Sudden Cardiac Death In Adults Research Articles

Primary Prevention of Sudden Cardiac Death in Adults with Transposition of the Great Arteries: A Review of Implantable Cardioverter-Defibrillator Placement.

Transposition of the great arteries encompasses a set of structural congenital cardiac lesions that has in common ventriculoarterial discordance. Primarily because of advances in medical and surgical care, an increasing number of children born with this anomaly are surviving into adulthood. Depending upon the subtype of lesion or the particular corrective surgery that the patient might have undergone, this group of adult congenital heart disease patients constitutes a relatively new population with unique medical sequelae. Among the more common and difficult to manage are cardiac arrhythmias and other sequelae that can lead to sudden cardiac death. To date, the question of whether implantable cardioverter-defibrillators should be placed in this cohort as a preventive measure to abort sudden death has largely gone unanswered. Therefore, we review the available literature surrounding this issue.

Evaluation of cardiac electrophysiological properties in an experimental model of right ventricular hypertrophy and failure.

Malignant arrhythmias are a major cause of sudden cardiac death in adults with congenital heart disease. We developed a model to serially investigate electrophysiological properties in an animal model of right ventricular hypertrophy and failure. We created models of compensated (cHF; n=11) and decompensated (dHF; n=11) right ventricular failure in Wistar rats by pulmonary trunk banding. Healthy controls underwent sham operation (Control; n=13). Surface electrocardiography was recorded from extremities, and inducibility of ventricular tachycardia was evaluated in vivo by programmed stimulation. Isolated right ventricular myocardium was analysed for mRNA expression of selected genes. Banding caused an increased mRNA expression of both connexin 43 and the voltage-gated sodium channel 1.5, as well as a prolongation of PQ, QRS and QTc intervals. Ventricular tachycardia was induced in the majority of banded animals compared with none in the healthy control group. No differences were found between the two degrees of failure in neither the electrophysiological parameters nor inducibility. The electrophysiological properties of rat hearts subjected to pulmonary trunk banding were significantly changed with increased susceptibility to ventricular tachycardia, but no differences were found between compensated and decompensated right ventricular failure. Furthermore, we demonstrate that in vivo electrophysiological evaluation is a sensitive method to characterise the cardiac electric phenotype in an experimental rat model.

Domperidone-associated sudden cardiac death in the general population and implications for use in patients undergoing hemodialysis: a literature review.

Domperidone, an effective prokinetic agent, is commonly used to manage symptoms of gastroparesis. Health regulatory agencies have issued warnings about an increased risk of sudden cardiac death associated with use of this drug. To evaluate the evidence for domperidone-associated sudden cardiac death and to determine whether this drug can be safely used for gastroparesis in patients undergoing dialysis. Two databases (MEDLINE [1965 to September 2014] and Embase [1980 to September 2014]) were searched using the Medical Subject Headings "domperidone", "sudden cardiac death", and "cardiac arrhythmia". The search was limited to studies conducted in humans and published in English. Advisories from health regulatory agencies (Health Canada, the European Medicines Agency, and the US Food and Drug Administration) were identified and reviewed. Studies eligible for inclusion in this narrative review were randomized controlled trials and cohort, case-control, cross-sectional, and other epidemiological studies comparing use and non-use of domperidone for the outcome of sudden cardiac death in adults. Abstracts of eligible case reports and case series were also included. Despite inconsistencies in their decisions, the various drug regulatory authorities have acknowledged the potential safety concern of increased risk of sudden cardiac death associated with domperidone. To date, no randomized controlled studies have shown an increased risk of this outcome secondary to domperidone use. Current regulatory recommendations and approval decisions are based on 2 large observational epidemiological studies that generated a signal of increased risk. The strengths and limitations of these studies were evaluated in detail. No direct evidence applicable to patients with end-stage renal disease was found. In vitro evidence suggests that the risk of sudden cardiac death is dose-related. Given gaps in the literature, use of domperidone for patients undergoing dialysis should be assessed on a case-by-case basis. Extreme caution should be used for patients taking more than 30 mg/day of this drug.

