Forensic significance of conduction system abnormalities as a precise cause of accidental death

Histologic spectrum of the cardiac conducting tissue in non-natural deaths under 30 years of age: an analysis of 43 cases with special implications for sudden cardiac death

In the past, histological findings of the cardiac conduction system or its adjacent structures, such as filiform fibers at the transition from bundle of His to bundle branches, connective tissue at the apex of the ventricular septum, or fibromuscular alterations of the arteries has been considered as a cause of death. However, the prevalence of such findings in a healthy population has been rarely analyzed systematically. In the present study, the morphology of the cardiac conduction system of 43 heart-healthy individuals who died of non-natural causes (ages 0 to 30 years) was investigated. In a high percentage of cases, connective tissue at the apex of the ventricular septum (97.7%), filiform fibers at the transition from bundle of His to the bundle branches (27.9%), and fibromuscular proliferations of the sinoatrial node artery (41.9%), and the AV-node artery (39.5%) could be detected. Based on our observations, these alterations should not be considered as a pathologic entity or as a cause of death.

A case of sudden death after Japanese encephalitis vaccination

Japanese encephalitis (JE) virus is estimated to result in 3500-50,000 clinical cases every year, with mortality rates of up to 20-50% and a high percentage of neurological sequelae in survivors. Vaccination is the single most important measure in preventing this disease. Inactivated Vero cell culture-derived JE vaccines have not been linked to any fatalities, and few serious adverse events after vaccination have been reported. Here, we report a case of sudden death in which a 10-year-old boy experienced cardiopulmonary arrest 5 min after receiving a Japanese encephalitis vaccination. He had been receiving psychotropic drugs for the treatment of pervasive developmental disorders. Postmortem examinations were nonspecific, and no signs of dermatologic or mucosal lesions or an elevation of the serum tryptase level, which are characteristic of anaphylaxis, were observed. A toxicological examination revealed that the blood concentrations of the orally administered psychotropic drugs were within the therapeutic ranges. The patient was considered to have died of an arrhythmia that was not directly associated with the vaccination.

The sudden and unexpected death of a female-to-male transsexual patient

A 32-year-old woman, who was intramuscularly injected with testosterone enanthate (125 mg) once or twice a month over a two-year period for female-to-male transsexualism, died suddenly. A forensic autopsy was performed to investigate the cause of death. Concentric cardiac hypertrophy was macroscopically observed. In the left and right coronary arteries, atherosclerosis was generally observed within the endothelium. In particular, there was severe stenosis (>90%) at the start of the left descending branch. In the myocardium, both coagulation necrosis and contraction band necrosis were microscopically observed. Moreover, myocardial fibrosis and myocardial calcification were diffusely detected, respectively. The cause of death was diagnosed as ischemic heart disease due to coronary stenosis. There is some debate as to whether cross-hormone replacement is related to the occurrence of coronary artery disease or not, however, it is possible that the development of ischemic heart disease was aggravated by the administration of testosterone enanthate in the current case.

Relationship between cardiopulmonary resuscitation and injuries of the cardiac conduction system: Pathological features and pathogenesis of such injuries*

OBJECTIVE

The purpose of this study was to assess the incidence, features, and pathogenesis of microscopic injuries to the cardiac conduction system caused by cardiopulmonary resuscitation.

DESIGN

: Prospective study.

SETTING

Autopsy unit of the university.

PATIENTS

Victims who had been transferred to the emergency room due to cardiac arrest arising from nontraumatic cause plus age-matched control patients.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

The cardiac conduction system of 80 hearts without gross injury from patients who had received cardiopulmonary resuscitation due to nontraumatic causes was examined. Of these 80 patients, seven (9%) showed fresh injuries, including a lesion that had gone unreported in the previous literature. Localized hemorrhage without inflammatory reaction was evident in six of these patients. Three of the six patients showed hemorrhage in the sinoatrial node, whereas the other three patients showed hemorrhage in the atrioventricular conduction system. The remaining one patient showed localized dissection of the atrioventricular node artery with the appearance of red blood cells in the false lumen. There was no significant difference with regard to age, gender, cause of cardiopulmonary arrest, whether victim had received electrical shock treatment, whether victim had received anticoagulants, and the duration of cardiopulmonary resuscitation between the seven patients with fresh injuries and the other 73 patients. Fracture of the sternum or rib was found in only one of the seven patients but in 14 of the 73 patients. No pathologic lesions were found in the 30 control patients who did not receive cardiopulmonary resuscitation.

CONCLUSIONS

It can be presumed that injuries to the conduction system do occur in limited regions during cardiopulmonary resuscitation. Minute differences in the location of the cardiac silhouette or cardiac conduction system also need to be considered, rather than just the severity of force to the anterior chest, when determining the pathogenesis of these injuries.

