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

ABSTRACT 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.