Task Force 4: HCM and other cardiomyopathies, mitral valve prolapse, myocarditis, and Marfan syndrome

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.

Exercise recommendations for patients with hypertrophic cardiomyopathy

Individuals with hypertrophic cardiomyopathy (HCM) have historically been advised to limit exercise and sports participation to mild-intensity activities due to concerns for sudden cardiac arrest (SCA). However, more contemporary data have shown SCA is rare in patients with HCM and emerging data is shifting towards support for the safety of exercise in this patient population. Recent guidelines endorse exercise in patients with HCM after a comprehensive evaluation and shared-decision making with an expert provider.

Return-to-Play for Elite Athletes With Genetic Heart Diseases Predisposing to Sudden Cardiac Death

BACKGROUND

People diagnosed with genetic heart diseases (GHDs) associated with sudden cardiac death (SCD) have historically been restricted from competitive sports. Recent data documenting return-to-play (RTP) experiences following shared decision making (SDM) suggest that cardiac event rates for athletes with a GHD are lower than previously described, thereby suggesting an opportunity to reconsider this paradigm.

OBJECTIVES

The purpose of this study was to evaluate clinical outcomes among National Collegiate Athletic Association Division I university and professional athletes diagnosed with a GHD.

METHODS

A multicenter retrospective analysis was performed to examine demographics, clinical characteristics, RTP outcomes, and cardiac events among elite athletes with a GHD.

RESULTS

A total of 76 elite (66%, Division I, 34% professional) athletes (age 19.9 ± 5 years, 28% women) diagnosed with a GHD (hypertrophic cardiomyopathy [53%], long QT syndrome, long QT syndrome [26%]) comprise this cohort. Most athletes were asymptomatic (48 of 76, 63%) before diagnosis and had their GHD detected during routine preparticipation cardiovascular screening. Most athletes (55 of 76, 72%) were initially disqualified from their sport but subsequently opted for unrestricted RTP after comprehensive clinical evaluation and SDM. To date, (mean follow-up 7 ± 6 years), only 1 exercise-related (1.3%) and 2 nonexercise-related GHD-associated adverse cardiac events occurred. There have been no fatalities during follow-up.

CONCLUSIONS

This is the first study describing the experience of athletes with a known SCD-predisposing GHD who are competing at the elite level. After careful evaluation, risk stratification, and tailoring of their GHD therapy, RTP following SDM appears associated with low, nonfatal events rates at elite levels of sport.

[Analysis of sudden cardiac death in competitive athletes, possibilities for reducing cases]

INTRODUCTION

Sudden cardiac death in athletes is rare (0.5 to 1 per 100 000 athlete years), but sudden cardiac death in known athletes causes general shock.

OBJECTIVE

Our research aim was to collect and study as many sudden cardiac death cases as possible, judge the role of stress and look for ways to reduce fatal tragedies.

METHOD

From registers and newspaper articles found on the Internet, we collected 360 (including 14 women) athletes' sudden cardiac death cases where the sport, age and place of death (during training/competition/after) could be determined. From these, a single database has been prepared in order of the year of death. The cases were grouped and analyzed by sports. Based on our results and literature data, we made recommendations to reduce fatalities.

RESULTS AND CONCLUSION

There were more sudden cardiac deaths in competitions than in trainings (239 vs. 99), but tragedies also happened during warm-ups and chess without physical exertion, furthermore, there was no sudden cardiac death in the stakeless training of marathon/half marathon/triathlon athletes; all these prove the role of stress, so we recommend a psychological conversation before a high-stakes race. There were also a lot of sudden cardiac deaths (79/360) during team sports trainings, so we recommend reanimation readiness there as well. After training/competition, sudden cardiac death happened mainly in sports requiring high static effort, where post-competition monitoring is also recommended. Those who died in training were younger than those who died during the race (p<0.01), so young people should be monitored more closely for medical and (under)fitness. Marathon runners and triathletes were older than team athletes (p<0.005) and only died in competition, so for them a basic examination and an ECG within 1 month before competition are recommended. Conclusions drawn from literature data: sports medicine examination should be standardized and documented in an accessible way; since resuscitation started earlier and professionally is more effective, all competitors should receive reanimation training. Orv Hetil. 2023; 164(29): 1155-1163.

