Characteristics of Mechanical Asphyxia:A Retrospective Epidemiological Study in Two Developed Cities in China

Background:Mechanical asphyxia(MA)is multi-classified.Some epidemiological characteristics are shared and the others different among different MA types.Aims and Objectives:To reveal the characteristics of different types of MA and provide reference data for forensic identification of MA.Materials and Methods:We analyzed 913 cases to reveal the epidemiological characteristics of MA in Dongguan and Guangzhou,China.Results:Seven types of MA were identified and strangulation accounted for up to 89.2%.Those aged 20-29 were the most susceptible to all types,except for traumatic and positional asphyxia.Suicide accounted for 96.6%of hanging cases,and accident was the main manner of death in cases of choking,traumatic,and positional asphyxia.Homicide was the most common in cases of ligature strangulation(LS),manual strangulation(MS),smothering,and asphyxia concomitant with lethal mechanical injury.The homicide rate in LS was positively correlated with the rate of female victims(P<0.001,OR=21.14).In MS,the ratio of female:male was 101:15 in homicide.Compared to native residents,migrant workers were more likely to suffer from LS and MS.Rope was used in 50.8%of hanging cases,while LS tools were evenly distributed.Ligature marks were mostly found above the thyroid cartilage in both hanging and LS cases.The U shaped marks were shown in 51.01%of hanging cases but absent in LS cases.In LS,ligature marks completely encircling the neck,discontinuous marks,as well as≥two marks,were more(P<0.001)than in hanging.In LS and MS cases,abrasion and subcutaneous hemorrhages on the neck were more frequent than in hanging cases(P=0.004 and P<0.001),but the difference in frequency of blister marks was opposite(P<0.001).Conclusion:In summary,this study revealed the epidemiological characteristics of the MA cases in Guangzhou and Dongguan cities.The characteristics of death scene and autopsy findings are important in differentiation of different types of MA,especially between suicide and homicide.

Brugada syndrome:a fatal disease with complex genetic etiologies–still a long way to go

Brugada syndrome(BrS)is an arrhythmogenic disorder which was first described in 1992.This disease is a channelopathy characterized by ST-segment elevations in the right precordial leads and is susceptible to sudden death.BrS is a fatal disease with gender and age preferences.It occurs mainly in young male subjects with a structurally normal heart and silently progresses to sudden death with no significant symptoms.The prevalence of BrS has been reported in the ranges of 5-20 per 10000 people.The disease is more prevalent in Asia.Nowadays,numerous variations in 23 genes have been linked to BrS since the first gene SCN5A has been associated with BrS in 1998.Not only can clinical specialists apply these discoveries in risk assessment,diagnosis and personal medicine,but also forensic pathologists can make full use of these variations to conduct death cause identification.However,despite the progress in genetics,these associated genes can only account for approximately 35%of the BrS cases while the etiology of the remaining BrS cases is still unexplained.In this review,we discussed the prevalence,the genes associated with BrS and the application of molecular autopsy in forensic pathology.We also summarized the present obstacles,and provided a new insight into the genetic basis of BrS.

The forensic pathological analysis of sport-related sudden cardiac death in Southern China

Studies regarding sport-related sudden cardiac death(SCD)mainly focus on competitive ath-letes;similar data are rare in the general population,especially in China.We conducted a retrospective study(from September 1998 to August 2013)to investigate the aetiological distribution and epidemiological features of sport-related SCD in Southern China.Selections of cases are based on details,and two subgroups were established:one was the sport-related SCD group,and the other was the disease-free accident victims group which was matched with the sport-related SCD group in gender,age and year of death.Among the 3770 sudden-death cases,1656 cases were SCD cases.A total of 65 cases(57 males)out of 1656 SCD cases were sport-related.The age range of the 65 sport-related SCD cases was from 12 to 68 years old with a mean(35.92±14.23)years old.Only two of these cases were competitive athletes.The most common circumstances of the 65 sport-related SCD cases were heavy physical labour(46.15%)and running(30.77%).The three leading forensic diag-noses were the coronary atherosclerotic disease(CAD,28 cases),cardiomyopathy(CM,14 cases)and sudden unexplained death(7 cases).CM was the most common forensic diagno-sis in those?35 years old,while CAD was the most common one in those>35 years old.Left anterior descending in which atherosclerotic plaques was most commonly found was the principal artery branch associated with sport-related SCD.There was a statistically signifi-cant difference in the weight of hearts between the 65 sport-related SCD cases and 65 dis-eases-free accidental cases.This study highlights the need to attract public attention to sport-related SCD and to issue a prevention strategy to the public,and to make the SCD-related genetic sequencing a routine tool in both forensic pathological examination and clinic screening.

Sudden Cardiac Death and Cardiac Sodium Channel Diseases

Sudden cardiac death(SCD),accounting for a substantial part of the forensic autopsy,is a leading cause of mortality worldwide.Lethal arrhythmia due to sodium channel diseases is recognized as one of the most prevalent etiologies of SCD.In these disorders,defective cardiomyocytes,including the pacemaker and the working cardiomyocytes,would manifest as abnormal electrical activity and morphology,thereby predisposing individuals to SCD.It is always a problem for forensic pathologists to adjudicate a sudden death caused by sodium channel diseases since structural changes in those cases are often inconspicuous.With the advent of the molecular autopsy,forensic pathologists can conduct targeted gene testing to identify the risk of SCD for family members of the probands.This review aims to discuss the relationship between SCD and sodium channel diseases,clarify the underlying mechanisms,and provide prophylactic suggestions for the relatives of SCD patients at risk.