Background: The development in ultrasound technology has allowed the use of non-invasive transthoracic echocardiography (TTE) for the study of coronary artery physiology and pathophysiology. TTE can be used to detect atherosclerotic changes in epicardial coronary arteries and to study the effects of specific interventions on coronary microcirculation.
Aim: The purpose of this review was to summarize the development of TTE, and outweigh the strenghts and weaknesses of the method for the evaluation of coronary artery blood flow. Moreover, findings from clinical trials studying microcirculatory reactivity using TTE are presented.
Conclusions: TTE is a feasible and reproducible method for the evaluation of coronary artery blood flow. It can also be used in assessing the vasodilation of the epicardial coronary artery simultaneously with flow velocity measurement during the cold pressor test and coronary flow velocity reserve assessment. It is specifically suitable for repeated measurements in interventional trials.