Mitral valve prolapse and physical performance in Asian military males: The CHIEF Heart study

The impact of mitral valve prolapse (MVP) and mitral regurgitation (MR) on physical performance has not been examined. Of 1,808 physically fit Asian military males, we compared the physical fitness between 62 subjects with MVP (MVP(+)) and 1,311 age- and anthropometrics-matched controls from the 1,746 participants without MVP (MVP(-)). MVP and MR grade were defined based on the American Society of Echocardiography criteria. Aerobic endurance capacity was evaluated by a 3000-m run and muscular endurance capacity was separately evaluated by 2-min sit-ups and 2-min push-ups. Analysis of covariance was used to determine the difference between groups. As compared to the MVP(-), the MVP(+) completed the 3000-m run test faster (839.2 ± 65.3 sec vs. 866.6 ± 86.8 sec, p = 0.019), but did fewer push-ups (41.3 ± 3.92 vs. 48.0 ± 10.1, p = 0.02) and similar sit-ups within 2 min. Of the MVP(+), those with any MR (trivial, mild or moderate) completed the 3000-m run test faster than those without MR (830.6 ± 61.7 sec vs. 877.2 ± 61.7 sec, p = 0.02). Our findings suggest that in physically active Asian military males, the MVP(+) may have greater aerobic endurance capacity but lower muscular endurance capacity than the MVP(-). The presence of MR may play a role for the MVP(+) to have greater aerobic endurance capacity.

Rediscovering the value of exercise in patients with hypertrophic cardiomyopathy

It was previously thought that hypertrophic cardiomyopathy is the leading cause of sudden cardiac death in athletes. This was also extrapolated to the general population. Thereby, exercise was restrained in patients with hypertrophic cardiomyopathy. However, recent studies have shown that hypertrophic cardiomyopathy is not the main cause of sudden cardiac death, and moderate exercise is not only safe but beneficial for patients with hypertrophic cardiomyopathy. With the accumulation of evidence, relevant guidelines recommend low-intensity exercise from the beginning, then gradually recommend moderate-high intensity exercise for patients with hypertrophic cardiomyopathy. This suggests that we should rediscover the value of exercise in patients with hypertrophic cardiomyopathy. It is now widely accepted that patients with hypertrophic cardiomyopathy can benefit from the positive effects of exercise through an individualized exercise prescription based on a comprehensive assessment. This review summarizes the evidence showing patients with hypertrophic cardiomyopathy can exercise safely, and the methods to formulate related exercise prescriptions.

Symptoms and ECG changes precede sudden cardiac death in hypertrophic cardiomyopathy—A nationwide study among the young in Sweden

Background

Hypertrophic cardiomyopathy (HCM) is a major cause of sudden cardiac death (SCD) in the young. We aimed to characterize detailed family history, symptoms, hospital utilization and ECG changes before SCD.

Methods

We extracted all cases suffering SCD with HCM from the SUDDY cohort, which includes all cases of SCD between 2000–2010 in Sweden among individuals aged 0–35 years along with their controls. We gathered data from mandatory national registries, autopsy reports, medical records, ECGs (including military conscripts), and detailed family history from an interview-based questionnaire (with relatives, post-mortem).

Results

Thirty-eight cases (7 female), mean age 22 years, with HCM were identified. Among these, 71% presented with possible cardiac symptoms (chest pain [26%], syncope [22%], palpitations [37%]), before death; 69% received medical care (vs 21% in controls) within 180 days before death. The majority (68%) died during recreational activity (n = 14) or exercise/competitive sports (n = 12). Fifteen (39%) had a known cardiac disorder prior to death, with HCM being diagnosed pre-mortem in nine cases. 58% presented with abnormal ECG recordings pre-mortem, and 50% had a positive family history (1^st-3^rd generation) for heart disease.

Conclusion

In this comprehensive, nationwide study of SCD due to HCM, 87% (33/38) of cases had one or more abnormality prior to death, including cardiac symptoms, a positive family history, known cardiac disease or ECG abnormalities. They sought medical care prior death, to a larger extent than controls. These findings suggest that cardiac screening should be expanded beyond competitive athletes to aid SCD prevention in the young population with HCM.

Evaluation of the DBA/2J mouse as a potential background strain for genetic models of cardiomyopathy

