Sudden unexpected cardiac death—a practical approach to the forensic problem

Sudden cardiac death can usually be resolved by the pathologist into ischaemic heart disease, non-vascular cardiac disease such as aortic stenosis or hypertrophic obstructive cardiomyopathy and infrequently a morphologically normal heart on naked eye examination. When ischaemic heart disease is present one third of cases have a recent occlusive coronary artery thrombosis. Two thirds of patients have coronary stenosis only; the minimum degree of disease reasonably associated with sudden death is one area of 85% stenosis. The majority of patients, however, have multiple areas of stenosis. The predominant causes of non-ischaemic sudden death are severe LV hypertrophy, hypertrophic obstructive cardiomyopathy and the prolapsing mitral valve syndrome. Where the heart and coronary arteries are morphologically normal, review of any previous ECG's, a family history and histological examination of the myocardium and conduction system may reveal a cause or at least allow a reasonable assumption of cardiac arrhythmia to be made. Sudden unexpected death where the circumstances strongly suggest a cardiac cause may pose problems for the pathologist. Ischaemic heart disease (coronary atherosclerosis) is undoubtedly the most frequent cause but even when this is so the detailed pathology is controversial. It is when coronary artery disease is conspicuously absent, often in young individuals previously in good health, that a problem exists. Sudden death in infancy (cot death) is a different entity with its own problems and is not here discussed further.     

Cardiac disease and risk of sudden death in the young: the burden of the phenomenon

Sudden cardiovascular death is a rare but catastrophic event in young men and women throughout the world. Sudden death is difficult to study. Factors that need elucidation are (1) the definition of sudden death; (2) diagnosis of the cause of sudden death; (3) the true incidence of sudden death, and (4) age and gender of individuals being studied. The “burden” of sudden death is far-reaching and involves medical, emotional, and economic burdens on the family members at risk, the entire family of the victim, and society in general. The pathologist trying to evaluate a case of sudden death also has a burden to make the correct diagnosis, especially since the cause of the sudden death may determine risk to the victim's family members. Sudden death is difficult to prevent since it may be the first and last manifestation of the cardiovascular disease. Also, paradoxically, the greatest number of deaths occurs in “low-risk” groups. The most common causes of cardiovascular deaths in the young are cardiomyopathy, coronary anomaly, obstructive coronary artery disease, myocarditis, valvular disease, channelopathy, and aortic disease leading to dissection or rupture. Many sudden deaths in the young occur during or shortly after exercise. Appropriate pre-participation screening of competitive athletes can reduce the incidence of sudden cardiovascular death in the young. Which measures to try to prevent these rare deaths are indicated and/or cost effective is a matter of discussion and controversy.     

Cardiac sarcoidosis: infiltrating under cover

This article describes a case of a heart explanted at transplantation for a clinical diagnosis of dilated cardiomyopathy associated with heart block. Pathological examination of the heart demonstrated non-necrotising granulomas with replacement fibrosis, consistent with sarcoidosis. Cardiac involvement in sarcoidosis may cause chronic cardiac failure, arrhythmia, or sudden cardiac death, and may occur in patients without clinical involvement of other organ systems. Most cases of cardiac sarcoidosis treated by heart transplantation are unsuspected until the explanted heart is examined, with most cases thought to be dilated cardiomyopathy on clinical grounds.     

54例心源性猝死患者心传导系统病变的分析

目的 探讨心源性猝死的死亡原因。方法 采用本组建立的心脏传导系统检查法,对１２０例心源性猝死者进行常规组织学检查。结果 发现５４例猝死与ＣＣＳ病变有关。猝死者８５．２％为年青人,２０－３０岁为猝死高峰年龄,男性我于女性。病变以ＣＣＳ炎症最多见,其后顺序是脂肪浸润,肥厚性心肌病伴发ＣＣＳ病变,出血,发育异常,心脏神经组织病变,纤维化及肿瘤等。     

Sudden death caused by chronic Chagas disease in a non‐endemic country: Autopsy report

