When Substrate Meets Device: ICD Implantation and Therapy across the Spectrum of Cardiomyopathies

INTRODUCTION: Implantable cardioverter-defibrillators (ICDs) are the cornerstone of sudden cardiac death prevention in cardiomyopathies, but disease-specific structural and electrophysiological substrates profoundly affect device performance and outcomes. Understanding these distinctions is critical for tailoring therapy and improving patient safety. AREAS COVERED: This review examines current evidence and practical experience regarding ICD implantation, programming, and management in hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), and cardiac amyloidosis (CA). We performed a structured narrative synthesis to identify phenotype-specific technical challenges, programming strategies, and complication trends. For HCM, lead placement and programming to minimize inappropriate therapies are emphasized; for ARVC, issues of lead instability, oversensing, and ATP efficacy are explored; and for CA, defibrillation thresholds, sensing difficulties, and individualized indications are discussed. EXPERT OPINION: ICD therapy in cardiomyopathies must be individualized, balancing arrhythmic protection against disease-specific risks and device-related complications. Tailored programming, careful system selection, and remote monitoring are key to improving outcomes. Emerging technologies such as modular and extravascular ICD systems promise safer and more phenotype-driven care.