Causes of Sudden Death in Patients with Obstructive Sleep Apnea

There are few autopsy studies of patients dying suddenly with obstructive sleep apnea (OSA). Twenty‐five forensic autopsies of unexpected sudden death in individuals with OSA were reviewed. The causes of death were as follows: cardiomyopathy (n = 11); sudden unexpected death without morphologic findings (SUDNA, n = 6); and other cardiovascular diseases not related to OSA (n = 8). The cardiomyopathy group comprised five hearts with concentric left ventricular hypertrophy without dilatation and six with left ventricular diameter >4 cm (dilated cardiomyopathy). Four of six hearts in the SUDNA group showed right ventricular dilatation compared with seven of 11 showed cardiomyopathy and one of eight miscellaneous. The degree of obesity was greatest in the dilated cardiomyopathy group (10 of 11 obese) followed by the SUDNA group (four of six obese). The cardiac findings in patients dying suddenly and unexpectedly with OSA include nonspecific cardiomyopathy, other cardiac conditions, and hearts without a morphologic cause of death, which show frequent right ventricular dilatation as the only finding.     

Anomalous Anterior Papillary Muscle as an Autopsy Finding in Two Cases

Anomaly in the anterior papillary muscle (APM) is known to cause left ventricle outflow tract (LVOT) obstruction, and this rare congenital condition could be a cause of sudden cardiac death. This anomaly and its hemodynamic effects is similar to valvular heart disease. In our two described cases, in which cause of death was, respectively, hypertrophic cardiomyopathy and suicide by hanging, the cephalad portion of the left APM was inserted directly into the ventricular surface of the anterior mitral leaflet and chordae tendineae were absent in the area of the direct anomalous muscle insertion; the aberrant papillary muscle was very large and showed an exaggerated anterior displacement within the left ventricular cavity. The described anomaly is a cause of LVOT obstruction. This condition is considered to be rare, although incidence estimates do not exist. In the absence of other possible causes, this finding may indicate arrhythmia as being the immediate cause of death.     

Alcoholic cardiomyopathy versus chronic myocarditis--immunohistological investigations with LCA, CD3, CD68 and tenascin

Dilated cardiomyopathy (DCM) is a disorder of unknown aetiology characterized by the left ventricular cavity enlargement and wall thinning associated with reduced left ventricular wall motion. DCM in chronic alcoholics is supposed to be caused by alcohol induced myocardial damage (alcoholic cardiomyopathy). Nevertheless, cardiotropic viruses, such as enteroviruses have long been suspected as causative agents for at least some forms of DCM. In the present study, 13 cases of DCM in chronic alcoholics were investigated with qualification and quantification of infiltrating leucocytes using immunohistological antibodies against leucocyte common antigen (LCA), T-lymphocytes (CD3) and macrophages (CD68). In addition, the expression of tenascin, playing a role in the initiation of fibrotic changes, was examined. All antigens were known to be possibly enhanced in cases of chronic myocarditis. Using these immunohistological techniques, 2 out of 13 cases had evidence for chronic inflammatory myocardial alterations in the sense of lymphocytic infiltrates (>2.0 CD3 T-lymphocytes/visual field at 400 x (HPF); >7 CD3 T-lymphocytes per mm(2)). These cases were diagnosed as having inflammatory cardiomyopathy. The other cases without myocardial inflammation were diagnosed as idiopathic/alcoholic DCM.     

Sudden death in right ventricular dysplasia with minimal gross abnormalities

Arrhythmogenic right ventricular cardiomyopathy is emerging as a relatively common cause of exercise-induced sudden death in the young. The diagnostic criteria at autopsy are, however, not fully established, leading to both over- and underdiagnosis. We report a young man and a young woman dying suddenly of right ventricular dysplasia during exercise, in whom the gross autopsy findings in the right ventricle were minimal or even absent. However, the histologic features in both right and left ventricles were typical of the disease, and consisted of fibrofatty infiltrates with typical myocyte degeneration of the right ventricle and subepicardial regions of the left ventricle. These cases illustrate that microscopic findings are diagnostic and may be present in the absence of gross findings. Marked fat replacement is not essential for the diagnosis of right ventricular dysplasia, and the right ventricle should be extensively sampled histologically in all cases of sudden unexpected death, especially those that are exercise related.     