Sudden Cardiac Death in Young Adult

Cardiovascular disease represents one of the most important public health problem in the Western countries, with sudden cardiac death (SCD) being the most common cause of death in adults under 65years of age. The objective of the present study is to evaluate the leading causes of SCD in young adults who died suddenly in Northern Portugal between 2007 and 2012. This study included 288 cases of 20- to 45-year-old adults who died suddenly of a cardiac cause and whose forensic autopsy was performed in the North Branch of the National Institute of Legal Medicine and Forensic Sciences between 2007 and 2012. Data included the cause of death, forensic autopsy findings, previous medical history and cardiovascular risk factors. The mean age of the population was 37.36years. Coronary artery disease (CAD) was the leading cause of death, representing 55.6% of all cases (92.5% of men and 7.5% of women). Females died mostly from probable primary arrhythmia. From those who died of coronary disease, 72 (25% of total cases) had histological evidence of a fatal acute infarction. Age, previous coronary disease, hypercholesterolemia, smoking habits and alcohol consumption seem to be associated with an increased risk of SCD by CAD. A total of 55.6% of deaths were attributed to CAD. Prevention of cardiovascular risk factors should therefore be considered to prevent atherosclerosis in young adults.

Abstract 18004: Diagnosis of Obstructive Sleep Apnea in Patients With Congenital Long QT Syndrome

Introduction: Obstructive sleep apnea (OSA) is a common health problem which affects about a quarter of US adults. OSA is increasingly linked to cardiovascular diseases including hypertension, heart failure, myocardial infarction, cardiac arrhythmias and sudden cardiac death (SCD). Congenital long QT syndrome (LQTS) is a common cause of SCD in children and young adults during exercise and sleep. LQT3 (SCN5A) and LQT2 (HERG) genotypes are particularly at increased risk for SCD during sleep. We tested the hypothesis that increased numbers of patients with congenital LQTS have OSA compared to controls matched for age gender and BMI. Methods: A complete medical history and a standard 12-lead surface ECG were obtained in LQTS and controls. Polysomnography (PSG) was conducted in 32 LQTS patients (20 LQT1 and 12 LQT2) and 40 controls matched for age, gender and BMI. Blinded interpretation of the sleep studies were carried out by a single investigator board certified in Sleep Medicine. OSA was defined by the presence of AHI ≥5 events/hour for adults (≥18 years) and >1 event/hour for children (<18 years). Results: The PSG results show that 16 LQTS patients (50%) have clinically significant OSA compared to 6 controls (15%) in the controls. There are 7 LQTS patients who have history of early childhood adenotonsillectomy and only 2 of them have OSA on the PSG results. Considering very close relationship between adenotonsillar hypertrophy in children and OSA, these children might have OSA in early childhood. Therefore, total 21 LQTS patients (65%) have OSA on the PSG and/or adenotonsillectomy. Presence of OSA is equally distributed in LQT1 and LQT2 genotypes. Conclusion: OSA is more common in patients with congenital LQTS compared to healthy matched controls. Apneic events during sleep are associated with exaggerated sympathetic responses which might be potential mechanisms for triggering arrhythmias and thus increased risk of SCD during sleep.

Microvolt T wave alternans in adults with congenital heart diseases characterized by right ventricle pathology or single ventricle physiology: a case control study

