An ominous MINOCA mimicker

Description of Clinical Presentation: A 35-year-old male, with no significant cardiovascular risk factors, initially presented with severe chest pain. Troponin I was markedly elevated, but both ECG and coronary angiography were normal. He was managed conservatively and remained stable. Four years later, he experienced another episode of severe chest pain with positive troponin, again with normal ECG and unobstructed coronaries on angiography. These recurrent events of myocardial injury in the absence of coronary artery disease prompted further evaluation with cardiac MRI.

Diagnostic Techniques and Their Most Important Findings: Cardiac MRI revealed normal-sized ventricles with mild global hypokinesis and borderline biventricular dysfunction (LVEF 51%, RVEF 44%). Strain analysis showed reduced LV global longitudinal strain (–14.9%). Quantitative tissue characterization demonstrated elevated global native T1 (1338 ms), increased extracellular volume (29%), and elevated native T2 values (45 ms), consistent with diffuse myocardial injury and edema. PSIR imaging revealed a smooth ring-like pattern of subepicardial late gadolinium enhancement (LGE) along the lateral wall, extending to a mid-myocardial distribution in the interventricular septum. These findings suggested an active inflammatory process with early fibrotic remodeling. Genetic testing with a cardiomyopathy gene panel confirmed a pathogenic variant in the desmoplakin (DSP) gene. Integrating the imaging and genetic findings, a diagnosis of the “hot phase” of desmoplakin-related arrhythmogenic cardiomyopathy (ACM) was established.

Learning Points from this Case: This case highlights the clinical importance of cardiac MRI in evaluating troponin-positive chest pain with unobstructed coronary arteries. The multimodality tissue characterization and specific LGE patterns were pivotal in differentiating genetic cardiomyopathy from myocarditis or ischemic injury. Recognition of the “hot phase” of desmoplakin-related ACM is crucial, as it may mimic acute myocarditis or myocardial infarction but carries distinct prognostic and management implications, including arrhythmic risk stratification and genetic counseling. Cardiac MRI, when integrated with genetic testing, enables early diagnosis, guides therapy, and informs family screening in desmosomal cardiomyopathies.

Normal Electrocardiogram
PSIR images in short axia (top row) and long axis (bottom row) show smooth ring like LGE that is mid myocardial at the septum and subepicardial at other walls (orange arrow head)
(A) Pre contrast T1 mapping shows elevated T1 values in the regions with LGE (black arrow), (B) Post contrast T1 mapping shows low T1 values at regions of LGE (white arrow) indicating ECV expansion/Fibrosis, (C) T2 mapping showing elevated T2 values in regions of LGE (black arrow) suggestive of edema.