Sudden Cardiac Death in Athletes: Facts and Fallacies

Exercise related versus non exercise related out of hospital cardiac arrest - A retrospective single-center study

Background

Physical activity prevents cardiovascular disease, but it may also trigger acute cardiac events like sudden cardiac death in patients with underlying heart disease. The chance of surviving an out-of-hospital cardiac arrest remains low, despite improving medical treatment and rescue chain. Prior studies signaled increased survival in exercise related out-of-hospital cardiac arrest.

Objective

The aim of this study was to evaluate the differences between exercise related out-of-hospital cardiac arrest and out-of-hospital cardiac arrest during daily activity in an urban setting.

Methods

Retrospective analysis of all out-of-hospital cardiac arrests from 2014 to 2021 treated at a cardiac arrest center of a tertiary hospital. The primary outcome was survival to discharge. Secondary outcomes included differences in pre-hospital care, in-hospital treatment, hypoxic ischemic encephalopathy, and laboratory parameters.

Results

478 OHCA patients were reviewed of which 432 patients (exercise related 36 (8.4%) vs. daily activity 396 (91.6%)) were included in the analysis. Patients suffering an exercise related arrest were younger (57 vs 65 years, p = 0.002) and mostly male (88.9 vs 74.5%, p = 0.054).The exercise related cohort received bystander cardiopulmonary resuscitation (77.8 vs 53.4%, p = 0.005) to a higher extent and had a shorter no-flow time (1.5 vs 2 min, p = 0.049). Exercise related arrest patients more often presented with a shockable rhythm (80.6 vs 64.1%, p = 0.032).At hospital admission exercise related arrest patients had a higher initial pH (7.24 vs 7.19, p = 0.015). In the exercise related group, a cardiac cause was numerically more frequent compared to the daily activity group (80.6 vs 68.7%, p = 0.09). In both groups myocardial infarction (47.2 vs 43.2%) was the most common cause, but a primary arrhythmic event (33.3 vs 25.5%) was more often documented in exercise related arrest patients. Exercise related arrest was mostly related to endurance training (52.8%) followed by ball sports (19.4%) and occurred directly during exercise in 77.8% of cases. Patients suffering exercise related arrest had higher survival till discharge (66.7 vs 47.7%, p = 0.036).

Conclusion

Based on this observational data from a highly selected group of out-of-hospital cardiac arrest patients treated at a cardiac arrest center, patients suffering an exercise related out-of-hospital cardiac arrest, differed in substantial characteristics and in the first line response compared to daily activity out-of-hospital cardiac arrest patients. The better survival to discharge of the exercise related out-of-hospital cardiac arrest group might be driven by these beneficial differences. This study underlines the need for public awareness for the importance of a fast first response and a broad distribution of automated external defibrillators in public sport areas since most of the exercise related out-of-hospital cardiac arrest patients presented with a cardiac cause and an initial shockable rhythm.

International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death Tool

BACKGROUND

Studies reporting on the incidence of sudden cardiac arrest and/or death (SCA/D) in athletes commonly lack methodological and reporting rigor, which has implications for screening and preventative policy in sport. To date, there are no tools designed for assessing study quality in studies investigating the incidence of SCA/D in athletes.

METHODS AND RESULTS

The International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death tool (IQ-SCA/D) was developed following a Delphi process. Sixteen international experts in sports cardiology were identified and invited. Experts voted on each domain with subsequent moderated discussion for successive rounds until consensus was reached for a final tool. Interobserver agreement between a novice, intermediate, and expert observer was then assessed from the scoring of 22 relevant studies using weighted and unweighted κ analyses. The final IQ-SCA/D tool comprises 8 domains with a summated score of a possible 22. Studies are categorized as low, intermediate, and high quality with summated IQ-SCA/D scores of ≤11, 12 to 16, and ≥17, respectively. Interrater agreement was "substantial" between all 3 observers for summated IQ-SCA/D scores and study categorization.

CONCLUSIONS

The IQ-SCA/D is an expert consensus tool for assessing the study quality of research reporting the incidence of SCA/D in athletes. This tool may be used to assist researchers, reviewers, journal editors, and readers in contextualizing the methodological quality of different studies with varying athlete SCA/D incidence estimates. Importantly, the IQ-SCA/D also provides an expert-informed framework to support and guide appropriate design and reporting practices in future SCA/D incidence trials.