BackgroundAmong adults with congenital heart diseases (CHD) evaluation of sudden cardiac death (SCD) risk remains a great challenge. Although microvolt T-wave alternans has been incorporated into SCD risk stratification algorithm, its role in adults with CHD still requires investigation. We sought to determine the incidence of MTWA in this specific group and its coincidence with ventricular arrhythmia (VA) and other clinical findings presumably associated with SCD.MethodsA case–control study was performed in which 102 patients with CHD characterized by right ventricle pathology or single ventricle physiology (TGA, UVH, Ebstein’s anomaly, ccTGA, Eisenmenger syndrome, DORV, CAT, unoperated ToF) were compared to 45 age- and sex-matched controls. All subjects underwent spectral MTWA test, ambulatory ecg monitoring, cardiopulmonary test, BNP assessment. After excluding technically inadequate traces, the remaining MTWA results were classified as positive(+), negative(−) and indeterminate(ind). Due to similar prognostic significance MTWA(+) and (ind) were combined into a common group labeled ‘abnormal’.ResultsAbnormal MTWA was present more often in the study group, compared to controls (39.2% vs 2.3%, p = 0.00001). Sustained ventricular tachycardia (sVT) was observed more often among subjects with abnormal MTWA compared to MTWA(−): 19.4% vs 3.6%, p = 0.026. The patients with abnormal MTWA had a lower blood saturation (p = 0.047), more often were males (p = 0.031), had higher NYHA class (p = 0.04), worse cardiopulmonary parameters: %PeakVO2 (p = 0.034), %HRmax (p = 0.003). Factors proven to increase probability of abnormal MTWA on multivariate linear regression analysis were: sVT (OR = 20.7, p = 0.037) and male gender (OR = 15.9, p = 0.001); on univariate analysis: male gender (OR = 2.7, p = 0.021), presence of VA (OR = 2.6, p = 0.049), NYHA > I (OR = 2.06, p = 0.033), %HRmax (OR = 0.94, p = 0.005), %PeakVO2 (OR = 0.97, p = 0.042), VE/VCO2slope (OR = 1.05, p = 0.037).ConclusionsAbnormal MTWA occurs significantly more often in adults with the chosen forms of CHD than among healthy subjects. The probability of abnormal MTWA increases in patients with malignant VA, in males and among subjects with heart failure and cyanosis. MTWA might be of potential role in risk stratification for SCD in adults with CHD.

ELECTRICAL REMODELING PREDICTS RISK OF SUDDEN CARDIAC DEATH IN ASYMPTOMATIC ADULTS

Background: The majority of sudden cardiac death (SCD) cases occur in asymptomatic adults. Improved strategies are urgently needed to identify individuals at high risk. Electrical remodeling measured by the sum absolute QRST integral (SAI QRST) has recently emerged as a predictor of SCD in heart failure patients with implanted cardioverter-deibrillators. We hypothesized that SAI QRST is an independent predictor of SCD in asymptomatic adults.

Physical Activity Recommendations for Patients With Electrophysiologic and Structural Congenital Heart Disease: A Survey of Canadian Health Care Providers

Determining safe levels of physical activity for children and adolescents with electrophysiologic and structural congenital heart disease is a challenging clinical problem. The body of evidence for making these recommendations is limited and likely based on expert opinion, medicolegal concerns, and perceived risks of sudden cardiac death (SCD) with activity. The Bethesda Conference has established consensus guidelines for determining the eligibility of athletes with cardiovascular abnormalities for competitive sports and their disqualification from them. However, literature on guidelines for noncompetitive physical activity is not available. A survey was designed to determine practice patterns for patients with electrophysiologic and structural congenital heart disease. Between July 2011 and December 2011, approximately 350 health care providers working with this group of patients were recruited by email or while attending professional meetings. The survey received 81 responses, primarily from pediatric cardiologists (70 %). The findings indicate that the majority of Canadian cardiac care providers surveyed are only partially implementing current recommendations. Areas of variance included physical activity recommendations for hypertrophic cardiomyopathy, long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, and heart transplantation, among others. The development of comprehensive consensus guidelines for activity recommendations was supported by 96 % of the respondents. The heterogeneity of responses may be attributable to conflicting and poorly evidenced information in the literature, a lack of emphasis on recreational activity, an entrenched tendency toward bed rest in the cardiology community, and a lack of awareness by cardiac care providers regarding the actual risk associated with physical activity in electrophysiologic and structural congenital heart disease. A balanced discussion is required in considering both the significant benefit of physical activity in reducing cardiovascular risk factors and the small possibility of SCD in children and young adults with electrophysiologic and structural congenital heart disease.

