Commotio Cordis Caused by Violence in China

Commotio cordis (CC) is a recognized rare cause of sudden death in which an apparently minor blow to the chest causes ventricular fibrillation and cardiac arrest. CC diagnosis is still a challenge for forensic pathologists. A retrospective study of 9794 autopsy cases was conducted at the Department of Forensic Medicine, Tongji Medical College (DFMTMC, China) from 1955 to 2014. A total of 39 cases (0.4%) were determined to be caused by CC. A male preponderance (male to female of 37:2) was found in the victims, whose age ranged from 13 to 47 years, including more than 85% individuals in their 10s and 20s. Most victims (27 cases, 69.2%) came from village. The highest rate of victims was found for middle school and college students (15 cases, 38.5%), followed by prisoners (11 cases, 28.2%), farmers (9 cases, 23.1%), workers (3 cases, 7.7%), and office staff (1 case, 2.6%). Chest blows were produced by fists (28 cases, 71.8%), feet (6 cases, 15.4%), knee (2 case, 5.1%), head (1 case, 2.6%), or objects (2 cases, 5.1%). Witness statements indicated that most victims collapsed after being impacted in the precordium. The autopsy findings were unremarkable except bruises, contusions, or subcutaneous hemorrhage in the anterior chest (13 cases), bleeding of intercostal muscles (5 cases), and disperse focal petechiae of the epicardium (11 cases). All CC cases in this study were caused by violent attacks and related to criminal processes. Correct diagnosis of CC due to violence has important implications in the judicial system. (Medicine 94(51):e2315) Abbreviations: BMI = body mass index, CC = commotio cordis, DFM-TMC = Department of Forensic Medicine, Tongji Medical College. INTRODUCTION , PhD, Wei Lin, MD, and Hongmei Dong, PhD like impact to the precordium that, through intrinsic cardiac mechanisms, which gives rise to disturbances of cardiac rhythm of various type, duration, and severity, including sudden cardiac death, in the absence of structural damage which would explain the observed effects.’’ In the middle of the 18th century, CC was firstly described in the context of chest trauma among workers due to accidents; then it was distinguished from contusio cordis by Schlomka. In recent years, CC has been increasingly reported and is considered an important cause of sudden cardiac death in young individuals mainly involved in sporting activities. Data from the National Commotio Cordis Registry in Minneapolis showed that 224 cases were reported from 1996 to 2010. It is now realized that CC events also can occur in violent attack, indeed sporadic accounts of CC caused by violent attack have been documented in forensic practice. However, this has not attracted widespread attention in the general public and even the medical community. Moreover, this kind of CC is very likely to enter the criminal justice system for murder prosecution. Thus, CC due to violent attack should be paid more attention in the forensic science. To our knowledge, relatively few detailed analytical data from autopsy studies on CC caused by violent attack have been published. The objective of this study was to describe the epidemiological characteristics of the 39 CC autopsy cases examined by the Department of Forensic Medicine, Tongji Medical College (DFM-TMC), Wuhan, ficulty, and forensic implications of CC due to violent attack were also discussed. MATERIALS AND METHODS Study Sample As 1 of the 6 major forensic institutes in China, DFM-TMC assists police, courts, public health departments, hospitals, and sometimes the decedents’ families to provide forensic services such as autopsy, pathological examination, and toxicological analysis in central China. All autopsy cases assessed by DFMTMC from January 1, 1955 to December 31, 2014 were reviewed. The causes of death were determined after complete and systematic autopsy, medical history review, suspect and witnesses’ testimony, and toxicological analysis. Age, gender, occupation, police investigation reports, and autopsy findings were analyzed. According to the references, the inclusion criteria of CC was: verifiable documentation of the event occurrence; a witnessed event that victim collapsed instantly after a blunt blow to precordial area; no structural injury of the sternum, ribs, ing cardiovascular diseases. Excluded re tissue