The potential use of the D2.mdx mouse (the mdx mutation on the DBA/2J genetic background) as a preclinical model of the cardiac aspects of Duchenne muscular dystrophy (DMD) has been criticized based on speculation that the DBA/2J genetic background displays an inherent hypertrophic cardiomyopathy (HCM) phenotype. Accordingly, the goal of the current study was to further examine the cardiac status of this mouse strain over a 12-month period to determine if observable signs of HCM develop, including histopathology and pathological enlargement of the myocardium. Previous reports have documented heightened TGFβ signaling in the DBA2/J striated muscles, as compared to the C57 background, which, as expected, is manifested as increased cardiomyocyte size, wall thickness, and heart mass as compared to the C57 background. While normalized heart mass is larger in the DBA/2J mice, compared to age-matched C57/BL10 mice, both strains similarly increase in size from 4 to 12 months of age. We also report that DBA/2J mice contain equivalent amounts of left ventricular collagen as healthy canine and human samples. In a longitudinal echocardiography study, neither sedentary nor exercised DBA/2J mice demonstrated left ventricular wall thickening or cardiac functional deficits. In summary, we find no evidence of HCM, nor any other cardiac pathology, and thus propose that it is an appropriate background strain for genetic modeling of cardiac diseases, including the cardiomyopathy associated with DMD.

Arrhythmogenic Mitral Valve Prolapse

Mitral valve prolapse (MVP) is a common condition present in 1–3% of the population. There has been evidence that a subset of MVP patients is at higher risk of sudden cardiac death. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. ECG features include ST-segment depression, T wave inversion or biphasic T waves in inferior leads, and premature ventricular contractions arising from the papillary muscles and the fascicular system. Echocardiography can identify MVP and mitral annular disjunction, a feature that has significant negative prognostic value in MVP. Cardiac MRI is indicated for identifying fibrosis. Patients with high-risk features should be referred for further evaluation. Catheter ablation and mitral valve repair might reduce the risk of malignant arrhythmia. MVP patients with high-risk features and clinically documented ventricular arrhythmia may also be considered for an ICD.

The prevalence of thoracic aorta aneurysm as an important cardiovascular disease in the general population

BACKGROUND

The aorta is the largest and main artery in the body. The enlargement of the aortic diameter known as ectasia results in aneurysm. Thoracic aorta aneurysm can involve one or more segments of the aorta. Non-invasive imaging techniques play an important role in identifying patients, estimating maximal aneurysm diameter, following up patients, and detecting complications. So, this study was performed to estimate the prevalence of ascending thoracic aorta aneurysm in the general population of Iran.

METHODS

People with an abnormal aortic size (˃ 36 mm) were enrolled and subjected to diagnostic tests, and related risk factors were assessed.

RESULT

Of the 3400 people examined, 410 (12%) had abnormal aorta sizes, and 42 (1.2%) had ascending aorta aneurysm. Out of the 410 patients with elevated aorta size, 235 (57%) were males, and 175 (43%) were females. Overall, 229 patients (56%) had hypertension, and 255 (62%) were over 60 years old.

CONCLUSION

In this study, we showed that the prevalence of ascending aorta aneurysm in the general population of Iran was about 1.2%. Ascending aorta aneurysm is a threatening pathology of the aorta. The high prevalence of hypertension may explain the high incidence of aneurysm in our studied population. Therefore, it is necessary to implement an accurate screening plan to identify patients with hypertension and provide appropriate treatment and adequate follow up to patients. Patients with ascending aorta aneurysm are also recommended to modify their lifestyles.

A complex unit for a complex disease: the HCM-Family Unit

Hypertrophic cardiomyopathy (HCM) is a group of heterogeneous disorders that are most commonly passed on in a heritable manner. It is a relatively rare disease around the globe, but due to increased rates of consanguinity within the Kingdom of Saudi Arabia, we speculate a high incidence of undiagnosed cases. The aim of this paper is to elucidate a systematic approach in dealing with HCM patients and since HCM has variable presentation, we have summarized differentials for diagnosis and how different subtypes and genes can have an impact on the clinical picture, management and prognosis. Moreover, we propose a referral multi-disciplinary team HCM-Family Unit in Saudi Arabia and an integrated role in a network between King Faisal Hospital and Inherited and Rare Cardiovascular Disease Unit-Monaldi Hospital, Italy (among the 24 excellence centers of the European Reference Network (ERN) GUARD-Heart).   Graphical Abstract.

Hypertrophic Cardiomyopathy: Updates Through the Lens of Sports Cardiology

Purpose of review

This review will summarize the distinction between hypertrophic cardiomyopathy (HCM) and exercise-induced cardiac remodeling (EICR), describe treatments of particular relevance to athletes with HCM, and highlight the evolution of recommendations for exercise and competitive sport participation relevant to individuals with HCM.

Recent findings

Whereas prior guidelines have excluded individuals with HCM from more than mild-intensity exercise, recent data show that moderate-intensity exercise improves functional capacity and indices of cardiac function and continuation of competitive sports may not be associated with worse outcomes. Moreover, recent studies of athletes with implantable cardioverter defibrillators (ICDs) demonstrated a safer profile than previously understood. In this context, the updated American Heart Association/American College of Cardiology (AHA/ACC) and European Society of Cardiology (ESC) HCM guidelines have increased focus on shared decision-making and liberalized restrictions on exercise and sport participation among individuals with HCM.