Chagas disease is a tropical disease that is prevalent in Latin America. Described herein is an autopsy case of the sudden death of a 48‐year‐old Brazilian man who had stayed in Japan for 7 years. The man, who had a history of Chagas disease, collapsed unexpectedly at work. Because the cause of death was unknown, forensic autopsy examination was performed. As gross findings, the heart was dilated and rounded with an increase in size and weight. The esophagus and large intestine were dilated moderately, with extensive interstitial inflammatory infiltration in the cardiac muscle, but no apparent parasite nest was observed in various tissues. On post‐mortem laboratory examinations, indirect immunofluorescence antibody test indicated the presence of IgG antibody specific to Trypanosoma cruzi in the serum. Subsequent polymerase chain reaction amplification using DNA extracted from blood yielded the specific product derived from T. cruzi genomic DNA. These examinations indicate that the infection had resulted from the Tripanosoma parasite. The cause of death was judged to be chronic cardiomyopathy caused by Chagas disease. It is important for pathologists to know the possible involvement of chronic Chagas disease in sudden unexpected deaths in the current globalized society of Japan.     

Discrepancies in initial death certificate diagnoses in sudden unexpected out-of-hospital deaths: the role of cardiovascular autopsy

BACKGROUND: The accuracy of death certificates issued for out-of-hospital sudden deaths has been questioned. METHODS: We retrospectively studied a series of consecutive autopsies performed at two community hospitals. RESULTS: Fifty-four autopsies in which the deaths were sudden and that occurred outside the hospital were retained for study. The indication for autopsy was largely driven by the wishes of family or physician who was uncertain about the diagnosis. The overall discrepancy rate was 52%. The death certificate diagnosis, rendered before autopsy, was coronary artery disease in 44/54 autopsies (81%). At autopsy, coronary artery disease was the cause of death in 26 cases (48%), cardiomyopathy in 10 (18%), ruptured aneurysm in 8 (15%), pulmonary embolism in 7 (13%), and valve disease in 3 (6%). The diagnosis of coronary artery disease on the death certificate was accurate only 50% of the time. The discrepancy rate was lowest in patients with a history of cardiovascular disease (33%) and was 60% in patients with no prior medical history. The accuracy rate of death certificates was under one third in cases of cardiomyopathy, valve disease, ruptured aneurysm, pulmonary embolism, and valve disease. CONCLUSIONS: We conclude that in a highly selected group of sudden deaths, in which there was often a question about cause of death, the rate of initial death certificate accuracy is only one half. Furthermore, coronary artery disease as the cause of death is less than 50%, far less than initial death certificate diagnoses would indicate.     

Sudden coronary death in children

Coronary disease is an uncommon cause of severe morbidity and death in the young. The great majority of lesions are congenital, and anomalous origins and courses of the coronary arteries are the most common groups of diseases in the age group. Intimal proliferation and coronary arteritis are even less common causes of death in this age population. For this review, we retrospectively studied cases of coronary cardiac death in children and adolescents, from 2004 to 2007, from a statewide medical examiner's office. There were 197 natural deaths in children ages ≤16 years and 58 deaths from sudden infant death syndrome. Of these, the largest group of deaths showed no morphologic abnormalities and was attributed to arrhythmias. The next largest group of deaths comprised complex congenital heart disease (n=13; 20%), followed by myocarditis (n=11; 17%), coronary disease (n=9; 14%), cardiomyopathy (n=8; 12%), valve disease (n=4; 6%), and cardiac fibroma (n=1). Nine coronary deaths occurred in seven boys and two girls, ranging from 14 days to 16 years of age (mean, 8 years). An anomalous course of the coronaries was seen in seven of the nine coronary deaths, and the other two casualties were examples of intimal proliferations involving the coronaries. The rare examples of coronary lesions in the young are discussed in this article.     

