BackgroundImprovements in ultrasound technology has enabled direct, transthoracic visualization of long portions of coronary arteries : the left anterior descending (LAD), circumflex (Cx) and right coronary artery (RCA). Transthoracic measurements of coronary flow velocity were proved to be highly reproducible and correlated with invasive measurements. While clinical applications of transthoracic echocardiography (TTE) of principal coronary arteries are still very limited they will likely grow. The echocardiographers may therefore be interested to know the ultrasonic views, technique of examination and be aware where to look for coronary arteries and how to optimize the images.MethodsA step-by-step approach to direct, transthoracic visualization of the LAD, Cx and RCA is presented. The technique of examination is discussed, correlations with basic coronary angiography views and heart anatomy are shown and extensively illustrated with photographs and movie-pictures. Hints concerning optimization of ultrasound images are presented and artifacts of imaging are discussed.ConclusionsDirect, transthoracic examination of the LAD, Cx and RCA in adults is possible and may become a useful adjunct to other methods of coronary artery examination but studies are needed to establish its role.

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Transthoracic echocardiography allowed for accurate stenosis assessment of principal coronary arteries after successful PTCA. Feasibility of lesion site visualization was 100% for the LAD, 75% for the Cx and 43% for the RCA. Ultrasound contrast agent improved the quality of the RCA images.

The aim of this study was to evaluate the relation of coronary flow velocity (CFV) and coronary flow reserve (CFR) to exercise capacity in ten verapamil-treated patients with hypertrophic cardiomyopathy (HC). Using Doppler transesophageal echocardiography, we assessed diastolic CFV in the proximal left anterior descending coronary artery at baseline and after administering 0.56 mg/kg intravenous dipyridamole. The CFR was calculated as the post-dipyridamole/baseline diastolic CFV ratio. A maximal symptom-limited exercise treadmill test was performed according to a modified Bruce protocol and the exercise capacity was expressed as metabolic equivalents. The mean value for baseline diastolic CFV was 59 +/- 27 cm/s; this increased after dipyridamole to 134 +/- 57 cm/s. The CFR was 2.37 +/- 0.67. Baseline diastolic CFV correlated negatively with both exercise duration (r = -0.69; P < 0.05) and value for metabolic equivalents (r = -0.70; P < 0.05). CFR was weakly and non-significantly related to exercise duration (r = 0.40; P > 0.05) and to the value for metabolic equivalents (r = 0.32; P > 0.05). Shortening of exercise time and decreasing metabolic equivalents were correlated with increased baseline diastolic CFV. Dipyridamole-assessed CFR, was weakly related to parameters of exercise capacity.