Plasma Fatty Acid Binding Protein 4 and Risk of Sudden Cardiac Death in Older Adults

Although fatty acid binding protein 4 (FABP4) may increase risk of diabetes and exert negative cardiac inotropy, it is unknown whether plasma concentrations of FABP4 are associated with incidence of sudden cardiac death (SCD). We prospectively analyzed data on 4,560 participants of the Cardiovascular Health Study. FABP4 was measured at baseline using ELISA, and SCD events were adjudicated through review of medical records. We used Cox proportional hazards to estimate effect measures. During a median followup of 11.8 years, 146 SCD cases occurred. In a multivariable model adjusting for demographic, lifestyle, and metabolic factors, relative risk of SCD associated with each higher standard deviation (SD) of plasma FABP4 was 1.15 (95% CI: 0.95–1.38), P = 0.15. In a secondary analysis stratified by prevalent diabetes status, FABP4 was associated with higher risk of SCD in nondiabetic participants, (RR per SD higher FABP4: 1.33 (95% CI: 1.07–1.65), P = 0.009) but not in diabetic participants (RR per SD higher FABP4: 0.88 (95% CI: 0.62–1.27), P = 0.50), P for diabetes-FABP4 interaction 0.049. In summary, a single measure of plasma FABP4 obtained later in life was not associated with the risk of SCD in older adults overall. Confirmation of our post-hoc results in nondiabetic people in other studies is warranted.

PR Interval and Sudden Cardiac Death in Patients With HIV Infection

To the Editor—We read with interest the article by Worm and colleagues, who reported no significant association between current or recent protease inhibitor exposure and sudden death or nonhemorrhagic stroke in the D:A:D study [1]. The investigators reported 78 sudden deaths over 234 818 patient-years of follow-up, a rate of 0.33 cases per 1000 patient-years (95% confidence interval [CI], .26–.41). First, we would like to clarify the issue of PR prolongation. Worm et al. write, “Prolongation of the PR interval could be an early manifestation of an ongoing conduction defect that may lead to complete AV block. Although rarely seen without other cardiac abnormalities, one possible clinical manifestation of severe PR interval prolongation may be congestive heart failure” [1p535]. Recent observational studies suggesting more heart failure hospitalizations or higher all-cause mortality were in individuals with known coronary artery disease and a PR interval of >220 msec [2] or >200 msec [3], respectively. Thus, PR prolongation of <200 msec alone, in the absence of Mobitz type II second degree block or a widened QRS interval, is of no prognostic significance for progression to advanced AV block [4], heart failure, or mortality. The PR interval is well-known to vary by the time of day the electrocardiogram is taken (a reflection of variation in vagal tone that influences AV nodal conduction), drugs taken (such as beta blockers), and heart rate. PR prolongation may also be a marker of heart failure because often such patients are prescribed beta blockers, which can prolong AV nodal conduction and thus the PR interval. Second, we found a mean sudden cardiac death rate of 2.6 cases per 1000 person-years (95% CI, 1.8–3.8) over a 10-year period in a single-center, retrospective cohort study of 2860 consecutive patients receiving care in a public human immunodeficiency virus (HIV) specialty clinic in San Francisco, California [5]. Cardiac deaths accounted for 13% of the overall mortality, and 86% of the cardiac deaths occurred suddenly. Although the sudden cardiac death rate was 4-fold lower than the rate of AIDS-related deaths (11.4 cases/1000 patient-years [95% CI, 9.6–13.6]), it was 4.5-fold higher than the contemporaneous citywide (98% HIV negative) adult sudden cardiac death rate in San Francisco [6], adjusted for age, sex, and ethnicity. The low sudden death rate reported by Worm and colleagues is in apparent conflict with our observed rate, which is much higher. However, this discrepancy is likely due to a major methodological difference, which is their use of a nonstandard definition of sudden death that specifically excluded causes due to coronary artery disease [7]. Coronary artery disease is in fact the largest overall contributor to sudden cardiac death, contributing to up to 80% of such deaths, according to many epidemiological studies [8]. Since coronary artery disease is a very important risk factor for sudden cardiac death, we specifically included these causes in our definition. Therefore, the sudden cardiac death rate reported in the D:A:D study may be some 5-fold lower than the actual rate, since only rare ion channelopathy (genetic) and cardiomyopathy causes of sudden cardiac death are captured after exclusion of coronary artery disease causes. In fact, multiplication of the sudden cardiac death rate reported in the D:A:D study (0.33 cases/1000 person-years) by 5 results in a rate more in range with the sudden cardiac death rate observed in our study (1.65 cases/1000 person-years vs 2.6 cases/1000 person-years). This discrepancy also highlights the difficulties with retrospective observational studies of deaths. For example, although we cross-checked multiple records, how many sudden cardiac deaths were not actually cardiac? What is the contribution of unmeasured factors such as drug use or occult overdoses? What is the role of antiretroviral drugs and coadminstered drugs, particularly in terms of QT interval prolongation? Thus, while prior studies may have underestimated sudden cardiac death rates, we may have overestimated it. Future prospective studies, including systematic autopsy evaluation, which is ongoing at our site, will be needed to provide additional insight into the actual causes of death, as well as the mechanisms underlying this disease process.

