Triiodothyronine has been introduced as a promising new supplement for patients undergoing openheart surgery. This manuscript will review the existing literature regarding supplementation with triiodothyronine in children.

Infants and children undergoing cardiac surgery experience a profound decrease in levels of free and total triiodothyronine. These decreases are of sufficient magnitude to effect cardiac function. Supplementation with triiodothyronine has been shown to enhance myocardial performance, improve recovery of circulating levels of triiodothyronine, and to result in an increase in mixed venous oxygen saturation. As encouraging as these results are, there is no definitive study which demonstrates that triiodothyronine improves clinical outcome in children. Thus, while triiodothyronine appears to have promise as a supplement for children undergoing openheart surgery, more studies are needed to establish the efficacy of such therapy scientifically.