[Reproducibility of the exercise test and coronary vasomotor tonus]

The effect of coronary vasomotor tone on exercise test reproducibility was evaluated in two groups of patients. All had an apparently stable angina, a positive first exercise test and at least one significant stenosis at coronary arteriography. Group A patients (n = 30) had a positive ergonovine test (dynamic stenosis) whereas this test was negative (fixed stenosis) in group B patients (n = 29). Patients of both groups underwent two exercise tests without treatment, each of these tests being performed on a different day of the same week, at the same time and according to Bruce's procedure. The reproducibility of angina was poor in group A patients: 6/15 (40 p. 100) as against 18/20 (90 p. 100) in group B patients (p less than 0.05). Moreover, the initially positive exercise test subsequently become negative in 6 of the group A patients and in none of the group B patients (p less than 0.05). The time elapsed before ischaemia appeared was globally increased to the same extent in both groups, but individual variations were more pronounced in group A: a more than 1 minute variation was noted in 63 p. 100 of group A patients and in 18 p. 100 of group B patients (p less than 0.01). Similarly, the double product of ischaemia (-1 mm) varied by more than 20 p. 100 in 37 p. 100 of group A patients and in 14 p. 100 of group B patients. In contrast, the maximum stress parameters were increased to the same degree in both groups, including the double product duration.(ABSTRACT TRUNCATED AT 250 WORDS)