Cardiac Ventricular Laceration Due to Child Abuse: Abusive Ventricular Laceration

Traumatic cardiac ventricular ruptures in children are rare. Only a single case of left ventricular rupture due to child abuse has been reported. We report a child who sustained a fatal left ventricular apical rupture. It appeared to have resulted from hydrostatic forces resulting from abusive blunt thoracic injury. That he was being abused was previously missed when he was presented to the emergency department with facial pyoderma. It was not noted that he also had lip and oral mucosal injury, sites not affected by staph toxins. As a result, his underlying, abusive and secondarily infected, facial flow type scald burn was not appreciated. Within a week thereafter his fatal injury occurred, accompanied by extensive and obvious associated abusive injuries. Postmortem high‐detail whole body computed tomography scanning aided the autopsy. Although rare, ventricular rupture from abusive blunt thoracic injury can occur.     

Is there progress in the autopsy diagnosis of sudden unexpected death in adults?

Sudden death is now currently described as natural unexpected death occurring within 1h of new symptoms. Most studies on the subject focused on cardiac causes of death because most of the cases are related to cardiovascular disease, especially coronary artery disease. The incidence of sudden death varies largely as a function of coronary heart disease prevalence and is underestimated. Although cardiac causes are the leading cause of sudden death, the exact incidence of the other causes is not well established because in some countries, many sudden deaths are not autopsied. Many risk factors of sudden cardiac death are identified: age, gender, heredity factors such as malignant mutations, left ventricular hypertrophy and left ventricle function impairment. The role of the police surgeon in the investigation of sudden death is very important. This investigation requires the interrogation of witnesses and of the family members of the deceased. The interrogation of physicians of the rescue team who attempted resuscitation is also useful. Recent symptoms before death and past medical history must be searched. Other sudden deaths in the family must be noted. The distinction between sudden death at rest and during effort is very important because some lethal arrhythmia are triggered by catecholamines during stressful activity. The type of drugs taken by the deceased may indicate a particular disease linked with sudden death. Sudden death in the young always requires systematic forensic autopsy performed by at least one forensic pathologist. According to recent autopsy studies, coronary artery disease is still the major cause of death in people aged more than 35 years. Cardiomyopathies are more frequently encountered in people aged less than 35 years. The most frequent cardiomyopathy revealed by sudden death is now arrhythmogenic right ventricular cardiomyopathy also known simply as right ventricular cardiomyopathy (RVC). The postmortem diagnosis of cardiomyopathies is very important because the family of the deceased will need counseling and the first-degree relatives may undergo a possible screening to prevent other sudden deaths. In each case of sudden death, one important duty of the forensic pathologist is to inform the family of all autopsy results within 1 month after the autopsy. Most of the recent progress in autopsy diagnosis of sudden unexpected death in the adults comes from molecular biology, especially in case of sudden death without significant morphological anomalies. Searching mutations linked with functional cardiac pathology such as long-QT syndrome, Brugada syndrome or idiopathic ventricular fibrillation is now the best way in order to explain such sudden death. Moreover, new syndromes have been described by cardiologists, such as short-QT syndrome and revealed in some cases by a sudden death. Molecular biology is now needed when limits of morphological diagnosis have been reached.     

致心律不齐性右室心肌病的研究进展

致心律不齐性右室心肌病是以右室心肌被纤维脂肪取代为特征的一种原因不明的心肌病,通常表现为局限性右室病变。亦可弥漫性进展,侵犯左室,最终导致左心功能不全。近年来,致心律不齐性右室心肌病导致心源性猝死已越来越引起人们的注意。在法医实际工作中,相关研究报道较少。本文综述了致心律不齐性右室心肌病的发病病因、发病机理、病理变化、临床特点和鉴别诊断等方面的研究进展。     

Extra- and intracranial injuries of the cerebral arteries as a sequela of assault

