POSTOPERATIVE HEMODYNAMIC IMPROVEMENT WITH PACED LINKAGE OF THE DONORAND RECIPIENT HEARTS FOLLOWING HETEROTOPIC CARDIAC TRANSPLANTATION

It has been shown that following heterotopic heart transplantation the recipient left ventricle ejects more effectively when it contracts ou t of phase with the donor left ventricle. However, this is rarely the situation, as the two hearts beat independently of one another and the denervated donor heart tends to beat faster than the recipient. In th is study the hemodynamic effects of connecting the two hearts by an ex ternal temporary dual-chamber pacemaker were evaluated. The donor righ t ventricle was sensed and the recipient right atrium paced after a ti med delay. The delay was adjusted so that recipient systole coincided with donor diastole. Eleven patients were studied in the first postope rative day. Pacing resulted in an improvement in cardiac output from 5 .0 to 5.6 l/min (p = 0.003) and a reduction in pulmonary capillary wed ge pressure from 16 to 12 mmHg (p = 0.0035). This was associated with a 35% reduction in inotrope requirements. It is concluded that sequent ial pacing of the two hearts is a useful adjunct to inotropic support in the postoperative period.