Coronary angiography is indicated in most cardiac arrest survivors. Conventional invasive coronary angiography is preferred in patients with clinical suspicion of CAD or evidence of myocardial infarction (eg: elevated cardiac enzymes or abnormalities on cardiac imaging). However, coronary angiography by computed tomography now offers a non-invasive alternative for the assessment of coronary artery anatomy, particularly in patients with low clinical suspicion of CAD (eg: young patients with no cardiovascular risk factors and normal left ventricular dysfunction).

Coronary spasm and consequent myocardial ischemia may precipitate ventricular arrhythmias. Minor, non-obstructive coronary stenoses are typical in patients with coronary spasm, and a completely normal coronary angiogram is unusual. Provocation testing with ergonovine or acetylcholine is generally limited to selected cases in view of the small risk of precipitating potentially fatal myocardial infarction and arrhythmias. Magnetic resonance imaging (MRI) detection of late gadolinium enhancement may be useful for detecting occult infraction that warrants consideration of a careful search for coronary spasm.