in a 72-year-old white Caucasian man. The patient was admitted with symptoms of weakness, dizziness and chest discomfort for several hours. His electrocardiogram showed a wide-complex tachycardia with left bundle branch block morphology and left axis deviation. Because of continuing hemodynamic instability, the patient was cardioverted to sinus rhythm with a single 300 J shock. His post-cardioversion electrocardiogram, cardiac echocardiogram, coronary angiogram, magnetic resonance imaging and electrophysiological study confirmed the diagnosis of arrhythmogenic right ventricular cardiomyopathy. The patient was treated with an implantable cardioverter defibrillator and discharged on sotalol. Conclusion This case report demonstrates that arrhythmogenic right ventricular cardiomyopathy may have a very late presentation and this diagnosis should be considered as a potential cause of sustained ventricular tachycardia of right ventricular origin among the elderly and should be treated accordingly.

  2. Acute impact of pacing at different cardiac sites on left ventricular rotation and twist in dogs.

    Zhi-Wen Zhou

    Full Text Available We evaluated the acute impact of different cardiac pacing sites on two-dimensional speckle-tracking echocardiography (STE derived left ventricular (LV rotation and twist in healthy dogs.Twelve dogs were used in this study. The steerable pacing electrodes were positioned into right heart through the superior or inferior vena cava, into LV through aorta across the aortic valve. The steerable pacing electrodes were positioned individually in the right atrium (RA, right ventricular apex (RVA, RV outflow tract (RVOT, His bundle (HB, LV apex (LVA and LV high septum (LVS, individual pacing mode was applied at 10 minutes interval for at least 5 minutes from each position under fluoroscopy and ultrasound guidance and at stabilized hemodynamic conditions. LV short-axis images at the apical and basal levels were obtained during sinus rhythm and pacing. Offline STE analysis was performed. Rotation, twist, time to peak rotation (TPR, time to peak twist (TPT, and apical-basal rotation delay (rotational synchronization index, RSI values were compared at various conditions. LV pressure was monitored simultaneously.Anesthetic death occurred in 1 dog, and another dog was excluded because of bad imaging quality. Data from 10 dogs were analyzed. RVA, RVOT, HB, LVA, LVS, RARV (RA+RVA pacing resulted in significantly reduced apical and basal rotation and twist, significantly prolonged apical TPR, TPT and RSI compared to pre-pacing and RA pacing (all P<0.05. The apical and basal rotation and twist values were significantly higher during HB pacing than during pacing at ventricular sites (all P<0.05, except basal rotation at RVA pacing. The apical TPR during HB pacing was significantly shorter than during RVOT and RVA pacing (both P<0.05. The LV end systolic pressure (LVESP was significantly lower during ventricular pacing than during pre-pacing and RA pacing.Our results show that RA and HB pacing results in less acute reduction on LV twist, rotation and LVESP compared

  3. Predictors of left ventricular remodelling and failure in right ventricular pacing in the young

    Gebauer, Roman A.; Tomek, Viktor; Salameh, Aida; Marek, Jan; Chaloupecký, Václav; Gebauer, Roman; Matějka, Tomáš; Vojtovič, Pavel; Janoušek, Jan


    Aims To identify risk factors for left ventricular (LV) dysfunction in right ventricular (RV) pacing in the young. Methods and results Left ventricular function was evaluated in 82 paediatric patients with either non-surgical (n = 41) or surgical (n= 41) complete atrioventricular block who have been 100% RV paced for a mean period of 7.4 years. Left ventricular shortening fraction (SF) decreased from a median (range) of 39 (24–62)% prior to implantation to 32 (8–49)% at last follow-up (P +2z-values) and dysfunction (SF < 0.26) was found to increase from 1.3% prior to pacemaker implantation to 13.4% (11/82 patients) at last follow-up (P = 0.01). Ten of these 11 patients had progressive LV remodelling and 8 of 11 were symptomatic. The only significant risk factor for the development of LV dilatation and dysfunction was the presence of epicardial RV free wall pacing (OR = 14.3, P < 0.001). Other pre-implantation demographic, diagnostic, and haemodynamic factors including block aetiology, pacing variables, and pacing duration did not show independent significance. Conclusion Right ventricular pacing leads to pathologic LV remodelling in a significant proportion of paediatric patients. The major independent risk factor is the presence of epicardial RV free wall pacing, which should be avoided whenever possible. PMID:19286675

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

    Hugo Van Herendael


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

  5. [Ventricular fibrillation following deodorant spray inhalation].

    Girard, F; Le Tacon, S; Maria, M; Pierrard, O; Monin, P


    We report one case of out-of-hospital cardiac arrest with ventricular fibrillation following butane poisoning after inhalation of antiperspiration aerosol. An early management using semi-automatic defibrillator explained the success of the resuscitation. The mechanism of butane toxicity could be an increased sensitivity of cardiac receptors to circulating catecholamines, responsible for cardiac arrest during exercise and for resuscitation difficulties. The indication of epinephrine is discussed.

  6. Ventricular Assist Devices: Physiology Meets Technology


    vaslr resbane, and icrue systemic cir(nlatkm O(Mchet at aL. 1988). Non-ulsatile flow results in VADs 19 mico ulatory shiting snd edema formation...than 45 ininHg, and the oxygen saturation greater than 95 percent (Ley,, 1991). Hypoxeinia. initially may be due to pulmonary edema or a mild form of...1990). Combined Registry for the clinical use of mechanical ventricular assist devices: postcardiotomy cardiogenic shock. o36(1), 43-46. Mondejar, E

  7. Sequential Notch activation regulates ventricular chamber development

    D'Amato, Gaetano


    Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 15 de enero de 2016 Ventricular chamber morphogenesis is a beautiful example of tissue interactions orchestrating a precise gene regulatory network essential for tissue patterning, cellular proliferation and differentiation that ultimately lead to a fully compacted and functional adult ventricle. The Notch signaling pathway is a crucial regulator ...

  8. Diastolic Left Ventricular Dysfunction : A Clinical Appraisal

    Bronzwaer, J.G.F.


    Diastolic left ventricular (LV) distensibility is determined by the material properties of the LV wall and by LV geometry (i.e., LV shape, LV volume and LV wall thickness). These material properties are influenced both by the physical structure of the LV myocardium and by the dynamic process of myocardial relaxation. The material properties of the myocardium dictate the strain that follows a given stress, and determine position and shape of the myocardial stress-strain relationship. The mater...

  9. Positional Right Ventricular Obstruction in Pectus Excavatum.

    Underwood, Katherine; Vorsanger, Matthew; Saric, Muhamed; Skolnick, Adam H


    Pectus excavatum is one of the most common congenital chest wall deformities. The degree of sternal depression, which may result in compression of the right heart by the chest wall, is variable. While typically asymptomatic, there are various symptoms that can result from severe pectus excavatum. We report on a patient with severe pectus excavatum leading to dynamic obstruction of the right ventricular outflow tract in the seated position.

  10. Left ventricular heart failure and pulmonary hypertension†

    Rosenkranz, Stephan; Gibbs, J. Simon R.; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc


    In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. PMID:26508169

  11. Non-compaction of the ventricular myocardium

    Livio Dei Cas


    Full Text Available Non-compaction of the left ventricle (LVNC is a disorder of endomyocardial morphogenesis that results in multiple trabeculations in the left ventricular (LV myocardium. This rare disorder is characterized by an excessively prominent trabecular meshwork and deep intratrabecular recesses. This idiopathic cardiomyopathy is characterized by an altered structure of the myocardial wall as a result of intrauterine arrest of compaction of the myocardial fibers in the absence of any coexisting congenital lesion. It can be associated with neuromuscular disorders and can co-exist with other cardiac malformations, and it is accompanied by depressed ventricular function, systemic embolism and ventricular arrhythmia. Echocardiography is the method of choice for diagnosing LVNC, but the correct diagnosis is often missed or delayed due to a lack of knowledge concerning this uncommon disease and its similarity to other diseases of the myocardium and endocardium. There is a two-layered structure of the myocardial wall consisting of a thin compacted epicardial layer and a thick non-compacted endocardial layer with prominent trabeculations and deep recesses. (Heart International 2006; 3-4: 178-83

  12. Functional effects of the late sodium current inhibition by AZD7009 and lidocaine in rabbit isolated atrial and ventricular tissue and Purkinje fibre.

    Persson, Frida; Andersson, Birgit; Duker, Göran; Jacobson, Ingemar; Carlsson, Leif


    AZD7009 (tert-Butyl-2-(7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl)ethylcarbamate) is an antiarrhythmic agent that increases atrial refractoriness, shows high antiarrhythmic efficacy and has low proarrhythmic potential. This study was primarily undertaken to determine the effects of AZD7009 on the late sodium current and to examine the impact of late sodium current inhibition on action potential duration in various myocardial cells. AZD7009 inhibited the late sodium current in Chinese Hamster Ovary K1 (CHO K1) cells expressing hNa(v)1.5 with an IC(50) of 11+/-2 microM. The late sodium current in isolated rabbit atrial and ventricular myocytes was also concentration dependently inhibited by AZD7009. Action potentials were recorded during exposure to 5 microM E-4031 (1-[2-(6-methyl-2pyridyl)ethyl]-4-(4-methylsulfonyl aminobenzoyl)piperidine), a compound that selectively inhibits the rapid delayed rectifier potassium current (I(Kr)), and to E-4031 in combination with AZD7009 or lidocaine in rabbit atrial and ventricular tissue and Purkinje fibres. In Purkinje fibres, but not in ventricular tissue, AZD7009 and lidocaine attenuated the E-4031-induced action potential duration prolongation. In atrial cells, AZD7009, but not lidocaine, further prolonged the E-4031-induced action potential duration. E-4031 induced early afterdepolarisations (EADs) in Purkinje fibres, EADs that were totally suppressed by AZD7009 or lidocaine. In conclusion, excessive action potential duration prolongation induced by E-4031 was attenuated by AZD7009 and lidocaine in rabbit Purkinje fibre, but not in atrial or ventricular tissue, most likely by inhibiting the late sodium current. Furthermore, the opposite effect by AZD7009 on action potential duration in atrial tissue suggests that AZD7009, in addition to inhibiting I(Kr), also inhibits other repolarising currents in the atria.

  13. Intracellular Ca 2+ nonlinear wave behaviours in a three dimensional ventricular cell model

    Li, Pan; Holden, Arun V.


    Intracellular Ca 2+ activity regulates a wide range of cellular biochemical processes; in muscle cells, it links membrane excitation to contraction. Ca 2+ dynamics includes both synchronous oscillations, and nonlinear wave phenomena, both arising from the superposition of spatially localised stochastic events, such as Ca 2+ sparks. We incorporated individualised cell geometry reconstructed from confocal microscopy with realistic spatial distribution of RyR clusters into the three dimensional ventricular cell model, and reproduced complex spatio-temporal intracellular wave patterns from Ca 2+ sparks. We also introduced a detailed nuclear Ca 2+ handing model to simulate prolonged nuclear Ca 2+ transient, and study the effects of cytosolic-nuclear coupling on intracellular Ca 2+ dynamics. The model provides a computational platform to study intracellular Ca 2+ with the ability to interact with experimental measurements of subcellular structures, and can be modified for other cell types.

  14. Congenital left ventricular aneurysm coexisting with left ventricular non-compaction in a newborn.

    Ootani, Katsuki; Shimada, Jun; Kitagawa, Yosuke; Konno, Yuki; Miura, Fumitake; Takahashi, Toru; Ito, Etsuro; Ichinose, Kouta; Yonesaka, Susumu


    Described herein is the case of a rare combination of congenital left ventricular (LV) aneurysm and left ventricular non-compaction (LVNC) in a newborn. The patient developed refractory heart failure soon after birth and died at 5 months of age. The etiology of both congenital LV aneurysm and LVNC seems to be maldevelopment of the ventricular myocardium during early fetal life. Treatment should be individually tailored depending on clinical severity, and treatment options are limited. Given that this combination of congenital LV aneurysm and LVNC is significantly associated with poor prognosis, it appears that patients with congenital LV aneurysm and LVNC are candidates for early, aggressive intervention, including surgical aneurysmectomy and evaluation for transplantation. It is important to be aware of this combination of congenital LV aneurysm and LVNC, and to make earlier decisions on therapeutic strategy.

