Arrhythmic events in athletes with structural heart disease

Competitive sport places unusual demands on the heart: intense exercise, dehydration, electrolyte shifts and sympathetic activation can expose an underlying substrate that remains quiet at rest. For an athlete with structural heart disease, a documented arrhythmic event changes the question from “Is this person fit to play?” to “Which risks can be identified, treated and monitored for participation?” The answer requires cardiology expertise, sporting context and a plan the athlete and club can follow.

Screening is one part of that response, not a substitute for clinical assessment. Resting findings, symptoms, family history, disease phenotype and previous events must be interpreted together. This matters in Australia, where recreational and semi-professional sport is common, pre-participation processes vary widely, and some athletes train far from a tertiary electrophysiology service. A useful return-to-play decision should be written, specific and reviewed over time.

Why prior arrhythmia changes the sporting plan

An arrhythmic event—such as exertional syncope, sustained atrial arrhythmia, ventricular tachycardia or aborted sudden cardiac arrest—should prompt structured review. Immediate priorities are to prevent another event and establish whether the cause is structural, ischaemic, congenital, inflammatory or inherited. Clinicians should obtain recordings, witness accounts, resuscitation details and medication information because the exact diagnosis influences urgency and treatment.

Structural disease may include hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, significant valve disease, congenital defects or previous myocardial injury. Some conditions become more arrhythmogenic under exercise or adrenergic drive, while others increase risk through fibrosis, ventricular dilation or impaired coronary reserve. A prior event can reveal disease that was not apparent on earlier screening.

The sporting plan should distinguish a reversible episode from ongoing high-risk substrate, and temporary restriction during investigation from durable advice based on disease severity. This reduces under-recognition of danger and unnecessary exclusion while preserving the athlete’s right to an informed decision.

Build a staged screening pathway

The first assessment should establish what happened and what the athlete usually manages. Details include exercise intensity at onset, recovery time, palpitations, chest discomfort, breathlessness, trauma, family history and prior testing. Examination should assess blood pressure in both arms, heart sounds, murmurs, heart-failure signs and features of inherited disease. Growth and development matter in children and adolescents.

A resting 12-lead ECG is useful when interpreted with recognised athlete criteria, including physiological patterns seen in black athletes. It cannot exclude dangerous disease by itself. Echocardiography is needed when history or examination suggests structural abnormality, and repeat testing may suit evolving disease. Screening improves detection only when interpretation is trained, equipment is sound and follow-up is available.

Australian arrangements are uneven: state and club policies differ, and pre-competition assessment may be arranged by a family GP, school health clinician or club medical officer. Medicare subsidises clinically indicated GP and specialist care, while clubs, schools or competitions often fund screening; private or bulk-billed echocardiography may shorten waits. Protocols in Melbourne’s AFL clubs and rugby leagues across Sydney and Brisbane can be more formal than those in smaller competitions. Clinicians can consult the about the journal page to understand Journal of Arrhythmia’s peer-reviewed scope and find relevant electrophysiology and ablation literature.

Define the structural and electrical substrate

Echocardiography defines many structural findings, including ventricular hypertrophy and outflow obstruction, chamber size and function, valve disease and pulmonary pressure. Cardiac magnetic resonance imaging can add information about fibrosis, right ventricular morphology, pericardial disease and myocardial scar. A “normal” echocardiogram does not settle the question when exertional syncope or sustained ventricular arrhythmia has occurred; targeted CMR, exercise imaging and rhythm monitoring may be required.

The suspected diagnosis should guide the next test. In hypertrophic cardiomyopathy, exercise testing, ambulatory monitoring and CMR may reveal different parts of risk. In arrhythmogenic right ventricular cardiomyopathy, ventricular tachycardia morphology, ECG changes, imaging and family history can be more informative than any single result. If no structural disease is found, a channelopathy assessment remains possible rather than assuming the episode was benign.

