[Abolition of pacing induced akinesia after aorto-coronary bypass grafting in patients with stable angina (author's transl)].

Abstract

Hemodynamic studies were performed in 6 normal individuals, 8 patients with severe obstruction (more than 85% stenosis) of the left anterior descending coronary artery (LAD), 10 patients with patent LAD grafts and 4 patients with stenosed or occluded LAD grafts. All patients were suffering from stable angina before operation. Monoplane ventriculograms and left ventricular pressure determinations were carried out at rest and immediately after ventricular pacing (170/min.). Anterior wall motion was determined from half-diameter shortening and ejection fraction was calculated using the area-length method. Heart rate and left ventricular systolic pressure were comparable in all 4 groups at rest and after pacing. Normal individuals and patients with patent grafts to the LAD showed no significant change of anterior wall motion, ejection fraction and left ventricular enddiastolic pressure after pacing as compared to rest. Patients with LAD stenosis showed a significant decrease of anterior wall motion, of ejection fraction and an increase of left ventricular end-diastolic pressure. Patients with graft failure revealed a drastic though not significant decrease of anterior wall motion. Decrease of ejection fraction and increase of left ventricular end-diastolic pressure were significant. Thus, in patients with stable angina and severe coronary stenosis regional and total left ventricular function may well be maintained at rest but become severely impaired after pacing. Successful revascularization abolishes this ischemic response.