  15. Anti-addiction Drug Ibogaine Prolongs the Action Potential in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

    Rubi, Lena; Eckert, Daniel; Boehm, Stefan; Hilber, Karlheinz; Koenig, Xaver


    Ibogaine is a plant alkaloid used as anti-addiction drug in dozens of alternative medicine clinics worldwide. Recently, alarming reports of life-threatening cardiac arrhythmias and cases of sudden death associated with the ingestion of ibogaine have accumulated. Using whole-cell patch clamp recordings, we assessed the effects of ibogaine and its main metabolite noribogaine on action potentials in human ventricular-like cardiomyocytes derived from induced pluripotent stem cells. Therapeutic concentrations of ibogaine and its long-lived active metabolite noribogaine significantly retarded action potential repolarization in human cardiomyocytes. These findings represent the first experimental proof that ibogaine application entails a cardiac arrhythmia risk for humans. In addition, they explain the clinically observed delayed incidence of cardiac adverse events several days after ibogaine intake. We conclude that therapeutic concentrations of ibogaine retard action potential repolarization in the human heart. This may give rise to a prolongation of the QT interval in the electrocardiogram and cardiac arrhythmias.

  16. Acute and Chronic Changes and Predictive Value of Tpeak-Tend for Ventricular Arrhythmia Risk in Cardiac Resynchronization Therapy Patients

    Cong Xue; Wei Hua; Chi Cai; Li-Gang Ding; Zhi-Min Liu; Xiao-Han Fan; Yun-Zi Zhao


    Background:Prolongation of the Tpeak-Tend (TpTe) interval as a measurement of transmural dispersion of repolarization (TDR) is an independent risk factor for chronic heart failure mortality.However,the cardiac resynchronization therapy's (CRT) effect on TDR is controversial.Therefore,this study aimed to evaluate CRTs acute and chronic effects on repolarization dispersion.Furthermore,we aimed to investigate the relationship between TpTe changes and ventricular arrhythmia.Methods:The study group consisted of 101 patients treated with CRT-defibrillator (CRT-D).According to whether TpTe was shortened,patients were grouped at immediate and 1-year follow-up after CRT,respectively.The echocardiogram index and ventricular arrhythmia were observed and compared in these subgroups.Results:For all patients,TpTe slightly increased immediately after CRT-D implantation,and then decreased at the l-year follow-up (from 107 ± 23 to 110 ± 21 ms within 24 h,to 94 ± 24 ms at 1-year follow-up,F=19.366,P < 0.001).No significant difference in the left ventricular reverse remodeling and ventricular tachycardia/ventricular fibrillation (VT/VF) episodes between the TpTe immediately shortened and TpTe immediately nonshortened groups.However,patients in the TpTe at 1-year shorten had a higher rate of the left ventricular (LV) reverse remodeling (65% vs.44%,x2 =4.495,P =0.038) and less VT/VF episodes (log-rank test,x2 =10.207,P =0.001) compared with TpTe 1-year nonshortened group.TpTe immediately after CRT-D independently predicted VT/VF episodes at l-year follow-up (hazard ratio [HR],1.030;P =0.001).Conclusions:Patients with TpTe shortened at l-year after CRT had a higher rate of LV reverse remodeling and less VT/VF episodes.The acute changes of TpTe after CRT have minimal value on mechanical reverse remodeling and ventricular arrhythmia.

  17. [Ventricular tachyarrhythmias. A retrospective analysis of etiology, demography and treatment

    Christensen, A.H.; Henningsen, K.; Svendsen, Jesper Hastrup


    to ventricular tachyarrhythmias. MATERIALS AND METHODS: We conducted a retrospective review of 993 patients discharged from Rigshospitalet over 6 years and 5 months with the diagnostic codes ventricular tachycardia, ventricular fibrillation or premature ventricular contractions. RESULTS: The population had...... an average age of 59 years (ranging 15-95 years) with a majority of males (76%). Among the patients with known etiology ischemic heart disease (60%), dilated cardiomyopathy (6%) and arrhythmogenic right ventricular cardiomyopathy (6%) were the most frequent. A substantial number of the patients (15%) had...... unknown etiology; 492 (50%) of the patients overall had an ICD implanted, the majority of whom had been categorized as having ventricular tachycardia (92%); 168 patients had previous cardiac arrest, 127 of whom did not have a potential reversible cause. Of this group 75 (59%) had an ICD implanted...


    G. P. Itkin


    Full Text Available The paper presents a review of the problems of mechanical circulatory support with left ventricular bypass in total cardiac failure. Dysfunction of right ventricular defines the high mortality on left ventricular device. One of the effective methods for solving this problem is the use of right ventricular assisted devices. There are considered of the basic physiological mechanisms of interaction between the right and left ventricles of the heart, affecting on the function of the right heart. Shows the need to assess right ventricular function before deciding on mechanical circulatory support. Provides examples of the estimation the predictors of the right ventricular failure. The basic methods and devices of biventricular circulatory support were con- sidered. 

  19. Cellular graded responses and ventricular vulnerability to reentry by a premature stimulus in isolated canine ventricle.

    Gotoh, M; Uchida, T; Mandel, W J; Fishbein, M C; Chen, P S; Karagueuzian, H S


    The cellular mechanism by which a point strong premature stimulus (S2) induces reentry is unknown. We hypothesized that cellular graded responses induced by an S2 mediate and control tissue vulnerability to reentry. Reentry is induced in normal canine ventricular epicardial slices (30x38x2 mm, n=30) by an S2 at intervals shorter than the effective refractory period. The S1 is applied at the edge and the S2 at the center of the tissue. The line connecting the S1-S2 sites is parallel to the long axis of the fiber orientation. Isochronal activation maps were constructed with 56 to 480 bipolar electrodes, and the activation pattern was visualized dynamically. Reentry induced by an S2 is mediated by the graded responses as follows: The induced graded responses propagate with decrement toward recovered cells. When the amplitude of the propagated depolarizing graded responses reaches threshold relative to the recovering cells, an action potential is initiated along the fiber 2 to 3 mm away from the cathode of the S2. The distally initiated activation wave front blocks near the S2 site because the same S2-induced graded response prolongs the refractory period. The "broken" wave front then circulates around both sides of the block and reenters when the site of block recovers its excitability, completing the first figure-eight reentry cycle. Reentry cannot be induced when the S2 strength is >72+/-21 mA (upper limit of vulnerability) because these strong S2-induced graded responses convert the unidirectional block to bidirectional block by excess prolongation of the refractoriness. We conclude that the magnitude and the propagation of S2-induced cellular graded responses mediate and control vulnerability to reentry in the ventricular epicardium.

  20. Usefulness of 14-Day Holter for Detection of Nonsustained Ventricular Tachycardia in Patients With Hypertrophic Cardiomyopathy.

    Weissler-Snir, Adaya; Chan, Raymond H; Adler, Arnon; Care, Melanie; Chauhan, Vijay; Gollob, Michael H; Ziv-Baran, Tomer; Fourey, Dana; Hindieh, Waseem; Rakowski, Harry; Spears, Danna A


    Nonsustained ventricular tachycardia (NSVT), defined as ≥3 consecutive ventricular beats at ≥120 beats/min lasting Holter monitoring as part of SCD risk stratification. We sought to assess the difference in diagnostic yield of 14-day Holter monitoring compared to 24-48 hours for the detection of NSVT and to assess the prevalence and characteristics of NSVT in patients with HC with prolonged monitoring. We retrospectively analyzed the 14-day Holter monitors of 77 patients with HC from May 2014 to March 2016. Number of episodes and maximal length and rate on each day were recorded. NSVT was detected in 75.3% of patients during 14-day Holter monitoring. The median number of runs was 2 (range 0 to 26 runs). The median number of beats of the longest run was 10.5 (range 3 to 68 beats) with a mean maximum rate of 159.5 ± 20.8.4 beats/min (range 102 to 203 beats/min). First episodes of NSVT were detected throughout the 14 days, with only 22.5% and 44.8% of the episodes captured within the first 24 and 48 hours of monitoring, respectively. In conclusion, prolonged Holter monitoring revealed ≥1 episode of NSVT in 75% of patients with HC of which Holter monitoring may be superior for SCD risk stratification in HC. However, the high prevalence of NSVT in this population may limit its utility in evaluating the risk for SCD of the individual patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Assessment of left ventricular function by tissue Doppler imaging in patients with ankylosing spondylitis

    Osman Kuloglu


    Full Text Available Ankylosing spondylitis (ASpis a chronic, inflammatory and systemic disease affecting pericardium, myocardium and the conduction system of the heart. In this study, we aimed to analyse left ventricular systolic and diastolic functions using tissue Doppler imaging (TDI. 30 patients with ASp and 30 healthy volunteers having the similar demographic characteristics were included. Left ventricular systolic and diastolic functions were assessed by using two dimensional (2D echocardiography, M-mode, pulsed-wave (PW and tissue Doppler echocardiography. The peak systolic velocity (Sm, early diastolic myocardial peak velocity (m, late diastolic myocardial peak velocity (Am, isovolumic acceleration (IVA, myocardial precontraction time (PCTm, myocardial contraction time (CTm, myocardial relaxation time (RTm, and myocardial performance index (MPI were measured at septal and lateral mitral annulus. In conventional echocardiography, end-diastolic interventricular septum and posterior wall diameters were higher in patients with ASp than the control group. The ratio of E/A was significantly lower and deceleration time was significantly prolonged in patients with ASp, but mitral E and A velocities, isovolumic relaxation time and MPI were similar in patient and control group (P>0.05. Left ventricular lateral and septal wall tissue Doppler echocardiography showed that Em, Em/Am ratio and CTm were significantly lower, IVRTm was longer and MPI was higher in patients with ASp. No significant differences were detected between the groups for IVA, Sm, Am, PCTm, PCTm/CTm ratio (P>0.05. We have demonstrated that in patients with ASp, diastolic functions were impaired but systolic functions were preserved by using TDI.

  2. Ventricular assist devices in heart failure: how to support the heart but prevent atrophy?

    Pokorný, M; Cervenka, L; Netuka, I; Pirk, J; Koňařík, M; Malý, J


    Ventricular assist devices (VAD) have recently established themselves as an irreplaceable therapeutic modality of terminal heart failure. Because of the worldwide shortage of donors, ventricular assist devices play a key role in modern heart failure therapy. Some clinical data have revealed the possibility of cardiac recovery during VAD application. On the other hand, both clinical and experimental studies indicate the risk of the cardiac atrophy development, especially after prolonged mechanical unloading. Little is known about the specific mechanisms governing the unloading-induced cardiac atrophy and about the exact ultrastructural changes in cardiomyocytes, and even less is known about the ways in which possible therapeutical interventions may affect heart atrophy. One aim of this review was to present important aspects of the development of VAD-related cardiac atrophy in humans and we also review the most significant observations linking clinical data and those derived from studies using experimental models. The focus of this article was to review current methods applied to alleviate cardiac atrophy which follows mechanical unloading of the heart. Out of many pharmacological agents studied, only the selective beta2 agonist clenbuterol has been proved to have a significantly beneficial effect on unloading-induced atrophy. Mechanical means of atrophy alleviation also seem to be effective and promising.

  3. Effect of ramipril on the electrophysiological characteristics of ventricular myocardium after myocardial infarction in rabbits.

    Zhong, Ya; Cao, Ping; Tong, Chuanfeng; Li, Xia


    The current study aims to explore the effect of ramipril on the occurrence of ventricular arrhythmias and its possible mechanism after myocardial infarction (MI) in rabbits. A total of 24 rabbits were divided into three groups: the sham operation group (SHAM), the MI group, and the ramipril group (RAM). All groups were subjected to thoracotomy under sterile conditions; the MI and RAM groups underwent ligation of the left anterior descending coronary artery. On the second day after surgery, the RAM group was given ramipril (1 mg/kg per day). The rabbits in each group were fed for 12 weeks. The monophasic action potentials of the epicardium, mid-myocardium and endocardium in each group were, respectively, recorded before the MI and at 12 weeks after the MI. Meanwhile, the episodes of ventricular tachycardia or fibrillation (VT/VF) induced by procedure stimulations were counted, and the changes in L-type Ca flux (Ica-L) were recorded by means of the whole-cell patch-clamp technique. The episodes of VT/VF were decreased in the RAM group after MI. At 12 weeks after MI, the transmural dispersion of repolarization (TDR) in the MI group was prolonged significantly compared with the SHAM and RAM groups. The density of Ica-L in the MI group was significantly lower than that any other group. Ramipril manifestly decreases the incidence of VT/VF after MI in rabbits, and the mechanism may be associated with its inhibitory effect on electrical remodeling after MI.

