The objective was to determine which factors might help to predict the need for mechanical right ventricular support following insertion of a left ventricular assist device (LVAD). A retrospective analysis was performed on 24 patients with cardiomyopathies who had insertion of a LVAD as a bridge to heart transplantation at Presbyterian University Hospital during the period 1987 to 1991. Group 1 consisted of 18 patients who could be adequately supported with the LVAD alone, while Group 2 consisted of 6 patients who required additional support with a right ventricular assist device. Group 2 exhibited longer periods of hypotension on cardiopulmonary bypass, increased inotropic support and decreased right ventricular ejection fraction at time of chest closure post-LVAD.