The case of an 47-year-old man is reported, who was injured in a fight while under the influence of alcohol. The culprit knocked him down and stamped several times on the left side of his head. The victim became unconscious. At the hospital, subarachnoid hemorrhage and massive ventricular bleeding was diagnosed via CT. Despite the implantation of a ventricular shunt, there was repeated massive cerebral pressure and arterial bleeding. Brain death occurred after 8 days. The main finding at autopsy was nearly complete disruption of the left inferior posterior cerebellar artery as the source of the lethal bleeding. The histological examination showed some additional, incomplete ruptures of this vessel and of the left intracranial vertebral artery. This is a typical result of "minor head injuries" sustained in fights: arterial rupture (ipsilateral) as a result of overstretching. Fracture of the left zygomatic arch and maxilla; no skull fracture; no primary traumatic brain damage. The extracranial carotid arteries were intact. When the vertebral arteries were examined (in the undamaged cervical spine), there was a surprising finding: distant dissection of the right vertebral artery between C1 and C2, which perhaps occurred as a result of compression (contralateral to the impact) of this region.     

Total anomalous pulmonary venous drainage and sudden death in infancy.

The clinicopathologic features of four infants with undiagnosed total anomalous pulmonary venous return who died suddenly and unexpectedly are presented. Two infants were found dead in their beds and two collapsed following very non-specific episodes of mild tachypnoea and tachycardia, respectively. Pulmonary venous blood drained via a common channel to the left innominate vein, the superior vena cava, the inferior vena cava at the junction of the hepatic vein and the supradiaphragmatic portion of the inferior vena cava. All cases demonstrated right atrial and ventricular hypertrophy and in one case there was associated hypoplastic left heart syndrome. Although those mechanisms responsible for sudden infant death syndrome could not definitely be excluded in two cases, the presence of anomalous pulmonary drainage with significant right-sided cardiac cardiac hypertrophy in each patient strongly suggests a contributing role for the vascular malformation in the aetiology of sudden unexpected death. The importance of careful in situ dissection of the major vessels in all cases of paediatric sudden death is emphasised, particularly in the presence of other congenital cardiac anomalies.     

Cardiac hydatid cyst rupture as cause of death

Echinococcosis is a frequent parasitic human infection in sheep-farming areas. It is caused by the larval or the cyst stage of a tapeworm, mainly Echinococcus granulosis. Humans can be infected by ingesting tapeworm eggs, from which cysts will be developed mostly in the liver and the lung. Cardiac involvement of echinococcosis is rare and its clinical evolution is silent till the complication stage. A young adult died suddenly. The autopsy showed a ruptured hydatid cyst hollowed on the right side of the interventricular septum, protruding in the ventricle. The left pulmonary artery contained white-colored fragments of a membrane, similar to the one found in the right ventricle, associated to small vesicles. All these elements were obstructing this vessel, extending to small pulmonary arterial branches. Dissection of the other organs did not show other locations. Microscopic examinations ascertained the diagnosis of echinococcosis. Death was imputed to a right ventricular hydatid cyst rupture with pulmonary artery embolism.     

Cor triatriatum sinistrum: a rare congenital cardiac anomaly presenting in an adult with chronic atrial fibrillation

Cor triatriatum is a rare congenital cardiac anomaly in which the left atrium is divided into proximal (dorsal or upper) and distal (ventral or lower) chambers by a fibromuscular septum. The upper chamber receives the pulmonary veins and the lower chamber contains the atrial appendage and the mitral valve. The 2 chambers communicate through a defect in the membrane. Cor triatriatum is often associated with other congenital cardiac anomalies. Most frequently, the upper chamber communicates with the right atrium through a patent foramen ovale or atrial septal defect, and the clinical symptoms simulate anomalous pulmonary venous return. Less commonly, the foramen ovale communicates with the distal chamber and the clinical features mimic mitral stenosis. When cor triatriatum is the only abnormality, the clinical findings are also similar to mitral stenosis with development of pulmonary hypertension and subsequent right ventricular hypertrophy and atrial enlargement. The diagnosis is usually made in infancy or childhood, and the lack of treatment results in death in 75% of patients.We report the case of a woman who presented much later in life. The patient was a 57-year-old female with a clinical history of chronic atrial fibrillation who presented to the emergency department because of a "funny sensation" in her chest, though she denied chest pain, nausea, vomiting, or diaphoresis. EKG revealed atrial fibrillation with a rapid ventricular response and a tachycardic rate of 157. She had a therapeutic level of digoxin, and cardiac enzymes were normal. The patient was admitted and placed on Cardizem drip. Serial EKGs remained normal and heart rate control was achieved. On hospital day 2, the patient became dyspneic and cyanotic. She went into cardiac arrest and died.Autopsy revealed cardiomegaly (610 g) with 4-chamber dilatation. A septum divided the left atrium into 2 chambers. The defect in the dividing membrane measured 1 cm in diameter. No other congenital defects were noted. The large size of the defect in the membrane likely accounted for the late onset of symptoms that allowed this patient to survive into adulthood without previous diagnosis or surgical intervention (which is usually required in childhood).     

