Structure of the human tricuspid valve leaflets and its chordae tendineae in unexpected death. A forensic autopsy study of 400 cases

OBJECTIVE: Congenital variations are known to be potential candidates for mechanical trauma leading to tricuspid valve lesions. For this reason, a detailed examination of heart valves as well as chordae tendineae should carefully be performed to clarify the reason of sudden death with no apparent cause. The aim of this study is to investigate the relationship of valvachordal anatomy in tricuspid valve in sudden deaths, and mainly cardiac disease in connection with its structure as well as leading congenital changes.

METHODS: The 400 human hearts were collected between 2000 and 2002 from 400 autopsy cases during a medicolegal autopsy with permission from the Council of Forensic Medicine, Izmir, Turkey. Morphometric and morphological data were obtained in Ege University Faculty of Medicine, Department of Anatomy from each valve namely area, basal width, depth of leaflets, depth of commissure, number of chordae tendineae and their relation to the leaflets. These data were correlated for cardiac and noncardiac death cases.

RESULTS: The results of this anatomical study may explain the increased incidence in wide variations of chordae tendineae in deaths of cardiac origin. In 40 hearts, we found 2 leaflets (20%), in 140 (70%) 3 leaflets and in 20 hearts there were 4 leaflets (10%) in deaths of noncardiac origin. We found 2 leaflets in 36 hearts (18%), 3 leaflets in 130 hearts (65%) and there were 4 leaflets in 34 hearts (17%) in deaths of cardiac origin. Although chordal abnormalities were extremely rare in cardiac death cases, some chordae tendineae retained a normal or near-normal appearance, while others were thickened and shortened in cardiac death cases. Higher ratio of abnormal chordae that were too short and too thick was also significant.

CONCLUSION: This condition negatively affects the feeding of chordae and leaflets and acts as a culprit of cardiac deaths, since aging starts at an early stage. This situation changes the verdict in legal affairs. For this reason, the valvachordal structure should be carefully examined prospectively in autopsies.