decomposition, lethal diseases s, and positive toxicological evaluation. www.md-journal.com | 1 by farming and had a lower education; and the other 2 female Total 39 cases were diagnosed as CC. During the same period, 39 cases of sudden non-CC deaths, that matched the CC by age and gender, were selected as control group. The control group included 26 cases died of severe craniocerebral injury, 7 cases of electrothanasia, 4 cases of mechanical asphyxia, and 2 cases of high falling death. Statistical Analysis Statistical analyses were conducted by SPSS 20.0. Continuous data are presented as mean standard deviation, whereas categorical variables were expressed as number and/ or percentage. Independent samples t-test was performed to compare the means between two groups. P value< 0.05 was considered statistically significant. RESULTS Between 1955 and 2014, a total of 9794 deaths were investigated by DFM-TMC, among which 39 cases (0.4 %) were determined to be caused by CC (Table 1). There were 37 males (94.9%) and 2 females (5.1%), aged between 13 and 47 years, including more than 85% individuals in their 10s and 20s (Figure 1). The highest rate of victims was found for middle school and college students (15 cases, 38%), followed by prisoners (11 cases, 28%), farmers (9 cases, 23%), workers (3 cases, 8%), and office staff (1 case, 3%) as shown in Figure 2. Accordingly, most cases occurred at school, home, in the prison or outdoors, and all were caused by fight or assaults. Chest blows were produced by fists (28 cases, 71.8%), feet (6 cases, 15.4%), knee (2 case, 5.1%), head (1 case, 2.6%), or objects (2 cases, 5.1%). Generally, the victims collapsed immediately after being impacted in the precordium. Some manifestations included pallor (9 cases, 23.1%), urinary incontinence (8 cases, 20.5 %), ptysis (7 cases, 18.0%), dyspnea (5 cases, 12.9%), and hyperspasmia (2 cases, 5.1%) (Table 2). Cardiopulmonary resuscitation was attempted only in 2 victims. In one case, the emergency medical services arrived on the scene within 15 minutes. Vital signs showed: heart rate, 30/ minutes, blood pressure, 40/10 mmHg. In the second case, paramedics came 10 minutes after blow and found the victim in cardiac arrest. She was administered chest compressions immediately and electrocardiography showed ventricular fibrillation (Figure 3). Despite aggressive resuscitation, the victims finally died. The systematic autopsy and toxicological reports for each case were reviewed carefully (Table 3). The victims’s average body mass index (BMI) was 21.14 1.2, which was a little lower than that of the control group. However, the difference of BMI between the 2 groups is not significant (P> 0.05). Notably, all cases were witnessed or had documentation of the events leading to CC. Gross examination of the body revealed no remarkable finding except for bruise, contusion, or subcutaneous hemorrhage in the anterior side of the chest in 13 cases (33.3%) (Figure 4). Internal examination showed no injury of the sternum, ribs, lungs, heart, or main artery. There was intercostal muscle bleeding around the precordium in 5 cases (12.8%) and disperse equirotal petechiae of the epicardium in 10 cases (25.6%). The hearts were normal in size and 6 cases that showed relative heart hypertrophy (330–360 g). However, the difference of heart weight between the 2 groups is not significant (P> 0.05). No abnormalities were observed in the coronary arteries, cardiac valves, pericardium, or conduction Mu et al system except for disperse focal petechiae of the epicardium in 11 cases (28.2%), and focal contraction band necrosis in 1 case. The remaining internal organs were normal macroscopically 2 | www.md-journal.com and microscopically. Postmortem toxicological analysis yielded negative results. All victims came from central China including Hubei and Henan Province, of which 27 cases (69.2%) from village, 7 cases (18 %) from county, and 5 cases (12.8%) from city. A total of 14 of the 39 cases had the detailed police investigation about family information, with 5 cases that showed special family background: a middle school student lived with her grandma after her parents’ divorce; a high school student was a ‘‘left behind’’ children whose parents and 2 brothers were migrant workers and rarely at home; a technology high school student was raised by his