Viral myocarditis in combination with genetic cardiomyopathy as a cause of sudden death. An autopsy series.

Sudden cardiac death (SCD) is a major public health issue worldwide. In the young (< 40 years of age), genetic cardiomyopathies and viral myocarditis, sometimes in combination, are the most frequent, but underestimated, causes of SCD. Molecular autopsy is essential for prevention. Several studies have shown an association between genetic cardiomyopathies and viral myocarditis, which is probably underestimated due to insufficient post-mortem investigations. We report on four autopsy cases illustrating the pathogenesis of these combined pathologies. In two cases, a genetic hypertrophic cardiomyopathy was diagnosed in combination with Herpes Virus Type 6 (HHV6) and/or Parvovirus-B19 (PVB19) in the heart. In the third case, autopsy revealed a dilated cardiomyopathy and virological analyses revealed acute myocarditis caused by three viruses: PVB19, HHV6 and Epstein-Barr virus. Genetic analyses revealed a mutation in the gene coding for desmin. The fourth case illustrated a channelopathy and a PVB19/HHV6 coinfection. Our four cases illustrate the highly probable deleterious role of cardiotropic viruses in the occurrence of SCD in subjects with genetic cardiomyopathies. We discuss the pathogenetic link between viral myocarditis and genetic cardiomyopathy. Molecular autopsy is essential in prevention of these SCD, and a close collaboration between cardiologists, pathologists, microbiologists and geneticians is mandatory.

Sudden death with cardiac involvement in a neonate with carnitine-acylcarnitine translocase deficiency.

A female neonate born with normal Apgar scores at 38+2 weeks of gestational age unexpectedly passed away within less than 30 hours after birth. The situation mirrored her brother's earlier demise within 24 hours post-delivery, suggesting a possible genetic disorder. Gross examination revealed widespread cyanosis and distinct yellowish changes on the cardiac ventricles. Histopathological examination disclosed lipid accumulation in the liver, heart, and kidneys. Tandem mass spectrometry detected elevated levels of 10 amino acids and 14 carnitines in cardiac blood. Trio-whole genome sequencing (Trio-WGS) identified the SLC25A20 c.199-10T>G mutation associated with carnitine-acylcarnitine translocase disease (CACTD), a type of fatty acid oxidation disorders (FAODs) with a potential for sudden death. Further validation of gene expression confirmed the functional deficiency of SLC25A20, ultimately diagnosing CACTD as the underlying cause of the neonate's demise. This case highlights the importance of prenatal metabolic and genetic screening for prospective parents and emphasizes the need for forensic doctors to integrate metabolomic and genomic investigations into autopsies for suspected inherited metabolic diseases.

Sudden unexpected intrapartum death and left ventricular noncompaction involving the right ventricle.

Left ventricular noncompaction (LVNC), involving mainly the right ventricle, is a rare form of congenital heart disorder characterized by a developmental arrest in myocardial compaction, resulting in a spongy appearance of the myocardium, mainly of the right ventricle, rarely detected in fetuses. We report the case of a female fetus with a gestational age of 41+4 weeks who came to our attention for intrapartum sudden unexpected death, resulting in stillbirth. The ventricular walls, particularly the right ventricular wall, appeared thick, hypertrabeculated and spongy, leading to the diagnosis of LVNC involving mainly the right ventricle. The atrioventricular node and His bundle presented areas of fetal dispersion and resorptive degeneration; islands of conduction tissue were detected in the central fibrous body. Arcuate nucleus of the brainstem showed bilateral severe hypoplasia. The right bundle branch was hypoplastic. The final cause of death was an electrical conduction disfunction in an LVNC involving mainly the right ventricle. To the best of our knowledge, the herein described case is the first reported observation of sudden intrapartum death from LVNC involving mainly the right ventricle well documented post-mortem with cardiac conduction and brainstem studies. Our findings confirm the need of an accurate post-mortem examination including the study of the cardiac conduction system on serial section in every case of sudden unexpected fetal death, although there are no universally recognized guidelines.

Pathological Characteristics and Classification of Unstable Coronary Atherosclerotic Plaques.