  4. Postexertional Supraventricular Tachycardia in Children with Catecholaminergic Polymorphic Ventricular Tachycardia

    Scott D. N. Else


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

  5. Tamponade by an expanding left ventricular pseudoaneurysm: A unique presentation.

    Mahesh, Balakrishnan; Ong, Ping; Kutty, Ramesh; Abu-Omar, Yasir


    Left ventricular free wall rupture secondary to myocardial infarction is an uncommon but catastrophic event requiring emergency surgery. We describe a unique presentation of left ventricular free wall rupture as delayed tamponade caused by a gradually expanding pseudoaneurysm compressing the left atrium, leading to pulmonary congestion that required increasing respiratory support to maintain oxygenation, and necessitated emergency surgery. We discuss the options available to treat pseudoaneurysms due to left ventricular free wall rupture.

  6. The Ventricular System of the Brain: Anatomy and Normal Variations.

    Stratchko, Lindsay; Filatova, Irina; Agarwal, Amit; Kanekar, Sangam


    The cerebral ventricular system is intimately associated with the forebrain and brainstem. The ventricular system functions to produce and circulate cerebrospinal fluid, which plays an important role in mechanical protection and regulation of homeostasis in the central nervous system. This article discusses anatomy and neuroimaging of the ventricular system and highlights normal anatomical variations that may be mistaken for pathology. Applied surgical anatomy is reviewed with emphasis on operative approach and potential risk to adjacent central nervous system structures.

  7. Comparison of epinephrine and Shen-Fu injection on resuscitation outcomes in a porcine model of prolonged cardiac arrest

    Yin Wenpeng; Guo Zhijun; Li Chunsheng


    Background Epinephrine has been used as a first-choice vasopressor drug for cardiac arrest (CA) since 1974.However,the administration of epinephrine is controversial.This study aims to compare the effects of Shen-Fu injection (SFI) and epinephrine on resuscitation outcomes in a porcine model of prolonged CA.Methods Ventricular fibrillation (VF) was electrically induced.After 8 minutes of untreated VF and 2 minutes of chest compressions,24 pigs were randomly divided into 3 groups (n=8 per group):central venous injection of SFI (SFI group),epinephrine (EPI group),or saline solution (SA group).The haemodynamic status and oxygen metabolism parameters,including cardiac output,mean arterial pressure,left ventricular dp/dtmax and negative dp/dtmax,oxygen delivery (DO2),and oxygen consumption (VO2),were calculated.Results SFI shortened the time to restoration of spontaneous circulation (ROSC) and decreased the number of shocks,similar to epinephrine.However,the mean arterial pressure,cardiac output,left ventricular dp/dtmax and negative dp/dtmax were significantly higher in the SFI group than in the EPI group at 4 and 6 hours after ROSC.VO2 and ERO2 decreased after ROSC and then increased.VO2 and ERO2 were significantly higher in the SFI group than in the EPI and SA groups after ROSC,while those were lowest in the EPI group among all groups.Conclusions SFI shortened the time to ROSC and decreased the number of shocks,similar to epinephrine.However,SFI improved oxygen metabolism,and produced a better hemodynamic status compared with epinephrine.SFI might be a potentially vasopressor drug for the treatment of CA.

  8. Ventricular rate control of atrial fibrillation in heart failure.

    Rienstra, Michiel; Van Gelder, Isabelle C


    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indications; the optimal ventricular rate-control target, including detailed results of the Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison Between Lenient versus Strict Rate Control II (RACE II) study; and the pharmacologic and nonpharmacologic options to control the ventricular rate during AF in the setting of HF.

  9. Right ventricular function before and after percutaneous balloon mitral valvuloplasty.

    Burger, W; Brinkies, C; Illert, S; Teupe, C; Kneissl, G D; Schräder, R


    Aim of this study was to evaluate right ventricular performance in patients with mitral stenosis and its modification by balloon valvuloplasty. Right ventricular volumes of 24 patients with postrheumatic mitral stenosis were determined by thermodilution 1 or 2 days before and 1 or 2 days after valvuloplasty. Right ventricular ejection fraction at rest was 43 (36-47)% (median and interquartile range). Right ventricular end-diastolic volume was 100 (86-119) ml/m2. Supine bicycle exercise (50 Watt) reduced right ventricular ejection fraction to 30 (29-37)% (P volume to 124 (112-141) ml/m2 (P improvement of right ventricular ejection fraction correlated inversely with the value of this parameter before valvuloplasty (r = -0.88, P volume (r = 0.57, P < 0.01). The right ventricular function curve, disturbed before commissurotomy, was reestablished by the procedure. In conclusion, at the here investigated stage of mitral stenosis right ventricular function is reversibly impaired. This is predominantly caused by the hemodynamic consequences of the valvular defect and not by an impairment of right ventricular myocardial function.

  10. A dual-chamber pacing mode to minimize ventricular pacing

    Peter Rakovec


    Full Text Available Background: Though patients with sick sinus syndrome theoretically need an atrial pacemaker only, they usually receive a ventricular or a dual-chamber pacemaker because of possible developement of atrioventricular conduction abnormalities. Right ventricular pacing produces left bundle branch block (i.e. pacing-induced ventricular desynchronization, promoting heart failure and atrial fibrillation. This problem can be solved by a special pacing mode which on one hand preserves the safety of dual-chamber pacing and on the other hand minimizes right ventricular pacing.

  11. Right ventricular strain in heart failure: Clinical perspective.

    Tadic, Marijana; Pieske-Kraigher, Elisabeth; Cuspidi, Cesare; Morris, Daniel A; Burkhardt, Franziska; Baudisch, Ana; Haßfeld, Sabine; Tschöpe, Carsten; Pieske, Burket


    The number of studies demonstrating the importance of right ventricular remodelling in a wide range of cardiovascular diseases has increased in the past two decades. Speckle-tracking imaging provides new variables that give comprehensive information about right ventricular function and mechanics. In this review, we summarize current knowledge of right ventricular mechanics in heart failure with reduced ejection fraction and preserved ejection fraction. We searched PubMed, MEDLINE, Ovid and Embase databases for studies published from January 2000 to December 2016 in the English language using the following keywords: "right ventricle"; "strain"; "speckle tracking"; "heart failure with reduced ejection fraction"; and "heart failure with preserved ejection fraction". Investigations showed that right ventricular dysfunction is associated with higher cardiovascular and overall mortality in patients with heart failure, irrespective of ejection fraction. The number of studies investigating right ventricular strain in patients with heart failure with reduced ejection fraction is constantly increasing, whereas data on right ventricular mechanics in patients with heart failure with preserved ejection fraction are limited. Given the high feasibility, accuracy and clinical implications of right ventricular strain in the population with heart failure, it is of great importance to try to include the evaluation of right ventricular strain as a regular part of each echocardiographic examination in patients with heart failure. However, further investigations are necessary to establish right ventricular strain as a standard variable for decision-making. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Supplementation of Ascorbic Acid in Weanling Horses Following Prolonged Transportation

    Michelle Stives


    Full Text Available Though horses synthesize ascorbic acid in their liver in amounts that meet their needs under normal circumstances, prolonged stress results in low plasma concentrations due to enhanced utilization and renal excretion and can reduce immune function. It was hypothesized that plasma ascorbic acid could be maintained in weanling horses by oral supplementation following prolonged transportation. Weanlings were supplemented with no ascorbic acid (Tx 0: n = 4, 5 grams ascorbic acid twice daily for 5 days (Tx 1: n = 4 or for 10 days (Tx 2: n = 4 following >50 hours of transportation. Supplementation caused slight (P < 0.2 increases in plasma ascorbic acid concentrations. Both supplemented groups had decreased (P < 0.05 plasma concentrations for 1 to 3 weeks following cessation of supplementation, possibly due to increased renal excretion or suppressed hepatic synthesis. Supplementation of ascorbic acid following prolonged stress will increase plasma concentrations, but prolonged supplementation should be avoided.

  13. Exercise Induced Cardiac Fatigue Following Prolonged Exercise in Road Cyclists

    Wyatt, Frank; Pawar, Ganesh; Kilgore, Lon


    The purpose of this study was to examine cardiac function following a 100-mile ride in high ambient temperatures by healthy, competitive cyclists. Methods: Subjects were six (n=6) competitive cyclists racing in a 100-mile road race. Measures (pre/post) included: body mass (kg); E:A ratio (ventricular compliance); stroke volume (ml); ejection…

  14. Effect of preceding inspiratory speed and end-inspiratory pause on forced expiratory manoeuvre in healthy subjects and chronic obstructive pulmonary disease patients.

    Boni, Enrico; Chiari, Stefania; Trigiani, Marco; Gatta, Diego; Pini, Laura; Tantucci, Claudio


    Lower peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV(1)) have been consistently found after slow inspiration with end-inspiratory pause (EIP). It was the aim of this study to establish the respective influence of the speed of preceding inspiration (SPI) and EIP on the parameters obtained from the following expiratory forced vital capacity (FVC) manoeuvre. In 8 healthy subjects and 12 patients with chronic obstructive pulmonary disease (COPD), a number of inspirations with different SPI and EIP were performed. In the subsequent FVC manoeuvre, maximal expiratory flows, including PEF, and maximal expired volumes at different times, including FEV(1), were measured. For each FVC manoeuvre, peak expiratory time, expired volume at PEF (as % of FVC), flow limitation by the negative expiratory pressure technique and FVC were checked to be sure of achieving a similar expiratory effort and starting inflation lung volume. The highest values of PEF and FEV(1) were found in normal subjects and COPD patients after fastest SPI without EIP (p 2 s) without EIP were followed by lower PEF in COPD patients (p COPD patients (p COPD patients, unless SPI is too slow (inspiratory time >2 s), while any EIP decreases these indices in all individuals. (c) 2009 S. Karger AG, Basel.

  15. Prolongation structure of the Landau–Lifshitz equation

    Roelofs, G.H.M.; Martini, R.


    The prolongation method of Wahlquist and Estabrook is applied to the Landau–Lifshitz equation. The resulting prolongation algebra is shown to be isomorphic to a subalgebra of the tensor product of the Lie algebra so(3) with the elliptic curve v α 2−v β 2=j β−j α (α,β=1,2,3), which is essentially a s

  16. Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D

    Kutyifa, Valentina; Bloch Thomsen, Poul Erik; Huang, David T.


    Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited.......Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited....

  17. Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D

    Kutyifa, Valentina; Bloch Thomsen, Poul Erik; Huang, David T.;


    Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited.......Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited....

  18. Epicardial radiofrequency ablation for left ventricular aneurysm related ventricular arrhythmias during off-pump coronary artery bypass surgery

    YU Yang; GAO Ming-xin; LI Hai-tao; ZHANG Fan; GU Cheng-xiong


    Background Left ventricular aneurysm (LVA) is one of the serious complications after acute myocardial infarction.We attempted to evaluate the preliminary efficacy of LVA repair combined with epicardial radiofrequency ablation for ventricular arrhythmia during off-pump coronary artery bypass grafting (OPCAB).Methods From June 2009 to April 2011,31 patients with LVA had angina symptoms and ventricular arrhythmia.In all patients,circular and cross-shaped radiofrequency epicardial ablations were performed using unipolar ablation pen along the border between the aneurysm wall and normal cardiac tissue and in the central zone of the aneurysms,followed by a linear placation of ventricular aneurysms on beating heart.Results All the patients showed complete recovery.The average number of grafted vessels was 2.7±1.3.Intraoperative examinations revealed that the ventricular arrhythmia was effectively controlled by radiofrequency ablation.All cases had been followed up for one year.Holter monitoring revealed a significant reduction in ventricular arrhythmias (P <0.05).Echocardiography showed significant increase in left ventricular ejection fraction (P <0.05) and decrease in left ventricular end-diastolic diameter (P <0.05).Conclusions For patients with ventricular aneurysm and preoperative malignant arrhythmia,aneurysm repair plus epicardial radiofrequency ablation in OPCAB was found to be an effective and feasible therapeutic technique.However,medium-to long-term therapeutic efficacy of this method remains to be determined by future studies and observations.

