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Figure 1 Typical examples of the different myocardial alterations detected by contrast-enhanced magnetic resonance in patients undergoing primary percutaneous coronary intervention at an increasing time delay from the onset of the chest pain. Upper, middle, and lower panels respectively show contrast-enhanced magnetic resonance images obtained at two different short-axis levels and in a long-axis two-chamber plane for four different patients. (Patient A, left column) Male, age 76 years; hypertension, history of smoking, dyslipidemia, familiarity of coronary artery disease; electrocardiographic evidence of anterior ST-segment elevation myocardial infarct (STEMI); pain to balloon time: 70 min; troponin I peak: 11.7 ng/ml. After six days from acute event, no signs of necrosis are shown at the late contrast-enhancement magnetic resonance image (MRI) ("aborted" infarct). (Patient B, left center column) Male, age 49 years, hypertension, familiarity of coronary artery disease; electrocardiographic evidence of anterior STEMI; pain to balloon time: 170 min; troponin I peak: 38.6 ng/ml. After six days from acute event, MRI shows a nontransmural necrosis in the middle and apical segments of the anterior wall. (Patient C, right center column) Male, age 78 years, hypertension; electrocardiographic evidence of anteroseptal STEMI; pain to balloon time: 240 min; troponin I peak: 199 ng/ml. After eight days from acute event, MRI shows a transmural necrosis of the entire anterior wall and of the apical segment of the inferior wall. (Patient D, right column) Female, age 73 years; no cardiovascular risk factor; electrocardiographic evidence of septal, anterior and inferior STEMI; pain to balloon time: 310 min; troponin I peak: 258 ng/ml. After seven days from acute event, MRI shows a transmural necrosis of the anterolateral, anterior, and septal wall. In the same area of the infarct, there is evidence of a subendocardial dark zone referred as to severe microvascular obstruction.