Effects of surgery for postinfarction ventricular tachycardia on parameters of left ventricular function

Heart failure is the leading cause of death in patients after surgery for v entricular tachycardia. This study examines the effects of antiarrhythmic s urgery on 4 parameters of left ventricular (LV) function. Global ejection f raction, segmental wall motion score, homogeneity of contraction, and diast olic Function were measured in 32 patients by technetium-99m radionuclide v entriculography. Ejection fraction was measured from the left anterior obli que image. Wall motion score was assessed semiquantitatively for 11 LV segm ents from 3 projections. Homogeneity of contraction was expressed as the SD of the LV phase analysis curve during systole from the left anterior obliq ue image. Diastolic function was expressed in terms of peak and mean first time derivative of the action potential (dV/dt) of the LV function curve. S ubgroup analyses were performed to distinguish the effects of aneurysmectom y, coronary artery bypass grafting, and changes in angiotensin converting e nzyme inhibitor therapy. Mean systolic function improved after surgery (eje ction fraction 22% vs 32%, p <0001; wall motion score: 20 vs 13, p <0.0001; phase analysis 18 vs 12, p <0.03), Mean diastolic function also improved ( peak dV/dt 0.83 +/- 0.32 vs 1.49 +/- 0.35, p = 0.006; mean dV/dt 0.41 +/- 0 .15 vs 0.76 +/- 0.27, p = 0.006), Improvements were not confined to those w ho had aneurysmectomy or coronary bypass grafting and were not explained by changes in vasodilator therapy. Thus, antiarrhythmic surgery does not inhe rently damage LV function. Significant improvements were observed in most p atients. Failure to improve indicated a poor longer term prognosis. (C)2000 by Excerpta Medico, Inc.