  19. Dual Endothelin Receptor Blockade Abrogates Right Ventricular Remodeling and Biventricular Fibrosis in Isolated Elevated Right Ventricular Afterload.

    Eva Amalie Nielsen

    Full Text Available Pulmonary arterial hypertension is usually fatal due to right ventricular failure and is frequently associated with co-existing left ventricular dysfunction. Endothelin-1 is a powerful pro-fibrotic mediator and vasoconstrictor that is elevated in pulmonary arterial hypertension. Endothelin receptor blockers are commonly used as pulmonary vasodilators, however their effect on biventricular injury, remodeling and function, despite elevated isolated right ventricular afterload is unknown.Elevated right ventricular afterload was induced by progressive pulmonary artery banding. Seven rabbits underwent pulmonary artery banding without macitentan; 13 received pulmonary artery banding + macitentan; and 5 did not undergo inflation of the pulmonary artery band (sham-operated controls.Right and left ventricular collagen content was increased with pulmonary artery banding compared to sham-operated controls and ameliorated by macitentan. Right ventricular fibrosis signaling (connective tissue growth factor and endothelin-1 protein levels; extra-cellular matrix remodeling (matrix-metalloproteinases 2 and 9, apoptosis and apoptosis-related peptides (caspases 3 and 8 were increased with pulmonary artery banding compared with sham-operated controls and decreased with macitentan.Isolated right ventricular afterload causes biventricular fibrosis, right ventricular apoptosis and extra cellular matrix remodeling, mediated by up-regulation of endothelin-1 and connective tissue growth factor signaling. These pathological changes are ameliorated by dual endothelin receptor blockade despite persistent elevated right ventricular afterload.

  20. Outcome of Induction of Labour in Prolonged Pregnancy.

    Nasrin, S; Islam, S; Shahida, S M; Begum, R A; Haque, N


    This was a hospital based prospective clinical study conducted among women having prolonged pregnancy to assess the outcome of induction of labour in prolonged pregnancy cases. One hundred and thirty nine women having uncomplicated prolonged pregnancy were studied. The study was carried out in Sir Salimullah Medical College & Mitford Hospital, Dhaka from 01 July 2010 to 30 March 2011. In this study 66% of the respondents had vaginal delivery on routine induction of labour and in 34% cases induction failed. Ninety three percent (93%) of the multigravida had vaginal delivery and in primigravida their vaginal delivery rate was 47.5%. Regarding cervical condition for delivery, 75% of the respondents having favourable cervix had vaginal delivery and in case of unfavourable cervix respondents, they had 55% cases of vaginal delivery. About the foetal outcome it was evidenced from this study that the perinatal adverse outcome increases with the increasing age of gestation beyond 40 completed weeks of gestation. This study showed that the use of prostaglandins for cervical ripening and by confirming the diagnosis of prolonged pregnancy, the delivery outcome in prolonged pregnancy can be improved. The study also showed that induction of labour is not associated with any major complications and the routine induction of labour in prolonged pregnancy is beneficial for both mother and the baby.

  1. Diagnosis, antenatal surveillance and management of prolonged pregnancy: current perspectives.

    Vitale, S G; Marilli, I; Rapisarda, A M; Iapichino, V; Stancanelli, F; Cianci, A


    Prolonged pregnancy is defined as a pregnancy that extends beyond 42 weeks of gestation (294 days) from the first day of the last normal menstrual period. An accurate estimation of the 'natural' incidence of prolonged pregnancy would require meticulous early pregnancy dating. The use of ultrasound to establish gestational age reduces the number of pregnancies that are classified as prolonged. Prolonged pregnancy is associated with an increased perinatal mortality and morbidity in pregnancies which appear to be otherwise low risk. Postterm births are easily preventable by intervening to deliver with the use of induction of labor. Thus, this potentially problematic condition deserves further attention and careful consideration. The focus of this article is to review and challenge some current concepts surrounding the diagnosis and management of prolonged pregnancy. We outline how to identify those women with prolonged pregnancy and which is the appropriate moment to start monitoring the fetal wellbeing. Finally we address the question of benefits and hazards of induction of labor strategies.

  2. Ventricular septal rupture and right ventricular intramyocardial dissection secondary to acute inferior myocardial infarction.

    Bittencourt, Márcio Sommer; Seltmann, Martin; Muschiol, Gerd; Achenbach, Stephan


    A 61-year-old female patient presented with sub acute myocardial infarction with an occluded right coronary artery on invasive evaluation and a ventricular septal rupture on echocardiogram. Cardiac computed tomography (CT) was performed to better define the septal anatomy. As the anatomy on cardiac CT was considered unfavorable for percutaneous intervention, the patient underwent successful surgical repair.


    刘明辉; 苏鸿熙; 李功宋; 王加利; 董超; 童健


    The efficacy of right atrial-pulmonary artery (RA-PA)bypass during acute right ventricular failure(RVF)produced by pulmonary artery constriction in dogs was examined in this study Control group (n=7)was supported with conventional volume loading and inotropic therapy.In the experimental animals (n=8),RA-PA bypass was initiated 5 min.after the onset of severe RVF.Three control animals died from refractory ventricular fibrillation within one hour of RVF.No animals in the experimental group died within two hours of RA-PA bypass,but the histological study of the lungs in these animals demonstrated peribronchial,preivascular and intraalveolar hemorrhage.Lighr microscopic and electron microscopic examination of the myocardial specimens of the right ventricular free wall displayed the myocardial structures and ultrastructues were maintained effectively with RA-PA bypass wile irreversible myocardial injuries occurred in the control animasls after two hours of RVF with conventional therapy.During the 2hours of RA-PA bypass,the hemodynamic indices were also maintained better when compared to the control animals.It may be concluded,a roller pump right ventricular assist device effectively unloads the acute faijing right ventricle,maintains systemic cardisc output,and significatly reverses the myocardial ischemia during right venrricular failure,but RA-PA bypass may induce pulmonary hypertension due to increased pulmonary vascular resistance secondary to pulmonary edeme and interstitial hemorrhage.

  4. Rare Complication of External Ventricular Drainage:Intra-ventricular Drain Section

    Hanane Ezzouine; Abdellatif Benslama


    The external ventricular derivation is an invasive technique used to cure hydrocephalus.Sometimes,it may have infectiousand mechanical complications and needs specific cares.Very rarely, the drain line can be cut with an intraventricular section tip as in thecase reported.

  5. Taquicardia ventricular polimórfica catecolaminérgica Catecholaminergic polymorphic ventricular tachycardia

    Alejandro Velasco


    Full Text Available Catecholaminergic Polymorphic Ventricular Tachycardia is an inherited heart rhythm disorder recently discovered by genetic and electrophysiological diagnostic advancements. It consists of an inherited disorder characterized by the induction of bi-directional ventricular tachycardia in the presence of catecholamines, without a structural cardiac abnormality. Mutations in the Ryanodine receptor gene RyR2, have been linked with an autosomic dominant form, while mutations in the Calsequestrin gene CASQ 2 have showed correlation with an autosomic recessive form. The average age of onset is between 7 and 9 years of age, and clinical symptoms vary from syncope to sudden cardiac death. The diagnosis is confirmed by inducting ventricular tachycardia through a stress test or during an infusion of sympathicomimetic drugs like Isoproterenol, aided by the identification of mutations in the RyR2 and CASQ2 genes through gene analysis. Implantable cardiodefibrillator devices remain a valid therapeutic option in many cases due to the fact that antiarrhythmic drugs have not shown efficacy. Sympathetic cardiac denervation can be useful in some special cases. Catecholaminergic Polymorphic Ventricular Tachycardia opens a wide field for the development of new antiarrhythmic drugs and the use of gene therapy for cardiac rhythm disorders.

  6. Extracorporeal life support for refractory ventricular tachycardia

    Joseph, Nicholas; Hofmann, James P.; Saranteas, Theodosios; Papadimos, Thomas J.


    Extracorporeal life support (ECLS) is a very effective bridging therapy in patients with refractory ventricular tachycardia (VT) associated with cardiogenic shock. A moribund patient in extremis, is not amenable to optimization by standard ACC/AHA guidelines. New approaches and novel salvage techniques are necessary to improve outcomes in patients with refractory clinical settings such as malignant ventricular arrhythmias, cardiac arrest, cardiogenic shock and/or pulmonary failure until further management options are explored. Data base searches were done using key words such as ECLS, VT, cardiac arrest, VT ablation, venoarterial extra-corporeal membrane oxygenation (VA-ECMO). The use of ECLS has been described in a few case reports to facilitate VT ablation for incessant VT refractory to medical therapy. For patients with, out-of- hospital ventricular fibrillation (VF) and VT, Minnesota Resuscitation Consortium has implemented emergent advanced perfusion and reperfusion strategy, followed by coronary angiography and primary coronary intervention to improve outcome. The major indications for ECLS are cardiogenic shock related to acute myocardial infarction, myocarditis, post embolic acute cor pulmonale, drug intoxication and post cardiac arrest syndrome with the threat of multi-organ failure. ECLS permits the use of negative inotropic antiarrhythmic drug therapy, facilitates the weaning of catecholamine administration, thereby ending the vicious cycle of catecholamine driven electric storm. ECLS provides hemodynamic support during ablation procedure, while mapping and induction of VT is undertaken. ECLS provides early access to cardiac catheterization laboratory in patients with cardiac arrest due to shockable rhythm. The current evidence from literature, supports the use of ECLS to ensure adequate vital organ perfusion in patients with refractory VT. ECLS is a safe, feasible and effective therapeutic option when conventional therapies are insufficient to support

  7. Ventricular shunt infections: Immunopathogenesis and clinical management

    Gutierrez-Murgas, Yenis; Snowden, Jessica N.


    Ventricular shunts are the most common neurosurgical procedure performed in the United States. This hydrocephalus treatment is often complicated by infection of the device with biofilm-forming bacteria. In this review, we discuss the pathogenesis of shunt infection, as well as the implications of the biofilm formation on treatment and prevention of these infections. Many questions remain, including the contribution of glia and the impact of inflammation on developmental outcomes following infection. Immune responses within the CNS must be carefully regulated to contain infection while minimizing bystander damage; further study is needed to design optimal treatment strategies for these patients. PMID:25156073

  8. Pseudo ventricular tachycardia: a case report.

    Riaz, A


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

  9. Long QT, alteration of calcium-phosphate product, prevalence of ventricular arrhythmias and sudden death in peritoneal dialysis patients: a Holter study

    Pierluigi Di Loreto


    Full Text Available Materials and methods We studied 79 patients on peritoneal dialysis. Each underwent 24-h electrocardiography (Holter monitoring and measurement of the rate-corrected QT interval (QTc. We analyzed the correlation between QTc and plasma levels of Ca++, PO4−, K+, Na+, Mg++, and parathyroid hormone (PTH. Results The mean QTc was 0.445 ± 0.04 s. In 55 patients, the QTc was prolonged (> 0.45 s. Mean laboratory values for the group were: PTH 344 ± 25 pg/mL, Ca++ 9.27 ± 0.11 mg/dL, PO4− 5.5 ± 1.5 mg/dL, Na+ 139.6 ± 3.4 mmol/L, K+ 4.04 ± 0.64 mmol/L, and Mg++ 2.52 ± 0.43 mg/dL. Holter monitoring revealed complex premature ventricular contractions in 44 patients, monomorphic premature ventricular contractions in 16, and nonsustained ventricular tachycardia (NSVT in 10. The QTc was significantly correlated with plasma levels of PO4− (r = 0.045, p < 0.05, PTH (r = 0.077, p < 0.02, and Ca++ (r = 0.076, p < 0.02. Eleven patients had Lown class 4a or 4b ventricular arrhythmias, and their mean QTc was 465 ± 0.02 ms. Ten had NSVT and their QTc was 464 ± 0.03 ms. Eleven patients died suddenly (mean QTc 465 ± 0.03 ms; all 11 had either NSTV or Lown class 4 ventricular arrhythmias. Conclusions Long QTc seems to be associated with an increased prevalence of ventricular arrhythmias that may be the cause of sudden cardiac death.