mother since his father died, his mother lived Medicine Volume 94, Number 51, December 2015 victims were all housewives and suffered from physical abuse by their intimate partner. DISCUSSION This study presented the first-hand material regarding forensic examination of CC deaths in China by an independent institute. All the CC deaths were caused by violent attack, with many aspects in epidemiology differencing from findings described for US cases, where CC mostly occurs in sporting activities (Table 4). The preference in violent events may be explained in part by the typical American sports such as baseball and ice hockey, which are considered risk activities for CC in US, are not as popular in China. Currently, the precise incidence of CC resulting from assaults is still unknown because of the worldwide absence of systematic and mandatory reporting. On the basis of data from the National Commotio Cordis Registry in US, only 6 CC cases resulting from blow during fights and scuffles were found from 1991 to 2001 (0.6 cases per annum). We identified 39 cases of CC after reviewing 9794 autopsies during the past 60 years (0.65 cases per annum), the incidence is similar to that of US. As previously reported, most CC victims in this study were adolescents and young individuals. The higher prevalence of CC in individuals younger than 20 years is likely related to more ball-related sports and fighting participations. Moreover, that the relatively thin, underdeveloped, compliant chest cage (and immature intercostals musculature) in young people allows a more easier transmission of energy to the heart upon impact. However, the average BMI of the victim was not statistically different compared to the control group in our study. Notably, victims are overwhelmingly male. A plausible explanation for the male predominance is that they are more aggressive compared with females and more likely influenced by fight participation. Link et al speculated that differences in genes encoding ion channels and their biological modification by sex hormones may also be related to a higher incidence of CC in males. Unlike most US CC decedents who were players, the majority of victims were immature students and louche prisoners in the present study. Our findings indicate that these individuals might be a high risk group for CC occurring as a result of violent attack. According to the current study, most victims came from village and born of a worker or farming family in which most of family member did not have a good economic situation and receive a good education. Family history showed some victims were ‘‘left behind’’ children or came from the single parent family. So, the special familial environment might affect the victim’s psychological development, who are more irritable and aggressive. Therefore, inharmonious, poor socioeconomic family might be the social risk factors of CC due to violence. Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. TABLE 1. Summary of Cases Case Sex/ Age Province Residence Occupation Site Impact Object Clinical Manifestations Rescue Witness 1 F/26 HuBei County Worker Home Knee Collapsed, pallor 2 M/18 HuBei Village Worker Dormitory Fist Collapsed, despnoe, urinary incontinence, and ptysis þ 3 M/17 HuBei City Student Dormitory Fist Collapsed, pallor and urinary incontinence þ 4 M/20 HuBei Village Prisoner Outdoor Fist Collapsed þ 5 M/37 HuBei Village Farmer Outdoor Feet Collapsed þ 6 M/20 HuBei Village Prisoner Detention house Fist Collapsed, pallor þ 7 M/25 HuBei Village Prisoner Detention house Brick Collapsed, pallor, and urinary incontinence þ 8 M/18 HuBei Village Student School Fist Collapsed, despnoe, urinary incontinence þ 9 M/23 HeNan County Prisoner Detention house Fist Collapsed þ 10 M/19 HuBei Village Student School Fist Collapsed þ 11 M/26 HuBei County Prisoner Detention house Fist Collapsed, ptysis þ 12 M/21 HuBei Village Farmer Outdoor Fist Walked 10 steps and Collapsed þ 13 M/17 HuBei Village Student School Fist Collapsed þ 14 M/20 HuBei Village Prisoner Detention house Fist Collapsed þ 15 M/15 HeNan Village Student School Fist Collapsed, pallor, and urinary incontinence þ 16 M/18 HuBei County Student School Fist Collapsed þ 17 M/19 HuBei Village Student School Fist Collapsed þ 18 M/15 HuBei Village Student School Fist Collapsed þ 19 M/21 HuBei County Farmer Outdoor