A 45-year-old man without past medical history was referred for acute chest pain and suspected non-ST-segment elevation myocardial infarction. His cardiovascular risk factors were diabetes, obesity and current smoking. Physical examination was normal. The 12-lead ECG demonstrated ST-segment depression in leads V2 to V6 ( Fig. 1 A ). Troponin I was elevated at 10 μg/L. Quantitative coronary angiography revealed a 65% diameter stenosis of the mid portion of the LAD coronary artery ( Fig. 1 B). LV angiography showed severe LV dysfunction involving the anterior wall ( Fig. 1 B, Video A ). Because of the clinical presentation associated with the ECG and the biological and angiographic features, percutaneous coronary angioplasty of the LAD coronary artery was performed successfully with stent implantation. The following day, the patient developed sustained ventricular tachycardia that resolved spontaneously ( Fig. 1 C). Transthoracic echocardiography revealed severe global LV dysfunction with moderate RV dilatation. Because of the discrepancy between the moderate troponin elevation and the severe LV dysfunction, the patient underwent CMR imaging (Siemens Espree ® 1.5T, Erlangen, Germany). Cine MRI acquired before contrast injection showed dilated and severely hypokinetic left and right ventricles ( Fig. 1 D). The RV myocardium was thin and showed segmental outward systolic wall motion particularly in the anterior wall of the RV outflow tract ( Fig. 1 D, Video B ). T1-weighted black-blood fast spin echo images revealed the presence of intramyocardial areas of hypersignal within the RV and LV myocardium, indicative of intramyocardial fat ( Fig. 1 E). Late-enhanced CMR imaging acquired 10 minutes after contrast injection demonstrated multiple intramyocardial foci of late enhancement in the region of the RV outflow tract, consistent with the presence of myocardial fibrosis ( Fig. 1 E). Based on CMR imaging findings, the diagnosis of biventricular dysplasia with fibro-fatty replacement was made without evidence for signs of recent myocardial infarction.
