CARDIAC SYNDROME X

CARDIAC SYNDROME X (SCX) or microvascular angina is a typical retrosternal chest pain with ischemia documented on noninvasive test (ST depression and/or perfusion abnormality) in the absence of any significant coronary artery disease. Associated with increased cardiovascular risk. 

MECHANISM

Possible mechanism of Coronary Syndrome X is microvascular endothelial dysfunction with decreased vasodilatation reserve; probable hypersensitivity to pain.

40-50% of the resistance to coronary flow is derived from the microvasculature; an insufficient vasodilatation reserve decreases coronary perfusion on exertion.

Some studies show increased risk of other vasospastic disorders in cardiac microvascular angina parients, such as migraine and Raynaud's phenomenon. 

Nosology should be ruled out: Prinzmetal angina, Esophageal spasm

DIAGNOSIS of Coronary Syndrome X is a diagnosis of exclusion.

Normal coronary angiography;

Angiography with acetylcholine can show microvascular dysfunction.

Echocardiography: absence of myocardial dysfunction.

Electrocardiography: ST changes are typically similar to those of coronary artery disease.

MANAGEMENT

Nitrates administration is the first step;

Aspirin;

Clopidogrel;

ACE inhibitors;

Calcium channel blockers;

Statins (improve endothelial dysfunction);

Beta blockers , but avoid nonselective BB (risk of unopposed alpha stimulation);

Treatment of risk factors; 

Regular exercise;