A case of sudden infant death due to a primary cardiac sarcoma

The case reported herein concerns the unexpected death of a 3-month-old female newborn who suddenly collapsed in her mother's arms and was dead on arrival at the hospital. The clinical histories of the baby and her parents were negative for symptoms or signs of illness, even those of cardiovascular origin. Furthermore, no clinical appearance of a pathologic status was noted by pediatricians after the birth until the last emergency recovery. The autopsy excluded external and internal signs of violence but revealed a large primary cardiac tumor arising from the free wall of the left ventricle, which had totally invaded the heart causing mitral valve deformation. Histological examination showed a low-grade sarcoma that completely infiltrated the myocardial tissue. The pathogenesis of this sudden infant death was postulated as being owing to a fatal ventricular fibrillation combined with a tumor-related restrictive cardiomyopathy obstructing left ventricular filling.     

Factors affecting strontium absorption in drownings

This study examines the effects of age, gender, a cold water medium versus warm water medium, and salinity on strontium levels determined in left ventricular blood in drownings. Significant differences in the amount of strontium absorbed into the bloodstream (p<0.001) were detected between individuals who drowned in fresh water versus those drowning in seawater, and between those drowning in cold water versus warm water (p=0.030). However, no significant differences were noted in the strontium concentrations of left ventricular blood according to gender or age.     

Bone marrow emboli versus fat emboli as the cause of unexpected death

Thromboemboli were found diffusely throughout the pulmonary vasculature system of a 76-year-old white female who died unexpectedly 3 days following injury and repair of a left hip intracapsular fracture. A diffuse chronic nonspecific myocarditis with marked fat atrophy, an acute myocardial infarct of the posterior left ventricular papillary muscle, and an acute right lower lobe bronchopneumonia are believed to be the cause of death.     

Subvalvular aortic stenosis as a cause of sudden death: two case reports

Sudden death is defined as a death that occurs suddenly, develops during an unpredictable course, and is due to natural or unnatural causes. Although there is no universally standardized definition on how "sudden" a sudden death is, WHO defines sudden death as a death that occurs within 24 hours after the onset of symptoms. The aim of this study is to present 2 rarely reported autopsy cases and to emphasize the importance of systemic autopsy at sudden death. On macroscopic examination, crescent-shaped, thick, fibrous membranes, located 5 mm and 3 mm away from the aortic valves, were detected. Fibrous membranes extended from the ventricular septum to the left ventricular outflow tract, thus apparently narrowing this region. Left ventricular wall and septum were slightly thickened, and there were scattered grayish-white areas of a small diameter. These became more intense in the septum and myocardium of the left ventricle on the anterior plane of the myocardial sections. In both cases, the aortic valves of were thickened and also markedly narrowed on one of them. In this case, the fibrous membrane adhered to the aortic valve and extended to the anterior leaflet of the mitral valve at one side. Both aortic valves comprised 3 leaflets. Other valves and coronary arteries showed no macroscopic pathologic findings. Microscopic examination of both cases demonstrated that the fibrous membrane comprising abundant collagen fibers was situated on the ventricular septum. Hypertrophy, moderate to severe interstitial fibrosis, and focal areas of scarring were observed in the specimens taken from the septal and ventricular myocardium. No abnormality was found on the conduction system examinations. Toxicologic analysis results in blood were negative. Based on the findings, membranous-type (discrete type) subvalvular aortic stenosis, diagnosed during the autopsy, was considered as the cause of sudden death in both cases.     

