The purpose of the study is to describe and analyze the histopathological changes of the cardiac conduction system in the Sudden Infant Death Syndrome (SIDS). The teory that SIDS may be related to lethal cardiac arrhythmias or heart block due to structural abnormalities of the conduction system is attractive and still of particular interest. Postnatal morphogenesis of the human heart is an important part of its normal development. The term "resorptive degeneration", suggested by James in 1968, indicates the normal process of postnatal cardiac molding. Such moulding consists of cell degeneration, death and replacing in an orderly programmed way. However, such process, if exaggerated, could provoke blocking disruption of the pathway itself, and if defective could leave in place some accessory communication between the atrio-ventricular pathway and the adjacent ordinary myocardium. We analyze 69 hearts from autopsied cases of SIDS. The hearts were from 46 males and 23 females, ranging in age from 2 days to 13 months. All patients had no apparent reason other than SIDS to explain the cause of death. We analyzed 13 hearts as controls (explained death, ED). from 6 males and 7 females of the same age. Histological observations were focused on the heart's conduction system. The hearts were fixed in 10% formalin solution. Histological observations were focused on the cardiac conduction system which was removed in two blocks: the first included the sino-atrial node (SAN) and the "crista terminals", the second contained the atrio-ventricular node (AVN), His bundle and bundle branches. For the histological examination of the conduction system these blocks were cut on serial sections, with the technique devised by one of the present authors (L. Rossi). Were observed the following changes: resorptive degeneration (97% of SIDS, 77% of ED), His bundle dispersion (67% of SIDS, 31% of ED) Mahaim fibers (42% of SIDS, 31% of ED), cartilagineous meta-hyperplasia (55% of SIDS, 23% of ED), intramural right bundle (20% of SIDS, 23% of ED), intramural left bundle (1,5% of SIDS, 8% of ED), hemorrhage of the atrio-ventricular junction (19% SIDS) anomalous bifurcation (13% of SIDS), AVN dispersion (7% of SIDS), ring tissue (6% of SIDS), SAN hypoplasia (6% of SIDS), Kent fibers (3% of SIDS), Zahn node (1,5% of SIDS), His bundle hypoplasia (1,5% of SIDS). Despite the non-specificity of most of these findings, we believe that these changes, associated with particular conditions and/or neurovegetative stimuli, could cause potentially malignant arrhythmias. These data suggest the need for an accurate approach and examination of the cardiac conduction system in all SIDS cases.
|Titolo:||Pathology of the cardiac conduction system in the sudden infant death syndrome (SIDS) : preliminary results|
|Parole Chiave:||Cardiac conduction system ; sudden infant death syndrome ; SIDS ; post-mortem investigation|
|Settore Scientifico Disciplinare:||Settore MED/08 - Anatomia Patologica|
|Data di pubblicazione:||mag-1999|
|Enti collegati al convegno:||European Society of the Study and Prevention of Infant Death (ESPID)|
|Appare nelle tipologie:||01 - Articolo su periodico|