Impaired regional left ventricular function has been shown to improve after successful transluminal coronary angioplasty, but there are no data concerning the effect of coronary restenosis on this recovery. Therefore, the short- (1 month) and midterm (5.5 months) evolution of systolic regional left ventricular function was prospectively investigated in 41 patients undergoing successful coronary angioplasty. In patients with resting hypokinetic areas before angioplasty and no restenosis (n = 8), regional function improved from -6.0 +/- 2.9 to -2.9 +/- 2.4 SD/segment (P < 0.01) in the short-term, without further significant changes at mid-term. Patients with hypokinetic areas and coronary restenosis > or = 70% (n = 15) also showed early functional recovery from -5.1 +/- 2.2 to -1.4 +/- 2.5 SD/segment (P < 0.00001) but, in contrast with the other subset of patients, a significant reduction to -3.9 +/- 2.3 SD/segment (P < 0.0001) was observed at mid-term. In spite of this, regional function was still better than before angioplasty (P < 0.01). No significant changes were observed in patients without either asynergy or restenosis (n = 16). The small number of cases without preliminary hypokinesis and development of restenosis > or = 70% (n = 2) precluded an analysis of this situation, but a new and severe hypokinetic defect was recognized in one patient in a later study. We conclude that the improvement in regional myocardial function observed early after successful dilation of the culprit vessel is partially lost when significant restenosis develops.