Electrocardiography, cardiac biomarkers, echocardiography and coronary angiography help identify myocardial infarction, assess complications and guide revascularisation.
Electrocardiographic findings
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The illustrated acute transmural inferolateral myocardial infarction shows ST elevation in inferior leads II, III and aVF and lateral leads V4–V6.
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Reciprocal ST depression is present in leads aVL and V2. The recording was obtained 4 hours after the onset of severe chest pain.
Cardiac biomarker sequence
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Creatine kinase and troponins T and I rise first, followed by aspartate aminotransferase and then lactate (hydroxybutyrate) dehydrogenase.
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Reperfusion therapy produces a rapid rise in plasma creatine kinase because of a washout effect.
Echocardiography
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Echocardiography is normally performed before hospital discharge to assess ventricular function.
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It can detect mural thrombus, cardiac rupture, ventricular septal defect, mitral regurgitation and pericardial effusion.
Coronary angiography
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Coronary arteriography should be considered with a view to revascularisation in patients at moderate or high risk of another event.
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Relevant features include failure to settle with medical therapy, extensive electrocardiographic changes, elevated cardiac troponin and severe pre-existing stable angina.
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Angiography often identifies disease amenable to percutaneous coronary intervention or urgent coronary artery bypass grafting.