[The coronary collaterals influence in the recovery phase after exercise-induced myocardial ischemia].

: The role of coronary collaterals in conditioning the recovery from exercise-induced myocardial ischaemia has not been investigated. We studied 60 patients (54 men, age 59.3 +/- 6.7 years) with low threshold effort angina and documented coronary artery disease, who underwent repeat exercise testing in 2 consecutive days. On the second day, Thallium 201 stress/rest myocardial perfusion scintigraphy was also performed. At angiography, 30 patients (Group A), had more severe disease (Gensini score: 46.9 +/- 16) and angiographically visible collaterals (grade 2-3 Cohen and Rentrop classification) perfusing the ischaemic zone; the other 30 (Group B), had lesser disease (Gensini score: 28.6 +/- 18, p less than 0.001 vs Group A) and non visible collaterals to the ischaemic areas. Maximal ST depression and total exercise duration were similar in the 2 groups (2.5 +/- 0.6 vs 2.5 +/- 0.7 mV and 6.2 +/- 1.8 vs 6.8 +/- 1.9 min, respectively) but time and rate-pressure product to 1 mm ST depression were lesser in Group A (3.5 +/- 0.8 vs 4.8 +/- 0.6 min, p less than 0.01, and 14189 +/- 2451 vs 16081 +/- 2215 b/min x mmHg, p less than 0.04). Surprisingly, in Group A, the ST segment returned to the baseline more rapidly (5.5 +/- 1.6 vs 11.7 +/- 3.3 min, p less than 0.001), and the ischaemic area [time (s) x ST (mV)], measured in the recovery period, was also smaller (301 +/- 163 vs 621 +/- 260, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)