Sudden Cardiac Death in Adult Congenital Heart Disease

Sudden cardiac death (SCD) is a major cause of mortality in adults with congenital heart disease (CHD). The aim of this study was to determine the adult CHD population at risk of SCD and the clinical parameters associated with SCD. We performed a multicenter case-control study. Patients who died suddenly as a result of proven or presumed arrhythmia were included (cases). For each case, 2 controls matched on diagnosis, type of surgical intervention, age, and gender were included. From 3 databases including 25 790 adults with CHD, 1189 deaths (5%) were identified, of whom 213 patients (19%) died suddenly. Arrhythmic death occurred in 171 of 1189 patients. The underlying cardiac lesions were mild, moderate, and severe CHD in 12%, 33%, and 55% of the SCD cases, respectively. Clinical variables associated with SCD were supraventricular tachycardia (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.5-7.9; P=0.004), moderate to severe systemic ventricular dysfunction (OR, 3.4; 95% CI, 1.1-10.4; P=0.034), moderate to severe subpulmonary ventricular dysfunction (OR, 3.4; 95% CI, 1.1-10.2; P=0.030), increased QRS duration (OR, 1.34 [per 10-ms increase]; 95% CI, 1.10-1.34; P=0.008), and QT dispersion (OR, 1.22 [per 10-ms increase]; 95% CI, 1.22-1.48; P=0.008). The clinical parameters found to be associated with SCD in adults with a broad spectrum of CHD, including systemic right ventricles, are similar to those in ischemic heart disease. Moreover, even those patients with mild cardiac lesions are potentially at risk for SCD. This highlights the need for further prospective studies as well as vigilant ongoing follow-up of the adult with CHD.

Hypothesis: holiday sudden cardiac death: food and alcohol inhibition of SULT1A enzymes as a precipitant.

Sudden cardiac death is a significant health issue, causing millions of deaths worldwide annually. Studies have found that the likelihood of such death is higher in winter. Further studies identified that the highest likelihood occurs on Christmas Day and New Years Day, but not the interim period. Thanksgiving, Independence Day and the Islamic holiday Eid Al-Fitr also show significant increases in the rate of cardiac events or death. A number of mechanisms have been proposed, but none have satisfactorily explained the evidence. This article reviews the data supporting the existence of a holiday cardiac death phenomenon, the involvement of catecholamines and the normal modes of human catecholamine deactivation. Further evidence is reviewed that supports a hypothesized mechanism whereby critical SULT1A catecholamine deactivation enzymes can in some patients be inhibited by naturally-occurring phenols and polyphenols in foods and alcohols. If deactivation is inhibited by holiday consumption excesses, holiday stress or excitement could lead to a buildup of catecholamines that can cause fatal arrhythmias. Awareness of this mechanism could reduce deaths, both through doctor/patient education leading to a moderation in consumption and through the potential identification of patients with a predisposition to SULT1A inhibition. This hypothesis also raises parallels between sudden cardiac death in adults and Sudden Infant Death Syndrome (SIDS). The possible involvement of SULT1A inhibition in SIDS is discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Cardiomegaly is a common arrhythmogenic substrate in adult sudden cardiac deaths, and is associated with obesity