Summary

New data demonstrating the safety of exercise in individuals with HCM and in athletes with ICDs, in addition to a focus on shared decision-making, have led to the most updated guidelines easing restrictions on exercise and competitive athletics in this population. Further athlete-specific studies of HCM, especially in the context of emerging therapies such as mavacamten, are important to inform accurate risk stratification and eligibility recommendations.

Cardiac-CT with the newest CT scanners: An incoming screening tool for competitive athletes?

Competitive athletes of all skill levels are at risk of sudden cardiac death (SCD) due to certain heart conditions. Prior to engagement in high-intensity athletics, it is necessary to screen for these conditions in order to prevent sudden cardiac death. Cardiac-CT angiography (CCTA) is a reliable tool to rule out the leading causes of SCD by providing an exceptional overview of vascular and cardiac morphology. This allows CCTA to be a powerful resource in identifying cardiac anomalies in selected patients (i.e. unclear symptoms or findings at ECG or echocardiography) as well as to exclude significant coronary artery disease (CAD). With the advancement of technology over the last few years, the latest generations of computed tomography (CT) scanners provide better image quality at lower radiation exposures. With the amount of radiation exposure per scan now reaching the sub-millisievert range, the number of CT examinations it is supposed to increase greatly, also in the athlete's population. It is thus necessary for radiologists to have a clear understanding of how to make and interpret a CCTA examination so that these studies may be performed in a responsible and radiation conscious manner especially when used in the younger populations. Our work aims to illustrate the main radiological findings of CCTAs and highlight their clinical impact with some case studies. We also briefly describe critical features of state-of-the-art CT scanners that optimize different acquisitions to obtain the best quality at the lowest possible dose.

Is Exercise Helpful or Harmful in Dealing With Specific Arrhythmia

Exercise is universally known to benefit health by lowering risk for cardiovascular disease and mortality. However, in patients with pre-existing cardiac conditions, including channelopathies, cardiomyopathies and coronary artery disease, exercise can cause sudden cardiac death (SCD). In this review, we explore exercise related risks and current recommendations for specific conditions. The risk of myocardial infarction (MI) during strenuous exercise in asymptomatic individuals with coronary artery disease is decreased with habitual exercise, especially if they have a normal ejection fraction and no ischemia. Furthermore, cardiac rehabilitation has been shown to be beneficial in heart failure. On the other hand, surgery is recommended for certain anomalous coronaries prior to engaging in vigorous activity. In addition, both exercise-induced disease progression and SCD in arrhythmogenic cardiomyopathy restrict ability to engage in competitive sports, as is the case in hypertrophic cardiomyopathy. Other diseases, like myocarditis only cause temporary risk for SCD. Previously considered benign, common conditions like early repolarization do increase SCD risk. Finally, certain gear including thicker chest protectors for athletes engaging in sports with hard, small spherical objects decrease risk of commotio cordis. While significant advances have been achieved in diagnosing and treating previously unrecognized conditions that predispose to sudden cardiac death, more research is needed to further tailor recommendations to allow beneficial exercise in those with rarer conditions that are under-represented in large systemic studies.

Myocarditis in the Athlete: Arrhythmogenic Substrates, Clinical Manifestations, Management, and Eligibility Decisions

Myocarditis is as an important cause of sudden cardiac death (SCD) among athletes. The incidence of SCD ascribed to myocarditis did not change after the introduction of pre-participation screening in Italy, due to the transient nature of the disease and problems in the differential diagnosis with the athlete's heart. The arrhythmic burden and the underlying mechanisms differ between the acute and chronic setting, depending on the relative impact of acute inflammation versus post-inflammatory myocardial fibrosis. In the acute phase, ventricular arrhythmias vary from isolated ventricular ectopic beats to complex tachycardias that can lead to SCD. Atrioventricular blocks are typical of specific forms of myocarditis, and supraventricular arrhythmias may be observed in case of atrial inflammation. Athletes with acute myocarditis should be temporarily restricted from physical exercise, until complete recovery. However, ventricular tachycardia may also occur in the chronic phase in the context of post-inflammatory myocardial scar.

