Athletic Activity for Patients With Hypertrophic Cardiomyopathy and Other Inherited Cardiovascular Diseases: JACC Focus Seminar 3/4

2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

New Insights and Recommendations for Athletes With Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) has long been considered to be a high-risk cardiac condition for which exercise was thought to increase the risk of sudden cardiac death (SCD). This was founded in part by initial autopsy studies reporting HCM to be a leading medical cause of SCD among young athletes. Most forms of competitive sport and exercise were therefore thought to increase the risk of SCD to a prohibitive level. Resultant expert consensus guideline recommendations universally restricted athletes with HCM from participation in moderate- to vigourous-intensity sport and exercise in a binary "yes" or "no" clinical decision making process with the goal of reducing the risk of sports-related SCD. HCM is, however, a heterogeneous genetic condition with variable penetrance and risk. The degree to which sports and exercise increases the risk of SCD at an individual patient level continues to be an area of clinical uncertainty. Emerging data and clinical experience from the past several decades have provided important new insights into exercise-related risks and have brought into question the appropriateness of overly restrictive binary clinical decision making for exercise recommendations in HCM. This includes an improved understanding of the overall prevalence of HCM in the general population, improved observational estimates of the risk of SCD related to continued sport and exercise participation, and a general shift toward improved patient-centred approaches to care through shared decision making processes. The rules by which the game is played may be changing for athletes with HCM.

Association of duration and intensity of exercise with phenotypic expression in hypertrophic cardiomyopathy

OBJECTIVES

There is limited data regarding the impact of exercise on phenotypic expression in hypertrophic cardiomyopathy (HCM). We aimed to investigate whether such an association exists in a cohort of genotype-positive HCM patients.

METHODS

In this cross-sectional study of genotype-positive HCM families, we used structured questionnaires to obtain data regarding intensity and duration of exercise of participants starting at the age of 10, as well as data regarding exercise recommendations and their impact on quality of life (QOL). The association of cumulative metabolic-equivalent hours of exercise at different ages with different measures of phenotypic expression (maximal wall thickness, left atrial diameter, extent of late gadolinium enhancement) was analyzed.

RESULTS

The study included 109 patients from 55 families, including 43 male (39%) and 90 (83%) phenotype-positive. No association was identified between exercise duration or intensity with any of the phenotypic markers with the exception of greater cumulative exercise associated with younger age at presentation. Similar results were obtained when analysis was limited to exercise until the age of 20, until the age of 30 or only after 30. Among phenotype-positive patients, 89% recalled receiving recommendations regarding exercise restriction, 29% noted reduction in exercise level following such recommendations and 25% noted this having a significant impact on their QOL.

CONCLUSION

We found no association between exercise intensity or duration and phenotypic expression in genotype-positive HCM patients. These findings are important for physician-patient discussions and support the recent trend towards more permissive exercise restrictions in HCM.

Electrocardiographic findings in pediatric versus young-adolescent athletes: A comparative analysis using general international criteria

BACKGROUND

The inclusion of electrocardiogram (ECG) in medical examinations for sports practice serves as a valuable tool for identifying potential life-threatening conditions during physical exercise. However, its applicability in young individuals remains a subject of controversy, primarily due to relatively high rates of false positives and the associated costs of further investigations. Furthermore, the validation of International Criteria for athletes below 12 years of age in optimizing pre-participation screening for young athletes is yet to be established. In light of these considerations, this study aims to describe the prevalence of ECG findings in a sample of children and young-adolescent athletes aged 11-16 years, employing refined Seattle interpretation criteria. Additionally, we seek to compare these findings based on age group and sex.

METHODS

This was a retrospective and observational study of 3747 athletes 11-16 year-olds. Evaluation included interviewer-administered questionnaires for relevant history, physical examination and resting 12 - lead ECG for each participant. The primary outcome measure was abnormal ECG findings according to the International Recommendations for Electrocardiographic Interpretation in Athletes.

RESULTS

Among the evaluated population of pediatric and young adolescent athletes (77.5% boys; >99% Caucasian), the vast majority exhibited normal electrocardiogram (ECG) results, with adaptive findings related to sports participation being more frequent among young adolescents and males. The presence of significant ECG abnormalities in young-adolescent athletes was uncommon (2.05%; 1.92% children and 2.32% young-adolescent) and required additional examinations. 0.27% of the total population were diagnosed with a previously unknown cardiac pathology only through the ECG.