Important forensic diagnostic indicators of sudden death in coronary atherosclerotic heart disease, such as acute or chronic myocardial ischemic changes, sometimes make it difficult to locate the ischemic site due to the short death process, the lack of tissue reaction time. In some cases, the deceased died of sudden death on the first-episode, resulting in difficulty for medical examiners to make an accurate diagnosis. However, clinical studies on coronary instability plaque revealed the key role of coronary spasm and thrombosis caused by their lesions in sudden coronary death process. This paper mainly summarizes the pathological characteristics of unstable coronary plaque based on clinical medical research, including plaque rupture, plaque erosion and calcified nodules, as well as the influencing factors leading to plaque instability, and briefly describes the research progress and technique of the atherosclerotic plaques, in order to improve the study on the mechanism of sudden coronary death and improve the accuracy of the forensic diagnosis of sudden coronary death by diagnosing different pathologic states of coronary atherosclerotic plaques.

Transthyretin-derived amyloid (ATTR) and sarcoidosis: Does ATTR deposition cause a granulomatous inflammatory response in older adults with sarcoidosis?

This study aimed to assess the frequency and association between transthyretin-derived (ATTR) amyloidosis and sarcoidosis in a large autopsy cohort including many cases of sudden cardiac death (SCD). We identified 73 sporadic ATTR amyloidosis cases and 11 sarcoidosis cases, among which we found two cases with concomitant ATTR amyloidosis and sarcoidosis (2.4% of all cases; 2.7% within the sporadic ATTR group). The first case involved a 92-year-old man who experienced SCD. In this patient's heart, we observed ATTR deposition and noncaseating epithelioid granulomas consistent with sarcoidosis. Focally, ATTR deposits and granulomas co-localized, with histiocyte phagocytosis of transthyretin-immunoreactive fragments. However, in most lesions, they were distributed independently. The second case was that of an 86-year-old woman who also experienced SCD. In this patient, we detected ATTR deposition in the heart and lung, while noncaseating epithelioid granulomas were only observed in the lung, liver, kidney, and thyroid. Furthermore, no co-localization of the two lesions was observed. Based on these findings, we concluded that the coexistence of ATTR amyloidosis and sarcoidosis was likely coincidental. Nevertheless, despite the rarity of the combination of these two diseases, it should be recognized as a potential cause of SCD, especially among elderly people.

Forensic significance of intracardiac expressions of Nrf2 in acute myocardial ischemia.

When exposed to oxidative and electrophilic stress, a protective antioxidant response is initiated by nuclear factor erythroid 2-related factor 2 (Nrf2). However, the extent of its importance in the forensic diagnosis of acute ischemic heart diseases (AIHD), such as myocardial infarction (MI), remains uncertain. On the other hand, immunohistochemical analyses of fibronectin (FN) and the terminal complement complex (C5b-9) prove valuable in identifying myocardial ischemia that precedes necrosis during the postmortem diagnosis of sudden cardiac death (SCD). In this study, we investigated the immunohistochemical levels of Nrf2, FN, and C5b-9 in human cardiac samples to explore their forensic relevance for the identification of acute cardiac ischemia. Heart samples were obtained from 25 AIHD cases and 39 non-AIHD cases as controls. Nrf2 was localized in the nuclei of cardiomyocytes, while FN and C5b-9 were detected in the myocardial cytoplasm. The number of intranuclear Nrf2 positive signals in cardiomyocytes increased in AIHD cases compared to control cases. Additionally, the grading of positive portions of cardiac FN and C5b-9 in the myocardium was also significantly enhanced in AIHD, compared to controls. Collectively, these results indicate that the immunohistochemical investigation of Nrf2 combined with FN, and/or C5b-9 holds the potential for identifying early-stage myocardial ischemic lesions in cases of SCD.

Insights into malignant mitral valve degenerative disease from a sudden cardiac death cohort highlighting significant measurement differences from normal.