Myocardial tissue characterization by gadolinium-enhanced cardiac magnetic resonance imaging for risk stratification of adverse events in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy with a wide spectrum of clinical manifestations. Patients can be asymptomatic or suffer major adverse events including sudden cardiac death, ventricular arrhythmias, and heart failure. Identification of individuals with HCM who are at risk for these complications remains challenging. While echocardiography remains the mainstay of diagnostic evaluation, cardiac magnetic resonance imaging (CMR) is an important adjunctive diagnostic modality with emerging applications for risk-stratification of adverse events in the HCM population. Although not included in current guidelines for HCM management, there is increasing evidence to support the use of CMR for routine prognostic assessment of HCM patients. In this review we discuss the use of CMR techniques, including late gadolinium enhancement, T1 mapping, and quantification of extracellular volume fraction, for the risk stratification of three major adverse events in HCM: sudden cardiac death, ventricular arrhythmias, and congestive heart failure.

Viral Myocarditis-Incidence, Diagnosis and Management

Viral myocarditis has an incidence rate of 10 to 22 per 100,000 individuals. The presentation pattern of viral myocarditis can range from nonspecific symptoms of fatigue and shortness of breath to more aggressive symptoms that mimic acute coronary syndrome. After the initial acute phase presentation of viral myocarditis, the virus may be cleared, resulting in full clinical recovery; the viral infection may persist; or the viral infection may lead to a persistent autoimmune-mediated inflammatory process with continuing symptoms of heart failure. As a result of these 3 possibilities, the diagnosis, prognosis, and treatment of viral myocarditis can be extremely unpredictable and challenging for the clinician. Herein, the incidence, etiology, definition and classification, clinical manifestation, diagnosis, pathogenesis, prognosis, and treatment of viral myocarditis are reviewed, and how acute clinical care teams might differentiate between viral myocarditis and other acute cardiac conditions is discussed.

Institutional Marfan syndrome surgical volume influences mitral valve surgical strategy in patients with Marfan syndrome

BACKGROUND/AIM

The goal of this study was to evaluate trends in mitral valve (MV) operations performed on patients with Marfan syndrome (MfS) and determine the influence of an institution's MfS and MV surgical volume on MV surgical strategy in the US.

METHODS

The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 1126 patients with MfS were identified who underwent MV operations meeting our inclusion criteria. Linear regression was performed to assess trends of MV repair (MVr) rates over time. Patients were stratified into tertiles depending on the institution's annual MfS and MV surgical volumes. Multivariate analysis was used to determine the impact of institutional MV and MfS surgical volume on whether a patient received an MV replacement (MVR).

RESULTS

The MVR rate was 60% for the entire cohort. There was a decreasing trend of MVR rates during the study period (82% in 1998-99 vs 49% in 2010-2011, P < .05). Multivariate analysis revealed that patients operated on at high (odds ratio [OR], 0.65; P < .05) and medium (OR, 0.66; P < .05) volume MfS centers were less likely to undergo MVR when compared to lower-volume MfS centers. In contrast, MV volume was not a significant predictor of surgical strategy in this cohort.

CONCLUSION

The national MVR rate in the MfS population is higher than published reports. Data from this study suggest that MfS patients with indications for MV surgery should be referred to high-volume MfS surgical centers to have the best opportunity for MVr.

Papillary muscle ventricular arrhythmias in patients with arrhythmic mitral valve prolapse: Electrophysiologic substrate and catheter ablation outcomes

BACKGROUND

Mitral valve prolapse (MVP) is a common valve condition and has been associated with sudden cardiac death. Premature ventricular contractions (PVCs) from the papillary muscles (PMs) may play a role as triggers for ventricular fibrillation (VF) in these patients.

OBJECTIVES

To characterize the electrophysiological substrate and outcomes of catheter ablation in patients with MVP and PM PVCs.

METHODS

Of 597 patients undergoing ablation of ventricular arrhythmias during the period 2012-2015, we identified 25 patients with MVP and PVCs mapped to the PMs (64% female). PVC-triggered VF was the presentation in 4 patients and a fifth patient died suddenly during follow-up. The left ventricle ejection fraction (LVEF) was 50.5% ± 11.8% and PVC burden was 24.4% ± 13.1%. A cardiac magnetic resonance imaging was performed in nine cases and areas of late gadolinium enhancement were found in four of them. A detailed LV voltage map was performed in 11 patients, three of which exhibited bipolar voltage abnormalities. Complete PVC elimination was achieved in 19 (76%) patients and a significant reduction in PVC burden was observed in two (8%). In patients in which the ablation was successful, the PVC burden decreased from 20.4% ± 10.8% to 6.3% ± 9.5% (P = 0.001). In 5/6 patients with depressed LVEF and successful ablation, the LV function improved postablation. No significant differences were identified between patients with and without VF.

