Heterotopic heart transplantation: mid-term hemodynamic and echocardiographic analysis--the concern of arteriovenous-valve incompetence.

To assess the hemodynamic contribution of both hearts after heterotopic heart transplantation, we examined recipients by cardiac catheterization and Doppler echocardiography. Since September 1984, immunosuppression consisted of cyclosporine, azathioprine, methylprednisolone, and antithymocyte globulin. In this time interval, 55 orthotopic and 14 heterotopic transplants have been performed. The indications for heterotopic transplant were elevated pulmonary vascular resistance (greater than 4 Wood units), in 10 patients, or gross (greater than 20%) donor-recipient weight mismatch, in six patients. Two patients belonged to both groups. The 1-year survival rate was 63%; currently seven of the 14 patients are alive. Cardiac output (as measured by dye dilution curves and by the Fick method) increased from 4.2 L/min preoperatively to 6.1 L/min in both groups postoperatively (mean follow up, 5.3 months; p less than 0.0005); the transpulmonary gradient fell from 18.5 to 12.3 mm Hg, the pulmonary vascular resistance from 4.4 to 2.4 Wood units (p less than 0.01). The echocardiographic findings were as follows: left ventricular end-diastolic diameter (mm) in the recipient heart was 67.4 +/- 12 and in the donor heart, 42.6 +/- 8.7. Fractional shortening (%) in the recipient heart was 7.1 +/- 2.9 and in the donor heart, 30.4 +/- 10.4. The Doppler technique revealed a cardiac output contribution-ratio (CO donor/CO recipient) of 3.0 +/- 0.61 on average. In all recipient hearts mild and moderate mitral and tricuspid regurgitation was discovered. In the donor heart all mitral and tricuspid valves were found to be incompetent; this was severe in 66% and 11% of the mitral and tricuspid valves, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)