Hemorrhagic Myocardial Infarction Implicating Left Ventricular Thrombus.

BACKGROUND

Left ventricular thrombus formation following ST-segment elevation myocardial infarction is typically attributed to blood stasis in an akinetic apex. However, thrombus can form even in the presence of anticoagulation, suggesting alternative mechanisms may be at play.

CASE SUMMARY: A 44-year-old man with an anterior ST-segment elevation myocardial infarction underwent primary percutaneous coronary intervention with successful restoration of TIMI flow grade 3. Despite receiving 19,000 U of heparin, a mobile apical thrombus formed. Cardiac magnetic resonance revealed a large intramyocardial hemorrhage. Feature-tracking strain analysis quantified a "mechanical tug of war" at the infarct border. The magnitude of the shear was spatially concordant with a suspected endocardial disruption, creating structural nidus for thrombosis.

DISCUSSION: This case demonstrates that severe reperfusion intramyocardial hemorrhage can induce a mechanical breach of the endocardium. Recognition of hemorrhagic dissection via cardiac magnetic resonance shifts the management paradigm from treating generic stasis to managing a specific structural failure.