CONCLUSIONS

PM PVCs are a source of VF in patients with MVP and can induce PVC-mediated cardiomyopathy that reverses after PVC suppression. Catheter ablation is highly successful with more than 80% PVC elimination or burden reduction.

Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by hypertrophy of the left ventricular myocardium and is most often caused by mutations in sarcomere genes. The structural and functional abnormalities are not explained by flow-limiting coronary artery disease or loading conditions. The disease affects at least 0.2% of the population worldwide and is the most common cause of sudden cardiac death in young people and competitive athletes because of fatal ventricular arrhythmia. In some patients, however, HCM has a benign course. Therefore, it is of utmost importance to properly evaluate patients and single out those who would benefit from an implanted cardioverter defibrillator. In this article, we review and summarize the sudden cardiac death risk stratification algorithms, methods of preventing death due to HCM, and novel factors that may improve the existing prediction models.

Practice Variation among an International Group of Genetic Counselors on when to Offer Predictive Genetic Testing to Children at Risk of an Inherited Arrhythmia or Cardiomyopathy

Cascade predictive genetic testing is available for many families as a means to identify individuals at risk of long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC). The general issue of offering predictive genetic testing to minors has been an area of ethical debate among genetic counselors and other healthcare professionals for many years. An online questionnaire was circulated to four international genetic counseling associations to assess the views of cardiac genetic counselors regarding when to offer predictive genetic testing to children at risk of LQTS, CPVT, HCM, and ARVC. Analysis was both quantitative and qualitative. The study sample comprised 98 respondents. The majority reported that they offer predictive genetic testing before 5 years of age to children at risk of LQTS (83%) and CVPT (75%) and before 10 years of age to children at risk of HCM (66%) or ARVC (70%). Influencing factors included country of practice, clinical setting, and years of experience. The rationale provided for when to offer predictive genetic testing is encompassed by the ethical principles of beneficence, non-maleficence, autonomy, and informed consent. In conclusion, significant practice variation exists among cardiac genetic counselors regarding predictive genetic testing for children at risk of an inherited cardiomyopathy. These variations call for more research in the area to assist with the development of evidence-based guidelines.

Cardiovascular Clearance for Sports Participation

Sudden cardiac death (SCD) in a young athlete is a rare but tragic occurrence. The goal of this article is to provide information about the risks of sudden cardiac death in athletes by reviewing the epidemiology and describing the current screening recommendations of the American Heart Association/American College of Cardiology. ¹ The specifics of and reasons for differences between screening guidelines in the United States and the screening guidelines in Europe are highlighted. Electrocardiogram (ECG) changes that can be expected in the setting of conditioning vs pathology are described. Intrinsic cardiac pathologies and disorders, with related cardiac findings, are reviewed, including prevalence and inheritance patterns. Also included is a brief medical-legal discussion about physician liability in the course of making sports clearance decisions. In an area in which there is no single national standard but in which there is an expectation by almost all states for a clearance examination, this article aims to help physicians make thoughtful decisions when evaluating a seemingly healthy patient in order to detect those rare athletes who may be at increased risk of succumbing to a sudden cardiac death during sports participation. ²¹.

Premature ventricular beats in the athlete: management considerations

INTRODUCTION

Premature ventricular beats (PVBs) in competitive athletes are incidentally found during pre-participation ECG screening. Their clinical significance remains debatable with several studies suggesting they are a benign reflection of athlete's heart, and others proposing they may indicate underlying structural heart disease and heightened risk for sudden cardiac death (SCD). Areas covered: Effective management of athletes with PVBs may best be accomplished using an algorithmic approach for risk stratification with a goal of differentiating benign PVBs from those reflective of underlying cardiomyopathies. Current AHA/ACC consensus recommendations provide a platform for determining optimal medical and invasive therapeutic strategies for symptom control and management of long-term complications without erroneously restricting an athlete's ability to play. Utilizing a shared decision-making model is an optimal method for managing expectations and guiding exercise recommendations. Expert commentary: Though pre-participation ECG screening as the standard of care for competitive athletes remains controversial in the United States, a 12-lead ECG is often the first indication of underlying structural heart disease in athletes with PVBs and can therefore identify athletes at greater risk of SCD. Advancements in non-invasive imaging continue to improve in diagnostic potential and prognostication. Invasive therapies provide a curative strategy for refractory PVBs and PVB-induced cardiomyopathy.