AIMS: Mitral valve prolapse (MVP) is an accepted cause of sudden cardiac death (SCD) in most autopsy series. Diagnosis at autopsy relies upon subjective assessment with no established objective pathological criteria. This study set out to establish objective measurements to help pathologists dealing with SCD. METHODS: We diagnosed 120 (1.5%) cases of MVP in 8108 cases of SCD. We measured the mitral annulus, anterior and posterior leaflets, rough zone and mitral annular disjunction (MAD) in 27 MVP cases and compared them to 54 age- and sex-matched normal mitral valves. RESULTS: Age of death was 39 ± 16 years, with 59 females and 61 males. History of mild MV disease was present in 19 (16%). Eleven (9%) died associated with exertion. Left ventricular hypertrophy was present in nine (15%) females and 10 (16%) males. Both MV leaflets showed thickening and ballooning in all individuals. MVP showed highly significantly increased annular circumference, elongation and thickening of both leaflets as well as increased MAD (all P < 0.001). Left ventricular fibrosis was present in 108 (90%), with interstitial fibrosis in the posterolateral wall and papillary muscle in 88 (81%) and coexisting replacement fibrosis in 40 (37%). CONCLUSION: This is the largest MVP associated with SCD series highlighting a young cohort with equal representation of males and females. There is involvement of both leaflets with significant annular dilatation, elongation and thickening of both leaflets with MAD. Left ventricular fibrosis explains arrhythmia. Our quantitative measurements should serve as a reference for pathologists assessing post-mortem hearts for MVP.

The grading diagnostic strategy of molecular autopsy combined with pathological autopsy in the forensic diagnosis of cardiomyopathy.

The diagnosis of cardiomyopathy often relies on the subjective judgment of pathologists due to the variety of morphologic changes in the condition and its low specificity. This uncertainty can contribute to unexplained sudden cardiac deaths (USCD). To enhance the accuracy of hereditary cardiomyopathy diagnosis in forensic medicine, we proposed a combination of molecular autopsy and pathologic autopsy. By analyzing 16 deceased patients suspected of cardiomyopathy, using whole exome sequencing (WES) in molecular autopsy, and applying a combined diagnostic strategy, the study found pathogenic or likely pathogenic variants in 6 cases. Out of the 16 cases, cardiomyopathy was confirmed in 3, while 3 exhibited conditions consistent with it. Data for 4 cases was inconclusive, and cardiomyopathy was ruled out in 6. Notably, a novel variant of the TTN gene was identified. This research suggests that a grading diagnostic strategy, combining molecular and pathological evidence, can improve the accuracy of forensic cardiomyopathy diagnosis. This approach provides a practical model and strategy for precise forensic cause-of-death determination, addressing the limitations of relying solely on morphologic assessments in cardiomyopathy cases, and integrating genetic information for a more comprehensive diagnosis.

Hidden Coronary Artery Ostium and Sudden Death.

A 1-week-old girl died suddenly and unexpectedly. At autopsy the major finding was of a right dominant coronary artery circulation with an inapparent left coronary artery ostium. After careful examination, an anomalous origin of the left coronary artery was found with the ostium located in the non-coronary cusp immediately adjacent to the commissure of the non- and left coronary cusps. The ostium was of small caliber with an obliquely oriented artery (<45°) with no ostial ridges. The artery coursed anteriorly past the left coronary cusp between the aorta and the left atrial appendage to then follow its usual course inferiorly along the anterior aspect of the left ventricle. The reminder of the autopsy was unremarkable. Death was, therefore, attributed to an anomalous and hypoplastic left coronary artery (and ostium) with an acute angle of take-off. Tracing coronary arteries in the very young may be technically difficult due to their small size, thus identifying the location of ostia is important. This may be difficult when the ostium was located close to a commissure.

Commotio cordis: Another cardiac arrest "sine materia". The 1707 early report and interpretation by G.M. Lancisi.

Sudden death by commotio cordis is rare. It is the consequence of a blunt trauma of the chest overlying the heart. The mechanism is a cardiac arrest by ventricular fibrillation in the absence of grossly or microscopically apparent myocardial injury. It has been reproduced in animals. The first historical case was reported by Giovanni Maria Lancisi in his book "De Subitaneis Mortibus'' published in 1707. Sudden death occurred in a man receiving a powerful blow under the xiphoid cartilage. Lancisi advanced the hypothesis of acute heart failure by a diastolic stand still ("death in diastole'').

Morphological and Genetic Aspects for Post-Mortem Diagnosis of Hypertrophic Cardiomyopathy: A Systematic Review.

