Sudden death in the young

BACKGROUND: Sudden death is rare in young people, but it has a disproportionate impact on the community. OBJECTIVES: The purpose of this study was to determine the causes of sudden, natural death in persons aged 5-35 years. METHODS: All autopsies conducted at a forensic medicine facility in the years 1995-2004 (inclusive) were reviewed. This facility serves more than 2.5 million people in the eastern part of Sydney, Australia. Data collected included subject age, height, weight, gender, circumstances of death, and pathologic findings at autopsy. Deaths caused by trauma, accidental causes, drowning, and drug toxicity were excluded from analysis. RESULTS: There were 427 nontraumatic, sudden deaths in the 10-year period (70.7% male). Cardiac causes accounted for 56.4%, noncardiac causes 39.3%, and undetermined cause 4.3%. The most common cardiac cause of sudden death was presumed arrhythmia in those with no or minimal structural heart disease (29.0%). Other cardiac causes were acute myocardial infarction (24.5%), myocarditis (11.6%), hypertrophic cardiomyopathy (5.8%), aortic dissection (5.4%), and dilated cardiomyopathy (5.4%). More than two thirds of deaths caused by acute myocardial infarction occurred in the age group from 30-35 years. Sudden cardiac death occurred during physical activity in 10.8% of cases. Sudden cardiac death was reported in a first-degree relative in 4.5% of decedents. The most common noncardiac causes of sudden death were epilepsy (23.8%), intracerebral hemorrhage (23.8%), asthma (16.1%), and pulmonary embolism (12.5%). CONCLUSION: Presumed cardiac arrhythmia is the most common cause of sudden, natural death in the young. There was no reported history of sudden death among the relatives of most decedents.     

Myocardial disease mortality in children and young adults. A population-based observational study

INTRODUCTION AND OBJECTIVES. Few studies have investigated death due to myocardial disease in children and young adults. The aim of this study was to analyze the epidemiological, clinical, and pathologic characteristics of death in these cases. PATIENTS AND METHOD. Population-based observational study of all deaths in individuals aged 1-35 years in the Spanish province of Biscay over a period of 12 years. RESULTS. Forty deaths from myocardial disease occurred in 29 males and 11 females (mean age 25.3 years): 30 sudden and 10 non-sudden deaths. The mortality rate was 0.64 per 100,000 persons-year. The relative risk of sudden death was significantly greater than that of non-sudden death, particularly in adolescents and young males. The cause of death was myocarditis in 12 cases (83.3% sudden death), dilated cardiomyopathy in 10 (80% non-sudden death), arrhythmogenic cardiomyopathy in seven, hypertrophic cardiomyopathy in six, and idiopathic concentric left ventricular hypertrophy in five (100% sudden death). Myocardial disease was diagnosed before sudden death in only three cases. Ten subjects had symptoms and electrocardiogram abnormalities but their cardiomyopathy had not been diagnosed. Six individuals had a comorbid condition (morbid obesity in four), six had prodromal symptoms, and 11 had arrhythmic triggering factors (sporting activity in seven). Ventricular fibrillation was frequently observed during cardiopulmonary resuscitation. CONCLUSIONS. Mortality due to myocardial disease in children and young adults is uncommon. Most deaths are sudden. However, some may be preventable. Preventative measures should be aimed at sudden death in adolescents and young males. There was a noticeable association between arrhythmogenic cardiomyopathy and sporting activity.     

Sudden death of school children in Japan

The autopsy findings of sudden deaths of school children revealed that the main causes of death were latent myocarditis and arrhythmia, followed by idiopathic cardiomyopathy. The incidence of sudden death of school children in recent years is gradually increasing and 150 cases of sudden death occurred during the 1983 school year. A high incidence of sudden death in senior high school students was found. Sudden cardiac death accounted for approximately 80% of total deaths. The incidence of sudden cardiac death revealed prominent regional differences in Japan. The average for deaths was 0.40/100,000 children/5 years and the highest prefecture revealed 0.70 and the lowest 0.07. The cause of such differences is not clear and requires further analysis.     

