Cardiac Syndrome X and Microvascular Angina

Abstract

Cardiac syndrome X is defined as the occurrence of typical chest pain and evidence of myocardial ischemia on noninvasive stress tests (mainly, ST-segment depression during exercise stress test), in the presence of normal coronary arteries at angiography and in the absence of any other cardiac diseases. This condition is now mainly defined as primary microvascular angina (MVA). Abnormalities of endothelium-dependent and endothelium-independent coronary microvascular dilation have been described in many studies, using different invasive and noninvasive methods. An increased coronary microvascular constriction is also involved. The causes of the coronary microvascular dysfunction are likely multiple and may include common cardiovascular risk factors, an abnormal cardiac adrenergic function, insulin resistance, inflammation and, in women, estrogen deficiency. Prognosis is good, but quality of life can significantly be impaired in 10–20 % of patients. Treatment includes classical anti-ischemic drugs and several other pharmacological and nonpharmacological therapeutic tools for those with symptoms refractory to standard antianginal and anti-ischemic therapy.