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiovascular diseases, and it shows an autosomal dominant pattern of inheritance. HCM can be clinically silent, and sudden unexpected death due to malignant arrhythmias may be the first manifestation. Thus, the HCM diagnosis could be performed at a clinical and judicial autopsy and offer useful findings on morphological features; moreover, it could integrate the knowledge on the genetic aspect of the disease. This review aims to systematically analyze the literature on the main post-mortem investigations and the related findings of HCM to reach a well-characterized and stringent diagnosis; the review was performed using PubMed and Scopus databases. The articles on the post-mortem evaluation of HCM by gross and microscopic evaluation, imaging, and genetic test were selected; a total of 36 studies were included. HCM was described with a wide range of gross findings, and there were cases without morphological alterations. Myocyte hypertrophy, disarray, fibrosis, and small vessel disease were the main histological findings. The post-mortem genetic tests allowed the diagnosis to be reached in cases without morpho-structural abnormalities; clinical and forensic pathologists have a pivotal role in HCM diagnosis; they contribute to a better definition of the disease and also provide data on the genotype-phenotype correlation, which is useful for clinical research.

Sudden unexpected death from subvalvular hemorrhagic cyst complicated with coronary heart disease in an adult.

Cardiac blood cysts are rare benign tumors. It is commonly found in the heart valve and left ventricle of newborns by autopsy and is rarely seen in adults [1, 2]. The typical histopathology of cardiac blood cysts is a closed, round, blood-containing cystic mass attached to the heart valve or endocardium. This article reports a rare case of sudden death due to a giant subaortic cardiac blood cyst with coronary heart disease in an adult patient and summarizes the pathological features, aiming to provide a reference for the forensic pathological identification of cardiac blood cysts.

Lesions of the Cardiac Conduction System and Sudden Death.

ABSTRACT: When a young previously healthy person dies suddenly, occasionally, the scene is noncontributory and the autopsy and drug screen are negative. In such cases, additional studies, including genetic assessment and cardiac conduction system examination, should be performed. We performed a literature search and reviewed our own material to identify possible or definite conduction system anomalies that may cause death. We identified intrinsic conduction system disease including cystic tumor of the atrioventricular node, atrioventricular node (cystic tumor of the AV node), and fibromuscular dysplasia of the atrioventricular node artery to be likely causes of death. Extrinsic causes, in which a generalized disease affects the conduction system, include tumors, autoimmune disease, infiltrative disorders, and others, are a second category of diseases that can affect the conduction system and cause atrioventricular block and sudden death.

Sudden death related to sexual activity: A multicenter study based on forensic autopsies (2010-2021).

INTRODUCTION AND OBJECTIVES: To investigate the epidemiological characteristics, clinic-pathological findings and recent use of substances of abuse and prescribed drugs in sexual activity-related sudden death (SArSD). METHODS: Multicenter population-based study on forensic autopsies conducted in 27 provinces of Spain over 12 years (2010-2021). RESULTS: Out of 18046 autopsied natural deaths, 64 cases (0.35 %) of SArSD were investigated (87 % males). Women were younger than males (50.5 ± 13.4 years vs 37.2 ± 14.2; p = 0.017). Sudden cardiac deaths (SCD) accounted for 87 % of cases. Ischemic heart disease was the predominant pathology (58 %), mainly affecting men ≥ 36 years of age. Cerebral haemorrhage (8 %) and asthma (5 %) were the leading non-cardiac causes. In young adults, SADS (36 %) and asthma (27 %) were the main causes The disease responsible of SCD was diagnosed in life in 7 subjects. In 64 % there were cardiovascular risk factors, mainly obesity. Toxicological analysis detected illicit drugs (23 %), mainly cocaine, medications for erectile dysfunction (9 %), and ethanol ≥ 0.5 g/L (8 %). Deaths occurred usually in the context of heterosexual intercourse and during or immediately after sexual activity. The most common location was at home (63 %). In 12 men the sexual partner was a sex worker. CONCLUSIONS: SArSD has a low incidence in the general population affecting middle-aged males during intercourse with a heterosexual partner. It is of cardiovascular origin, mainly due to ischemic heart disease that frequently remained silent during life. There is a frequent association with obesity, use of cocaine (and, to a lesser extent, medications for erectile dysfunction) and performing unconventional sexual practices. Forensic investigation is useful for developing prevention strategies.

Anomalous origin of left main coronary artery from the right sinus of Valsalva.

