Assessment of Isolated Right Ventricular Myocardial Infarction by Magnetic Resonance Imaging
A 47-year-old man with no history of cardiac disease was admitted because of chest pain 3 days earlier. At presentation, he was asymptomatic and hemodynamically stable. On physical examination, an elevated venous pressure was noted.
Measurement of cardiac enzymes (creatine kinase 1085 U/L [normal <174], creatine kinase-MB 66 U/L [normal <10], and lactic dehydrogenase 686 U/L [normal <225]) at the time of admission suggested subacute myocardial infarction. However, ECG including right precordial leads showed no significant abnormalities, and single photon emission computed tomography imaging of the heart revealed a normal myocardial perfusion pattern. Echocardiography, limited by poor imaging quality, suggested a dilated right ventricle (RV). Further evaluation by late enhancement magnetic resonance imaging (MRI) using an ECG-gated 3-dimensional inversion recovery TurboFLASH sequence 20 minutes after contrast injection (0.2 mmol gadolinium-diethlenetriamine pentaacetic acid) demonstrated hyperenhancement of the free right ventricular wall with sparing of the left ventricle (Figure 1). Additionally, cine-MRI (ECG gated 2-dimensional TurboFLASH sequence) displayed a markedly dilatated RV with impaired systolic function (ejection fraction 19%) but a normal left ventricle, leading to the diagnosis of subacute isolated right ventricular myocardial infarction (Movie IA and IB). Subsequent angiography revealed an occlusion of a small, nondominant right coronary artery that could not be reperfused by percutaneous coronary intervention (Figure 2). The patient had an uneventful follow-up, and MRI 6 months later still showed a persistent delayed contrast enhancement within the right ventricular wall with reduced RV function (ejection fraction 28%) (Figure 3).
The online-only Data Supplement, which contains Movie IA and IB, can be found at http://circ.ahajournals.org/cgi/content/full/113/6/e78/DC1.