Both coronary artery disease (CAD) and cardiomyopathy may present with sudden cardiac death (SCD). It is generally accepted that CAD is the most common cause of SCD in adults, but the frequency of cardiomegaly as a primary or contributing cause is less known. We retrospectively studied the cardiac findings of all cases of adult SCD attributed to cardiomegaly, severe atherosclerosis, or both, in the absence of specific cardiomyopathy. Association between findings and risk factors was studied. There were 484 sudden cardiac deaths, of which 402 met study criteria. Mean age was 49 ± 13 years, with 289 men and 159 African Americans (AAs). Cardiomegaly with presumed hypertensive, multifactorial or unknown cause, was the sole arrhythmogenic substrate in 38% of men and 49% of women (p = 0.003); CAD was the sole cause of SCD in 19% of men and 26% of women, and mixed CAD + cardiomegaly the cause of death in 43% of men and 25% of women. Cardiomegaly was associated by univariate analysis with younger age (46 ± 12 years versus 53 ± 14 for CAD, p < 0.0001), AA race (p = 0.004), and body mass index (p < 0.0001). Among adults with a mean age of about 50 years, cardiomegaly is a frequent cause of sudden cardiac death, and is highly associated with obesity. Cardiomegaly is also frequent in SCD with severe CAD. The causes and classification of cardiomegaly in patients without specific cardiomyopathy, and in patients with and without hypertension or coronary disease need to be better studied.

Au-delà du cœur, une sensibilisation nécessaire du public aux urgences vitales

More than any other circumstances, life-threatening emergencies require rapid and appropriate management. Public involvement is, in many cases, essential for optimal outcome. The victim, a relative or a bystander, if they do the right thing, can facilitate emergency service intervention. Adult sudden cardiac death is one area where public involvement has been particularly encouraged. Based on this experience, the aim of this article is to examine possible extension to other life-threatening emergencies, as well as the consequences of this involvement in terms of public health and community awareness.

Abstract P122: Plasma Fatty Acid Binding Protein 4 is Associated with the Incidence of Sudden Cardiac Death in Non-Diabetic Adults in the Cardiovascular Health Study

Background: Fatty acid binding protein 4 (FABP4) is an adipokine that plays a role in lipid transport. Previous studies have reported that FABP4 may increase the risk of diabetes and exert negative inotropy on the myocardium. It is unknown whether plasma FABP4 is associated with the risk of sudden cardiac death (SCD). Objective: To test the hypothesis that plasma FABP4 is associated with a higher incidence of SCD in older adults and determine if diabetes status modifies this association. Methods: We prospectively analyzed data on 4,564 men and women aged 65+ years from the Cardiovascular Health Study. FABP4 was measured at baseline using ELISA and SCD events were adjudicated through review of medical records (inter-reviewer agreement of 88% and kappa of 0.74). We used Cox proportional hazards model to examine the association between FABP4 and SCD. Results: During a median follow up of 11.8 years, 146 new cases of SCD occurred. In a multivariable model adjusting for age, sex, race, clinic, education, glomerular filtration rate based on cystatin C, high-sensitive C-reactive protein, leisure time physical activity, hormone replacement therapy, alcohol intake, self-reported general health status, smoking, prevalent coronary heart disease, and prevalent heart failure, each higher standard deviation (SD) of plasma FABP4 was associated with a non-significant 14% (95% CI: -5% to 37%) higher risk of SCD. When stratified by prevalent diabetes status, FABP4 was associated with a higher risk of SCD in non-diabetic participants, [HR per SD of FABP4: 1.37 (95% CI: 1.11-1.67)] but not in diabetic participants [HR per SD of FABP4: 0.77 (95% CI: 0.52-1.15)], p for diabetes-FABP4 interaction was 0.026. Conclusion: A single measure of plasma FABP4 obtained later in life was associated with a higher risk of SCD among older adults without diabetes but not among those with diabetes. If confirmed in other studies, these data may point to novel mechanisms and opportunities for SCD prevention.

