Angina and Myocardial Infarction Without Significant Coronary Stenosis

• Myocardial Infarction and Unstable Angina with Absence of Significant Angiographic Stenosis
• Overview
• Severe Reversible Acute Cardiomyopathy Secondary to Severe Stress
• Coronary Spasm and Myocardial Infarction or Unstable Angina

Reversible stress cardiomyopathy in the absence of significant coronary disease.

An article published in Circulation (2005;111:472-479) described 22 patients with an acute and reversible cardiomyopathy.

The patients were all women with:

• acute chest pain triggered by severe emotional stress
• ECGs showing ST segment elevation or T wave inversion
• wall motion abnormalities mostly confined to the mid- and apical segments, with a markedly reduced ejection fraction (mean 29 percent)
• absence of significant coronary artery disease
• rapid restoration of left ventricular ejection fraction over several days.

It is now recognised that stress cardiomyopathy can also occur in the setting of a physical illness and not just with the stress associated with emotional distress.

We certainly see a significant number of patients each year with a milder form of this syndrome, who have had chest pain in relation to severe emotional stress, patients who often have elevation of troponins, and who evolve deep T wave changes or biphasic T wave changes on the ECG. These patients often have some wall motion abnormalities at echocardiography.

In other words, there is strong suspicion that both the severe reversible acute cardiomyopathy and the more milder cases we see have the same pathophysiology.

The exact pathophysiologic process is not known. Possibilities include vasospasm of epicardial arteries in response to catecholamines or other vasoconstritors, or dysfunction of the microcirculation. Patients have had chest pain during angiography and observed to have spasm of large epicardial arteries. Others have had chest pain during angiography without apparent spasm of large epicardial vessels but with delayed flow in vessels suggestive of dysfunction of the microcirculation.