| Background: Coronary heart disease (CHD) is the primary cause of disease resulting in sudden death, and atherosclerosis (AS) in coronary artery is the pathological foundation of sudden coronary death (SCD). In fact, the pathologic change of tunica intima (TI) is the histological foundation of AS, and even more, it is determined by the state of the internal elastic lamina (IEL) intensively. Therefore, if more morphologic materials of the coronary arteries in CHD and SCD are known, it should be studied of the IEL and TI in coronary arteries.Objective: To investigate the relationship between the pathologic change of IEL and thickness of TI in coronary arteries and SCD.Methods: For anatomical material we used coronary arteries removed from cadavers of 60 people who were autopsied in the forensic pathology department of Tongji Medical College and divided into SCD group (30 cases) and the control group (30 cases) according to the cause of death. The control group was classified into two subgroups of control group 1 and 2 (15 cases for each subgroup) on the basis of the stenosis degree of coronary artery. The hearts and the coronary arteries were examined carefully by usual pathologic method. The proximal portions of the left anterior descending (LAD) of coronary arteries were taken from the hearts. The samples were embedded by usual method, sectioned (4μm) and stained by Hematoxylin-Eosin (H.E.) and dual-combination staining (displaying elastic fibers and collagen fibers). The pathologic change of cardiac muscle and coronary artery, especially internal elastic laminas, were observed by microscope. By using usual pathologic method and image analysis technology, the thickness of AS plaques in coronary artery was measured and the defective rate of IEL was calculated.Results: The coronary arteries of 60 subjects ranging in age from 17 to 83 years old were averaged 47.2 years old, including 45 males, 15 females. Of 30cases in SCD group, there were 24 males and 6 females, ranging in age from 30 to 83 years old (averaged 52 years). In the control group, there were 21 males and 9 females, with ranging in age from 17 to 80 years old (averaged 42.3 years). There were 23 cases ofⅣgrade stenosis in coronary artery and 7 cases ofⅢgrade in SCD group; 5 cases ofⅣgrade and 10 cases ofⅢgrade in control group 1, no serious stenosis was found in the cases of control group 2. Among the all 60 cases, which followed 30 cases being lipidosis, cholesterol crystallization, and 17 cases being calcareous deposit, especially in SCD and contrast 1 groups, including 4 cases plaque bleeding in SCD group. Specific stained of coronary arteries, elastic fibers including IEL and the second IEL were dyed to be blue and collagen fibers, red; the backgrounds, pallide-flavens. Some IEL became straight line and loose original curve. The second IEL emerged was 26.67% in SCD group and 53.33% in control group (46.67% in control group 1 and 60% in control group 2 respectively). The data of image analysis and statistic:①The thickness of TI: there was significant difference between the SCD group and the control group (P<0.01); ditto, there was significant difference between the SCD group and the control group 2 (P<0.01), and between the control group 1 and 2 (P<0.01); but there was no difference between the SCD group and the control group 1 (P>0.05).②Defective rate of IEL: there was significant difference between the SCD group and the control group (P<0.01); and, there was significant difference between the SCD group and the control group 2 (P<0.01) and between the control group 1 and 2 (P <0.01); and there was significant difference between the SCD group and the control group 1 (P<0.05).③Correlation of defective rate of IEL with the thickness of TI: for all cases, it was positive correlation (r=0.6579, P<0.01);but there was no correlation in the SCD group (r=0.0950, P>0.05); the defective rate of IEL correlated positively with the thickness of TI in the control group (r=0.8023, P<0.01), but there was no correlation in the control group 1 (r=0.5123, P>0.05) and the control group 2 (r=0.2217, P>0.05) respectively.④The pathological defection of IEL (≥20%): the differences were significance between the SCD group and the control group, between the SCD group and the control group 2, and between the control group 1 and 2, but no difference between the SCD group and the control group 1.Conclusions: There were some degree relationship of pathologic change of IEL and thickness of TI in human coronary arteries with SCD. And the defective rate of IEL correlated positively with the thickness of TI in human coronary arteries.
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