  10. Post-Pacing Abnormal Repolarization in Catecholaminergic Polymorphic Ventricular Tachycardia Associated with a Mutation in the Cardiac Ryanodine Receptor Gene (RyR2)

    Nof, Eyal; Belhassen, Bernard; Arad, Michael; Bhuiyan, Zahurul A.; Antzelevitch, Charles; Rosso, Raphael; Fogelman, Rami; Luria, David; Eli-Ani, Dalia; Mannens, Marcel M.A.M.; Viskin, Sami; Eldar, Michael; Wilde, Arthur A.M.; Glikson, Michael


    Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value. Objective We present a CPVT family in which marked post-pacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of RyR2 mutation carriers. Methods The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic ECG testing with epinephrine, adenosine and flecainide. Non-invasive clinical tests were normal in 10 patients evaluated, except for both epinephrine and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in LQTS as well as RyR2. Results Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent post-pacing QT changes. Conclusions M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked post-pacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family. PMID:21699856

  11. The Association between Myocardial Iron Load and Ventricular Repolarization Parameters in Asymptomatic Beta-Thalassemia Patients

    Mehmet Kayrak


    Full Text Available Previous studies have demonstrated impaired ventricular repolarization in patients with β-TM. However, the effect of iron overload with cardiac T2* magnetic resonance imaging (MRI on cardiac repolarization remains unclear yet. We aimed to examine relationship between repolarization parameters and iron loading using cardiac T2* MRI in asymptomatic β-TM patients. Twenty-two β-TM patients and 22 age- and gender-matched healthy controls were enrolled to the study. From the 12-lead surface electrocardiography, regional and transmyocardial repolarization parameters were evaluated manually by two experienced cardiologists. All patients were also undergone MRI for cardiac T2* evaluation. Cardiac T2* score <20 msec was considered as iron overload status. Of the QT parameters, QT duration, corrected QT interval, and QT peak duration were significantly longer in the β-TM group compared to the healthy controls. Tp−Te and Tp−Te dispersions were also significantly prolonged in β-TM group compared to healthy controls. (Tp-Te/QT was similar between groups. There was no correlation between repolarization parameters and cardiac T2* MRI values. In conclusion, although repolarization parameters were prolonged in asymptomatic β-TM patients compared with control, we could not find any relation between ECG findings and cardiac iron load.

  12. Ventricular rate control of atrial fibrillation in heart failure

    Rienstra, Michiel; Van Gelder, Isabelle C


    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indicati

  13. Bradyarrhythmias: first presentation of arrhythmogenic right ventricular cardiomyopathy?

    Burghouwt, Danielle E; Kammeraad, Janneke Ae; Knops, Paul; du Plessis, Frederik A; de Groot, Natasja Ms


    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder characterized by progressive replacement of myocardial cells by fibro-fatty tissue giving rise to ventricular tachyarrhythmias. In this case report, we describe a pediatric patient with sinoatrial arrests and second degree atrioventricular conduction block several years before ARVC became apparent. These findings suggest that bradyarrhythmias can also be the first expression of ARVC.

  14. Acupuncture Treatment for 98 Cases of Ventricular Premature Beat

    Han Baojie; Wang Feng; Wang Xinzhong


    @@ Ventricular premature beat is a commonly encountered arrhythmia,which can occur in patients with and without cardiac diseases.In TCM.ventricular premature beat fall into the category of palpitation and obstruction of qi in the chest.The authors treated it with acupuncture and obtained satisfactory thera-peutic effects.A summary follows.

  15. Patient's Guide to Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

    ... Page Patient’s Guide to Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy Past to Present Crystal Tichnell , Cynthia A. James , ... Info & Metrics eLetters Introduction Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited progressive disease of ...

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

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


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

  17. Ventricular tachycardia after administration of sildenafil citrate: a case report

    Rasmussen Jeppe G


    Full Text Available Abstract Background It has not previously been reported that sildenafil citrate causes malignant arrhythmias in humans. Case presentation A 41-year-old man developed sustained ventricular tachycardia following sildenafil citrate administration. Conclusion It cannot be dismissed that this patient experienced ventricular tachycardia as an adverse effect of sildenafil citrate administration.

  18. Evaluation of left ventricular volumes measured by magnetic resonance imaging

    Møgelvang, J; Thomsen, C; Mehlsen, J


    Left ventricular end-diastolic and end-systolic volumes were determined in 17 patients with different levels of left ventricular function by magnetic resonance imaging (MRI). A 1.5 Tesla Magnet was used obtaining ECG triggered single and multiple slices. Calculated cardiac outputs were compared...

  19. Ventricular septal defect closure in a patient with achondroplasia.

    Nakanishi, Keisuke; Kawasaki, Shiori; Amano, Atsushi


    Achondroplasia with co-morbid CHD is rare, as are reports of surgical treatment for such patients. We present the case of a 13-year-old girl with achondroplasia and ventricular septal defect. Her ventricular septal defect was surgically repaired focussing on the cardiopulmonary bypass flow, healing of the sternum, and her frail neck cartilage. The surgery and recovery were without complications.

  20. Ventricular rate control of atrial fibrillation in heart failure

    Rienstra, Michiel; Van Gelder, Isabelle C


    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the

  1. Aortic coarctation, aneurysm, and ventricular dysfunction in an asymptomatic infant.

    García, Ana I; Aguilar, Juan M; García, Enrique


    Aortic arch coarctation with post-coarctation aneurysm is rare in infants. We present the case of an asymptomatic 3-month-old infant with severe left ventricular dysfunction in this setting. The patient underwent surgical repair, and the left ventricular ejection fraction improved to recovery the 4th post-operative month.

  2. Left ventricular diastolic function in patients with advanced cystic fibrosis.

    Koelling, Todd M; Dec, G William; Ginns, Leo C; Semigran, Marc J


    To assess left ventricular systolic and diastolic function in adult patients with cystic fibrosis using radionuclide ventriculography. Although myocardial fibrosis has been described in autopsy specimens of patients with cystic fibrosis, the possibility that myocardial dysfunction may occur during life in adult patients with cystic fibrosis has not been explored. To assess the possibility of cardiac dysfunction occurring in cystic fibrosis, we studied 40 patients with advanced cystic fibrosis with first-pass radionuclide ventriculography and compared them to 9 patients with advanced bronchiectasis and 18 normal control subjects. Indexes of right ventricular systolic function were similarly impaired in patients with cystic fibrosis and patients with bronchiectasis. Left ventricular ejection fraction of patients with cystic fibrosis, patients with bronchiectasis, and normal control subjects did not differ. Fractional left ventricular filling at 50% of diastole, an index of diastolic function, was significantly lower in patients with cystic fibrosis (54 +/- 13%, mean +/- SD) in comparison to patients with bronchiectasis (66 +/- 4%, p = 0.009) or normal control subjects (69 +/- 14, p = 0.0002). The contribution of atrial systole to total diastolic left ventricular filling was greater in patients with cystic fibrosis (38 +/- 18%) than in patients with bronchiectasis (21 +/- 4%, p = 0.01) or normal control subjects (25 +/- 12%, p = 0.01). Patients with advanced cystic fibrosis demonstrate impaired left ventricular distensibility when compared to normal control subjects and patients with bronchiectasis. Patients with cystic fibrosis may be at risk of heart failure due to right ventricular dysfunction or left ventricular diastolic dysfunction.

  3. Right ventricular noncompacted cardiomyopathy-time for a new classification?

    Marija Zdravkovic; Mirjana Krotin


    @@ To the Editor: We read with a great interest the recent article by Zhang et al,~1 in which they reported a rare case of isolated right ventricular noncompaction with normal left ventricular systolic function in a 23-year-old female.

  4. Intermittent′ restrictive ventricular septal defect in Tetralogy of Fallot

    Sudhir S Shetkar


    Full Text Available Ventricular septal defect (VSD in Tetralogy of Fallot (TOF is usually large and non-restrictive with equalization of right and left ventricular pressures. Restrictive VSD in TOF is rare. We present an unusual case of TOF with restriction to VSD caused by accessory tricuspid valve tissue that varied with respiration.

  5. Muscular ventricular septal defects: A reappraisal of the anatomy

    Wenink, A.C.G.; Oppenheimer-Dekker, A.; Moulaert, A.J.


    Among 79 autopsy specimens of hearts with an isolated ventricular septal defect, there were 29 cases of muscular defect. Among 60 hearts with complete transposition of the great arteries and a ventricular septal defect, there were 13 cases with a muscular defect. All muscular defects could be classi

  6. Disfunção ventricular esquerda transitória por cardiomiopatia induzida por estresse Transient left ventricular dysfunction due to stress-induced cardiomyopathy

    Marcus Vinicius Simões


    Full Text Available Apresenta-se o caso de uma paciente de 71 anos que preencheu os critérios diagnósticos para cardiomiopatia induzida por estresse que foi desencadeada por intenso estresse emocional após atropelamento por bicicleta. O quadro clínico mimetizou o infarto agudo do miocárdio, manifestando-se com dor precordial, supradesnivelamento do segmento ST, seguido por ondas T profundas e prolongamento do intervalo QT, elevação discreta de enzimas cardíacas e cursando com disfunção sistólica apical do ventrículo esquerdo e hipercinesia das porções basais (conferindo o aspecto de "abaloamento apical", mas na ausência de obstrução coronariana subepicárdica. A função ventricular normalizou-se após a segunda semana de evolução.The case presented here is of a 71-yr-old female patient who met the diagnostic criteria for stress-induced cardiomyopathy, which was triggered by intense emotional stress after being hit by a bicycle. The clinical picture mimicked that of an acute myocardial infarction, manifesting as precordial pain, ST-segment depression followed by deep negative T waves and prolonging of the QT interval, slight increase in cardiac enzymes and coursing with transient apical ballooning of the left ventricle and hyperkinesis of the basal walls (conferring the aspect of "apical ballooning", although in the absence of subepicardial coronary obstruction. Ventricular function normalized after the second week of clinical evolution.

  7. Genetic bases of arrhythmogenic right ventricular cardiomyopathy

    Alessandra Rampazzo


    Full Text Available Arrhythmogenic right ventricular cardiomyopathy (ARVC is a heart muscle disease in which the pathological substrate is a fibro-fatty replacement of the right ventricular myocardium. The major clinical features are different types of arrhythmias with a left branch block pattern. ARVC shows autosomal dominant inheritance with incomplete penetrance. Recessive forms were also described, although in association with skin disorders. Ten genetic loci have been discovered so far and mutations were reported in five different genes. ARVD1 was associated with regulatory mutations of transforming growth factor beta-3 (TGFβ3, whereas ARVD2, characterized by effort-induced polymorphic arrhythmias, was associated with mutations in cardiac ryanodine receptor-2 (RYR2. All other mutations identified to date have been detected in genes encoding desmosomal proteins: plakoglobin (JUP which causes Naxos disease (a recessive form of ARVC associated with palmoplantar keratosis and woolly hair; desmoplakin (DSP which causes the autosomal dominant ARVD8 and plakophilin-2 (PKP2 involved in ARVD9. Desmosomes are important cell-to-cell adhesion junctions predominantly found in epidermis and heart; they are believed to couple cytoskeletal elements to plasma membrane in cell-to-cell or cell-to-substrate adhesions.

  8. Phase statistics approach to human ventricular fibrillation

    Wu, Ming-Chya; Watanabe, Eiichi; Struzik, Zbigniew R.; Hu, Chin-Kun; Yamamoto, Yoshiharu


    Ventricular fibrillation (VF) is known to be the most dangerous cardiac arrhythmia, frequently leading to sudden cardiac death (SCD). During VF, cardiac output drops to nil and, unless the fibrillation is promptly halted, death usually ensues within minutes. While delivering life saving electrical shocks is a method of preventing SCD, it has been recognized that some, though not many, VF episodes are self-terminating, and understanding the mechanism of spontaneous defibrillation might provide newer therapeutic options for treatment of this otherwise fatal arrhythmia. Using the phase statistics approach, recently developed to study financial and physiological time series, here, we reveal the timing characteristics of transient features of ventricular tachyarrhythmia (mostly VF) electrocardiogram (ECG) and find that there are three distinct types of probability density function (PDF) of phase distributions: uniform (UF), concave (CC), and convex (CV). Our data show that VF patients with UF or CC types of PDF have approximately the same probability of survival and nonsurvival, while VF patients with CV type PDF have zero probability of survival, implying that their VF episodes are never self-terminating. Our results suggest that detailed phase statistics of human ECG data may be a key to understanding the mechanism of spontaneous defibrillation of fatal VF.


