scholarly journals A Clinical Review of Ventricular Arrhythmias in Patients with Congestive Heart Failure

Author(s):  
Noel Boyle

Heart failure is an increasingly prevalent condition, which is associated with ventricular arrhythmias. The reduction in cardiac pumping efficiency leads to the activation of several compensatory mechanisms. These mechanisms eventually lead to cardiac remodelling and a decline in haemodynamic status, contributing to the formation of a substrate conducive to arrhythmias, including increased automaticity, triggered activity, and, most commonly, re-entry circuits. In turn, ventricular arrhythmias can lead to the worsening of heart failure. A diagnosis of heart failure and ventricular arrhythmias is obtained using the patient’s history, examination findings, and investigation results. A key tool in this is echocardiogram imaging, which visualises the cardiac chambers, determines ventricular ejection fraction, and identifies structural abnormalities. A reduction in ejection fraction is a significant risk factor for the development of ventricular arrhythmias. Arrhythmias are diagnosed by ECG, Holter monitoring, and telemetry or event monitoring, and should initially be treated by optimising the medical management of heart failure. Anti-arrhythmic drugs, including beta-blockers, are usually the first-line therapy. Sudden cardiac death is a significant cause of mortality in heart failure patients, and implantable cardioverter defibrillator devices are used in both primary and secondary prevention. Anti-arrhythmic drugs and catheter ablation are important adjunctives for minimising shock therapy. In addition, autonomic modulation may offer a novel method of controlling ventricular arrhythmias. The objective of this review is to provide a practical overview of this rapidly developing field in relation to current evidence regarding the underlying pathophysiology, burden of disease, and management strategies available.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Natasha Cuk ◽  
Jae H Cho ◽  
Donghee Han ◽  
Joseph E Ebinger ◽  
Eugenio Cingolani

Introduction: Sudden death due to ventricular arrhythmias (VA) is one of the main causes of mortality in patients with heart failure and preserved ejection fraction (HFpEF). Ventricular fibrosis in HFpEF has been suspected as a substrate of VA, but the degree of fibrosis has not been well characterized. Hypothesis: HFpEF patients with increased degree of fibrosis will manifest more VA. Methods: Cedars-Sinai medical records were probed using Deep 6 artificial intelligence data extraction software to identify patients with HFpEF who underwent cardiac magnetic resonance imaging (MRI). MRI of identified patients were reviewed to measure extra-cellular volume (ECV) and degree of fibrosis. Ambulatory ECG monitoring (Ziopatch) of those patients were also reviewed to study the prevalence of arrhythmias. Results: A total of 12 HFpEF patients who underwent cardiac MRI were identified. Patients were elderly (mean age 70.3 ± 7.1), predominantly female (83%), and overweight (mean BMI 32 ± 9). Comorbidities included hypertension (83%), dyslipidemia (75%), and coronary artery disease (67%). Mean left ventricular ejection fraction by echocardiogram was 63 ± 8.7%. QTc as measured on ECG was not significantly prolonged (432 ± 15 ms). ECV was normal in those patients for whom it was available (24.2 ± 3.1, n = 9) with 3/12 patients (25%) demonstrating ventricular fibrosis by MRI (average burden of 9.6 ± 5.9%). Ziopatch was obtained in 8/12 patients (including all 3 patients with fibrosis) and non-sustained ventricular tachycardia (NSVT) was identified in 5/8 (62.5%). One patient with NSVT and without fibrosis on MRI also had a sustained VA recorded. In those patients who had Ziopatch monitoring, there was no association between presence of fibrosis and NSVT (X2 = 0.035, p = 0.85). Conclusions: Ventricular fibrosis was present in 25% of HFpEF patients in this study and NSVT was observed in 62.5% of those patients with HFpEF who had Ziopatch monitoring. The presence of fibrosis by Cardiac MRI was not associated with NSVT in this study; however, the size of the cohort precludes broadly generalizable conclusions about this association. Further investigation is required to better understand the relationship between ventricular fibrosis by MRI and VA in patients with HFpEF.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Daniel N Silverman ◽  
Jeanne d de Lavallaz ◽  
Timothy B Plante ◽  
Margaret M Infeld ◽  
Markus Meyer

Introduction: Recent investigation has identified that discontinuation of beta-blockers in subjects with normal left ventricular ejection fraction (LVEF) leads to a reduction in natriuretic peptide levels. We investigated whether a similar trend would be seen in a hypertension clinical trial cohort. Methods: In 9,012 subjects hypertensive subjects without a history of symptomatic heart failure, known LVEF <35% or recent heart failure hospitalization enrolled in the Systolic Blood Pressure Intervention Trial (SPRINT), we compared incidence of loop diuretic initiation and time to initiation following start of a new anti-hypertensive medication. The categorical relationship (new antihypertensive class followed by loop-diuretic use) and temporal relationship (time to loop diuretic initiation) were each analyzed. The categorical relationship was assessed using a Pearson’s chi-squared test and the temporal relationship using a Wilcoxon rank sum test. Bonferroni-corrected p-values were utilized for all comparisons. Results: Among the 9,012 subjects analyzed, the incidence of anti-hypertensive initiation and loop diuretic initiation was greatest following start of a beta-blocker (16.6%) compared with other antihypertensive medication classes (calcium channel blocker 13.8%, angiotensin converting enzyme-inhibitor/angiotensin receptor blocker 12.9% and thiazide diuretic 10.2%; p<0.001). In addition, the median time between starting a new antihypertensive medication and loop diuretic was the shortest for beta-blockers and longest for thiazides (both p <0.01). No significant differences in renal function were identified between groups. Conclusion: Compared to other major classes of hypertensive agents, starting beta-blockers was associated with more common and earlier initiation of a loop diuretics in a population without heart failure at baseline. This finding may suggest beta-blocker induced heart failure in a population with a predominantly normal ejection fraction.


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