Secondary elastic recoil after transluminal coronary angioplasty is a constant and immediate phenomenon after successful coronary angioplasty. It was studied by quantitative coronary angiography in 75 consecutive patients undergoing transluminal coronary angioplasty. This procedure was performed on lesions presumed to be responsible for the clinical presentation. The population was divided into 3 groups: stable angina (25 patients), unstable angina (25 patients) and recent post-infarction ischaemic syndromes (25 patients). There were 57 men and 18 women (mean age 59 +/- 11 years) with 31 left anterior descending (LA), 29 right coronary (RC) and 15 left circumflex (Cx) dilatations. The lesions dilated were eccentric in 29 cases and calcified in 37 cases whereas only one thrombus was detected at coronary angiography. The elastic recoil appreciated 10 mn after the last balloon inflation was 0.97 +/- 0.28 mm for the whole population. There was no significant difference between the 3 groups studies (respectively 0.94 +/- 0.24 mm; 0.96 +/- 0.26 mm; 0.99 +/- 0.33 mm). This appeared to be greater than the RC (1.06 +/- 0.30 mm) with respect to the Cx (0.86 +/- 0.23: p < 0.02) or LAD (0.92 +/- 0.25 mm: p < 0.04). Overall, a balloon to vessel diameter ratio > 1 and a lesion length > 10 mm were parameters predicting greater secondary elastic recoil (p < 0.07 and p < 0.001 respectively), whereas the degree of eccentricity only played a role in the post-infarction ischaemic syndromes and calcification only in unstable angina (p < 0.01 and p < 0.001 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)