Facilitation of ventricular tachycardia induction with abrupt changes in ventricular cycle length

Denker, Stephen; Lehmann, Michael H.; Mahmud, Rehan; Gilbert, Carol J.; Akhtar, Masood

doi:10.1016/0002-9149(84)90022-5

Cited by 118 publications

(39 citation statements)

References 19 publications

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“…In addition, the irregular rhythm of AF leads to short-long-short sequences that could be intrinsically proarrhythmic. 35 AF also results in the reduction of cardiac output through the loss of atrial mechanical function and decreased diastolic filling time, which might increase preload and, via mechanoelectric coupling, increase susceptibility to VT. 36 The hemodynamic effects of atrial tachyarrhythmias may also cause a reflex increase in sympathetic tone and a 37 From a viewpoint of clinical implications, in HCM patients undergoing surgery for symptom relief, every effort should be made to relieve LVOT obstruction, with the understanding that, in some patients, it might be necessary to perform concomitant mitral valve surgeries to achieve optimal results. In the current study, the frequency of concomitant mitral valve procedures was significantly higher than in previous reports.…”

Section: Discussionmentioning

confidence: 99%

Predictors of Long-Term Outcomes in Symptomatic Hypertrophic Obstructive Cardiomyopathy Patients Undergoing Surgical Relief of Left Ventricular Outflow Tract Obstruction

et al. 2013

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The study population is part of an ongoing institutional review boardapproved registry of HCM patients at a single tertiary care center (Cleveland Clinic, Ohio), with the initial visit between January 1997Background-We report the predictors of long-term outcomes of symptomatic hypertrophic cardiomyopathy patients undergoing surgical relief of left ventricular outflow tract obstruction. Methods and Results-We studied 699 consecutive patients who have hypertrophic cardiomyopathy with severe symptomatic left ventricular outflow tract obstruction (47±11 years, 63% male) intractable to maximal medical therapy, who were referred to a tertiary hospital between January 1997 and December 2007 for the surgical relief of left ventricular outflow tract obstruction. We excluded patients <18 years of age, those with an ejection fraction <50%, those with hypertensive heart disease of the elderly, and those with more than mild aortic or mitral stenosis. Clinical, echocardiographic, and Holter data were recorded. A composite end point of death, appropriate internal cardioverter defibrillator discharges, resuscitated from sudden death, documented stroke, and admission for congestive heart failure was recorded. During a mean follow-up of 6.2±3 years, 86 patients (12%) met the composite end point with 30-day, 1-year, and 2-year event rates of 0.7%, 2.8%, and 4.7%, respectively. The hard event rate (death, defibrillator discharge, and resuscitated from sudden death) at 30 days, 1 year, and 2 years was 0%, 1.5%, and 3%, respectively. Stepwise multivariable analysis identified residual postoperative atrial fibrillation (hazard ratio, 2.12; confidence interval, 1. The degree of left ventricular (LV) hypertrophy in the study population was deemed significantly out of proportion to the duration and degree of hypertension; this decided after a thorough clinical evaluation by experienced physicians. We excluded the following patients:(1) patients <18 years and >65 years of age, (2) those with hypertensive heart disease of the elderly and concomitant LVOT obstruction, 13-16 (3) those with an ejection fraction <50%, and (4) those with the presence of more than mild aortic or mitral stenosis on the initial echocardiogram. Patients with hypertensive heart disease and concomitant LVOT obstruction were defined as those >65 years of age with a long-standing history of hypertension and characteristic sigmoid-shaped basal septal hypertrophy identified on echocardiography. These patients were excluded because they have a different pathophysiological and genetic profile from the typical HCM patients.13-16 Additionally, we eliminated the potentially confounding effects of end-stage disease (manifesting as depressed LV function) on outcomes by excluding such patients. Clinical DataDemographic, clinical (including standard and HCM-related risk factors, detailed family history, and examination), medication use (including antiarrhythmics and anticoagulation), and electrocardiographic data obtained at the time of the initial and follow-up visits were recor...

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Section: Discussionmentioning

confidence: 99%

Predictors of Long-Term Outcomes in Symptomatic Hypertrophic Obstructive Cardiomyopathy Patients Undergoing Surgical Relief of Left Ventricular Outflow Tract Obstruction

et al. 2013

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“…Earlier studies have shown that a sudden pause and a short-long-short sequence cause dispersion of the ventricular refractory period, which is regarded as a prerequisite for ventricular arrhythmia. [11][12][13][14][15] If the pacemaker feature is switched on, an effective ventricular stimulus after the pause will lead to an ectopic ventricular excitation. This may intensify the ventricular electrical instability to such an extent that an arrhythmia ensues.…”

