- Relevant clinical history and physical exam:
A 73-year-old man with a history of diabetes and hypertension was admitted to persistent chest pain after about 13 hr from symptom onset.

- Relevant test results prior to catheterization:
The initial ECG showed ST elevation without a Q wave in the precordial leads and reciprocal change of ST depression in the inferior leads (Fig. 1).

- Relevant catheterization findings:
Coronary angiogram revealed total occlusion of left main artery and well developed collaterals from RCA to LAD territory. (Fig 2, Fig 3)

Procedural step:
PCI was performed with sirolimus eluting stent resulting in restoration of TIMI III flow. (Fig 4, Fig 5)

After procedure, immediate echocardiography showed the severely reduced LV function with an estimated ejection fraction of 13% and the LCA territory was akinetic without thinning suggesting mostly stunning feature of anterior LV wall.( Movie 1) Cardiac MR revealed extensive transmural delayed hyperenhancement with massive "no reflow" zone along the LCA territory indicating nonviable myocardium in the entire LCA territory.(Fig 6) However, LV systolic function and the wall motion of LCA territory gradually improved over the period of 4 months in follow-up. LV ejection fraction on his last echocardiogram was 38%.( Movie 2)

1. Which imaging modality was right?
2. Was there extensive myocardial damage or more stunning in the anterior wall?
3. Is Cardiac MRI really accurate to assess myocardial viability and infarct size in the acute stage of myocardial infarction?