VALUES OF THE EXERCISE - RECOVERY LOOP AND HEART-RATE SLOPE DURING EXERCISE AND RECOVERY IN THE DIAGNOSIS OF CORONARY-ARTERY DISEASE AND RESTENOSIS AFTER ANGIOPLASTY

This study addresses the diagnostic value of two new criteria of exercise stress testing for primary coronary artery disease and restenosis after angioplasty : the slope of the linear relation between ST segment changes and heart rate during exercise; the exercise-recovery loop (clockwise direction in normal subjects and anticlockwise direction in coronary patients). These two critera were compared with the standard diagnostic criteria (horizontal or descending ST segment depression greater than 1 mm or ascending ST segment depression greater than 2 mm) in 125 patients with suspected coronary artery disease who underwent computerised exercise stress testing and coronary angiography (30 single, 31 double and 30 triple vessel disease; 34 without significant stenosis) and in 24 patients with single vessel disease who underwent successful angioplasty and who performed exercise stress testing before, immediately after and 6 months after angioplasty before routine control coronary angiography. The sensitivity (Se), specificity (Sp), positive predictive value (PPV) of the exercise-recovery loop for the diagnosis of coronary disease were 81 %, 82 %, 89 %, respectively, versus 69 %, 71 % and 88 % for the standard criteria. The detection of restenosis by these criteria also appeared to be better (71 %, 91 % and 91 % versus 46 %, 63 % and 60 %, respectively). However, for the classical threshold value of 2.4 mv//beat/min, the ST/HR criteria seemed to be less useful (Se : 80 %, Sp : 26 %).