CONCLUSIONS

This study provides valuable insights into the prevalence of normal, borderline, and abnormal electrocardiogram (ECG) findings in a large population of pediatric and young-adolescent athletes. These findings serve as guidance in detecting potentially serious cardiac alterations within this specific group, considering variations based on age and sex. The study confirms that ECG screening is a useful tool for identifying cardiac abnormalities in pediatric and young-adolescent athletes, even though the prevalence of significant findings in this population is relatively low. Furthermore, our findings support the utilization of the refined Seattle criteria as a sensitive and specific technique for screening pediatric and young-adolescent athletes, further enhancing the accuracy of ECG-based evaluations.

Exercise-Induced Arrhythmia or Munchausen Syndrome in a Marathon Runner?

A 36-year-old professional marathon runner reported sudden irregular palpitations occurring during competitions, with heart rates (HR) up to 230 bpm recorded on a sports HR monitor (HRM) over 4 years. These episodes subsided upon the cessation of exercise. Electrocardiograms, echocardiography, and cardiac magnetic resonance imaging results were borderline for athlete's heart. Because an electrophysiology study and standard exercise tests provoked no arrhythmia, doctors suspected Munchausen syndrome. Ultimately, an exercise test that simulated the physical effort of a competition provoked tachyarrhythmia consistent with the HRM readings. This case demonstrates the diagnostic difficulties related to exercise-induced arrhythmia and the diagnostic usefulness of sports HRMs.

Genetic Testing and Counselling in Hypertrophic Cardiomyopathy: Frequently Asked Questions

Genetic counselling and genetic testing in hypertrophic cardiomyopathy (HCM) represent an integral part of the diagnostic algorithm to confirm the diagnosis, distinguish it from phenocopies, and suggest tailored therapeutic intervention strategies. Additionally, they enable cascade genetic testing in the family. With the implementation of Next Generation Sequencing technologies (NGS), the interpretation of genetic data has become more complex. In this regard, cardiologists play a central role, aiding geneticists to correctly evaluate the pathogenicity of the identified genetic alterations. In the ideal setting, geneticists and cardiologists must work side by side to diagnose HCM as well as convey the correct information to patients in response to their many questions and concerns. After a brief overview of the role of genetics in the diagnosis of HCM, we present and discuss the frequently asked questions by HCM patients throughout our 20-year genetic counselling experience. Appropriate communication between the team and the families is key to the goal of delivering the full potential of genetic testing to our patients.

Editor-in-Chief's Top Picks From 2022

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16 million plus), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Basic & Translational Research, Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Congenital Heart Disease, Coronary Disease & Interventions, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, and Valvular Heart Disease.^1-100.

Leisure-time and competitive sport participation: a changing paradigm for HCM patients

HCM has long been considered the most frequent cause of death in athletes, and reason for disqualification from sport. However, our perception of the impact of sports on HCM is largely based on anecdotal evidence. In this review, we provide a reappraisal of current knowledge relative to 1) the impact of sport on LV remodeling, and 2) on the clinical outcome of HCM in athletes. 1) The limited available evidence argues against the hypothesis that intensive exercise conditioning may trigger and/or worsen the development of LV hypertrophy or cause changes in LV function in adult HCM athletes. 2) Recent observations challenge the concept of a detrimental effect of sport on HCM clinical course. The Reset-HCM study showed that 16-week moderate-intensity exercise resulted in a small, significant increase in exercise capacity and no adverse events. In a cohort of 88 low-risk HCM athletes followed for a 7-year period, survival analyses showed no difference in mortality between HCM who discontinued or pursued vigorous exercise programmes. Further reassurance was provided by the ICD Sports Safety Registry. Clinical implications: At present, patients' attitude to sport participation is highly variable, based on social and legal backgrounds surrounding medical practice in different countries. The shared-decision-making as suggested by current US and European guidelines allows the physician to deliver a tailored and more liberal advice. Physicians should be aware of the changing paradigm relative to exercise and sport prescription for HCM and promote active lifestyle as an integral component of modern management of HCM patients.