Causes of sudden death in competitive athletes

Cardiovascular diseases responsible for sudden unexpected death in highly conditioned athletes are largely related to the age of the patient. In most young competitive athletes (less than 35 years of age) sudden death is due to congenital cardiovascular disease. Hypertrophic cardiomyopathy appears to be the most common cause of such deaths, accounting for about half of the sudden deaths in young athletes. Other cardiovascular abnormalities that appear to be less frequent but important causes of sudden death in young athletes include congenital coronary artery anomalies, ruptured aorta (due to cystic medial necrosis), idiopathic left ventricular hypertrophy and coronary artery atherosclerosis. Diseases that appear to be very uncommon causes of sudden death include myocarditis, mitral valve prolapse, aortic valve stenosis and sarcoidosis. Cardiovascular disease in young athletes is usually unsuspected during life, and most athletes who die suddenly have experienced no cardiac symptoms. In only about 25% of those competitive athletes who die suddenly is underlying cardiovascular disease detected or suspected before participation and rarely is the correct clinical diagnosis made. In contrast, in older athletes (greater than or equal to 35 years of age) sudden death is usually due to coronary artery disease, and rarely results from congenital heart disease.     

The autopsy study of 553 cases of sudden cardiac death in Chinese adults

Despite a recent epidemiological study reporting a lower incidence of sudden cardiac death (SCD) in China as compared with that in Western countries, the exact causes of SCD are still unknown. Using a uniform review protocol and diagnostic criteria, a retrospective autopsy study identified 553 cases of SCD in 14,487 consecutive autopsies from eight regions in China representing different geographic and population features. Their ages ranged from 18 to 80 years (median 43.0 years) with a ratio of 4.3/1.0 for male/female. Out-of-hospital deaths and unwitnessed cases accounted for 74.3 and 22.6 %, respectively. The main causes of death were coronary atherosclerotic disease (CAD 50.3 %), myocarditis (14.8 %), and hypertrophic cardiomyopathy (4.5 %), with unexplained sudden death accounting for 12.1 % of the cases. CAD had a proportion of 10.4 % in victims <35 years, lower as compared with 59.0 and 83.0 % in victims aged 35–54 and in victims ≥55 years. On the other hand, myocarditis and unexplained sudden death were major causes and accounted for 34.7 and 22.5 % in victims <35 years. In order to differentiate the degree of the cause–effect relationship between autopsy findings and sudden death, a grading method was used in this series and characterized 24.3 % of findings as certain, 52.9 % as highly probable, and 22.8 % as uncertain. Our data indicated that there most likely are less CAD but more myocarditis and unexplained sudden death in Chinese youth with SCD than in populations from Western countries. Molecular genetic testing should be conducted in those cases with uncertain findings and unexplained sudden death in routine autopsy.     

Myocardial Inflammation and Sudden Death in the Inherited Cardiomyopathies

The best studied of the inherited cardiomyopathies—hypertrophic (HCM), dilated (DCM) and arrhythmogenic (ACM)—present overlapping clinical phenotypes with varying, often unrecognized, risk of sudden death. Risk assessment is informed by patient sex and by the specific disease-causing variant. HCM and arrhythmogenic right ventricular cardiomyopathy (ARVC) remain important causes of sudden death. A phenotype mimicking DCM in patients with inherited ACM is associated with premature sudden death in families with overlapping DCM and ACM phenotypes. The role of inflammation as a determinant of disease development and progression and sudden death is poorly understood but potentially important. Sudden death registries report myocarditis as the cause in 5% to 13%; examination of 30 hearts from victims of ARVC sudden death found focal myocarditis in areas of myocyte necrosis in 20 (67%). The link to specific disease-causing variants remains to be explored, including genetic determinants of the immune response. Clinical and experimental studies support immune- and autoimmune-mediated disease in DCM and ACM. Immunosuppression in biopsy-proven noninfectious myocarditis and inflammatory DCM is a treatment option. Recognition of ACM requires greater focus on distinguishing ACM from DCM. The potential to recognize disease before adverse events and to characterize patients who may benefit from immunosuppression or device therapy highlights the importance of more comprehensive genetic and immunologic characterization of patients with myocarditis and in those with a family history or clinical presentation of an inherited cardiomyopathy. This review will examine from a predominantly clinical perspective the potential importance of myocardial inflammation as a determinant of sudden death in inherited HCM, DCM, and ACM.     

