title: Accuracy of exercise-induced left axis QRS deviation as a specific marker of left anterior descending coronary artery disease.
abstract: In this prospective study, we examined the diagnostic accuracy of exercise-induced left QRS axis deviation as a marker of LAD coronary artery stenosis. The mean frontal QRS axis of 66 consecutive patients with chest pain and exercise-induced ST segment depression referred for diagnostic coronary angiography was analyzed and related to the angiographic findings. An exercise-induced leftward QRS axis deviation was found in 9/40 patients with and 0/26 patients without obstructive (> or = 70%) LAD disease (sensitivity 23%, specificity 100%, p = 0.025). In 7 of the 9 patients with left axis deviation, the lesion was proximal to and in 2 in the region of the first septal perforator. Inclusion of patients with 0 degrees exercise-induced QRS axis deviation provided a more sensitive but less specific marker of LAD disease [sensitivity 53% (21/40), specificity 81% (21/26), p = 0.015]. The findings were similar in patients with single and with multivessel coronary artery disease. Grouping all patients in the present prospective and two previous retrospective studies (n = 165), the sensitivity was 29% and specificity 100% (p < 0.0001). Exercise-induced left QRS axis deviation was a highly specific marker of LAD coronary artery stenosis.
authors.affiliation: Department of Cardiology, Lady Davis Carmel Medical Center, Bruce Rappaport School of Medicine, Technion-Israel Institute of Technology, Haifa.
authors.forename: A
authors.initials: A
authors.lastname: Shiran
authors.forename: D A
authors.initials: DA
authors.lastname: Halon
authors.forename: A
authors.initials: A
authors.lastname: Merdler
authors.forename: N
authors.initials: N
authors.lastname: Makhoul
authors.forename: N
authors.initials: N
authors.lastname: Khader
authors.forename: J
authors.initials: J
authors.lastname: Ben-David
authors.forename: B S
authors.initials: BS
authors.lastname: Lewis
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D003331:Coronary Vessels / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity