Sleep apnea and Q-T interval prolongation--a particularly lethal combination.

We have discovered a 20-day-old infant who possessed anatomic evidence of chronic hypoxemia with right ventricular hypertrophy and who died in hypoxic hypoxemia with a postmortem PO2 of 4 mm. Hg. Subsequently, and ECG was discovered which had been obtained at one day of age and showed Q-T interval prolongation along with T-wave alternation. We believe this case to be one of the first to substantiate the mechanism for SIDS as proposed by Schwartz, 26 with hypoxia acting synergistically with a prolonged Q-T interval causing sudden unexpected death in this infant--providing a link between cardiac and respiratory mechanisms of death.