Hypertrophic cardiomyopathy: Management issues in the new millennium

Hypertrophic cardiomyopathy is an inherited cardiac disorder. Sudden cardiac death frequently occurs in otherwise healthy individuals, and accounts for nearly 35% of all sudden deaths within this age group. Although symptoms occur commonly, they often go unreported. Despite this, a degree of functional limitation is often seen on objective assessment. Management of hypertrophic cardiomyopathy is aimed at relieving symptoms, identifying and treating those individuals at increased risk of sudden death, and screening family members.     

Sudden death and vigorous exercise--a study of 60 deaths associated with squash.

The circumstances surrounding 60 sudden deaths (59 men, one woman) associated with squash playing are described. The mean age (SD) of those who died was 46 (10.3) years (range 22-66 years). Necropsy reports were available in 51. The certified cause of death was coronary artery disease in 51 cases, valvar heart disease in four, cardiac arrhythmia in two cases, and hypertrophic cardiomyopathy in one case. There were only two deaths from non-cardiac causes. Forty five of those who died had reported prodromal symptoms, the most common of which was chest pain, and 22 were known to have had at least one medical condition related to the cardiovascular system during life, the most common of which was systemic hypertension (14 subjects). Those dying from coronary artery disease had a high frequency of risk factors. Some of these deaths might have been prevented by appropriate counselling of players after prospective medical screening, which would have detected most of the patients with overt cardiovascular disease and some of those with subclinical coronary artery disease.     

“Malignant” hypertrophic cardiomyopathy: Identification of a subgroup of families with unusually frequent premature death

Eight families were identified in which premature cardiac death due to hypertrophic cardiomyopathy occurred with unusual frequency. A total of 69 first degree relatives in the eight families were studied; 41 relatives had evidence of hypertrophic cardiomyopathy and 31 (75 percent) died of their heart disease. Eighteen of these 31 patients were less than 25 years of age at the time of death. Death was sudden and unexpected in 23 of the 31 patients; in 15 of these 23 patients sudden death was the initial manifestation of cardiac disease. The remaining eight patients (seven were from two families) died after a chronic cardiac illness characterized by congestive heart failure, atrial fibrillation or thromboembolic events.

Hence, premature cardiac death occurs frequently in certain families with hypertrophic cardiomyopathy. Such deaths are usually sudden, often occur in previously asymptomatic subjects and are common in children and young adults. These findings suggest that some families may manifest an unusually virulent expression of hypertrophic cardiomyopathy. Although this study cannot establish the precise prevalence with which “malignant” hypertrophic cardiomyopathy occurs, such families appear to be uncommon.     

Circadian variability in the occurrence of sudden cardiac death in patients with hypertrophic cardiomyopathy

