Spontaneous myocardial infarction: while the initial impression is often confirmed following coronary angiography or echocardiography, other conditions can present similarly. If no coronary mechanism is evident, echocardiography or cardiac magnetic resonance imaging may be required to identify alternative causes of acute myocardial injury, such as takotsubo cardiomyopathy or myocarditis. Secondary myocardial infarction: the diagnosis of secondary myocardial infarction due to an alternative condition requires evidence of a new regional wall motion abnormality or left ventricular impairment on echocardiography, or evidence of loss of viable myocardium on magnetic resonance imaging, or the presence of obstructive coronary artery disease on invasive or computed tomography coronary angiography. Patients with acute myocardial injury in this setting for whom secondary myocardial infarction is thought unlikely or has been excluded, may benefit from cardiac imaging to identify other nonischemic structural heart diseases unmasked by acute illness. Procedural myocardial infarction: Coronary complications following percutaneous coronary intervention are usually self-evident, but following cardiac surgery routine echocardiography to recognize asymptomatic procedural myocardial infarction should be performed in the postoperative period.
