The usefulness of exercise‐induced QRS axis shift as a predictor of coronary artery disease

Abstract

Summary:The QRS axis of 101 patients with coronary artery disease (CAD) and 57 nonnal subjects without CAD who underwent coronary arteriograms were measured before and after exercise testing. There was no improvement in the sensitivity of positive axis shifts (15 degnxs or greater) for CAD (1 8 %) when compared to the value of positive ST depression (61%). However, the specificity of positive axis shifts for CAD was significantly increased (98%) when compared to the value of positive ST depression (77 96). In addition, 39 96 of those patients with CAD (39 of 101) showed false negative ST depression, but 18% of these patients (7 of 39) showed a positive axis shift. In nonnal subjects 21 % (12 of 57) showed false positive ST depression, but all of the 21 % (12 of 12) showed negative axis shift. There was no significant difference in the increments of heart rate between positive ST depression, positive axis shift, and negative ST depression, negative axis shift. No statistical differences in the sensitivity of ST depression and an axis shift for one-, two-and threevessel diseases were noted. The specificity of left-axis shift for the left anterior descending attery lesion was 98 % and the specificity of right-axis shift for the right coronary artery and/or left circumflex artery lesion was 91 % . Therefore, the axis shift response is no more sensitive for the detection of CAD than ST depression. However, when a positive axis shift is observed, one can predict two things: the CAD and the localization of the coronary stenosis .

Improved Criteria for Localization of Coronary Artery Disease from the Exercise Electrocardiogram

“…In common with Ogino et al [ 15] we found left-axis deviation to be specific for LAD dis ease but by analyzing smaller changes were able to greatly increase the sensitivity (96%) with only a small reduction in specificity.…”

Accuracy of Exercise-Induced Left Axis QRS Deviation as a Specific Marker of Left Anterior Descending Coronary Artery Disease

“…Exercise-induced left axis deviation may be caused by ischemia of the left anterior fascicle, which is supplied only by septal perforating branches of the LAD [12]. Our study showed that complete left anterior hemiblock did not usually appear, possibly due to residual blood supply to the left anterior fascicle, but a leftward QRS shift or absence of the normal rightward change was probably of similar importance and represented partial hemiblock.…”

“…Ogino et al [12] reported exercise-induced left QRS axis deviation in 4 of 43 patients with LAD disease and only 1 of 58 patients without LAD disease (sensitivity 9%, specificity 98%. The low sensitivity in their study may have been due to use of a submaximal exercise protocol, with only a 16% increase in heart rate.…”

Koroner arteriyel baskınlık ve QRS ekseni arasındaki ilişki

“…When studies relating to QRS axis are evaluated, in clinical practice a QRS axis shift may be related to coronary artery disease (CAD). Recent reports have pointed out that an exercise-induced QRS axis shift may be related to CAD [10][11][12][13][14][15].…”