Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 224

One study assessed patients (age 63 ± 10) with a predominantly exertional chest pain and unobstructed coronary arteries (<20%) on angiography. Among patients who underwent a stress ECG before angiography, half had ischemic ECG changes. Upon provocative testing with acetylcholine, 62% of all patients developed macrovascular or microvascular spasm (28% macrovascular, 34% microvascular). Macrovascular spasm was often diffuse and distal.^6,121 Most of these patients were women.

Thus, macrovascular vasospasm, and more so, microvascular dysfunction, not only cause rest angina but are also a common cause of exertional angina in patients without CAD.^120-122 The stimulation of adrenergic α-receptors may induce epicardial coronary spasm. Alternatively, the epicardial or microvascular spasm induced by acetylcholine testing may be a marker of abnormal coronary vascular tone that prevents appropriate micro- and macrovascular dilatation with exercise.