Sudden unexpected death due to familial hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy is a familial condition with a very distinct risk of sudden death in males in certain families. The disease appears to be not uncommon in Sri Lanka. A sudden death in a 26-year-old healthy man is reported: At autopsy the heart was 500 g due mainly to left ventricular hypertrophy, and showed histological changes consistent with cardiomyopathy. Symptomless family members of the deceased were subsequently referred to a cardiologist. Cardiomyopathy was diagnosed in one of them.     

Kinking of a coronary artery as a rare complication in mitral valve replacement

We present the case of a 70-year old woman who had elective mitral and aortic valve surgery. She underwent surgery without complications for about 4h until 4 pm. Approx. 3h after surgery her condition deteriorated. 1500ml of blood were collected in the chest drainage until 11 pm. An emergency thoracotomy in the patient's bed showed a ventricular rupture. Death occurred around 11:30 pm. At autopsy, the implants of the biological mitral and aortic valves were found to be sewn tightly. There was no vascular injury and no unusual bleedings to the mediastinum. In the left ventricular wall, a rupture of 1cm and a surrounding fresh myocardial infarction area of 10cm×6cm was noted. Preparation of the coronary arteries showed moderate coronary atherossclerosis without stenosis or clots. The left circumflex coronary artery (LCX) showed a sharp, obviously stenosing kink which had been caused by the mitral valve surgery. Exsanguination due to ventricular rupture following myocardial infarction caused by implant-related "kinking" of a coronary artery, was found to be the cause of death.     

Sudden infant death with anomalous origin of the left coronary artery.

Autopsy of a 3-month-old girl, an apparent case of sudden infant death syndrome, revealed anomalous origin of the left coronary artery from the right aortic sinus. Acute angulation of the left coronary artery along the aortic root, as well as a focal intramyocardial course within the ventricular septum, may have contributed to episodic luminal narrowing. Anomalous coronary origins of similar type have been associated with sudden death in children, teenagers, and young adults, but have not necessarily been associated with sudden death in older adults. Somewhat similar malformations have been reported in sudden infant death; two cases involved the left coronary artery and six involved the right.     

Right ventricular damage due to pulmonary embolism: examination of the number of infiltrating macrophages

To investigate the pathological changes in the heart induced by pulmonary embolism, 20 autopsy cases of pulmonary embolism and 10 control cases of acute death from traumatic injury were examined. Adding to the routine hematoxylin-eosin (HE) staining, immunostaining with CD68 pan-macrophage marker was performed on the specimens obtained from both right and left ventricular walls. The number of macrophages was counted semi-quantitatively in 100 random high-power fields (HPF). Although typical pathological findings of myocardial infarction was not observed in any of the cases, 16 of the 20 pulmonary embolism cases showed an increase in the number of macrophages, mainly in the right ventricular wall. Four cases showed massive macrophage infiltration in the entire right ventricular wall. It is speculated that ischemia due to pulmonary embolism may be connected to its pathogenesis.     

Asymmetric septal hypertrophy of the heart. New findings concerning the possible etiology of sudden deaths in five males

This report describes certain interesting postmortem findings in the hearts of five subjects who died suddenly, silently, and unexpectedly, and in whom the only significant abnormality at autopsy was asymmetric septal hypertrophy (ASH) of the heart. Deep clefts, cystic faults, and dilated vascular channels were not only seen within the septal myocardium in all the hearts, but also within the left ventricular free walls of two hearts. The septal myocardium and the left ventricular free walls of two hearts and the A-V node and His bundle of one heart demonstrated mural and luminal thrombi of several dilated vascular channels. In another heart, foci of cardiocytic myofibrillar degeneration were seen, especially close to narrowed small coronary vessels. Fetal dispersion and fibrosis of the A-V node and His bundle were evident in one heart. These abnormalities in the conducting system and the ventricular myocardium suggest that the hearts of subjects with ASH are not only excellent anatomic substrates for lethal arrhythmias, but also are bound to be hemodynamically impaired. We believe that conditions such as hypoxia, increased oxygen demand by the heart or abnormal sympathetic stimulus may easily trigger fatal arrhythmias in such individuals, thereby causing sudden death.