A New Technique for Bridging to Heart Transplantation: Feasibility of Monoventricularization of Bilateral Ventricles with LVAD

Abstract

Because the prognosis of ventricular septal perforation (VSP) and mitral regurgitation (MR) after acute myocardial infarction (MI) is remarkably poor, heart transplantation would be necessary for many of those patients. A new bridging technique was examined in canine models. The bilateral ventricles communicating through VSP were monoventricularized with mitral valve closure and maintained the pulmonary circulation, which had low vascular resistance. The systemic circulation was maintained by a left ventricular assist device (LVAD) placed between the left atrium and the aorta. VSP and MR were made in eight mongrel dogs (pulmonary to systemic flow ratio = 2.24 +/- 0.90). They were then monoventricularized and equipped with LVADs. The hemodynamic state was evaluated (a) in intact hearts, (b) after VSP and MR were made, and (c) after monoventricularization and assisted circulation by LVAD. Cardiac output was (a) 90.60 +/- 23.16, (b) 42.23 +/- 15.76, and (c) 73.43 +/- 15.14 ml/min/kg (a vs. c: not significant; a vs. b and b vs. c: p less than 0.001); mean aortic pressure was (a) 96.75 +/- 24.69, (b) 30.25 +/- 11.08, and (c) 66.50 +/- 18.40 mm Hg (a vs. b: p less than 0.01, a vs. c and b vs. c: p less than 0.05); central venous pressure was (a) 4.76 +/- 1.68, (b) 8.94 +/- 2.17, and (c) 10.68 +/- 2.43 mm Hg (a vs. c: p less than 0.01, a vs. b: p less than 0.05, and b vs. c: not significant). Mean pulmonary arterial pressure and mean left atrial pressure did not show any significant difference among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)