This study compared regional and global left ventricular function of a population of patients with a stenosis of the left anterior descending (LAD) artery and a control population in a prospective 18 months protocol. The 25 patients in the LAD group, 21 men and 4 women (55 +/- 9 years), had a pure and isolated stenosis of the LAD artery (70 +/- 8%) without infarction with normal global systolic function. The 12 patients in the control group strictly no cardiovascular disease after extensive investigation. Cardiac catheterisation was carried out in the conventional manner under the same conditions in both groups, after withdrawal of all medication. Regional wall motion was studied on 30 degrees right anterior oblique selective left ventriculography by a technique derived from Ingel's method using every frame of a cycle in terms of amplitude, velocity and time of segmental shortening and lengthening. The patients in the LAD group had normal cardiac function and no hypo or akinesia. The principal characteristic was the finding of anterior wall asynergy which was significantly different from the uneven contraction common in control subjects. This asynergy is observed from the end of systole to early diastole and features: early termination of anterior wall contraction (normalised contraction time: 86 +/- 13% vs 97 +/- 4% in the control group; p less than 0.02; and 90% in the inferior zone, NS, compared with the control group and p less than 0.05 compared with the anterior wall); dephased velocities of segmental shortening at the end of ejection (positive velocities in the inferior zones 0.17 +/- 1.7 circ/sec and negative velocities in the anterior zones, -0.34 +/- 2.2.(ABSTRACT TRUNCATED AT 250 WORDS)