    华伟; JituVohra


    This paper presents our experieaee with radioreqencey ablation (RFA) for idiopathic ventricular tschycardia (VT) arising from right ventricle in 12 patients(pts). The age range d patients was 21~50, with a mean of 38. 5 years. Ten out of 12 were females, 1 patient had eandia failure due to almost incessant VT while the rest had normal left ventricular function.Twelve pts had VT arising from the fight ventricle; of those, 9 were from the outflow truct, 2 from the RV apex, and l from the RV inflow. In all tats the diagnostic study and therapeutic RFA were combined in a single procedure, pacemapping and local aetlvition time were used to guide the site of RFA in Ors with VT arising froth the tight ventricle.RFA was successful in 11 of the 12 pts ( 91%). Ntmaher of RF applications were 1~27, mean 9. 6; fluoroscopy time were 4~75, mean 26. 9 minutes. RFA for idiopathic RV has a high success rate. This mode of treament should be considered as a nonphartaaeologieal curative treatment for symptomatic pts.

  10. ECG manifestations of left ventricular electrical remodeling.

    Estes, E Harvey


    Research and thinking about the electrocardiographic manifestations of left ventricular hypertrophy has been constrained by a limited conceptual model of the process: heart disease produces chamber enlargement (increased mass), which in turn produces an altered electrocardiogram. The process is much more complex than can be represented in this simple model. A more robust and intricate model is proposed, in which heart (and vascular) disease causes structural changes, electrical changes, biochemical changes, and others, all of which interact to produce electrical remodeling of ventricular myocardium. This electrical remodeling results in a variety of ECG changes. All of these changes interact, leading to an altered clinical course, and to premature death. It is suggested that research, based on this model, can provide new clues to the processes involved, and improve the prediction of clinical outcomes. New directions in research, in recording equipment, and in organizational activities are suggested to test this new model, and to improve the usefulness of the electrocardiogram as a research and diagnostic tool.

  11. Left ventricular noncompaction: Clinical-echocardiographic study

    Nikolić Aleksandra


    Full Text Available Background/Aim. Left ventricular noncompaction (LVNC is a disorder in endomyocardial morphogenesis, seen either isolated (in the absence of other cardiac anomalies or in association with congenital heart disease and some neuromuscular diseases. Intrauterine arrest of the compaction of myocardial fibers is postulated to be the reason of LVNC. Recognition of this condition is extremely important due to its high mortality and morbidity that lead to progressive heart failure, ventricular arrhythmias and thromboembolic events. The aim of this study was to determine the prevalence and clinical presentation of LVNC among consecutive outpatients according to clinical and echocardiographyic findings. Methode. A total of 3,854 consecutive patients examined at the Institute for Cardiovascular Diseases within a period January 2006 - January 2007 were included in the study. All the patients underwent echocardiographic examination using the same equipment (Vivid 7, GE Medical System. Echocardiographic parameters and clinical presentation in patients with echocardiographic criteria for LVNC were analyzed. Results. Analyzing 3,854 consecutive outpatients, using two-dimensional Color Doppler echocardiography from January 2006 to January 2007, 12 patients met the criteria for LVNC. Seven of them were male. The mean age at diagnosis was 45 ± 15 years. Analyzing clinical manifestation of LVNC it was found that seven patients had signs of heart failure, six had arrhythmias with no embolic events. Conclusion. Our results suggest that the real prevalence of LVNC may be higher than expected. New studies have to be done to solve this problem.

  12. Myocardial performance is reduced immediately prior to ventricular ectopy

    Bloch Thomsen, Poul Erik; Hansen, Thomas Fritz; Jons, Christian;


    of impulse conduction would also lead to changes in the contractile performance of sinus beats preceding ventricular ectopy using Tissue Doppler echocardiography. Methods: Twenty-three consecutive patients with VPBs were examined in the apical 4-chamber view with a frame rate of 150 Hz (GE VIVID VII). Eleven......Background: We recently demonstrated local voltage potentials indicating conduction impairment and block in the sinus beats preceding ventricular premature beats (VPBs) originating in the ventricular outflow tracts. Objective: The purpose of this study was to test the hypothesis that impairment...... patients had no structural heart disease, 5 had dilated cardiomyopathy, 4 had ischemic heart disease, 2 had arrhythmogenic right ventricular dysplasia, and 1 had aortic stenosis. The ectopy originated in the ventricular outflow tracts in 15 patients and in the left ventricle 8. Eleven of the patients...

  13. Cardiac fibrosis as a determinant of ventricular tachyarrhythmias

    Norishige Morita, MD, PhD


    Full Text Available Animal and emerging clinical studies have demonstrated that increased ventricular fibrosis in a setting of reduced repolarization reserve promotes early afterdepolarizations (EADs and triggered activity that can initiate ventricular tachycardia and ventricular fibrillation (VT/VF. Increased ventricular fibrosis plays a key facilitatory role in allowing oxidative and metabolic stress-induced EADs to manifest as triggered activity causing VT/VF. The lack of such an arrhythmogenic effect by the same stressors in normal non-fibrotic hearts highlights the importance of fibrosis in the initiation of VT/VF. These findings suggest that antifibrotic therapy combined with therapy designed to increase ventricular repolarization reserve may act synergistically to reduce the risk of sudden cardiac death.

  14. Malignant ventricular tachycardia in acromegaly: a case report

    Zhe An

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

  15. Sex and regional differences in rabbit right ventricular L-type calcium current levels and mathematical modelling of arrhythmia vulnerability.

    Kalik, Zane M; Mike, Joshua L; Slipski, Cassandra; Wright, Moriah; Jalics, Jozsi Z; Womble, Mark D


    What is the central question of this study? Regional variations of ventricular L-type calcium current (ICa-L ) amplitude may underlie the increased arrhythmia risk in adult females. Current amplitude variations have been described for the left ventricle but not for the right ventricle. What is the main finding and its importance? Adult female rabbit right ventricular base myocytes exhibit elevated ICa-L compared with female apex or male myocytes. Oestrogen upregulated ICa-L in cultured female myocytes. Mathematical simulations modelling long QT syndrome type 2 demonstrated that elevated ICa-L prolonged action potentials and induced early after-depolarizations. Thus, ventricular arrhythmias in adult females may be associated with an oestrogen-induced upregulation of ICa-L . Previous studies have shown that adult rabbit left ventricular myocytes exhibit sex and regional differences in L-type calcium current (ICa-L ) levels that contribute to increased female susceptibility to arrhythmogenic early after-depolarizations (EADs). We used patch-clamp recordings from isolated adult male and female rabbit right ventricular myocytes to determine apex-base differences in ICa-L density and used mathematical modelling to examine the contribution of ICa-L to EAD formation. Current density measured at 0 mV in female base myocytes was 67% higher than in male base myocytes and 55% higher than in female apex myocytes. No differences were observed between male and female apex myocytes, between male apex and base myocytes, or in the voltage dependences of ICa-L activation or inactivation. The role of oestrogen was investigated using cultured adult female right ventricular base myocytes. After 2 days, 17β-estradiol (1 nm) produced a 65% increase in ICa-L density compared with untreated control myocytes, suggesting an oestrogen-induced upregulation of ICa-L . Action potential simulations using a modified Luo-Rudy cardiomyocyte model showed that increased ICa-L density, at the level

  16. Left and right ventricular diastolic function in hemodialysis patients

    Rudhani Ibrahim


    Full Text Available The aim of this prospective study was the assessment of left ventricular and right ventricular diastolic function in patients on hemodialysis (HD and the correlation of this func-tion with the duration of HD. The study included 42 patients (22 females and 20 males with chro-nic renal failure (CRF, treated with HD, and 40 healthy subjects (24 females and 16 males with no history of cardiovascular disease and with normal renal function, who constituted the control group. The groups were matched for age and sex. All study patients and control subjects under-went detailed history taking and physical examination. They also underwent electrocardiogram, echocardiography and biochemical and hematological blood analyses. Significant differences were noted between the two groups in the two-dimensional and M-mode echocardiography findings concerning aortic root dimension, transverse diameter of the left atrium, thickness of the inter-ventricular septum, thickness of the left ventricular posterior wall, left ventricular diastolic diameter, left ventricular systolic diameter, shortening fraction, ejection fraction as well as findings from the pulse Doppler study, including E wave, A wave, E/A ratio, deceleration time of E wave (DT-E, acceleration time of E wave (AT-E, tricuspid E and A waves (E tr and A tr and E tr /A tr , ratio. There were significant changes in HD patients without arterial hypertension as well in the control group subjects. Our study suggests that the left ventricular and left atrial dimensions as well as the left ventricular wall thickness are augmented in patients with CRF treated with HD compared with the control group. Additionally, the left and right ventricular diastolic function is also reduced in these patients. These differences were also noted in patients with CRF without arterial hypertension. Left ventricular diastolic dysfunction had no correlation with the duration of HD.

  17. Hemodynamic improvement by right ventricular septal pacing in elderly patients with chronic atrial fibrillation and slow ventricular response

    Wei HUA; Shidong GUO; Shu ZHANG; Fangzheng WANG; Lida ZHI; Hongxia NIU; Xin CHEN


    Background and objectives Right ventricular apical (RVA) pacing has been reported impairing left ventricular (LV)performance. Alternative pacing sites in right ventricle (RV) has been explored to obtain better cardiac function. Our study was designed to compare the hemodynamic effects of right ventricular septal (RVS) pacing with RVA pacing. Methods Ten elderly patients with chronic atrial fibrillation (AF) and long RR interval or slow ventricular response (VR) received VVI pacing. The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography (TTE). Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication. The left ventricular (LV) parameters,measured during RVA pacing including left ventricular ejection fraction (LVEF), FS, stroke volume (SV) and peak E wave velocity (EV) were decreased significantly compared to baseline data, while during RVS pacing, they were significantly better than those during RVA pacing. However, after 3-6 weeks there was no statistical significant difference between pre- and post- RVS pacing.Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data. The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing; RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.

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

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


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

  19. Atrial Remodeling Is Directly Related to End-Diastolic Left Ventricular Pressure in a Mouse Model of Ventricular Pressure Overload

    De Jong, Anne Margreet; Van Gelder, Isabelle C.; Baudoin, Inge; Cannon, Megan V.; Van Gilst, Wiek H.; Maass, Alexander H.


    Background: Atrial fibrillation (AF) is often preceded by underlying cardiac diseases causing ventricular pressure overload. Objective: It was our aim to investigate the progression of atrial remodeling in a small animal model of ventricular pressure overload and its association with induction of

  20. The Effect and Mechanism of Forsinopril on Ventricular Hypertrophy of SHR and Left Ventricular Pressure overloading Rat

    黄恺; 戴闺柱


    The effects and mechanism of long-term angiotensin converting enzyme inhibitor (ACEI)Forsinopril on left ventricular hypertrophy of spontaneous hypertension rat (SHR) and left ventricular pressure overloading rat were studied. The left ventricular index (left ventricle weight/body weight) was used to evaluate left ventricular hypertrophy and the in situ hybridization to investigate the TGF-β1 gene expression in left ventricle. The results showed that Forsinopril significantly decreased the left ventricular index of both SHR and left ventricle pressure overloading rat. Forsinopril reduced the integral photic density of TGF-β1 gene statement from 2. 836± 0. 314 to 1.91 ± 0. 217(P<0.01, n=8 ) of SHR rat and from 3. 071±0. 456 to 2. 37640. 379 (P<0.01, n=8) of left ventricular pressure overloading rat respectively. It was concluded that Forsinopril could prevent the occurrence of left ventricular hypertrophy and reduce the TGF-β1 gene expression in left ventricle of both SHR and left ventricular pressure overloading rat significantly.

  1. Relationship between right and left ventricular function in candidates for implantable cardioverter defibrillator with low left ventricular ejection fraction.

