The Hidden Scars of Arrhythmogenic (Right Ventricular) Cardiomyopathy

I n the ever-expanding world of cardiomyopa- thies, the once-simple classification is increasingly transformed into a complex landscape with a diverse array of genetic forms of disease. 1 This growing recognition of distinct cardiomyopathies challenges us to refine our understanding continuously, to remain open to new developments, and to see each patient not as a mere diagnosis but as a unique expression of an intricate genetic disease.Among these entities, arrhythmogenic cardiomyopathy (ACM) holds a special place, its threads of inheritance linked with the spectrum of structural and functional abnormalities and ventricular arrhythmias that often lead to sudden cardiac death at a young age. 2-4ACM and its well-known subtype, arrhythmogenic right ventricular cardiomyopathy (ARVC), draw attention to the distinct natural history of disease in specific genetic forms.ARVC predominantly affects the right ventricle (RV), although the left ventricle is increasingly considered to be involved in at least one-half of the cases. 5The diagnosis of ARVC is based on a combination of major and minor Task Force Criteria (TFC), which include functional, structural, electrocardiographic, arrhythmic, pathological, and genetic/family history information. 6The true nature of ARVC lies in its unpredictability-the ever-present prospect that ventricular arrhythmia may be the sentinel (and final) sign of disease, particularly in probands with pathogenic/likely pathogenic PKP2 variants.ARVC is typically caused by heterozygous pathogenic/likely pathogenic variants in desmosomal genes and follows an autosomal dominant inheritance pattern, with male sex and endurance exercise associated with a significantly higher risk of ventricular arrhythmias. 7In many cases, recognizing ARVC is appreciating a pattern that runs through families.Yet, awareness of the variable presentations of this disease remains limited within the cardiology community.Perhaps its rarity obscures its presence, or maybe the phenotypic overlap with other inherited and inflammatory cardiomyopathies makes timely diagnosis challenging. 8,9Moreover, the variable expressivity of disease leads to a significant proportion of cases mislabeled as idiopathic ventricular tachycardia (VT), which may eventually lead to underestimation of risk in this high-risk population, denying the potentially life-saving secondary preventive implantable cardioverter-defibrillator implantation. 10nsider the case of a young man, age 33 years, who was referred to our center following an encounter at an outside hospital.At the presentation to the emergency department, his only symptom was palpitations; his heart rate was found to be at 185 beats/min, and his blood pressure was in a normal range.His electrocardiogram (ECG) showed a wide complex tachycardia (Figure 1).After initiation of intravenous amiodarone, he developed symptomatic hypotension, and cardioversion was performed to restore sinus rhythm (Figure 2).He had no history of