Crib death : further support for the concept of fatal cardiac electrical instability as the final common pathway

This is a review of current knowledge as well as remaining challenges about the role of the cardiac conduction system in relation to crib death. Both the morphological and functional derangement underlying crib death remain poorly understood, assuring that it remains to be a major medical and social problem. The cardiac hypotheses postulating that crib death could be due to lethal cardiac electrical instability was considered of great interest in the 1970’s. After a general abandonment of the conduction studies in crib death, the cardiac concept of crib death is gathering a renewed interest, as well as the pathogenesis of infantile junctional tachycardia. The cardiac conduction system findings of resorptive degeneration, His bundle dispersion, Mahaim fibers, cartilaginous meta-hyperplasia, persistent fetal dispersion, left sided His bundle, hemorrhage of the atrio-ventricular junction, septation of the bifurcation, atrio-ventricular node dispersion, sinus node hypoplasia, Zahn node, His bundle hypoplasia, atrio-ventricular node and His bundle dualism have now all been observed and documented in various cases of crib death. Their important role in pathogenesis of crib death will be discussed.