Exercise electrocardiography test in patients with aortic stenosis. Differential features from that of coronary artery disease

Studies that have been conducted with an exercise test in patients with aortic stenosis (AS) have demonstrated that results of an exercise test can mimic that of coronary artery disease (CAD). The objective of our study was to investigate if there was any differential feature(s) of an exercise test in patients with AS compared to those with CAD.

We prospectively studied 42 patients with AS (AS group, age 37 +/- 23, range 8-75) with an averaged maximal gradient of 42 +/- 19 mmHg (range 26-95). All patients had undergone a coronary angiography within 1 week of the exercise test and none had CAD. Another 100 patients with CAD, diagnosis proven with coronary angiography, comprised our second group for the comparison (CAD group). Cornell protocol was used in all patients.

ST-segment depression was observed in all patients (160 +/- 25 microV in AS group and 170 +/- 20 microV in CAD group, P>0.05). Thirty-four (81%) patients in AS group and 88 (88%) patients in CAD group exceeded the classical threshold for the test positivity (P>0.05). ST/HR slopes derived from heart rate adjustment to ST-segment level did not differ between the study groups (3.2 +/- 2.3 and 3.7 +/- 2.2 microV/beat/min, in AS and CAD groups, respectively, P>0.05). Recovery-phase patterns of ST-segment in heart rate domain were quite different between AS and CAD (clockwise loop: 86% vs. 0%; counterclockwise loop: 9% vs. 88% in AS group and CAD group, respectively, both P<0.0001). Percentage of intermediate loop was 5% in AS group and 12% in CAD group (P>0.05).

Our study demonstrated that patients with AS could be distinguished from those with CAD with the method of rate-recovery loop analysis.