Theories of cardiovascular causes in sudden infant death syndrome.

The sudden infant death syndrome (SIDS) is defined as sudden death in infants, unexpected by history, for which no cause is found at autopsy . The peak rate of SIDS occurs between and 3 months of life, and it is uncommon before 1 month and after 6 months (1) . Survivors of episodes that seem to be life threatening (apparent life-threatening events) are usually called near-miss for SIDS, or simply near-SIDS . Although the relation between these live infants and those who die suddenly is disputed, there are no diseases known to humans that have no survivors ( ) . Without these living subjects very little can be determined about the pathophysiology of SIDS . In considering the cause of sudden death at any age, it is worth beginning with the final pathway to death, apnea versus arrhythmia . Froggatt et al . (3) asserted that identification of this final pathway was the outstanding problem in the study of SIDS . In this process, it is necessary to distinguish between primary and secondary-or terminaldisorders ; ventricular fibrillation secondary to prolonged hypoxia should be distinguished from that resulting from the Romano-Ward syndrome . This editorial review addresses the possibility that SIDS is due to a primary cardiac disorder .