Histopathological sinus node classification and its relation to coronary atherosclerosis using an atherometric system.

Studies were conducted into 100 consecutive subjects (autopsy material), 53 men and 43 women between 31 and 70 years old, who had died a natural death. The HUDSON-procedure was used for histopathological analysis of the cardiac conducting system (CCS). About 48 microscopic slides of each subject, including sinus node (SN) tissue, were inspected by 4 pathologists in a blind study. The findings were classified by 3 different groups according to histopathological data of the SN, viz. changes and distribution of P and T cells, stroma, artery, and innervation of SN. The 3 major epicardial branches of coronary arteries were prepared for morphometric studies by WHO standards. A digitizer coupled to a microcomputer LTEL (Cuba, IBM-compatible) was used for quantitative evaluation of atherosclerotic lesions (AL), and all data were subsequently processed on the same computer, using a statistical commercial package (Number Cruncher Statistical System) for results. An atherometric system was used and proved to be a properly standardized methodology, suitable to characterize AL in any vascular sector or group of patients. The most remarkable results were as follows: Three-group classification was useful in estimating the association between pathomorphological data of SN and coronary atherosclerosis. The atherometric system proved to be a powerful tool to study and characterize atherosclerotic lesions in coronary arteries.