The importance of the medico-legal autopsy

All deaths due to unnatural causes and deaths that are believed to be due to natural causes but where the medical cause of death is not certain or known are subjected to an inquest. The objective of an inquest is to ascertain facts pertaining to the death. This is achieved by inquiry and at the conclusion of the inquest a verdict is arrived as to whether the death was due to a natural, accidental, suicidal or a homicidal cause. An inquest is not a trial. There is no complainant or defendant and at the conclusion of the inquest no judgment is passed. The inquest system exists in all parts of the world. In the English legal system, the person who conducts an inquest is called a Coroner. In Scotland, he is called a Procurator Fiscal. The United States of America use the Medical Examiner system. Most continental European countries and their former colonies follow the Code Napoleon. A postmortem examination may become necessary in certain deaths that come up for inquests. In these situations the authority which conducts the inquest will order a doctor to perform a postmortem examination (medico-legal autopsy). To perform a medico-legal autopsy, consent from the relatives of the deceased is not required. In an unexpected sudden death, only a doctor after a postmortem examination may be able to determine the cause of death. However, it is often wrongly assumed that the objective of a postmortem examination is only to ascertain the cause of death. This article deals with the purpose of the inquest and roles of the medico-legal autopsy.     

Sudden cardiac death: an 11-year postmortem analysis in the region of Epirus, Greece

The aim of the study was to determine the rate of sudden cardiac death in people aged between 1 and 80 years, and to investigate its etiology. All autopsies performed during an 11-year period were reviewed. Circumstances of death, individual's information, and post-mortem findings were determined. Among 1254 sudden death autopsies performed during the study period, 688 cases were recognized as sudden cardiac death (79.8% males). The estimated annual frequency of sudden cardiac death in the region of Epirus was 18.6/100,000. The major cause of death was ischemic heart disease (82%), and in 2.6%, death was unexplained. Among our study's total population, 4.1% were <35 years old. The estimated annual rate of sudden cardiac death in the population 1-35 years old was 1.78/100,000. The most common etiology in that age group was atherosclerosis (17.8%), myocarditis (10.7%), and cardiomyopathies (10.7%), whereas 39.3% exhibited structurally normal heart. Although ischemic heart disease accounts for most of sudden cardiac death episodes, many other causes contribute. Most sudden deaths in the young were "unascertained". The likely cause of death in these cases might be a primary arrhythmogenic disorder. Correct identification of such cases at autopsy will enable an appropriate clinical screening of surviving relatives.     

Intracranial causes of death and their mechanisms

Intracranial causes of death trail in incidence behind cardiovascular and respiratory system pathologies in most deaths occurring in hospitals. When intracranial pathology becomes more important is in the forensic arena, where it is often supposed that in troublesome cases such as sudden and unexpected deaths or where there appears to be no anatomic cause of death revealed in the general autopsy, the cause must be in the brain. This hope is often dashed after a careful neuropathological examination. Intracranial causes of death are discussed here mostly within the context of the forensic exercise where complex processes may be involved such as: electrophysiological dysfunctions; disorders of respiratory control; dysfunction of the intracranial pressure/volume equilibrium.     

Are coroners' necropsies necessary? A prospective study examining whether a "view and grant" system of death certification could be introduced into England and Wales

AIMS: To determine whether the cause of death could be accurately predicted without the need for a necropsy, and thus to consider whether a "view and grant" system of issuing a cause of death could be introduced into England and Wales. METHOD: A one year prospective necropsy study was performed incorporating 568 deaths. Before necropsy, in each case the cause of death was predicted from the available history without examination of the body, and this cause was then compared with the cause of death found at necropsy. RESULTS: The ability of the pathologist involved in the study to predict a cause of death before necropsy, either while in the mortuary or as a paper exercise, was shown to vary between 61% and 74% of cases. After the necropsy, the number of correct predicted causes of death ranged from 39% to 46%. Ischaemic heart disease was found to be the most common and most accurately predicted cause of death. Some natural diseases were frequently misdiagnosed, whereas certain types of unnatural disease were always identified correctly. CONCLUSIONS: This study highlights the advantages and disadvantages of a view and grant system. Although it identifies a potential use of such a system, in some cases such as natural cardiac disease, because of the potentially high diagnostic error rate, the continuation of the present system of postmortem examination as part of the coroner's enquiry is recommended.     