How to Predict the Impact of Methylphenidate on Cardiovascular Risk in Children with Attention Deficit Disorder: Methylphenidate Improves Autonomic Dysfunction in Children with ADHD

Background. Although stimulants have long been touted as treatments for attention deficit disorder with or without hyperactivity (ADHD), in recent years, increasing concerns have been raised about the cardiovascular safety of these medications. We aimed to prove if measurements of autonomic function with time domain analysis of heart rate variability (HRV) in 24-hour Holter ECG are useful to predict the risk of sudden cardiac death in ADHD children and adolescents. Methods. We analysed HRV obtained from children with the diagnosis of ADHD prior to (N = 12) or during medical therapy (N = 19) with methylphenidate (MPH), aged 10.8 ± 2.0 years (mean ± SD), who were referred to our outpatient Paediatric Cardiology Clinic to rule out heart defect. As a control group, we compared the HRV data of 19 age-matched healthy children without heart defect. Results. Average HRV parameters from 24-hour ECG in the ADHD children prior to MPH showed significant lower values compared to healthy children with respect to rMSSD (26 ± 4 ms versus 44 ± 10 ms, P ≤ 0.0001) and pNN50 (6.5 ± 2.7% versus 21.5 ± 9.0%, P ≤ 0.0001). These values improved in MPH-treated children with ADHD (RMSSD: 36 ± 8 ms; pNN50: 14.2 ± 6.9%). Conclusion. Children who suffer from ADHD show significant changes in HRV that predominantly reflects diminished vagal tone, a well-known risk factor of sudden cardiac death in adults. In our pilot study, MPH treatment improved HRV.

Sudden cardiac death in athletes

To briefly review the field of sudden cardiac death (SCD) in the athlete and the impact of preparticipation screening on identification of at-risk cardiovascular disorders and mortality reduction. Competitive sports activity is associated with an increase in the risk of SCD in susceptible adolescents and young adults with clinically silent cardiovascular disorders. Screening including 12-lead electrocardiogram (ECG) has been demonstrated to allow identification of athletes affected by malignant heart muscle diseases at a presymptomatic stage and lead to substantial reduction of the risk of SCD during sports. The use of modern criteria for interpretation of the ECG in the athlete significantly improves the screening accuracy by reducing the false-positive rate (increased specificity), with the important requisite of maintaining the ability for detection of life-threatening heart diseases (preserved sensitivity). Screening including ECG has a more favourable cost-benefit ratio than that based on history and physical examination alone, with cost estimates per year of life saved below the threshold to consider a health intervention as cost-effective. Screening with exercise testing middle-aged/senior athletes engaged in leisure sports activity is likely to be cost-effective in older patients with coronary risk factors, while it is not justified in low-risk subgroups. Preparticipation screening is a life-saving and cost-effective strategy in young athletes in whom SCD is mostly caused by ECG-detectable heart muscle diseases.

Sudden Cardiac Death in the Young

Sudden cardiac death (SCD) in children and adolescents is an uncommon event, yet it is devastating to families who lose a child so suddenly and unexpectedly. Sudden cardiac death in adults is primarily caused by coronary artery disease; however, SCD in the young is due to different etiologies. This article presents the following etiologies associated with SCD in the young: structural and functional abnormalities, primary electrical diseases also known as channelopathies, and a lesser-known cause, that is, commotio cordis. Prevention and treatment strategies to be discussed include noninvasive testing for risk stratification, screening for competitive athletes, genetic testing, implantable cardioverter defibrillators, automated external defibrillators, and patient advocacy. Nursing implications will include guidance for patient and family education, recommendations for sports participation, and forging partnerships with communities.

Sudden cardiac death in adults: causes, incidence and interventions

Many nurses will be familiar with the unexpected death of an adult patient following a sudden, life-threatening cardiac event. It is a situation that demands sensitive nursing care and skilled interventions to provide a foundation for recovery and promote healthy bereavement. This article examines the causes and incidence of sudden cardiac death in adults. Possible reactions of those who are suddenly bereaved are described and immediate care interventions aimed at dealing with the grief process are discussed. The article concludes by identifying ways in which the incidence of sudden cardiac death may be reduced.

Sudden cardiac death in adults: causes, incidence and interventions

Sudden cardiac death in adults: causes, incidence and interventions