    Jimenez-Juan, Laura; Karur, Gauri R; Connelly, Kim A; Deva, Djeven; Yan, Raymond T; Wald, Rachel M; Singh, Sheldon; Leung, General; Oikonomou, Anastasia; Dorian, Paul; Angaran, Paul; Yan, Andrew T


    Indications for the primary prevention of sudden death using an implantable cardioverter defibrillator (ICD) are based predominantly on left ventricular ejection fraction (LVEF). However, right ventricular ejection fraction (RVEF) is also a known prognostic factor in a variety of structural heart diseases that predispose to sudden cardiac death. We sought to investigate the relationship between right and left ventricular parameters (function and volume) measured by cardiovascular magnetic resonance (CMR) among a broad spectrum of patients considered for an ICD. In this retrospective, single tertiary-care center study, consecutive patients considered for ICD implantation who were referred for LVEF assessment by CMR were included. Right and left ventricular function and volumes were measured. In total, 102 patients (age 62±14 years; 23% women) had a mean LVEF of 28±11% and RVEF of 44±12%. The left ventricular and right ventricular end diastolic volume index was 140±42 mL/m(2) and 81±27 mL/m(2), respectively. Eighty-six (84%) patients had a LVEF right ventricular systolic dysfunction. Although there was a significant and moderate correlation between LVEF and RVEF (r=0.40, pright ventricular systolic dysfunction (Kappa=0.041). Among patients being considered for an ICD, there is a positive but moderate correlation between LVEF and RVEF. A considerable proportion of patients who qualify for an ICD based on low LVEF have preserved RVEF, and vice versa.

  2. Nipro extra-corporeal left ventricular assist device fitting after left ventricular reconstruction with mitral valve plasty.

    Arakawa, Mamoru; Yamaguchi, Atsushi; Nishimura, Takashi; Itoh, Satoshi; Yuri, Koichi; Kyo, Shunei; Adachi, Hideo


    Both left ventricular assist device and left ventricular reconstruction are treatment choices for severe heart failure conditions. Our institution performed a left ventricular assist device installation following a left ventricular reconstruction procedure on a 42-year-old male patient who presented with dilated cardiomyopathy and low cardiac output syndrome. A mitral valve plasty was used to correct the acute mitral valve regurgitation and we performed a Nipro extra-corporeal left ventricular assist device installation on post-operative day 14. Due to the left ventricular reconstruction that the patient had in a previous operation, we needed to attach an apical cuff on posterior apex, insert the inflow cannula with a large curve, and shift the skin insertion site laterally to the left. We assessed the angle between the cardiac longitudinal axis and the inflow cannula using computed tomography. The patient did not complain of any subjective symptoms of heart failure. Although Nipro extra-corporeal left ventricular assist device installation after left ventricular reconstruction has several difficulties historically, we have experienced a successful case.

  3. Effects of droperidol on depolarization-induced automaticity, maximum upstroke velocity (Vmax) and the kinetics of recovery of Vmax in guinea-pig ventricular myocardium.

    Grant, A O; Hondeghem, L M; Katzung, B G


    The neuroleptic drug droperidol has been shown to have clinically useful antiarrhythmic activity. Prior reports have resulted in conflicting conclusions regarding actions on ventricular myocardial fibers. The present study was carried out to determine whether droperidol did in fact affect the electrophysiological properties of guinea-pig papillary muscle fibers. By means of microelectrode recordings from preparations mounted in a single sucrose gap, the effects of concentrations from 10(-6) to 4 X 10(-5) M were studied on depolarization-induced automaticity, and on Vmax and its recovery time under several conditions of membrane potential, stimulation rate and external ion concentration. The results showed that at clinically relevant concentrations, droperidol significantly slows ventricular pacemaker activity, a depression reversible by epinephrine. Furthermore, Vmax was decreased and the time constant for Vmax recovery was significantly prolonged under several conditions which pertain to clinical arrhythmias, i.e., reduced membrane potential, elevated extracellular potassium concentrations and increased stimulation rate.

  4. [Left ventricular function in hypertension without left ventricular hypertrophy: echographic study with modelisation of left ventricular-aortic coupling].

    Bonnet, B; Jourdan, F; du Cailar, G; Mimran, A; Fesler, P


    Because the functional interaction between the LV and arterial systems, termed ventricular-arterial coupling, is recognized as a key determinant of LV performance, the objective of the present study was to assess the impact of uncomplicated HT without LVH on LV performance using simultaneously echocardiography and carotid tonometry. LV maximal power (PmaxVG), cardiac power output (CPO), LV efficiency (CPO/PmaxVG), input aortic and output LV elastance (Ea and Ees) were assessed in 20 normotensive control subjects (NT) and 10 patients with untreated HT. PmaxVG was calculated according to the integral of the product of LV wall stress with strain rate (as an index of gradient velocity). Cyclic variation of wall thickness and SR were measured by speckel-tracking. Ea and Ees were derived and modelized from the pressure-volume curve. No difference in age, BMI and sex ratio was observed between NT and HT. Systolic BP (160±18 vs. 119±10mmHg), LV mass (99±15 vs. 76±12g/m(2)), PWV (9.7±2 vs. 6.9±1m/s) were significantly higher (P<0.01) in HT when compared to NT. In HT increased of CPO and Ea was compensated by an increase of LV (15±4 vs. 12±3%, P<0.02) and Ees (5.5±2 vs. 4.5±1.5mmHg/mL), which are significantly elevated in HT (P<0.05). No difference was observed in Ea/Ees between NT and HT. In conclusion at the early phase of HT, in patients without LVH, LV performance and ventricular-arterial coupling were adapted to post-load elevation. This adaptation may be the result of an increased of LV contractility.

  5. FSI simulation of intra-ventricular flow in patient-specific ventricular model with both mitral and aortic valves.

    Zhong, Liang; Su, Boyang; Zhang, Jun-Mei; Leo, Hwa Liang; Tan, Ru San


    Investigating the intra-ventricular flow is the most important to understand the left ventricular function. In this study, we proposed a fluid-structure interaction (FSI) approach to simulate the blood flow in patient-specific model by combining both mitral and aortic valves. To accommodate the large mesh deformation, moving arbitrary Lagrangian-Eulerian (ALE) meshes were used for moving ventricular wall and rotating leaflets of valves. The left ventricular wall was predescribed according to the points acquired from magnetic resonance image (MRI). Mitral and aortic valves were integrated into the model by assuming each leaflet as a rigid body. Fluid-structure interaction (FSI) approach was adopted to capture the rapid motion of leaflets. The simulation results were qualitatively similar to the measurements reported in literatures. To the best of our knowledge, this is the first to simulate the patient-specific ventricular flow with the presence of both mitral and aortic valves.

  6. Fast rate (≥ 250 beats/min) right ventricular burst stimulation is useful for ventricular tachycardia induction in arrhythmogenic right ventricular cardiomyopathy

    Ling-Min WU; Jing-Ru BAO; Yan YAO; Bing-Bo HOU; Li-Hui ZHENG; Shu ZHANG


    Background One of the major challenges in arrhythmogenic right ventricular cardiomyopathy (ARVC) ablation is ventricular tachy-cardia (VT) non-inducibility. The study aimed to assess whether fast rate (≥ 250 beats/min) right ventricular burst stimulation was useful for VT induction in patients with ARVC.Methods Ninety-one consecutive ARVC patients with clinical sustained VT that underwent electro-physiological study were enrolled. The stimulation protocol was implemented at both right ventricular apex and outflow tract as follows: Step A, up to double extra-stimuli; Step B, incremental stimulation with low rate (< 250 beats/min); Step C, burst stimulation with fast rate (≥ 250 beats/min); Step D, repeated all steps above with intravenous infusion of isoproterenol.Results A total of 76 patients had inducible VT (83.5%), among which 49 were induced by Step C, 15 were induced by Step B, 8 and 4 by Step A and D, respectively. Clinical VTs were induced in 60 patients (65.9%). Only two spontaneously ceased ventricular fibrillations were induced by Step C. Multivariate analysis showed that a narrower baseline QRS duration under sinus rhythm was independently associated with VT non-inducibility (OR: 1.1; 95% CI: 1.0–1.1;P = 0.019).ConclusionFast rate (≥ 250 beats/min) right ventricular burst stimulation provides a useful supplemental method for VT induction in ARVC patients.

  7. Arrhythmia in Acute Right Ventricular Infarction

    Azin Alizadeh Asl


    Full Text Available Acute inferior myocardial infarction (MI frequently involves the right ventricle (RV.1-3 We assessed the prognostic impact of RV myocardial involvement in patients with inferior MI. One hundred seventy patients were admitted to the cardiac care unit of Madani Heart Hospital (Tabriz-Iran with the diagnosis of inferior MI with (group1 or without (group2 the simultaneous involvement of RV during the study period (from 2005 to 2006. Patients presenting within 12h of symptom onset were eligible for inclusion. Patients with simultaneous anterior wall MI or renal impairment (creatinine > 2 mg/dl, as well as those undergoing primary percutaneous translational coronary angioplasty, were excluded. Eighty eight percent of the patients with RVMI and 75% of those with isolated inferior MI had some type of arrhythmia. Atrioventricular (AV block occurred in 42% of the infarctions with RV involvement and only in 29% of the control group. Intra-ventricular conduction disturbance (IVCD was also more frequent in RVMI (29.4% vs. 13.1%, p=0.021, especially right bundle branch block (RBBB (20% vs. 7.4%, P=0.003. There was, however, no meaningful difference in the incidence of left bundle branch block (LBBB between the two groups (3.5% vs. 2.35%, P=0.95. Ventricular fibrillation (VF was observed in 5.2% and 1.2% and ventricular tachycardia in 26% and 12.2% of the patients in groups 1 and 2, respectively. In 27% of patients with RVMI, it was necessary to implant a pacemaker as compared to 10% of those in the control group. Mortality was higher in the patients with inferior infarction extended to the RV (15.3% vs. 3.5%, P= 0.0001. Thus, the differences between the findings in the two groups in terms of the occurrence of post-MI arrhythmias and conduction disorders were quite significant, but there was no meaningful difference with respect to the incidence of LBBB between the two groups. Additionally, patients with inferior MI who also had RV myocardial involvement were

  8. Echocardiographic evaluation of ventricular septal defect haemodynamics

    Miranović Vesna


    Full Text Available Introduction Ventricular septal defect (VSD is an opening in the interventricular septum. 30-50% of patients with congenital heart disease have VSD. Objective The aim of the study was to determine the dependence of the left ventricular diastolic dimension (LVD, left ventricular systolic dimension (LVS, shortening fraction (SF, left atrium (LA, pulmonary artery truncus (TPA on the body surface and compare their values among experimental, control and a group of healthy children. Values of maximal systolic gradient pressure (Pvsd of VSD were compared with children from one experimental and control group. Method Children were divided into three groups: experimental (32 children with VSD that were to go to surgery, control (20 children with VSD who did not require surgery and 40 healthy children. Measurements of LVD, LVS, SF, LA, TPA were performed in accordance to recommendations of the American Echocardiographic Association. The value of Pvsd was calculated from the maximal flow velocity (V in VSD using the following formula: Pvsd=4xVІ (mm Hg. Results For children from the experimental group, the relationship between the body surface and the variability of the LVD was explained with 56.85%, LVS with 66.15%, SF with 4.9%, TPA with 58.92%. For children from the control group, the relationship between the body surface and the variability of LVD was explained with 88.8%, LVS with 72.5%, SF with 0.42%, PA with 58.92%. For healthy children, the relationship between the body surface and the variabilitiy of the LVD was explained with 88.8%, LVS with 88.78%, SF with 5.25% and PA with 84.75%. There was a significant statistical difference between average values of Pvsd in the experimental and control group (p<0.02. Conclusion The presence of the large VSD has an influence on the enlargement of LVD, LVS, SF, TPA. The enlargement of the size of the pulmonary artery depends on the presence of VSD and there is a direct variation in the magnitude of the shunt

  9. Treating critical supraventricular and ventricular arrhythmias

    Trappe Hans-Joachim


    Full Text Available Atrial fibrillation (AF, atrial flutter, AV-nodal reentry tachycardia with rapid ventricular response, atrial ectopic tachycardia and preexcitation syndromes combined with AF or ventricular tachyarrhythmias (VTA are typical arrhythmias in intensive care patients (pts. Most frequently, the diagnosis of the underlying arrhythmia is possible from the physical examination (PE, the response to maneuvers or drugs and the 12-lead surface electrocardiogram. In unstable hemodynamics, immediate DC-cardioversion is indicated. Conversion of AF to sinus rhythm (SR is possible using antiarrhythmic drugs. Amiodarone has a conversion rate in AF of up to 80%. Ibutilide represents a class III antiarrhythmic agent that has been reported to have conversion rates of 50-70%. Acute therapy of atrial flutter (Aflut in intensive care pts depends on the clinical presentation. Atrial flutter can most often be successfully cardioverted to SR with DC-energies < 50 joules. Ibutilide trials showed efficacy rates of 38-76% for conversion of Aflut to SR compared to conversion rates of 5-13% when intravenous flecainide, propafenone or verapamil was administered. In addition, high dose (2 mg of ibutilide was more effective than sotalol (1.5 mg/kg in conversion of Aflut to SR (70 versus 19%. Drugs like procainamide, sotalol, amiodarone or magnesium were recommended for treatment of VTA in intensive care pts. However, only amiodarone is today the drug of choice in VTA pts and also highly effective even in pts with defibrillation-resistant out-of-hospital cardiac arrest (CA. There is a general agreement that bystander first aid, defibrillation and advanced life support is essential for neurologic outcome in pts after cardiac arrest due to VTA. Public access defibrillation in the hands of trained laypersons seems to be an ideal approach in the treatment of ventricular fibrillation (VF. The use of automatic external defibrillators (AEDs by basic life support ambulance providers or

  10. Nucleic acid therapy for lifespan prolongation: Present and future

    Wing-Fu Lai


    Lifespan prolongation is a common desire of the human race. With advances in biotechnology, the mechanism of aging has been gradually unraveled, laying the theoretical basis of nucleic acid therapy for lifespan prolongation. Regretfully, clinically applicable interventions do not exist without the efforts of converting theory into action, and it is the latter that has been far from adequately addressed at the moment. This was demonstrated by a database search on PubMed and Web of Science, from which only seven studies published between 2000 and 2010 were found to directly touch on the development of nucleic acid therapy for anti-aging and/or longevity enhancing purposes. In light of this, the objective of this article is to overview the current understanding of the intimate association between genes and longevity, and to bring the prospect of nucleic acid therapy for lifespan prolongation to light.