Objectives. The present study examined whether sudden death in patients with hypertrophic cardiomyopathy occurred with a particular pattern of frequency throughout the day.Background. Previous investigators have shown a circadian distribution in the occurrence of sudden death and other cardiovascular events in patients with atherosclerotic coronary artery disease. Sudden death is also an important feature of the natural history of patients with hypertrophic cardiomyopathy.Methods. The study group comprised 94 patients with a time of death (or cardiac arrest) that could be ascertained accurately to the nearest hour. This hourly distribution was analyzed by harmonic regression.Results. Sudden death did not occur uniformly or randomly throughout the day. Rather, it was distributed in a bimodal pattern that conformed to a two-harmonic regression model. A disproportionate number of sudden deaths (43 [46%] of 94) occurred in the first peak in midmorning between 7 amand 1 pm. The second peak of sudden death was less distinct but was in the early evening, between 8 pmand 10 pm. This periodicity in occurnace of sudden cardiac death was not evident for the days of the week or months of the year and, furthermore, did not appear to be influenced by other clinical variables, such as age, gender, severity of symptoms, subaortic gradient or left ventricular wall thickness. Sudden death occurred most commonly during periods of severe exertion (37 [39%] of 94).Conclusions. Sudden death in hypertrophic cardiomyopathy demonstrates a bimodal pattern of circadian variability over the 24-h day, with a prominent midmorning peak similar to that described in patients with coronary artery disease, and a less striking early-evening peak of occurrence. These findings suggest that temporally related physiologic changes, possibly in the electrical vulnerability of the myocardial substrate, may play a role in the sudden death of patients with hypertrophic cardiomyopathy.     

Sudden unexpected death from cardiovascular disease in children. A cooperative international study

The results of an international cooperative study of sudden unexpected death from cardiovascular disease in children are reported. Sudden natural death was defined as death occurring instantaneously or within 24 hours of the onset of acute symptoms or signs in ambulatory, nonhospitalized children aged 1 to 21 years. Twenty institutions representing 10 countries contributed a total of 254 acceptable case reports. In 186 cases the child had had no cardiac surgery. Four heart conditions accounted for 53 percent of these “medical” deaths: congenital aortic stenosis (18 percent), Eisenmenger's syndrome (15 percent), cyanotic congenital heart disease with pulmonary stenosis or atresia (10 percent) and hypertrophic obstructive cardiomyopathy (9 percent). A total of 33 types of cardiovascular disease were reported. Sixty-eight chlldren died months or years after cardiac surgery. In 28 of these 68 patients death appeared to be causally related to the preceding surgery rather than to the underlying cardiovascular disease. All but 2 of the 28 probably died of an arrhythmia, usually without warning.The period between the onset of acute signs and symptoms (terminal episode) was less than an hour (usually instantaneous) in 73 percent of all 254 patients. In 95 percent of patients in the “medical” group heart disease was known or suspected, but a majority of these patients were asymptomatic. Warning syncope occurred in only 16 percent. A majority of the patients (58 percent) were inactive at the time of the terminal episode (Standing, sitting, lying or sleeping). Only 10 percent were engaged in active sports.This large study appears to establish better than previous data the relative frequency of sudden unexpected death among children with heart disease in Western Europe and Central and North America. Surgical and medical preventive measures, and the indications for engaging in sports, are discussed.     

Prognosis in hypertrophic cardiomyopathy

One hundred thirty-six patients with hypertrophic cardiomyopathy were followed up for 1 to 17 years. Twenty-one patients had died, 14 of them suddenly, two from heart failure, two from cerebral embolism, and three from noncardiac causes. Life table analysis revealed that sudden death was significantly associated with young age less than 20 years (relative risk [rr] = 8.63, when compared with those greater than 40 years) and with positive Master's single two-step test (rr = 3.55). Heart failure was more frequent in patients with positive Master's single test (rr = 4.27) and with left ventricular end-diastolic pressure greater than 20 mm Hg (rr = 2.58). Atrial fibrillation, observed in 15 patients, was a poor prognostic sign, resulting in five cardiac deaths and seven heart failures. In contrast, prognosis was favorable in patients with apical hypertrophy with giant negative T wave. Thus Japanese patients with hypertrophic cardiomyopathy showed a prognosis consistent with Western patients, except for excellent outcome of apical hypertrophy.     

