Usefulness of exercise testing performed with vasodilators for predicting the severity of myocardial ischaemia during daily activities and treatment.

Fifty patients (aged 53 +/- 7 years) with confirmed coronary disease performed two stress tests (baseline and following treatment with vasodilators) and were divided into two groups: (A) fixed ischaemic threshold (n = 27), and (B) variable ischaemic threshold (n = 23). All patients underwent 24-h baseline Holter monitoring and monitoring following treatment with nifedipine, placebo, propranolol and nifedipine + propranolol. In Group A, 92% of ischaemic episodes occurred at heart rates similar to those found during exercise testing. In Group B, the heart rate was lower in 66%. In Group A, positive stress testing before the first 3 min of exercise, or at < 140 beat,min-1 with ST segment depressions > or = 0.02 mV, correlated with higher Holter indexes. In Group A, propranolol reduced both the number of episodes and total ischaemia time. In Group B, the best effects were achieved with nifedipine and combined treatment. Our results further emphasize the contrasts between patients with angina and fixed and variable ischaemic thresholds and suggest that therapy tailored to the physiopathology may be most efficacious.