Intramyocardial Dissecting Hematoma After Myocardial Infarction Diagnosed by Multimodality Imaging

BACKGROUND: Intramyocardial dissection is a rare mechanical complication of myocardial infarction that may mimic left ventricular (LV) thrombus. CASE SUMMARY: A 47-year-old man presented with progressive dyspnea and severe LV dysfunction with a large LV mass initially presumed to be thrombus. Despite anticoagulation, he developed cardiogenic shock and ventricular tachycardia. Coronary angiography showed severe multivessel coronary artery disease. Cardiac magnetic resonance imaging demonstrated extensive anterior transmural infarction with a dissecting intramyocardial cavity consistent with intramyocardial dissection. Given profound LV dysfunction and hostile apical anatomy precluding LV assist device placement, he required temporary mechanical support and underwent successful orthotopic heart transplantation. DISCUSSION: Multimodality imaging is essential to distinguish intramyocardial dissection from thrombus and guide advanced heart failure therapy. TAKE-HOME MESSAGES: Consider intramyocardial dissection in post-myocardial infarction LV masses with clinical deterioration. Cardiac magnetic resonance imaging is critical for diagnosis and management.