Fatal ventricular arrhythmias in myocarditis: A review of current indications for defibrillator devices

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Myocarditis patients were historically treated with implantable cardioverter defibrillators (ICDs) only in the chronic phase.
• The perception of myocarditis reversibility excluded acute-phase patients from ICDs, despite evidence of frequent ventricular arrhythmias.
• Myocardial damage from myocarditis can persist long-term, challenging previous assumptions.

Purpose of the Study:

• To review updated guidelines for defibrillator use in acute and chronic myocarditis.
• To discuss the evolving role of ICDs and wearable cardioverter defibrillators (WCDs) in myocarditis management.
• To evaluate the potential benefits of WCDs for arrhythmia detection and patient selection.

Main Methods:

• Review of recent US and European guidelines (2022) for defibrillator use in myocarditis.
• Analysis of current literature on ventricular arrhythmias in acute and chronic myocarditis.
• Evaluation of studies on the efficacy of wearable cardioverter defibrillators (WCDs) in myocarditis patients.

Main Results:

• Updated 2022 guidelines now include ICD implantation during the acute phase of myocarditis.
• Ventricular arrhythmias are frequently observed even in the acute phase of myocarditis.
• Wearable cardioverter defibrillators (WCDs) show potential efficacy in myocarditis patients for arrhythmia detection and temporary protection.

Conclusions:

• ICD utilization is now supported for secondary prevention in acute myocarditis due to high arrhythmia risk.
• WCDs may help identify high-risk patients for ICD implantation and offer primary prevention.
• Further prospective studies are needed to determine optimal early ICD implantation strategies for myocarditis.