Fulminant Biventricular Desmoplakin Cardiomyopathy With a Myocarditis-Like Presentation.

BACKGROUND: Desmoplakin (DSP) cardiomyopathy is an inherited cardiomyopathy that may present with a myocarditis-like phenotype, delaying diagnosis and risk stratification. CASE SUMMARY: A previously healthy 23-year-old man developed rapidly progressive heart failure following 2 months of intermittent fever. Evaluation revealed severe biventricular systolic dysfunction (left ventricular ejection fraction, 11%), ventricular ectopy with nonsustained ventricular tachycardia, and cardiac magnetic resonance showing extensive circumferential subepicardial ring-like fibrosis. Infectious, autoimmune, inflammatory, infiltrative, and toxic causes were excluded. Whole-exome sequencing identified a likely pathogenic truncating DSP variant (c.2521C>T; p.Gln841Ter). Despite guideline-directed therapy and anticoagulation for right ventricular thrombi, he developed refractory ventricular tachycardia and died of electrical storm. DISCUSSION: DSP cardiomyopathy can mimic acute myocarditis and carries substantial arrhythmic and heart failure risk. TAKE-HOME MESSAGES: Myocarditis-like presentations with ventricular arrhythmias should prompt evaluation for DSP cardiomyopathy. Early genetic diagnosis may facilitate timely arrhythmic and advanced heart failure risk stratification.