BACKGROUND: Anomalous coronary arteries are rare congenital variations with cases ranging from asymptomatic to life-threatening. Given the wide variability of coronary anomalies, it is challenging to predict their clinical consequences. Here, we present the 'malignant' variant - interarterial course of the left coronary artery between the aorta and pulmonary trunk - given the highest risk of sudden cardiac death among the various coronary anomalies. CASE PRESENTATION: Our case presents a 22-year-old male presenting to the emergency department after a syncopal episode that occurred while the patient was driving a motor vehicle. Initial Computed Tomography (CT) of the chest performed as part of the trauma work-up revealed a rare case of an anomalous origin of the left main coronary artery (LMCA) originating from a common ostium with the right coronary artery (RCA). The LMCA was found to have a malignant course, as it was positioned between the aorta and pulmonary artery. Given the high risk of sudden cardiac arrest with this congenital variant, the patient underwent coronary artery bypass grafting. CONCLUSION: Anomalous coronary arteries remain the second leading cause of sudden cardiac death in young adult patients. The risk of sudden cardiac death depends on the congenital variant of the anomalous coronary artery as well as the course these vessels take. This case highlights a rare congenital variant featuring both the LMCA and RCA originating from a common ostium, with the LMCA having a malignant course, a variant with the highest risk of sudden cardiac death.

Sudden death in young South European population: a cross-sectional study of postmortem cases.

To describe the annual incidence and the leading causes of sudden non-cardiac and cardiac death (SCD) in children and young adult Portuguese population. We retrospectively reviewed autopsy of sudden unexpected deaths reports from the Portuguese National Institute of Legal Medicine and Forensic Sciences' database, between 2012 and 2016, for the central region of Portugal, Azores and Madeira (ages 1-40: 26% of the total population). During a 5-year period, 159 SD were identified, corresponding to an annual incidence of 2,4 (95%confidence interval, 1,5-3,6) per 100.000 people-years. Victims had a mean age of 32 ± 7 years-old, and 72,3% were male. There were 70,4% cardiac, 16,4% respiratory and 7,5% neurologic causes of SD. The most frequent cardiac anatomopathological diagnosis was atherosclerotic coronary artery disease (CAD) (33,0%). There were 15,2% victims with left ventricular hypertrophy, with a diagnosis of hypertrophic cardiomyopathy only possible in 2,7%. The prevalence of cardiac pathological findings of uncertain significance was 30,4%. In conclusion, the annual incidence of SD was low. Atherosclerotic CAD was diagnosed in 33,0% victims, suggesting the need to intensify primary prevention measures in the young. The high prevalence of pathological findings of uncertain significance emphasizes the importance of molecular autopsy and screening of first-degree relatives.

From Death to Life/Back to the Future: Detailed Premorbid Clinical and Family History Can Save Lives and Address the Final Diagnosis in Sudden Unexplained Deaths With Negative Autopsy.

Sudden cardiac death is a sudden, unexpected death developed by one of the many different causes of cardiac arrest that occur within 1 hour of the onset of new symptoms. Sudden unexplained death (SUD) comprises a normal heart at postmortem examination and negative toxicological analysis. SUD often arises from cardiac genetic disease, particularly channelopathies. Channelopathies, or inherited arrhythmia syndromes, are a group of disorders characterized by an increased risk of sudden cardiac death, abnormal cardiac electrical function, and, typically, a structurally normal heart. They share an underlying genetic etiology where disease-causing genetic variants may lead to the absence or dysfunction of proteins involved in the generation and propagation of the cardiac action potential. Our study aimed to evaluate the importance of next-generation sequencing in the postmortem investigations of SUD cases. In this study, 5 forensic SUD cases were investigated for inherited cardiac disorders. We screened a total of 68 cardiac genes for the sibling of case 1, as well as case 2, and 51 genes for cases 3, 4, and 5. Of the 12 variants identified, 2 likely pathogenic variants (16.7%) were the TMEM43 _ c.1000+2T>C splice site mutation and the SCN5A _ p.W703X nonsense mutation. The remaining 10 variants of uncertain significance were detected in the TRPM4 , RANGRF , A KAP9 , KCND3 , KCNE1 , DSG2 , CASQ1 , and SNTA1 genes. Irrespective of genetic testing, all SUD families require detailed clinical testing to identify relatives who may be at risk. Molecular autopsy and detailed premorbid clinical and family histories can survive family members of SUD cases.

