Myocardial perfusion during warm antegrade and retrograde cardioplegia: A contrast echo study

Background. We evaluated distribution of warm antegrade and retrograde card ioplegia in patients undergoing coronary artery bypass grafting (CABG). Methods. Myocardial perfusion was evaluated pre- and post-CABG using transe sophageal echocardiography with injection of sonicated albumin microbubbles (Albunex) during warm antegrade and retrograde cardioplegia. The left vent ricle (LV) was evaluated in five segments and the right ventricle (RV) was evaluated in two segments. Segmental contrast enhancement was graded as abs ent (score = 0), suboptimal or weak (score = 1), optimal or excellent (scor e = 2), or excessive (score = 3). Results. Pre-CABG cardioplegic perfusion correlated weakly with severity of coronary artery stenoses (r = 0.331 and 0.276 for antegrade and retrograde cardioplegia, respectively). Antegrade cardioplegia administration resulte d in 98% and 96% perfusion to the left ventricle pre- and post-CABG, respec tively. Retrograde cardioplegic administration resulted in reduced LV perfu sion, with 86%, (p = 0.032 from antegrade) and 59% (p < 0.001 from antegrad e) pre- and post-CABG, respectively. The average LV perfusion score (mean /- SEM) was greater with antegrade than retrograde cardioplegia both pre-CA BG (1.93 +/- 0.04 vs 1.53 +/- 0.11, p < 0.001) and post-CABG (1.63 +/- 0.07 vs 1.19 +/- 0.13, p = 0.004). RV perfusion was poor with both techniques p re-CABG, but improved significantly with antegrade cardioplegia post-CABG. Conclusions. We conclude that warm antegrade cardioplegia results in better left ventricular perfusion than warm retrograde cardioplegia. Right ventri cular cardioplegic perfusion was suboptimal, but the best delivery was achi eved with antegrade cardioplegia after coronary bypass. We therefore recomm end construction of the saphenous vein graft to the right coronary artery e arly in the operative procedure. (Ann Thorac Surg 1999;68:955-61) (C) 1999 by The Society of Thoracic Surgeons.