Sudden Unexpected Death in Children with Heart Disease

Objective. To review a mortality database, and identify all sudden unexpected deaths in patients followed by the cardiac program. Design. Retrospective review of prospectively maintained database. Results. Over 8 years, we identified 80 sudden unexpected deaths, among which there were sufficient data in 69 (24 females). Patients died at a median age of 17.2 months (28 days?18.8 years). Forty‐six patients had 2 functional ventricles and 23 had received palliation for a single‐functional ventricle. Patients with a single ventricle died at a younger age (median 120 days; 28 days?17.2 years) and sooner after last assessment (median 27 days; 1–146 days) than patients in the biventricular group (median age 2 years; 43 days?18.8 years; median time since last assessment 49 days, 1 days?1 year) (P < .01; P = .01). Thrombosis was the most common cause (61%) of death in the single‐ventricle group. Arrhythmia or presumed arrhythmia was the most common cause (46%) of death in the biventricular group. Fifty‐one patients had undergone surgery. Six patients had primary electrophysiological disease, and 5 had cardiomyopathy. Eight deaths occurred in patients with pulmonary vascular disease. Conclusion. Our study demonstrates that sudden unexpected death occurred at a frequency of at least 10 patients per year over an 8‐year period with 55 730 patient encounters. We were able to determine a clinical cause of death in most patients. Arrhythmias (30%) and pulmonary vascular disease (13%) are important causes of sudden death. Simple aortic valve disease and hypertrophic cardiomyopathy are rare (4%) causes of sudden death in childhood. Infants and young children with surgical shunts comprise 23% of sudden unexpected deaths that occur within a month of the last evaluation. Close surveillance of these patients is warranted.     

Sudden death associated with anomalous coronary origin and obstructive coronary disease in the young

Sudden cardiac death in a young patient is a catastrophic occurrence. Anomalous coronary origin (ACO) is a significant cause of sudden cardiac death among individuals under the age of 35 years. We sought to define the premortem clinical and postmortem histopathologic findings in victims of sudden cardiac death resulting from either ACO or obstructive atherosclerotic coronary artery disease (CAD) among U.S. military recruits (ages 17-35 years). The autopsy records of all sudden cardiac deaths occurring among recruits during their basic military training period from 1977 through 2001 were reviewed. Twenty-one deaths were associated with ACO and 10 with CAD. Recruits with ACO were more likely to have prodromal symptoms of exertional syncope and/or chest pain (48% vs. 0%, P = 0.011). All sudden cardiac deaths resulting from ACO involved a left main coronary artery takeoff from the right coronary sinus with a course between the aorta and the right ventricular outflow tract and an otherwise normal distribution of the major epicardial coronary arteries. Myocardial fibrosis was seen equally in those with both CAD and ACO (30% vs. 20%, P = 0.66), but the finding of necrosis tended to be more common among recruits with CAD (50% vs. 15%, P = 0.08). In conclusion, review of autopsy data of sudden cardiac deaths among U.S. military recruits reveals myocardial fibrosis or necrosis occurred in 70% of cases with CAD and 35% of cases with ACO. Sudden cardiac deaths resulting from ACO were more likely to be associated with premortem exertional chest discomfort and/or syncope compared with deaths resulting from CAD.     

