[Diagnostic value of ST depression corrected for heart rate in the post-exercise recovery period]

This study assessed the diagnostic value of two new electrocardiographic criteria of coronary artery disease: the ST/HR index and the slope of the linear relationship between ST segment changes and the heart rate during the first three minutes of the post-exercise recovery period. These two criteria were compared to the standard criteria (> or = 1 mm horizontal or descending ST depression or > or = 2 mm ascending ST depression) to Detrano's ST/HR exercise index (> 1.6 microV/bpm in coronary patient), the exercise ST/HR slope (> or = 2.4 microV/bpm in coronary patients) and the exercise recovery loop (clockwise in normal and anticlockwise in coronary patients) in 88 subjects investigated for suspected coronary artery disease who underwent a computerised exercise stress test and coronary angiography (25 single vessel, 21 double vessel, 20 triple vessel disease; 22 with no significant coronary disease). The ROC identified thresholds of abnormality of the ST/HR recovery index at > or = 2.1 microV/bpm and of the ST/HR recovery slope at > or = 2.52 microV/bpm. Global comparison of the areas under the ROC showed the diagnostic superiority of the exercise ST/HR indices (0.96) over the standard criteria (0.92) and recovery indices (0.86) but without statistically significant values (p = 0.65 and p = 0.15 respectively). The ST/HR index and slope during recovery identify coronary disease with a diagnostic accuracy of 80% and 77% respectively which is similar to that (84%) of the standard ST criteria. The exercise-recovery loop was less accurate (64%).