  11. Severe postpartum sepsis with prolonged myocardial dysfunction: a case report

    Chen Katherine T


    Full Text Available Abstract Introduction Severe sepsis during pregnancy or in the postpartum period is a rare clinical event. In non obstetric surviving patients, the cardiovascular changes seen in sepsis and septic shock are fully reversible five to ten days after their onset. We report a case of septic myocardial dysfunction lasting longer than ten days. To the best of our knowledge, this is the first report of prolonged septic myocardial dysfunction in a parturient. Case presentation A 24 year old Hispanic woman with no previous medical history developed pyelonephritis and severe sepsis with prolonged myocardial dysfunction after a normal spontaneous vaginal delivery. Conclusions Septic myocardial dysfunction may be prolonged in parturients requiring longer term follow up and pharmacologic treatment.

  12. QT prolongation in a child with thyroid storm

    Albert, Benjamin B; Eckersley, Luke Gerard; Skinner, Jonathan Robert; Jefferies, Craig


    Summary A 12-year-old girl presented with an acute confusional state and a 2-year history of weight loss, anxiety, agitation and recurrent fever. Thyroid function tests confirmed severe hyperthyroidism, and a diagnosis of thyroid storm was made (Burch and Wartofsky score=75). ECG showed a prolonged QTc interval of 506 ms. Acute treatment for thyroid storm consisted of Lugol's iodine, prednisolone, carbimazole and propranolol. She made a steady recovery and by 3 months her thyroid function had normalised; a repeat ECG showed a QTc within the normal range (430 ms). There was no relevant family history. This is a case of QTc prolongation with hyperthyroidism and normalisation with euthyroidism. It is not commonly recognised that hyperthyroidism in children may be associated with QTc prolongation. QTc measurement should be incorporated into management protocols for hyperthyroidism. PMID:24729112

  13. The effect of prolonged physical activity performed during extreme caloric deprivation on cardiac function.

    David Planer

    Full Text Available BACKGROUND: Endurance exercise may induce transient cardiac dysfunction. Data regarding the effect of caloric restriction on cardiac function is limited. We studied the effect of physical activity performed during extreme caloric deprivation on cardiac function. METHODS: Thirty-nine healthy male soldiers (mean age 20 ± 0.3 years were studied during a field training exercise lasted 85-103 hours, with negligible food intake and unlimited water supply. Anthropometric measurements, echocardiographic examinations and blood and urine tests were performed before and after the training exercise. RESULTS: Baseline VO(2 max was 59 ± 5.5 ml/kg/min. Participants' mean weight reduction was 5.7 ± 0.9 kg. There was an increase in plasma urea (11.6 ± 2.6 to 15.8 ± 3.8 mmol/L, p<0.001 and urine osmolarity (692 ± 212 to 1094 ± 140 mmol/kg, p<0.001 and a decrease in sodium levels (140.5 ± 1.0 to 136.6 ± 2.1 mmol/L, p<0.001 at the end of the study. Significant alterations in diastolic parameters included a decrease in mitral E wave (93.6 to 83.5 cm/s; p = 0.003, without change in E/A and E/E' ratios, and an increase in iso-volumic relaxation time (73.9 to 82.9 ms, p = 0.006. There was no change in left or right ventricular systolic function, or pulmonary arterial pressure. Brain natriuretic peptide (BNP levels were significantly reduced post-training (median 9 to 0 pg/ml, p<0.001. There was no elevation in Troponin T or CRP levels. On multivariate analysis, BNP reduction correlated with sodium levels and weight reduction (R = 0.8, p<0.001. CONCLUSIONS: Exposure to prolonged physical activity performed under caloric deprivation resulted in minor alterations of left ventricular diastolic function. BNP levels were significantly reduced due to negative water and sodium balance.

  14. Left Ventricular Hypertrophy Evaluation in Obese Hypertensive Patients: Effect of Left Ventricular Mass Index Criteria

    Eduardo Cantoni Rosa


    Full Text Available PURPOSE: To evaluate left ventricular mass (LVM index in hypertensive and normotensive obese individuals. METHODS: Using M mode echocardiography, 544 essential hypertensive and 106 normotensive patients were evaluated, and LVM was indexed for body surface area (LVM/BSA and for height² (LVM/h². The 2 indexes were then compared in both populations, in subgroups stratified according to body mass index (BMI: or = 30kg/m². RESULTS: The BSA index does not allow identification of significant differences between BMI subgroups. Indexing by height² provides significantly increased values for high BMI subgroups in normotensive and hypertensive populations. CONCLUSION: Left ventricular hypertrophy (LVH has been underestimated in the obese with the use of LVM/BSA because this index considers obesity as a physiological variable. Indexing by height² allows differences between BMI subgroups to become apparent and seems to be more appropriate for detecting LVH in obese populations.

  15. Use of Catheter Ablation in the Treatment of Ventricular Tachycardia Triggered by Premature Ventricular Contraction

    Isao Kato, MD


    Full Text Available A 50-year-old man who had suffered from old myocardial infarction presented with an episode of syncope. DC shock was required for the interruption of frequent pleomorphic ventricular tachycardia (VT. Although the treatment for heart failure decreased the frequency of VT attacks, hemodynamically unstable VT occurred several times. A 12-lead Holter electrocardiogram was used to determine the triggering premature ventricular contraction (PVC and catheter ablation was performed by targeting this PVC. The site of origin of the triggering PVC was considered to be located between damaged cardiac muscle and intact Purkinje's fiber. No episode of PVC and VT was observed after a few days of ablation. An implantable cardioverter defibrillator was implanted but VT did not recur for more than 20 months.

  16. P wave dispersion is prolonged in patients with Wilson's disease


    AIM: To investigate the P wave dispersion as a noninvasive marker of intra-atrial conduction disturbances in patients with Wilson's disease. METHODS: We compared Wilson's disease patients (n=18) with age matched healthy subjects (n=15) as controls. The diagnosis was based on clinical symptoms, laboratory tests (ceruloplasmin, urinary and hepatic copper concentrations). P wave dispersion, a measurement of the heterogeneity of atrial depolarization, was measured as the difference between the duration of the longest and the shortest P-waves in 12 lead electrocardiography. RESULTS: All the patients were asymptomatic on cardiological examination and have sinusal rhythm in electrocardiography. Left ventricular and left atrial diameters, left ventricular ejection fraction and left ventricular mass index were similar in both groups. The Wilson's disease patients had a significantly higher P wave dispersion compared with the controls (44.7+5.8vs 25.7±2.5,P<0.01=. CONCLUSION: There was an increase in P wave dispersion in cardiologically asymptomatic Wilson's disease patients which probably represents an early stage of cardiac involvement.

  17. Pretreatment of BAPTA-AM suppresses the genesis of repetitive endocardial focal discharges and pacing-induced ventricular arrhythmia during global ischemia.

    Wu, Tsu-Juey; Lin, Shien-Fong; Hsieh, Yu-Cheng; Lin, Tung-Chao; Lin, Jiunn-Cherng; Ting, Chih-Tai


    In isolated rabbit hearts, repetitive endocardial focal discharges (REFDs) were consistently observed during ventricular fibrillation (VF) with prolonged (>5 minutes) global ischemia (GI). We hypothesized that BAPTA-AM, a calcium chelator, can suppress these REFDs. Using a two-camera optical mapping system, we simultaneously mapped endocardial (left ventricle, LV) and epicardial (both ventricles) activations during ventricular arrhythmia with GI. In 5 hearts (protocol I), we infused Tyrode's solution (no BAPTA-AM) for ≥30 minutes before the onset of no-flow GI. In 7 additional hearts (protocol II), BAPTA-AM (20 μmol/L) was infused for ≥30 minutes before the initiation of GI. In protocol I, sustained VF (>30 seconds) was successfully induced in all 5 hearts with prolonged GI. REFDs were present in >85 % of recording time. In protocol II, however, ventricular arrhythmia was not inducible and REFDs were not observed after 5-minute GI in 5 hearts. Effects of BAPTA-AM on intracellular calcium (Ca(i) ) at the LV endocardium were also evaluated in 5 hearts (protocol III) using dual Ca(i) /membrane potential mapping. GI, both without and with BAPTA-AM pretreatment, caused a decrease of Ca(i) amplitude during S(1) pacing. However, this effect was more pronounced in the hearts with BAPTA-AM pretreatment (P AM pretreatment, caused broadening of Ca(i) transient. In contrast, GI, with BAPTA-AM pretreatment, caused narrowing of Ca(i) transient. BAPTA-AM pretreatment attenuates Ca(i) transient, suppressing the genesis of REFDs and pacing-induced ventricular arrhythmia during GI. These findings support the notion that Ca(i) dynamics is important in the maintenance of REFDs.  © 2011 Wiley Periodicals, Inc.

  18. Large Right Ventricular Clot in Pulmonary Atresia With Intact Ventricular Septum: In Defense of Biventricular Approach.

    Dutta, Nilanjan; Ghosh, Rajarshi; Awasthy, Neeraj; Iyer, Parvathi U; Girotra, Sumir; Iyer, Krishna S


    Thrombus formation within the right ventricle (RV) in the setting of pulmonary atresia with intact ventricular septum (PAIVS) is not a very common occurrence and can be catastrophic. We present the case of a seven-month-old child with PAIVS and RV clot who successfully underwent biventricular repair. We discuss the interesting case and the rationale for management by means of biventricular repair over single ventricle repair when feasible in such a setting.

  19. Bartonella henselae Infective Endocarditis Detected by a Prolonged Blood Culture

    Mito, Tsutomu; Hirota, Yusuke; Suzuki, Shingo; Noda, Kazutaka; Uehara, Takanori; Ohira, Yoshiyuki; Ikusaka, Masatomi


    A 65-year-old Japanese man was admitted with a 4-month history of fatigue and exertional dyspnea. Transthoracic echocardiography revealed a vegetation on the aortic valve and severe aortic regurgitation. Accordingly, infective endocarditis and heart failure were diagnosed. Although a blood culture was negative on day 7 after admission, a prolonged blood culture with subculture was performed according to the patient's history of contact with cats. Consequently, Bartonella henselae was isolated. Bartonella species are fastidious bacteria that cause blood culture-negative infective endocarditis. This case demonstrates that B. henselae may be detected by prolonged incubation of blood cultures. PMID:27746451

  20. Sponsored parachute jumps--can they cause prolonged pain?

    Straiton, N; Sterland, J


    A survey of parachute injuries sustained in 1984 at a local parachute club was made using hospital notes and a questionnaire. The overall injury rate was 0.2%. The injury rate in first time jumpers was 1.1%. The injuries often resulted in a prolonged hospital stay, time off work and residual pain and disability. Injury rates may be reduced by more prolonged and intensive training preceding the first jumps. Those people not interested in parachuting as a regular sport and who jump once only in...