Intramyocardial dissecting hematoma after anterior myocardial infarction in a 36-year-old patient: a rare case report.

BACKGROUND

Intramyocardial dissecting hematoma (IDH) is a rare and potentially fatal form of myocardial rupture that usually occurs following acute myocardial infarction (AMI). Due to its low incidence and nonspecific clinical manifestations, IDH is frequently misdiagnosed as left ventricular thrombus or pseudoaneurysm. Multimodality imaging, particularly cardiac magnetic resonance (CMR), plays a pivotal role in establishing the diagnosis and guiding treatment strategies.

CASE PRESENTATION: A 36-year-old man with a long-term smoking history presented with progressive chest tightness and dyspnea for two weeks. Electrocardiography demonstrated pathological Q waves with persistent ST-segment elevation in leads V2-V6, suggestive of subacute anterior myocardial infarction. Laboratory investigations revealed elevated cardiac troponin T and markedly increased N-terminal pro-brain natriuretic peptide levels. Transthoracic echocardiography showed severe left ventricular systolic dysfunction with a left ventricular ejection fraction (LVEF) of 29% and a heterogeneous apical mass measuring 63 × 57 × 25 mm. Contrast-enhanced computed tomography and cardiac magnetic resonance imaging identified a large lesion extending from the interventricular septum to the apex, highly suggestive of intramyocardial dissecting hematoma. Coronary angiography revealed severe proximal stenosis and complete mid-segment occlusion of the left anterior descending artery (LAD). The patient underwent successful percutaneous coronary intervention with implantation of three drug-eluting stents, achieving TIMI grade 3 flow. Following guideline-directed medical therapy, the patient's symptoms improved significantly without hemodynamic deterioration or hematoma progression.

CONCLUSION

This case highlights the importance of considering IDH in patients with subacute myocardial infarction presenting with left ventricular masses. Multimodality imaging, particularly CMR, is essential for differential diagnosis and therapeutic decision-making. Conservative management after successful revascularization may be feasible in hemodynamically stable patients with IDH.