Right ventricular cardiomyopathy and sudden death in young people

From 1979 to 1986, we conducted postmortem studies of 60 persons under 35 years of age who had died suddenly in the Veneto Region of northeastern Italy. Unexpectedly, we found that 12 subjects--7 males and 5 females ranging in age from 13 to 30 years--had morphologic features of right ventricular cardiomyopathy. This disorder had not been diagnosed or suspected before the subjects died. In five cases, sudden death was the first sign of disease; the remaining seven subjects had a history of palpitation, syncopal episodes, or both, and in five of those seven, ventricular arrhythmias had previously been recorded on electrocardiographic examination. Ten of the subjects had died during exertion. At autopsy, the subjects' heart weights were normal or moderately increased. Two main histologic patterns were identified--a lipomatous transformation or a fibrolipomatous transformation of the right ventricular free wall (6 cases each); in all cases, the left ventricle was substantially spared. Signs of myocardial degeneration and necrosis, with or without inflammatory infiltrates, were occasionally observed. These findings indicate that right ventricular cardiomyopathy, the cause of which is still unknown, may be more frequent than previously thought. At least in this area of Italy, it may represent an important cause of sudden death among young people.     

Sudden death in childhood and adolescence

Sudden natural deaths of individuals between the ages of 2 and 20 years which occurred during a 20-year period were identified from mortuary records. Necropsy reports and histological sections were reviewed; 169 sudden natural deaths were identified amongst 1012 deaths in that age group. Ninety-two sudden deaths occurred to children with recognized disorders; congenital heart disease, asthma, and epilepsy were the commonest problems identified. Amongst the 77 deaths of apparently healthy children, infection was the most frequently recognized disease. Only 11 deaths were unexplained, comprising 1 per cent of the necropsy population or 6.5 per cent of sudden natural deaths, a much smaller proportion than pertains in infancy. Necropsy examination of children dying suddenly yields useful information.     

The pathology of cot deaths.

An examination of the pathological features of 12 consecutive cases of sudden death in infancy was undertaken with particular reference to the lung changes used a combined radiological and pathological study of formalin vapour-inflated lungs. Certain common features in the cases in which there are no post mortem changes to explain death (typical cot deaths) are described and compared with cases with an acceptable cause of death and with control cases. It was concluded that severe dehydration is a potentially avoidable factor underlying cot deaths and many other sudden infant deaths with no explainable causes; that petechial haemorrhages are a constant feature of cot deaths and indicate a respiratory/hypoxic mode of death; that absence of petechiae indicates some other explanation for death. It is suggested that the minor respiratory or other infections which are usually present at autopsy in cot deaths may sometimes exaggerate a preexisting state of dehydration and that the dehydration may contribute more directly to death than the infection.     

Can sudden cardiac death be prevented?

Hypertrophic cardiomyopathy is regarded as the most common cause of sudden cardiac death in young people (including trained athletes). Introduction of implantable cardioverter-defibrillators to the hypertrophic cardiomyopathy patient population represents a new paradigm for clinical practice and perhaps the most significant advance in the management of this disease to date. Implantable defibrillators offer the only proven protection against sudden death by virtue of effectively terminating ventricular tachycardia/fibrillation and, in the process, altering the natural history of hypertrophic cardiomyopathy and providing the potential opportunity of normal or near-normal longevity for many patients. However, targeting the most appropriate candidates for prophylactic device therapy can be complex, compounded by the unpredictability of the underlying arrhythmogenic substrate, absence of a single dominant and quantitative risk marker in this heterogeneous disease, and the historical difficulty in assembling sufficiently powered prospective and randomized trials in large patient populations. Nevertheless, the current risk factor algorithm, when combined with a measure of individual physician judgment, is an effective strategy for identifying high-risk patients. Indeed, prevention of sudden death has now become an integral, albeit challenging, component of overall hypertrophic cardiomyopathy management.     

Coronary artery disease,sudden death and implications for forensic pathology practice

Coronary atherosclerosis is the leading cause of sudden death in developed nations. Triggers for sudden death include physical and emotional stress. At autopsy coronary artery atheroma is a common finding and may or may not be related to the cause of death. The forensic pathologist must consider the relative significant of disease, trauma and toxicological findings when determining the cause of death. This requires a consideration of evidence beyond the autopsy including the history, scene and ancillary investigations. Certain drugs including cocaine and methamphetamine are known to be atherogenic and acute and chronic use may be a factor in sudden death with underlying coronary artery atherosclerosis. Sudden death may also be associated with criminal conduct, when the scenario of “homicide by heart attack” needs to be considered. This review analyses forensic aspects of coronary artery disease.     