Mitral Prolapse: An Old Mysterious Entity - The Incremental Role of Multimodality Imaging in Sports Eligibility

Mitral valve prolapse is generally a benign condition characterized by fibromyxomatous changes of the mitral leaflet with displacement into the left atrium and late-systolic regurgitation. Although it is an old clinical entity, it still arouses perplexity in diagnosis and clinical management. Complications, such as mitral regurgitation (MR), atrial fibrillation, congestive heart failure, endocarditis, ventricular arrhythmias, and sudden cardiac death (SCD), have been reported. A large proportion of the overall causes of SCD in young competitive athletes is explained by mitral valve prolapse. Recent studies have shown the fibrosis of the papillary muscles and inferobasal left ventricular wall in mitral valve prolapse, suggesting a possible origin of ventricular fatal arrhythmias. Athletes with mitral valve prolapse and MR should undergo annual evaluations including physical examination, echocardiogram, and exercise stress testing to evaluate the cardiovascular risks of competitive sports and obtain the eligibility. In this setting, multimodality imaging techniques – echocardiography, cardiac magnetic resonance, and cardiac computed tomography – should provide a broad spectrum of information, from diagnosis to clinical management of the major clinical profiles of the disease.

Left Ventricular Noncompaction: A Distinct Genetic Cardiomyopathy?

Left ventricular noncompaction (LVNC) describes a ventricular wall anatomy characterized by prominent left ventricular (LV) trabeculae, a thin compacted layer, and deep intertrabecular recesses. Individual variability is extreme, and trabeculae represent a sort of individual "cardioprinting." By itself, the diagnosis of LVNC does not coincide with that of a "cardiomyopathy" because it can be observed in healthy subjects with normal LV size and function, and it can be acquired and is reversible. Rarely, LVNC is intrinsically part of a cardiomyopathy; the paradigmatic examples are infantile tafazzinopathies. When associated with LV dilation and dysfunction, hypertrophy, or congenital heart disease, the genetic cause may overlap. The prevalence of LVNC in healthy athletes, its possible reversibility, and increasing diagnosis in healthy subjects suggests cautious use of the term LVNC cardiomyopathy, which describes the morphology but not the functional profile of the cardiomyopathy.

Musculoskeletal Conditions in a Pediatric Population with Ehlers-Danlos Syndrome

OBJECTIVE

To describe musculoskeletal conditions in children with Ehlers-Danlos syndrome (EDS).

STUDY DESIGN

A retrospective medical record review was performed, which evaluated 205 patients with EDS (ages 6-19 years) seen in sports medicine or orthopedic clinic at a large pediatric hospital over a 5-year period.

RESULTS

Female (n = 147) and male (n = 57) patients were identified (mean age 12.7 years). The most common EDS subtype (55.6%) was hypermobility type. Patients had between 1 and 69 visits (median 4), and 764 diagnoses were recorded, most commonly laxity/instability, pain, subluxation, and scoliosis/spinal asymmetry. Nearly one-half of patients (46.8%) received a general diagnosis of pain because no more specific cause was identified, in addition to 8.3% who were diagnosed with chronic pain syndrome. The most common sites of presenting issue were knee (43.4%), back (32.2%), and shoulder (31.2%). Over three-fourths (77.1%) of patients had imaging. Most (88.1%) were prescribed physical therapy and/or other conservative measures, such as rest (40.5%), orthotics (35.6%), and medication (32.2%). Surgery was recommended to 28.8% of the study population.

CONCLUSIONS

Many pediatric and adolescent patients with EDS experience joint pain, instability, and scoliosis, along with other musculoskeletal issues. Despite extensive workup, the etiology of pain may not be identified. Large numbers of office visits, imaging studies, treatment prescriptions, and specialist referrals indicate considerable use of medical resources and highlight a great need for injury prevention and additional study.

Anomalous origin of the coronary artery arising from the opposite sinus: prevalence and outcomes in patients undergoing coronary CTA

AIMS

The impact of coronary computed tomographic angiography (CTA) on management of anomalous origin of the coronary artery arising from the opposite sinus (ACAOS) remains uncertain. We examined the prevalence, anatomical characterization, and outcomes of ACAOS patients undergoing CTA.

