Diagnostic algorithms

Abstract

Microvascular angina (MVA) is the likely diagnosis in most patients with chest pain typical enough to suggest obstructive coronary artery disease, but who show normal coronary arteries at angiography. A definitive diagnosis, however, requires documentation of coronary microvascular dysfunction (CMVD). To this aim, invasive methods, in particular, intracoronary Doppler wire recording of coronary blood flow is the reference method, but they can not be applied widely in routine clinical practice. Transthoracic Doppler echocardiography is a suitable non invasive method for the routine assessment of CMVD in patients with normal coronary arteries. Alternative methods include cardiovascular magnetic resonance, myocardial contrast echocardiography and positron emission tomography. These methods, however, are excellent research tools but have limitations for worldwide application in clinical routine. In patients with suspected MVA, CMVD should be assessed with endothelium-independent dilator stimuli, i.e. adenosine or dipyridamole and with the cold pressor test to assess endothelium-dependent vasodilation. The response to intracoronary administration of vasoconstrictor stimuli (like ergonovine or acetylcholine) is useful in patients with suspected coronary artery spasm