Abstract: In the preset study the general innervation of the cardiac conduction system(CCS) from four sudden infant death sydrome(SIDS) cases and three age-matched controls was investigated.This was achieved by the conbination of specific S100 and PGP 9.5 atibodies,indirect immunoenzymatic technique and autoclave pretrement for antigen retrieval.The results showed that in the three control cases,the general innervation was not uniform throughout the CCS,the rank order being sino-atrial node(S AN)>atrio-ventricular node(AVN)>bundle of His(HB). The four SIDS cases displayed the same pattern as the controls.Further detailed studies are required to clarify the possible role of the developmental abnormality of nerve elements associated with the CCS in genesis of SIDS.

Key words: sudden infant death syndrome, cardiac conduction system, nervous tissue, immunohisto-chemistry