Section: Discussionmentioning

confidence: 99%

Proarrhythmic Effect of Pacemaker Stimulation in Patients With Implanted Cardioverter-Defibrillators

et al. 2003

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Background-We sought to determine the potential of right ventricular VVI backup pacing to induce ventricular tachyarrhythmias in patients with implanted cardioverter-defibrillators. Methods and Results-All consecutive patients presenting exclusively with pacemaker-induced tachycardias (PITs) were included in a prospective study using a crossover protocol. Patients were randomized to either group 1 (augmentation of the baseline frequency of the pacemaker to 60 bpm) or group 2 (pacemaker turned off) and were followed up for 1 year and then crossed over to the other programming, looking for reoccurrence of PIT. Of 150 consecutive patients, 39 (26%) had PIT, 13 of them exclusively (8.6%). Forty of 1063 analyzed tachyarrhythmias of all the patients were PIT (3%). Before inclusion in the study, the patients had 2.7Ϯ0.9 PITs in 11Ϯ6.5 months with their pacemakers programmed empirically at 42.3 bpm. During the study phase, no PIT occurred while the pacemaker was turned off, whereas programming to 60 bpm led to the recurrence of PIT in 5 of 6 patients (1.4Ϯ0.6 per patient). At the end of the study, 9 patients underwent a prolonged follow-up with their pacemakers turned off, resulting in spontaneous episodes of ventricular tachycardia/fibrillation in 5 patients, but PITs were no longer observed. Conclusions-This crossover protocol proves the potential proarrhythmic effect of pacemaker stimulation in implantable cardioverter-defibrillator patients. Resulting PITs led to clinical symptoms and antitachycardia therapy by the implantable cardioverter-defibrillator. Thus, in patients presenting with PIT but without a pacemaker indication, the pacemaker feature should be turned off, or, alternatively, the longest possible escape interval should be programmed.

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“…6,7 In addition, the continuous exposure to short-long-short R-R intervals, present in AF, may be proarrhythmic and trigger VF, even in nondiseased hearts. 8 Second, AF may act as partner in crime with concomitant cardiac pathology that triggers VF. For example, rapid heart rates caused by AF may reduce coronary perfusion in patients with coronary artery disease and trigger acute myocardial infarction (AMI).…”

Section: Clinical Perspective On P 1039mentioning

confidence: 99%

Atrial Fibrillation Is an Independent Risk Factor for Ventricular Fibrillation

Bardai

Blom

Hoeijen

et al. 2014

Circ: Arrhythmia and Electrophysiology

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Background— Atrial fibrillation (AF) is associated with sudden cardiac death. We aimed to study whether AF is associated with ventricular fibrillation (VF), the most common cause of sudden cardiac death and whether this association is independent of confounders, ie, concomitant disease, use of antiarrhythmic or QT-prolonging drugs, and acute myocardial infarction. Methods and Results— We performed a community-based case-control study. Cases were patients with out-of-hospital cardiac arrest because of ECG-documented VF. Controls were age-/sex-matched non-VF subjects from the community. VF risk in AF patients was studied by means of (conditional) logistic regression, adjusting for all available confounders. We studied 1397 VF cases and 3474 controls. AF occurred in 215 cases (15.4%) and 90 controls (2.6%). AF was associated with a 3-fold increased risk of VF (adjusted odds ratio, 3.1 [2.1–4.5]). VF risk in AF cases was increased to the same extent across all age/sex groups and in AF cases who had no comorbidity (adjusted odds ratio 3.0 [1.6–5.5]) or used no confounding drugs (antiarrhythmics, 2.4 [1.4–4.3]; QT-prolonging drugs, 3.1 [1.8–5.4]). VF risk was similarly increased in AF cases with acute myocardial infarction–related VF (adjusted odds ratio 2.6 [1.4–4.8]), and those with non-acute myocardial infarction–related VF (adjusted odds ratio 4.3 [1.9–10.1]). Conclusions— AF is independently associated with a 3-fold increased risk of VF. Comorbidity, use of antiarrhythmic or QT-prolonging drugs, or acute myocardial infarction does not fully account for this increased risk.

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Facilitation of ventricular tachycardia induction with abrupt changes in ventricular cycle length

Cited by 118 publications

References 19 publications

Predictors of Long-Term Outcomes in Symptomatic Hypertrophic Obstructive Cardiomyopathy Patients Undergoing Surgical Relief of Left Ventricular Outflow Tract Obstruction

Predictors of Long-Term Outcomes in Symptomatic Hypertrophic Obstructive Cardiomyopathy Patients Undergoing Surgical Relief of Left Ventricular Outflow Tract Obstruction

Proarrhythmic Effect of Pacemaker Stimulation in Patients With Implanted Cardioverter-Defibrillators

Atrial Fibrillation Is an Independent Risk Factor for Ventricular Fibrillation

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