Differences in cardiac adaptation to exercise in male and female athletes assessed by noninvasive techniques: a state-of-the-art review

Athlete's heart is generally regarded as a physiological adaptation to regular training, with specific morphological and functional alterations in the cardiovascular system. Development of the noninvasive imaging techniques over the past several years enabled better assessment of cardiac remodeling in athletes, which may eventually mimic certain pathological conditions with the potential for sudden cardiac death, or disease progression. The current literature provides a compelling overview of the available methods that target the interrelation of prolonged exercise with cardiac structure and function. However, this data stems from scientific studies that included mostly male athletes. Despite the growing participation of females in competitive sport meetings, little is known about the long-term cardiac effects of repetitive training in this population. There are several factors-biochemical, physiological and psychological, that determine sex-dependent cardiac response. Herein, the aim of this review was to compare cardiac adaptation to endurance exercise in male and female athletes with the use of electrocardiographic, echocardiographic, and biochemical examination, to determine the sex-specific phenotypes, and to improve the healthcare providers' awareness of cardiac remodeling in athletes. Finally, we discuss the possible exercise-induced alternations that should arouse suspicion of pathology and be further evaluated.

The Impact of Heart Attack and Sudden Cardiac Death Risk Perception on Lifestyle Modification Intention Among Adults in Jazan Province

Purpose

This study aimed to assess the perception of sudden cardiac death (SCD) and heart attack risk and its influence on the intention to adopt healthy lifestyle behaviors among the general population in Jazan province, Saudi Arabia. SCD refers to an abrupt and unexpected loss of heart function resulting in death, and its incidence has been alarmingly increasing worldwide. Several factors, including smoking, hypertension, diabetes, obesity, and specific medications, have been associated with an elevated risk of SCD.

Methods

A descriptive cross-sectional study was conducted using a pretested questionnaire distributed among the general population in Jazan province. Descriptive statistics, chi-square, and t-tests were employed for data analysis.

Results

The study included 974 participants with a mean age of 27.90 ± 9.32 years, of whom 56% were female. More than half of the participants perceived themselves as highly susceptible to SCD, and all participants demonstrated a moderate willingness and readiness to modify their unhealthy lifestyle behaviors. Age, gender, marital status, body mass index (BMI), history of hypertension, dyslipidemia, medication use, physical exercise, and family history of chronic diseases and SCD were statistically associated with the perception of SCD.

Conclusion

The study revealed a high-risk perception and a moderate readiness to adopt lifestyle modifications. These findings can inform the development of effective strategies and support programs aimed at reducing the burden of SCD.

Can Hot Weather Cause Non-ST Elevation Myocardial Infarction in Young Athletic Male Runners?

Athletes are a group of people who have good activity, regular muscular exercise, an almost standard lifestyle, and should be in good condition with low rates of medical, particularly cardiovascular, complications. However, cardiac attacks, sudden cardiac deaths, and fatal arrhythmogenic syndromes have been reported in athletes with low incidences. We can determine external and internal factors that lead to cardiac attacks in athletes. The former include abnormal cardiac structures and genetics, while the latter include environmental conditions like extreme temperatures, smoking, and drug abuse. Here, we report a case of a cardiac attack with non-ST elevation myocardial infarction (NSTEMI) in a young athlete who was a non-smoker, did not have any abnormal heart structures or a history of drug abuse, and did not have a family history of cardiac disease or arrest. High humidity levels and temperatures were the main causes of the cardiac attack, which occurred during a sports exercise at high temperatures with high humidity levels. We hope to prevent the recurrence of such a case. We need to understand when and where sports exercises can be performed without the risk of medical complications.

Should young athletes be screened for cardiomyopathies to reduce the burden of sudden cardiac death in athletes?

In this correspondence, we highlight the risk of sudden cardiac death associated with undiagnosed cardiomyopathies. Life-threatening arrhythmias, which underlie sudden cardiac death, can be triggered by high-intensity exercise. It raises the question whether, and if so, how athletes should be screened for cardiomyopathies. The example of practice from Italy is discussed. We also briefly discuss novel developments, such as wearable biosensors and machine learning, which could be applied to screening for cardiomyopathies in future.

Sudden Cardiac Death in Athletes: Consensuses and Controversies

Exercise is widely considered beneficial for cardiovascular health. However, on rare occasions, athletes experience sudden cardiac death without any preceding symptoms. The devastating nature of these events necessitates us to understand the underlying causes. In younger athletes (age <35), the underlying causes are usually hereditary/genetic, whereas in older athletes (age >35), coronary artery disease is prevalent. Sudden cardiac death in athletes can occur regardless of the presence of any structural abnormality in the heart. Despite divergence between guidelines, the majority of cardiology societies recommend at least taking a comprehensive history and performing physical examinations for initial screening for all athletes. This article reviews the consensuses and controversies regarding the incidence, causes, and prevention of sudden cardiac death in athletes.