Mechanisms of transplant right ventricular dysfunction

Academic Article

Abstract

  • Objective: Right ventricular (RV) dysfunction remains the leading cause of early mortality after cardiac transplantation. The effect of brain death and subsequent hypothermic cardioplegic arrest and storage on subsequent post transplant right ventricular function was examined. Summary Background Data: Right ventricular dysfunction in the donor heart usually is attributed to failure of the donor right ventricle to adapt to the sudden increase in afterload (pulmonary vascular resistance) in the recipient. Strategies to improve ventricular mechanics in the postoperative period are aimed at reducing pulmonary vascular resistance with vasodilators or augmenting right ventricular contractility with inotropic agents. Events occurring in the donor heart (brain death, hypothermic cardioplegic arrest, and storage) also may be directly related to post transplant RV dysfunction. Methods: A canine model of brain death and orthotopic cardiac transplantation was used. A dynamic pressure-volume analysis of RV mechanics was performed using micromanometers and sonomicrometric dimension transducers. Systolic function was assessed by measurement of preload recruitable stroke work (PRSW). Brain death was induced in 17 dogs by inflation of an intracranial balloon. Right ventricular function then was assessed serially to 6 hours (PRSW). Right ventricular adrenergic β receptor density and function was sampled at control and after 6 hours of brain death. The effect of cardioplegic arrest and hypothermic storage was assessed in a second group of 17 dogs, using the same instrumentation and method of RV analysis. Results: A significant decrease in right ventricular PRSW occurred after brain death, with the average decrease being 37% ± 10.4% from the control. The RV myocardial β adrenergic receptor density did not significantly change (253 ± 34 fmol/ng control vs. 336 ± 54 fmol/ng after brain death). The adenylyl cyclase activity of the RV β receptor was assessed and was not altered by brain death. Orthotopic transplantation after cardioplegic arrest and hypothermic storage significantly decreased RV PRSW from 23.6 ± 2.0 x 103 erg to 13.5 ± 1.4 x 103 erg. Conclusions: These data indicate that the donor right ventricle is exposed to factors significantly detrimental to its mechanical performance well before facing an increased afterload in the recipient. Strategies to reduce RV dysfunction associated with brain death and hypothermic storage could positively impact post-transplant survival.
  • Authors

    Published In

  • Annals of Surgery  Journal
  • Digital Object Identifier (doi)

    Author List

  • Van Trigt P; Bittner HB; Kendall SW; Milano CA
  • Start Page

  • 666
  • End Page

  • 676
  • Volume

  • 221
  • Issue

  • 6