Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological ECG changes. Abnormalities, however, may be detected which represent expression of an underlying ...heart disease that puts the athlete at risk of arrhythmic cardiac arrest during sports. It is mandatory that ECG changes resulting from intensive physical training are distinguished from abnormalities which reflect a potential cardiac pathology. The present article represents the consensus statement of an international panel of cardiologists and sports medical physicians with expertise in the fields of electrocardiography, imaging, inherited cardiovascular disease, cardiovascular pathology, and management of young competitive athletes. The document provides cardiologists and sports medical physicians with a modern approach to correct interpretation of 12-lead ECG in the athlete and emerging understanding of incomplete penetrance of inherited cardiovascular disease. When the ECG of an athlete is examined, the main objective is to distinguish between physiological patterns that should cause no alarm and those that require action and/or additional testing to exclude (or confirm) the suspicion of an underlying cardiovascular condition carrying the risk of sudden death during sports. The aim of the present position paper is to provide a framework for this distinction. For every ECG abnormality, the document focuses on the ensuing clinical work-up required for differential diagnosis and clinical assessment. When appropriate the referral options for risk stratification and cardiovascular management of the athlete are briefly addressed.
Objectives The purpose of this study was to provide a meta-analysis to estimate the performance of 12 commonly reported risk stratification tests as predictors of arrhythmic events in patients with ...nonischemic dilated cardiomyopathy. Background Multiple techniques have been assessed as predictors of death due to ventricular tachyarrhythmias/sudden death in patients with nonischemic dilated cardiomyopathy. Methods Forty-five studies enrolling 6,088 patients evaluating the association between arrhythmic events and predictive tests (baroreflex sensitivity, heart rate turbulence, heart rate variability, left ventricular end-diastolic dimension, left ventricular ejection fraction, electrophysiology study, nonsustained ventricular tachycardia, left bundle branch block, signal-averaged electrocardiogram, fragmented QRS, QRS-T angle, and T-wave alternans) were included. Raw event rates were extracted, and meta-analysis was performed using mixed effects methodology. We also used the trim-and-fill method to estimate the influence of missing studies on the results. Results Patients were 52.8 ± 14.5 years of age, and 77% were male. Left ventricular ejection fraction was 30.6 ± 11.4%. Test sensitivities ranged from 28.8% to 91.0%, specificities from 36.2% to 87.1%, and odds ratios from 1.5 to 6.7. Odds ratio was highest for fragmented QRS and TWA (odds ratios: 6.73 and 4.66, 95% confidence intervals: 3.85 to 11.76 and 2.55 to 8.53, respectively) and lowest for QRS duration (odds ratio: 1.51, 95% confidence interval: 1.13 to 2.01). None of the autonomic tests (heart rate variability, heart rate turbulence, baroreflex sensitivity) were significant predictors of arrhythmic outcomes. Accounting for publication bias reduced the odds ratios for the various predictors but did not eliminate the predictive association. Conclusions Techniques incorporating functional parameters, depolarization abnormalities, repolarization abnormalities, and arrhythmic markers provide only modest risk stratification for sudden cardiac death in patients with nonischemic dilated cardiomyopathy. It is likely that combinations of tests will be required to optimize risk stratification in this population.
The purpose of this study was to define the incidence and characterization of cardiovascular cause of sudden death in the young.
The epidemiology of sudden cardiac death (SCD) in young adults is ...based on small studies and uncontrolled observations. Identifying causes of sudden death in this population is important for guiding approaches to prevention.
We performed a retrospective cohort study using demographic and autopsy data from the Department of Defense Cardiovascular Death Registry over a 10-year period comprising 15.2 million person-years of active surveillance.