Noncoding RNAs and Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes in Cardiac Arrhythmic Brugada Syndrome.

Hundreds of thousands of people die each year as a result of sudden cardiac death, and many are due to heart rhythm disorders. One of the major causes of these arrhythmic events is Brugada syndrome, a cardiac channelopathy that results in abnormal cardiac conduction, severe life-threatening arrhythmias, and, on many occasions, death. This disorder has been associated with mutations and dysfunction of about two dozen genes; however, the majority of the patients do not have a definite cause for the diagnosis of Brugada Syndrome. The protein-coding genes represent only a very small fraction of the mammalian genome, and the majority of the noncoding regions of the genome are actively transcribed. Studies have shown that most of the loci associated with electrophysiological traits are located in noncoding regulatory regions and are expected to affect gene expression dosage and cardiac ion channel function. Noncoding RNAs serve an expanding number of regulatory and other functional roles within the cells, including but not limited to transcriptional, post-transcriptional, and epigenetic regulation. The major noncoding RNAs found in Brugada Syndrome include microRNAs; however, others such as long noncoding RNAs are also identified. They contribute to pathogenesis by interacting with ion channels and/or are detectable as clinical biomarkers. Stem cells have received significant attention in the recent past, and can be differentiated into many different cell types including those in the heart. In addition to contractile and relaxational properties, BrS-relevant electrophysiological phenotypes are also demonstrated in cardiomyocytes differentiated from stem cells induced from adult human cells. In this review, we discuss the current understanding of noncoding regions of the genome and their RNA biology in Brugada Syndrome. We also delve into the role of stem cells, especially human induced pluripotent stem cell-derived cardiac differentiated cells, in the investigation of Brugada syndrome in preclinical and clinical studies.

Patient-specific iPSC-derived cardiomyocytes reveal variable phenotypic severity of Brugada syndrome.

BACKGROUND: Brugada syndrome (BrS) is a cardiac channelopathy that can result in sudden cardiac death (SCD). SCN5A is the most frequent gene linked to BrS, but the genotype-phenotype correlations are not completely matched. Clinical phenotypes of a particular SCN5A variant may range from asymptomatic to SCD. Here, we used comparison of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) derived from a SCN5A mutation-positive (D356Y) BrS family with severely affected proband, asymptomatic mutation carriers (AMCs) and healthy controls to investigate this variation. METHODS: 26 iPSC lines were generated from skin fibroblasts using nonintegrated Sendai virus. The generated iPSCs were differentiated into cardiomyocytes using a monolayer-based differentiation protocol. FINDINGS: D356Y iPSC-CMs exhibited increased beat interval variability, slower depolarization, cardiac arrhythmias, defects of Na+ channel function and irregular Ca2+ signaling, when compared to controls. Importantly, the phenotype severity observed in AMC iPSC-CMs was milder than that of proband iPSC-CMs, an observation exacerbated by flecainide. Interestingly, the iPSC-CMs of the proband exhibited markedly decreased Ca2+ currents in comparison with control and AMC iPSC-CMs. CRISPR/Cas9-mediated genome editing to correct D356Y in proband iPSC-CMs effectively rescued the arrhythmic phenotype and restored Na+ and Ca2+ currents. Moreover, drug screening using established BrS iPSC-CM models demonstrated that quinidine and sotalol possessed antiarrhythmic effects in an individual-dependent manner. Clinically, venous and oral administration of calcium partially reduced the malignant arrhythmic events of the proband in mid-term follow-up. INTERPRETATION: Patient-specific and genome-edited iPSC-CMs can recapitulate the varying phenotypic severity of BrS. Our findings suggest that preservation of the Ca2+ currents might be a compensatory mechanism to resist arrhythmogenesis in BrS AMCs. FUNDING: National Key R&D Program of China (2017YFA0103700), National Natural Science Foundation of China (81922006, 81870175), Natural Science Foundation of Zhejiang Province (LD21H020001, LR15H020001), National Natural Science Foundation of China (81970269), Key Research and Development Program of Zhejiang Province (2019C03022) and Natural Science Foundation of Zhejiang Province (LY16H020002).