Review

The non-invasive documentation of coronary microcirculation impairment: role of transthoracic echocardiography

Pawel Petkow Dimitrow¹ , Maurizio Galderisi² and Fausto Rigo³

¹2^nd Department of Cardiology, Collegium Medicum, Jagiellonian University, Cracow, Poland

²Division of Cardioangiology with CCU, Department of Clinical and Experimental Medicine, Federico II University of Naples, Italy

³Department of Cardiology Umberto I° Hospital Mestre-Venice, Italy

author email corresponding author email

Cardiovascular Ultrasound 2005, 3:18doi:10.1186/1476-7120-3-18

Published:	4 August 2005

Abstract

Transthoracic Doppler echocardiographic-derived coronary flow reserve is an useful hemodynamic index to assess dysfunction of coronary microcirculation. Isolated coronary microvascular abnormalities are overt by reduced coronary flow reserve despite normal epicardial coronary arteries. These abnormalities may occur in several diseases (arterial hypertension, diabetes mellitus, hypercholesterolemia, syndrome X, aortic valve disease, hypertrophic cardiomyopathy and idiopathic dilated cardiomyopathy). The prognostic role of impaired microvascular coronary flow reserve has been shown unfavourable especially in hypertrophic or idiopathic dilated cardiomyopathies. Coronary flow reserve reduction may be reversible, for instance after regression of left ventricular hypertrophy subsequent to valve replacement in patients with aortic stenosis, after anti-hypertensive treatment or using cholesterol lowering drugs. Coronary flow reserve may increase by 30% or more after pharmacological therapy and achieve normal level >3.0. In contrast to other non invasive tools as positron emission tomography, very expensive and associated with radiation exposure, transthoracic Doppler-derived coronary flow reserve is equally non invasive but cheaper, very accessible and prone to a reliable exploration of coronary microvascular territories, otherwise not detectable by invasive coronary angiography, able to visualize only large epicardial arteries.