Causes of sudden death during sports activities in Spain

INTRODUCTION AND OBJECTIVES: Sudden death during sports activities has a profound impact on relatives, society, and athletes. Medical screening programs usually fail to prevent sudden death. We report the characteristics of a series of sudden deaths that occurred during sports in Spain. METHODS: We reviewed cases of sudden death that occurred during sports activities from 1995 to 2001 in the registries of the Institute of Toxicology of Madrid, Spain (Ministry of Justice). RESULTS: The series included 61 cases ranging in age from 11 to 65 years (average 31.9 14.2), 59 males and 2 females. The sports most frequently involved were cycling (21), football (13), and gymnastics (5). The causes of death were atheromatous coronary disease: 25 (40.9%) (23 over 30 years); arrhythmogenic cardiomyopathy: 10 (16.3%) (7 under 30 years); hypertrophic cardiomyopathy: 4 (6.5%); idiopathic left ventricular hypertrophy: 3 (4.9%); postmyocarditis myocardial fibrosis: 2 (3.2%); dilated cardiomyopathy: 1 (1.6%); congenital anomalies in the origin of the coronary arteries: 2 (3.2%); aortic valve disease: 2 (3.2%); and others: 2 (3.2%). In 10 cases (16.3%) (all under 30), the cause of death was undetermined. In 16 cases (26.2%) there was a known pathological antecedent. The disease responsible for death had been diagnosed in only three cases. CONCLUSIONS: Arrhythmogenic cardiomyopathy and severe left ventricular hypertrophy were the most common causes of sports-related death in persons under the age of 30. In 30% the cause of death was undetermined. Atheromatous coronary disease was prevalent over the age of 30 years and associated with cycling. Medical screening programs actually in use fail to detect a significant proportion of athletes at risk for sudden death.     

Relation between extent of left ventricular hypertrophy and occurrence of sudden cardiac death in hypertrophic cardiomyopathy

Sudden unexpected death can be the first clinical manifestation of hypertrophic cardiomyopathy and is the most devastating feature of the natural history of the disease. Left ventricular hypertrophy appears to be an important determinant of many clinical features of hypertrophic cardiomyopathy, but the relation between its magnitude and the occurrence of sudden cardiac death has not been clearly defined. In this study, the magnitude of hypertrophy was assessed with two-dimensional echocardiography in 29 asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy who subsequently died suddenly or experienced cardiac arrest with documented ventricular fibrillation. Findings were compared with those obtained in a control group of 95 patients of similar age and symptomatic state. Maximal left ventricular wall thickness was significantly greater in patients with sudden death (26 +/- 7 mm) than in control patients (21 +/- 5 mm, p less than 0.001). Left ventricular wall thickness index, a quantitative expression of the overall extent of hypertrophy, was also greater in patients with sudden death (76 +/- 20 mm) than in surviving control patients (62 +/- 13 mm, p less than 0.001). Particularly marked and diffuse hypertrophy, with maximal wall thickness greater than or equal to 30 mm or wall thickness greater than or equal to 25 mm in two or more of the four segments into which the left ventricle had been divided, was eight times more common in patients with sudden death (11 [38%] of 29) than in control patients (5 [5%] of 95, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Sudden death in children and adolescents

OBJECTIVE—To identify the incidence, causes, and characteristics of sudden death at age 1-20 years.
DESIGN—A review of all deaths at age 1-20 years. Death certificates were obtained from the Office for National Statistics, and further information, where appropriate, from coroners, paediatricians, physicians, and pathologists.
SETTING—The resident population of one English health region in 1985-1994.
RESULTS—In a population of 806 500 children and adolescents aged 1-20 years there were 2523 deaths in 10 years. Medical causes accounted for 1017 deaths (40%); 1236 (49%) were unnatural, and 270 (11%) were sudden. These sudden deaths comprised 142 with a previous diagnosis, the commonest being epilepsy 49 (34%), cardiovascular disease 33 (23%), and asthma 30 (21%); 87 attributed to a cause discovered at necropsy, which was respiratory infection in 32 (37%), other infections in 17 (20%), and unsuspected cardiovascular abnormalities in 26 (30%); 41 remained unexplained.
CONCLUSIONS—Half of all sudden deaths in children or adolescents were attributed to an already diagnosed condition. Abnormalities identified at necropsy accounted for one third of sudden deaths. Undiagnosed hypertrophic cardiomyopathy caused less than one death per million person years in the population aged 1-20 years. Unexplained sudden death, which may be caused by primary cardiac arrhythmia, is probably about 10 times more common.


