Reconsider the Indication of Implantable Cardioverter Defibrillator in Patients With Cardiac Amyloidosis

Patients with wild-type transthyretin cardiac amyloidosis frequently experience fatal bradycardia; however, the implications of tachycardia remain poorly understood. Sehrawat et al. investigated the clinical significance of non-sustained ventricular tachycardia (NSVT) in this population [1]. Their findings indicate that while NSVT is prevalent and associated with an increased risk of future sustained ventricular arrhythmias, it does not correlate with overall mortality. These results raise several critical considerations. Notably, approximately 60% of mortality in cardiac amyloidosis cohorts is linked to bradycardia, underscoring the potential role of pacemaker implantation in preventing sudden cardiac death [2]. This contrasts with the utility of subcutaneous implantable cardioverter-defibrillators (ICDs) in this context, given the lack of pacemaker function. Given the study's findings that NSVT does not predict mortality [1], the routine use of ICDs as a primary preventative measure in this cohort warrants reconsideration. Comprehensive data on the prognostic implications of NSVT, including its impact on the trajectory of cardiac function and the incidence of hospital readmissions, would further refine decision-making regarding ICD implantation. The characteristics of ventricular tachycardia (VT) in this cohort also merit further investigation. For example, in patients with arrhythmogenic right ventricular cardiomyopathy, VT often occurs during physical exertion [3]. Such information is valuable for patient education and risk stratification. In the present study, the authors provided an electrocardiographic example of VT originating from the inferior-lateral wall of the left ventricle [1]. Did the study identify any patterns or trends regarding the origin of arrhythmias within the cohort? For instance, in dilated cardiomyopathy, the origin of VT can vary depending on the underlying genetic mutations [4]. Regular QRS tachycardia originating from scar tissue is typically associated with re-entrant mechanisms and may respond well to ICD implantation or catheter ablation. In contrast, irregular tachycardia in the absence of structural abnormalities is often linked to triggered activity and may be more effectively managed with pharmacological interventions such as beta-blockers. Clarifying these nuances would provide invaluable guidance for tailoring therapeutic strategies and optimizing outcomes in patients with wild-type transthyretin cardiac amyloidosis. The authors received no specific funding for this work. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. The authors have nothing to report.