Usefulness of exercise echocardiography in the diagnosis of coronary artery disease in patients with left bundle branch block

Objective. To assess the diagnostic value of exercise echocardiography in patients with complete left bundle branch block and clinical suspicion of coronary artery disease. Material and methods. Among 1,176 exercise echocardiograms performed from May of 1994 to November of 1996, 92 showed complete left bundle branch block in the resting electrocardiogram. We retrospectively analyzed data of 23 patients who had coronary angiography performed within 6 weeks of the exercise echo (19 males and 4 females, age 62 +/- 8, resting ejection fraction 52 +/- 10%). Previous acute myocardial infarction was demonstrated in 8 of them. The development of new or worsening regional dysfunction was considered an ischaemic response on exercise echo; whereas me assumed that there was significant coronary artery disease on the coronariography whether there was greater than or equal to 1 vessel disease in patients without previous myocardial infarction or greater than or equal to 2 vessel disease in patients with previous infarction. Results. Ten patients showed multivessel disease (greater than or equal to 2 vessels, 6 with previous infarction); 5 one-vessel disease; and 8 non significant coronary artery disease. Exercise echocardiography sensitivity for ischaemia detection in the entire group was 86% (95% confidence interval 67-100%); the specificity was 67% (36-98%), predictive value of a positive test was 80% and predictive value of a negative test was 75%. Sensitivity for the detection of > 50% stenosis in the left anterior descending coronary territory was 92% (76%-100%) and specificity 64% (35%-92%); for right coronary artery sensitivity was 80% (55%-100%) and specificity 77% (54-100%); and for left circumflex artery sensitivity was 70% (42%-98%) and specificity 69% (44%-94%). Conclusions. Exercise echocardiography may be useful in the evaluation of patients with left bundle branch block and clinical suspicion of coronary artery disease; with good sensitivity and low specificity.