Head Collapsed, pallor, and urinary incontinence þ 20 M/39 HuBei City Leader Outdoor Fist Collapsed þ 21 M/25 HuBei City Worker Poolroom Fist Collapsed þ 22 M/26 HuBei Village Farmer Outdoor Knee Collapsed, despnoe þ 23 M/28 HuBei Village Prisoner Detention house Feet Collapsed, pallor þ 24 M/47 HuBei Village Farmer Home Fist Collapsed, pallor þ 25 M/17 HuBei Village Prisoner Detention house Fist Collapsed þ 26 M/25 HuBei County Prisoner Detention house Fist Collapsed, despnoe, and ptysis þ 27 M/15 HuBei Village Student Dormitory Fist Collapsed þ 28 M/30 HeNan Village Farmer Dormitory Feet Collapsed and hyperspasmia þ 29 M/20 HuBei Village Prisoner Detention house Fist Collapsed, urinary incontinence þ þ 30 M/30 HeNan Village Prisoner Detention house Fist Collapsed þ 31 M/33 HuBei Village Farmer Outdoor Fist Collapsed þ 32 F/24 HuBei Village Farmer Home Fist Collapsed; despnoe þ 33 M/15 HeNan City Student Detention House Fist Collapsed; hyperspasmia, urinary incontinence, pallor, and ptysis þ 34 M/19 HuBei Village Student School Fist Collapsed þ 35 M/15 HuBei Village Student School Fist Collapsed; urinary incontinence, pallor, and ptysis þ 36 M/13 HuBei City Student School Feet Collapsed þ 37 M/20 HeNan Village Student School Feet Collapsed þ 38 M/42 HuBei Village Farmer Outdoor Bronze Ox Collapsed þ 39 M/14 HeNan County Student School Feet Collapsed R M1⁄4male, F1⁄4 female, 1⁄4 no, þ1⁄4 yes. Medicine Volume 94, Number 51, December 2015 Death Due to Commotio Cordis Caused by Violence Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. www.md-journal.com | 3 FIGURE 1. Distribution of commotio cordis events by age and sex. TABLE 2. The Clinical Manifestations of Victims After Being Impacted in the Precordium Clinical Manifestations No Proportion, % Instant collapse 39 100 Pallor 9 23.1 Urinary incontinence 8 20.5 Ptysis 7 18.0 Mu et al Medicine Volume 94, Number 51, December 2015 In general, cardiovascular collapse is virtually instantaneous. However, approximately 20% victims remain physically active for a few seconds after the chest blows, which may display that different people have different tolerance with FIGURE 2. Distribution of commotio cordis events by occupation. ventricular tachyarrhythmia. For example, a farmer being punched in the precordium was able to walk 10 steps before collapsing in one of the studied cases. CC is usually fatal. FIGURE 3. Electrocardiograms showing ventricular fibrillation. 4 | www.md-journal.com Mortality approaches 97% when resuscitative efforts are delayed longer than 3 minutes. Mortality is associated with the failure to initiate appropriate, aggressive, and timely measures of resuscitation by bystanders. In most US victims, efforts at cardiopulmonary resuscitation were initiated by bystanders or emergency medical technicians immediately or on time (within about three minutes), which resulted in higher survival rates of 35%. In stark contrast, the rescue rate was extremely low in our study. Therefore, it is important to enhance understanding and awareness of CC and popularize timely measures for cardiopulmonary resuscitation at the scene among the general public and the medical community in China. The underlying mechanisms of CC were proposed as early as the 1930s. It is well known that location, timing, and energy of blows are important factors. Link et al demonstrated that impact must be directly over the heart (particularly at or near the center of the cardiac silhouette). Experimental data have shown that the impact should occur within a very narrow time window of vulnerability during repolarization, that is, 30 to 15 ms before the T-wave peak. The impact energy is not uniform, but closely related to the shape, size, hardness, and velocity of the impact object: harder, smaller, and sphere-shaped projectiles, Dyspnoe 5 12.8 Hyperspasmia 2 5.1 such as baseball, softball, ice hockey, or lacrosse, are most likely to cause CC. High velocity impacts at about 64 km/ hour are most likely to cause CC in experimental studies. Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. T A B L E 3 . A u to p sy , H is to lo g ic a l Fi n d in g s, a n d To x ic o lo g ic a l A n a ly si s C as e H ei gh t, cm W ei gh t, k g B M I E xt er n al E xa m in at io n In te rn al E xa m in at io n H ea rt W ei gh t, g H is to lo gi ca l F in d in gs T ox ic ol og ic al