Triiodothyronine as an inotropic agent after open heart surgery

Two small, randomized, blind clinical trials comparing the administration of triiodothyronine with that of placebo have been carried out in patients undergoing myocardial revascularization. In patients with a left ventricular ejection fraction of less than 30% (study I), triiodothyronine administration at the end of operation and during the initial 24 hours after operation was associated with a significantly reduced need for conventional inotropic agents (p less than 0.02) and diuretics (p less than 0.02). In patients with a left ventricular ejection fraction of greater than 40% (study II), triiodothyronine administration resulted in significantly improved stroke volume (p less than 0.01) and cardiac output (p less than 0.02) and reduced systemic (p less than 0.01) and pulmonary (p less than 0.05) vascular resistances. There were no adverse reactions to triiodothyronine in the dosages that were used. Triiodothyronine appears to be beneficial to all patients undergoing open heart surgery.