Cardiac Magnetic Resonance Assessment of Acute Myocardial Infarction Involving the Right Ventricle

A 69-year-old man presented with dyspnea for 2 days. Initial electrocardiogram (ECG) showed ST-elevation in the inferior and right-sided precordial leads, and coronary angiography revealed a total occlusion of the proximal right coronary artery (Figure A). Primary stenting successfully improved coronary blood flow, but the ECG after revascularization indicated incomplete resolution of the ST-segment elevation (Figure B). He required several days of treatment for refractory right-sided heart failure. We performed cardiovascular magnetic resonance (CMR) to assess the myocardial injury. T2-weighted short-tau-inversion-recovery black-blood imaging revealed a hypointense core indicating intramyocardial hemorrhage (IMH) within myocardial edema (Figure C). Furthermore, late gadolinium enhancement imaging visualized a hypointense region within the hyperintense infarcted area (Figure D), a hallmark sign of microvascular obstruction (MVO).¹ Cine CMR detected right ventricular (RV) asynergy and systolic dysfunction (Figure E). Based on these findings, we speculated that irreversible microvascular injury in a massive area of myocardium involving the RV free wall contributed to the refractory right-sided heart failure. This is a rare report showing CMR-detected IMH and MVO, known as signs of poor prognosis, extending from the left ventricular inferior wall to the RV free wall. CMR may help understand the pathophysiology of RV infarction.

Figure.

Coronary angiography and ECG before (A) and after revascularization (B). (C) T2-weighted short-tau-inversion-recovery black-blood imaging on cardiovascular magnetic resonance (CMR) indicating myocardial edema (arrows) and intramyocardial hemorrhage (*). (D) Late gadolinium enhancement imaging on CMR indicating infarcted myocardial area (arrows) and microvascular obstruction (*). (E) Cine CMR findings showing akinesia in the left ventricular inferior wall, and right ventricular asynergy, and systolic dysfunction.

Disclosures

Y.S. is a member of Circulation Journal’s Editorial Team. The remaining authors have nothing to disclose.

Reference

• 1.   Wu KC. CMR of microvascular obstruction and hemorrhage in myocardial infarction. J Cardiovasc Magn Reson 2012; 14: 68.