METHODS AND RESULTS

Among 5991 patients referred for CTA at two tertiary hospitals between January 2004 and June 2014, we identified 103 patients (1.7% prevalence) with 110 ACAOS vessels. Mean age was 52 years (range 5-83, 63% male), with 55% previously known ACAOS and 45% discovered on CTA. ACAOS subtypes included: 39% interarterial (n = 40 anomalous right coronary artery, n = 3 anomalous left coronary artery), 38% retroaortic, 15% subpulmonic, 5% prepulmonic, and 2% other. ACAOS patients were assessed for symptoms, ischaemic test results, revascularization, all-cause or cardiovascular (CV) death, and myocardial infarction. CTAs were reviewed for ACAOS course, take-off height and angle, length and severity of proximal narrowing, intramural course, and obstructive coronary artery disease (CAD). In follow-up (median 5.8 years), there were 20 surgical revascularizations and 3 CV deaths. After adjusting for obstructive CAD (n = 21/103, 20%), variables associated with ACAOS revascularization included the following: CV symptoms, proximal vessel narrowing ≥50%, length of narrowing >5.4 mm, and an interarterial course.

CONCLUSION

The prevalence of ACAOS on CTA was 1.7%, including 45% of cases discovered incidentally. CTA provided excellent characterization of ACAOS features associated with coronary revascularization, including the length and severity of proximal vessel narrowing.

Exercise testing for long-term follow-up in arrhythmogenic right ventricular cardiomyopathy

OBJECTIVES

We investigated arrhythmia, electrocardiography and physical work capacity (PWC) in the follow-up of ARVC.

DESIGN

Twenty-three patients (13 men; age 41±12years) fulfilling diagnostic criteria were re-investigated after at least five years.

RESULTS

Ventricular arrhythmia during exercise testing (ET) was present in 14 patients (61%) and showed variation between examinations. In eleven (48%), complex ventricular ectopic activity was observed at peak exercise or immediately thereafter. Mutations known to be pathogenic in ARVC were present in 13 patients (57%) of which 11 developed complex ventricular arrhythmia at ET. PWC at baseline was 190±66W (104±26%) decreasing to 151±61W (91±23%, p=0.008) after 10.7years.

CONCLUSION

The appearance of ventricular arrhythmia during exercise testing showed temporal variation but was frequent in patients with relevant genetic mutation. Physical exercise capacity decreased over time in patients with ARVC in excess to the age-related deterioration and regardless of medication.

Exercise and β-blocker therapy recommendations for inherited arrhythmogenic conditions

BACKGROUND

Management of individuals with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy may involve exercise restriction and/or β-blocker therapy.

OBJECTIVE

This study assessed the practices of a group of paediatric electrophysiologists regarding the management of genotype-positive/phenotype-positive and genotype-positive/phenotype-negative individuals with these conditions.

METHOD

An online survey was circulated to members of the Pediatric and Congenital Electrophysiology Society in May, 2014. The survey included questions addressing the respondents' approach regarding exercise recommendations and prescription of β-blocker therapy.

RESULTS

A total of 45 cardiologists completed the survey. The majority of respondents restricted symptomatic patients from competitive sports; however, only approximately half restricted phenotype-negative mutation carriers from this level of activity. Recommendations were less consistent regarding other types of activities. A trend was identified regarding physician physical activity and exercise recommendations for phenotype-negative mutation carriers. Less-active physicians were more likely to restrict exercise. β-blocker therapy was discussed by the majority of respondents for symptomatic patients and a significant number of asymptomatic patients.

CONCLUSION

Exercise restriction for patients with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy varies based on several factors including phenotype, type of exercise, guidelines referred to, and physicians' own level of activity.

The role of cardiovascular magnetic resonance in sudden death risk stratification in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden death in young patients, but current risk stratification strategies do not identify all patients at risk. Contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can identify areas of abnormal myocardial substrate comprising fibrosis, the structural nidus for potentially life-threatening ventricular arrhythmias. More recently, follow-up studies have demonstrated a strong relationship between extent of LGE in patients with HCM and increased risk of adverse disease-related events, including sudden death.

Nature and Nurture in Arrhythmogenic Right Ventricular Cardiomyopathy - A Clinical Perspective

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy characterised by frequent ventricular arrhythmias and slowly progressive predominant RV dysfunction. Up to two-thirds of ARVD/C patients have mutations in genes encoding the cardiac desmosome. Mutations in other genes are increasingly recognised. Inheritance of ARVD/C is generally autosomal dominant with reduced age-related penetrance and significant variable expressivity. While the full explanation for this phenotypic heterogeneity remains unclear, there is increasing evidence that exercise plays a major role in disease penetrance and arrhythmic risk. The disproportionate representation of athletes among ARVD/C patients has long been noted. Recently, the association of exercise with earlier onset and more severe arrhythmic and structural disease has been documented. This article reviews current evidence regarding the association of genotype, exercise and clinical outcomes and discusses the emerging paradigm in which genetic predisposition and environmental factors (exercise) interact around a threshold for phenotypic expression of ARVD/C.