Coronary artery disease,sudden death and implications for forensic pathology practice

Coronary atherosclerosis is the leading cause of sudden death in developed nations. Triggers for sudden death include physical and emotional stress. At autopsy coronary artery atheroma is a common finding and may or may not be related to the cause of death. The forensic pathologist must consider the relative significant of disease, trauma and toxicological findings when determining the cause of death. This requires a consideration of evidence beyond the autopsy including the history, scene and ancillary investigations. Certain drugs including cocaine and methamphetamine are known to be atherogenic and acute and chronic use may be a factor in sudden death with underlying coronary artery atherosclerosis. Sudden death may also be associated with criminal conduct, when the scenario of “homicide by heart attack” needs to be considered. This paper analyses forensic aspects of coronary artery disease.     

Current concepts on sudden death

Sudden death is defined as the death occurring less than one hour before the onset of the patient's symptoms. It is a severe condition considered a public health issue in several countries and in ours, it accounts for 33 000 to 53 000 annual deaths mainly related to ischemic heart disease. The main cause of sudden death are severe ventricular arrhythmias, but determining what patients are at risk for such an episode is complex, that is why risk stratification is usually a low cost-effective intervention. In the present study, we describe different sudden death risk-stratification strategies. Different sudden death treatment strategies regarding general population have different success rates in different countries, nevertheless, among select high risk populations; the best therapy currently available is the automatic implantable cardioverter-defibrillator. We also discuss other treatment options. In Mexico it is deemed necessary to do an important effort for the early detection, prevention and treatment of sudden death in order to limit the consequences of this problem.     

A population-based autopsy study of sudden, unexpected deaths from natural causes among persons 5 to 39 years old during a 12-year period

All unexpected deaths in New Mexico from 1977 to 1988 were reviewed. By statute each such death must be reported to the Office of the Medical Examiner (OMI) and according to institutional policy autopsied even when death is presumed to be from natural causes. From this group the 650 index cases that form the basis of this report were obtained. The crude rate of sudden, unexpected death among New Mexico residents 5 to 39 years old during the study period was persons at risk. As documented by autopsy, the underlying cause of death in majority of these cases (53.4%) was related to cardiovascular disease and alcoholism. Male persons in general are at increased risk for sudden, unexpected death, and American Indian and black male persons are at greater risk than their Anglo and Hispanic counterparts. American Indians account for a disproportionate share of the unexpected deaths resulting from alcoholism, and black male persons are at particular risk for unexpected death resulting from cardiovascular diseases. This report emphasizes the importance of life style and diet in the well-being of persons 5 to 39 years old.     

Meta-analysis of clinical characteristics of 299 carriers of LMNA gene mutations: do lamin A/C mutations portend a high risk of sudden death?

This study evaluated common clinical characteristics of patients with lamin A/C gene mutations that cause either isolated dilated cardiomyopathy or dilated cardiomyopathy in association with skeletal muscular dystrophy. We pooled clinical data of all published carriers of lamin A/C gene mutations as cause of skeletal and/or cardiac muscle disease and reviewed ECG findings. Cardiac dysrhythmias were reported in 92% of patients after the age of 30 years; heart failure was reported in 64% after the age of 50. Sudden death was the most frequently reported mode of death (46%) in both the cardiac and the neuromuscular phenotype. Carriers of lamin A/C gene mutations often received a pacemaker (28%). However, this intervention did not alter the rate of sudden death. Review of the ECG findings typically showed a low amplitude P wave and prolongation of the PR interval with a narrow QRS complex. This meta-analysis suggests that cardiomyopathy due to lamin A/C gene mutations portends a high risk of sudden death, and that this risk does not differ between subjects with predominantly cardiac or neuromuscular disease. This implies then that all carriers of a lamin A/C gene mutation need to be carefully screened with particular emphasis also on tachyarrhythmias. Prospective studies are needed to evaluate risk stratification and proper treatment strategies.