Keywords: sudden death; necropsy; paediatric cardiology     

Sudden death in the general population in Okinawa: incidence and causes of death

Sudden unexpected death is generally considered to be caused by acute myocardial infarction and/or arrhythmia. To document the incidence and causes of sudden death in Japan, where the incidence of myocardial infarction is low, the present study examined death certificates, hospital records, the forensic medical records, and the police records of residents of the southern part of Okinawa island who died at the age of 20-74 years during a 3-year period from January 1, 1992 to December 31, 1994. Sudden death was defined as death within 24 h from the onset of unexpected symptoms. The study documented 126 (87 men and 39 women) sudden deaths. The crude incidence rate was 0.37/1,000 person per year (0.51 in men and 0.23 in women). According to the death certificates, 78 cases died of heart diseases. However, the cause of death could be determined by examination of all available records in only 64 cases: myocardial infarction in 10, non-ischemic heart diseases in 13, and stroke in 23 cases. Even when the analysis was limited to the cases who died within 1 h from the onset of symptoms, heart disease was the cause of death in only 22% of the cases while the cause of death could not be determined in 53% of the cases. Only 13% of those diagnosed as heart diseases on the death certificate were verified. The agreement rate between the diagnosis reached by the re-evaluation of the records and that on the death certificate was 82% for stroke and 33% for other diseases. In Okinawa, Japan, the frequencies of heart disease and stroke as the cause of sudden death may be similar. Except for stroke, the diagnosis appearing on the death certificate has substantial inaccuracy.     

Sudden cardiac death in 15-35-year olds in Sweden during 1992-99

OBJECTIVES: To study the incidence, pathogenesis and symptoms preceding sudden cardiovascular death amongst 15-35-year olds without substance abuse in Sweden during 1992-99. DESIGN: This was a register study of a national database of forensic medicine, Rattsbase. Clinical details were obtained from forensic, police and medical records and from interviews with family members. SETTING: The whole nation of Sweden. SUBJECTS: Individuals having suffered a sudden cardiac death. RESULTS: We found 181 cases of sudden cardiovascular death in a nationwide database, Rattsbase, in 15-35-year olds, of which 132 (73%) were male and 49 (27%) were female, and a rather stable incidence of 0.93 per 100,000 per year. Preceding symptoms were seen in half of the cases. The most common forensic diagnoses were: no structural abnormality (21.0%), coronary atherosclerosis (17.7%), dilated cardiomyopathy (12.2%), hypertrophic cardiomyopathy (10.5%) and myocarditis (10.5%). CONCLUSION: Sudden cardiovascular death was uncommon in the young, but the incidence was not decreasing. Postmortem diagnoses were often difficult to establish. There was a high frequency of structurally normal hearts. Because premortal cardiac-related symptoms are relatively common and treatment methods are developing, we should learn to recognize early symptoms of heart disease. To identify individuals at risk, further studies of preceding symptoms, life-style factors and electrocardiogram (ECG) changes are needed.     

Sudden death (V). Identification and treatment of patients with hypertrophic cardiomyopathy at risk of sudden death

During the last 20 years, the principal objective in hypertrophic cardiomyopathy research has been the refinement of algorithms for the identification and treatment of patients at risk of sudden death. Sudden death is an important problem in hypertrophic cardiomyopathy, with an incidence of 4-6% in referral populations and approximately 1% in non-referral centers and because it affects young and often asymptomatic patients. We now know that hypertrophic cardiomyopathy is not a single disease, but a group of diseases caused by mutations in genes encoding different sarcomeric proteins. The phenotypic expression depends on multiple modifying genetic and environmental factors. Even though genetic testing is not presently a practical approach in hypertrophic cardiomyopathy risk stratification, it is important to consider new genetic data in the prognostic evaluation of patients. In this paper, we review the published data on risk stratification in hypertrophic cardiomyopathy and we set forth our opinion with regard to the available therapeutic options and their indications in the prevention of sudden death.