EARLY HEMODYNAMIC-EFFECTS OF LEFT ATRIAL ADMINISTRATION OF EPINEPHRINE AFTER CARDIAC TRANSPLANTATION

We studied the hemodynamic effects of left atrial (LA) administration of epinephrine in 10 patients after cardiac transplantation, using a p rospective, randomized, double-blind, cross-over design. After allogra ft implantation, a LA catheter was inserted and epinephrine infusion c ommenced at 100 ng.kg(-1).min(-1). Each trial period consisted of 20 m in, with the LA and right atrial (RA) lines switched over between each period; hemodynamic measurements were taken after each time period. W hether epinephrine was administered via the RA or LA did not significa ntly alter hemodynamics (RA versus LA): mean (so) arterial blood press ure 67 (7.5) vs 64 (9.5) mm Hg (P = 0.16), mean pulmonary artery press ure 22 (4.0) vs 21 (9.4) mm Hg (P = 0.67), cardiac index 3.2 (1.1) vs 3.2 (1.1) L.min(-1).m(-2) (P = 0.83), pulmonary vascular resistance in dex 308 (157) vs 345 (157) dynes.s.cm(-5)/m(-2) (P = 0.30) or right ve ntricular ejection fraction 35% (11%) vs 32% (9.8%) (P = 0.23). Arteri al epinephrine plasma levels were similar (P = 0.16). There was no sig nificant pulmonary extraction of measured catecholamines. We observed no hemodynamic benefit of LA epinephrine administration. It may be tha t the cardiac transplantation population reacts differently compared w ith other cardiac surgical patients (possibly because pulmonary extrac tion of catecholamines is reduced). Because we did not observe a hemod ynamic advantage in patients immediately after cardiac transplantation , we would not recommend the use of LA epinephrine at the dose studied .