Fulminant heart failure in a patient with MYPN-associated cardiomyopathy: A case report.

Myopalladin (MYPN) is a Z-disc protein involved in sarcomere integrity and nuclear signaling, and pathogenic variants have increasingly been recognized as causes of inherited cardiomyopathy associated with arrhythmias and progressive heart failure. We report a 48-year-old African American woman with MYPN-associated nonischemic cardiomyopathy (ejection fraction <15%), atrial fibrillation, left ventricular thrombus, prior bilateral strokes, and ICD placement who presented with acute ischemic stroke after missing anticoagulation therapy. She underwent mechanical thrombectomy for a left M1 occlusion with subsequent re-occlusion. Her hospital course was complicated by recurrent polymorphic ventricular tachycardia requiring ICD shocks, refractory heart failure requiring inotropic support, acute kidney injury, sepsis, and multi-organ dysfunction despite maximal guideline-directed therapy. MYPN mutations disrupt both sarcomere structural stability and stress-response signaling, contributing to ventricular dysfunction and arrhythmogenesis. Similar to other inherited cardiomyopathies involving sarcomeric and cytoskeletal genes, MYPN-associated disease may progress rapidly despite conventional therapy. This case highlights the severe clinical course and systemic complications of MYPN-associated cardiomyopathy and underscores the importance of early genetic testing, family screening, and timely referral for advanced heart failure therapies.