A 49-year-old woman, an ex-smoker with a history of hypertension, presented to the emergency room 5 hours after the onset of acute chest pain. Electrocardiography showed ST-segment elevation in leads DI, DII and aVL. She was treated with aspirin, clopidogrel and eptifibatide in addition to low-molecular-weight heparin and beta-blockers, and was referred for immediate coronary angiography, which demonstrated proximal occlusion of the first diagonal ( Fig. 1 A, white arrow). Primary percutaneous coronary intervention was performed after thromboaspiration. Stenting was successfully performed in the diagonal with TIMI 3 flow at the end of the procedure ( Fig. 1 B). Chest pain and ST-segment elevation immediately improved. The patient underwent cardiovascular magnetic resonance (CMR) imaging on day 3. A T2-weighted sequence showed a large, well-demarcated area ( Fig. 1 C, white asterisks) of high signal intensity (bright signal), consistent with myocardial oedema of the anterior and lateral walls. An attenuated T2W signal was seen ( Fig. 1 C, white arrow), corresponding to blood in the infarct core and suggesting intramyocardial haemorrhage (IMH). Rest first-pass perfusion ( Fig. 1 D) showed a midventricular anterolateral perfusion defect corresponding to microvascular obstruction (MVO). MVO was confirmed by a 2-minute post-gadolinium steady-state free precession cine short-axis view ( Fig. 1 E, white arrow). On the T1 inversion recovery post-contrast sequence, microvascular damage appeared dark ( Fig. 1 F, white arrow) in the middle of transmural late gadolinium enhancement ( Fig. 1 F, white asterisks), representing the non-viable myocardial necrosis. Note that late gadolinium enhancement was less extended than the previous areas involving myocardial oedema, representing the myocardial area at risk.