We reviewed all nontraumatic sudden deaths in persons 18 years of age and over. We identified 902 subjects in whom the adjudicated cause of death was of potential cardiac etiology, with a mean age of 38 ± 11 years. The mortality rate for SCD per 100,000 person-years for the study period was 6.7 for males and 1.4 for females (p < 0.0001). Sudden death was attributed to a cardiac condition in 715 (79.3%) and was unexplained in 187 (20.7%). The incidence of sudden unexplained death (SUD) was 1.2 per 100,000 person-years for persons <35 years of age, and 2.0 per 100,000 person-years for those ≥ 35 years of age (p < 0.001). The incidence of fatal atherosclerotic coronary artery disease was 0.7 per 100,000 person-years for those <35 years of age, and 13.7 per 100,000 person-years for those ≥ 35 years of age (p < 0.001).
Prevention of sudden death in the young adult should focus on evaluation for causes known to be associated with SUD (e.g., primary arrhythmia) among persons <35 years of age, with an emphasis on atherosclerotic coronary disease in those ≥ 35 years of age.
We investigate contributions of independent directors to shareholder value by examining stock price reactions to sudden deaths in the US from 1994 to 2007. We find, first, that following director ...death stock prices drop by 0.85% on average. Second, the degree of independence and board structure determine the marginal value of independent directors. Third, independence is more valuable in crucial board functions. Finally, controlling for director-invariant heterogeneity using a fixed effect approach, we identify the value of independence over and above the value of individual skills and competences. Overall, our results suggest that independent directors provide a valuable service to shareholders.
Despite advancements in prevention and treatment, sudden cardiac death (SCD) remains a leading cause of mortality and is responsible for approximately half of all deaths from cardiovascular disease. ...Outcomes continue to remain poor following a sudden cardiac arrest, with most individuals not surviving. Although coronary heart disease remains the dominant underlying condition, our understanding of SCD is improving through greater knowledge of clinical risk factors, cardiomyopathies, and primary arrhythmic disorders. However, despite a growing wealth of information from studies in North America, Europe, and Japan, data from other global regions (and particularly from low-and middle-income countries) remains scarce.
Objectives The aim of this study was to determine the efficacy of implantable cardioverter-defibrillators (ICDs) in children and adolescents with hypertrophic cardiomyopathy (HCM). Background HCM is ...the most common cause of sudden death in the young. The availability of ICDs over the past decade for HCM has demonstrated the potential for sudden death prevention, predominantly in adult patients. Methods A multicenter international registry of ICDs implanted (1987 to 2011) in 224 unrelated children and adolescents with HCM judged at high risk for sudden death was assembled. Patients received ICDs for primary (n = 188) or secondary (n = 36) prevention after undergoing evaluation at 22 referral and nonreferral institutions in the United States, Canada, Europe, and Australia. Results Defibrillators were activated appropriately to terminate ventricular tachycardia or ventricular fibrillation in 43 of 224 patients (19%) over a mean of 4.3 ± 3.3 years. ICD intervention rates were 4.5% per year overall, 14.0% per year for secondary prevention after cardiac arrest, and 3.1% per year for primary prevention on the basis of risk factors (5-year cumulative probability 17%). The mean time from implantation to first appropriate discharge was 2.9 ± 2.7 years (range to 8.6 years). The primary prevention discharge rate terminating ventricular tachycardia or ventricular fibrillation was the same in patients who underwent implantation for 1, 2, or ≥3 risk factors (12 of 88 14%, 10 of 71 14%, and 4 of 29 14%, respectively, p = 1.00). Extreme left ventricular hypertrophy was the most common risk factor present (alone or in combination with other markers) in patients experiencing primary prevention interventions (17 of 26 65%). ICD-related complications, particularly inappropriate shocks and lead malfunction, occurred in 91 patients (41%) at 17 ± 5 years of age. Conclusions In a high-risk pediatric HCM cohort, ICD interventions terminating life-threatening ventricular tachyarrhythmias were frequent. Extreme left ventricular hypertrophy was most frequently associated with appropriate interventions. The rate of device complications adds a measure of complexity to ICD decisions in this age group.
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