Sudden unexpected death of a 17-year-old male infected with the influenza virus

We report a case of sudden unexpected death in a 17-year-old male student showing similar clinical background and pathological findings to Reye's syndrome. He was found following cardio-pulmonary arrest in his bed, and was immediately transferred to a hospital. However, resuscitation was not successful. He had a history of high fever of 38.3 degrees C, general malaise, myalgia, and gastrointestinal discomfort for the 2 days prior to his death, and an injection of pylazolon and medication comprising anti-emetics had been administered the day before he died. His biochemical findings showed almost normal levels of transaminase, electrolytes and protein fractions at the emergency room, but blood from the heart at autopsy revealed a high titer of the influenza A virus. Macroscopically, in addition to considerable fatty metamorphosis of the liver, concentric hypertrophy of the left ventricle, muscular bridge of left anterior descending artery, moderate coronary atherosclerosis, and mild downward displacement of the septal leaflet of the tricuspid valve were noted in the heart. Although panlobular microvesicular fatty infiltration of the liver was seen, deposition of lipid droplets was detected only in hepatocytes by frozen section of several organs. Serial sectioning of the epicardial coronary arteries showed about 50% stenosis at the distal site of the left circumflex artery, and diffuse interstitial fibrosis was evident in the bilateral ventricle and this was relatively severe for his age. In addition, the atrioventricular (AV) node artery showed severe narrowing just before entering the AV node, and downward displacement of the AV node with longitudinal elongation was also remarkable. We consider that the cause of death was sudden cardiac death rather than Reye's syndrome (RS), and that an arrhythmogenic event due to some preceding unusual cardiac lesions may have become overt due to the influenza infection and/or some related disorders. The present case would seem to suggest that a postmortem diagnosis of RS should be determined very carefully in cases of sudden death, even if the general circumstances would seem to be consistent with RS.

Sudden cardiac death in a child affected by Prader-Willi syndrome

A case of sudden cardiac death in a 3-year-old young male affected by Prader-Willi syndrome, clinically diagnosed and confirmed by means of DNA methylation, is presented. The infant suddenly collapsed at home and was taken apparently unconsciousness by his mother to the emergency clinic where he was pronounced dead. A complete postmortem examination was performed and the histological findings led to the definition of cardiac death with a typical picture of contraction band necrosis. Pulmonary hypoxic alterations are frequently reported as the primary cause of death in PWS cases. In this fatal case according to the macroscopic and microscopic findings, the cause of death was most likely cardiac and possibly related to contraction band necrosis linked with ventricular fibrillation and sudden death.

Suffocation and poisoning?the hard-hitting side of Munchausen syndrome by proxy

Munchausen syndrome by proxy (MSBP) is a severe and difficult to diagnose form of child abuse characterised by the simulation, aggravation or production of symptoms of illness in a child by an adult. MSBP often leads to multiple hospitalisations and has a high mortality and long-term morbidity. This study describes the cases of 5 families with 8 children affected who presented with unexplained neurological or gastrointestinal symptoms or even loss of consciousness. All were victims of poisoning or suffocation by their mothers. Two of those children died and were initially diagnosed as SIDS or natural death, respectively. They were only recognised as MSBP victims after another sibling had fallen ill with similar symptoms. The cases are discussed in consideration of the relevant literature. In addition warning signs of this forensically relevant syndrome and a strategy for the management of suspected MSBP cases are described.

Sudden cardiac death due to hypersensitivity myocarditis during clozapine treatment

The case concerns the sudden death of a 29-year-old male during clozapine therapy started 2 weeks before. He had a history of treatment-resistant chronic schizophrenia. A complete immunohistochemical study was performed on heart specimens. Histologically, the heart presented diffuse eosinophilic infiltrates located around perivascular structures and focal myocyte necrosis with numerous interstitial eosinophils admixed with histiocytes. The diagnosis of acute myocarditis with an eosinophilic infiltrate was established as the cause of death. The autopsy findings and a detailed medical history supported the conclusion that clozapine-induced hypersensitivity myocarditis was the most likely cause of death.

Sudden cardiac death in hereditary hemochromatosis: an underestimated cause of death?

Hereditary hemochromatosis (HH) is a frequent autosomal recessive disease which causes iron-overload of various organs. Of all northern European affected individuals, 90-95% show 1 of 3 known point mutations in the HFE gene. Symptoms and organs involved can vary considerably: Only a small fraction of the 200,000-400,000 persons affected in Germany develop the classical picture of liver cirrhosis and/or pancreatic fibrosis. Nevertheless, the life expectancy of persons with moderate or even subclinical symptoms is reduced, in many cases due to myocardial damage leading to cardiomyopathy with greatly increased risk of sudden cardiac death. Although the high prevalence of HH suggests that sudden cardiac death due to cardiac HH is a relatively common cause of death, the forensic literature lacks such reports. We present the case of sudden cardiac death in a young man with histological findings of massive cardial hemochromatosis which is characterized by the fact that none of the three known mutations for HH were found. This case demonstrates that genetic screening alone might not be sufficient to identify all persons at risk to developing HH.

Conduction system abnormalities in alcoholics with asymptomatic valvular disease who suffer sudden death

We examined the cardiac conduction system of three alcohol abusers who died suddenly. Cases 1 and 2 showed mitral valve disorder (mitral valve prolapse and rheumatic valvular disease), while Case 3 showed mild Ebstein's anomaly. On examination of the conduction system, Cases 1 and 2 showed severe fibrofatty infiltration into the conduction system, and we conclude that these findings were probably a complication of alcohol abuse. Both cases also demonstrated severe small artery disease. The conduction system of Case 3 showed an anomalous location of the bundle of His with its fragmentation. These three cases suggest that such considerable conduction system abnormalities may be significant findings in alcohol abusers with valvular disease. We consider that alcohol intake may be one of the direct accelerating factors for arrhythmogenic potential to the abnormal conduction system in alcohol abusers who have asymptomatic valvular disease.