Long-term recording depends on symptom frequency and the suspected rhythm. Patch and Holter monitors suit frequent symptoms; event recorders or implantable loop recorders can help with infrequent, unexplained events. For rural and remote athletes in northern Australia, remote transmission and telehealth review can support monitoring, but device logistics, skin care and a pathway for urgent face-to-face assessment still need local planning.

Estimate risk with the whole athlete in view

Risk assessment should combine disease severity with event severity and exercise demand. Important modifiers include previous ventricular fibrillation or sustained ventricular tachycardia, unexplained syncope, extensive fibrosis, severe hypertrophy, ventricular dysfunction, abnormal exercise blood-pressure response, apical aneurysm, young age at presentation and a family history of premature sudden death. Symptoms near maximal exertion deserve careful weight rather than being dismissed as dehydration.

No single number resolves the decision. A prior event may dominate prognosis even when imaging appears reassuring, while well-characterised disease with effective therapy may permit selective participation. Functional testing should reflect the athlete’s sport where possible, and results should be interpreted by clinicians familiar with high-level exertion. Psychological readiness and understanding of residual risk also matter after a frightening event.

Intervention is part of risk assessment. When recurrent ventricular tachycardia prompts catheter ablation, procedural evidence is increasingly relevant; the zero-fluoroscopy ablation outcomes review discusses feasibility and radiation reduction using electroanatomical mapping. Reduced ionising exposure is valuable, but operator experience, lesion durability and long-term follow-up remain central. An ablation plan should state what is expected to improve and how success will be measured.

Make participation and clearance a shared decision

Clearance should involve the athlete, family where appropriate, sports physician, cardiologist or electrophysiologist, and representatives of the club or competition. Each participant brings different information: the athlete knows symptoms and training load, the club understands collision and environmental demands, and specialist reviewers can connect test findings with arrhythmia mechanisms. The final recommendation should state whether participation is unrestricted, conditional, time-limited or advised against.

A temporary period away from competition is often sensible while investigations are pending or therapy is being established. Longer-term restriction may be appropriate for conditions associated with substantial risk during exertion. Recreational exercise, supervised rehabilitation and low-intensity activity can remain options when high-intensity competition is unsuitable. Decisions should consider age, competitive level, sporting career, personal goals and the consequences of recurrent arrhythmia and prolonged exclusion.

Every participating club needs an emergency plan that fits local conditions. Cricket on a hot field, coastal surf lifesaving and football in crowded stadiums each create different ambulance-access and defibrillator challenges. The plan should identify who carries an AED, who calls emergency services, where the nearest AED is located, and how an ICD shock will be communicated without revealing unnecessary medical details. Clear roles reduce confusion during a collapse.

Treat the cause before clearing the athlete

Treatment comes before clearance. Depending on the diagnosis, management may involve beta-blockers or other rate-control drugs, antiarrhythmic medication, catheter ablation, device implantation or correction of an underlying structural problem. Beta-blockers can reduce exercise capacity and peak heart rate, so medication effects should be assessed during sport-specific testing rather than inferred from a clinic walk. Anticoagulation and bleeding risk also require explicit review in contact sports.

Conduction disease deserves specialist attention because pacing choice can affect ventricular function. The His bundle pacing review compares outcomes with right ventricular pacing and is useful when counselling a patient with heart failure and a pacing indication. This is not a generic reason to select one device, and an implanted pacemaker does not by itself establish sporting safety. Synchronisation, programming, lead position and underlying disease all influence the plan.

Implantable cardioverter-defibrillators can be lifesaving in selected high-risk athletes, yet they bring sport-specific responsibilities. The team should document restrictions for high-contact or collision activities, infection risk around implanted leads, medication and device checks, and the response to an appropriate or inappropriate shock. A history of ventricular arrhythmia can lead to restrictions on driving, employment and competition that vary by jurisdiction, so Australian athletes should receive specific, current advice.

Turn the pathway into a practical action plan

A workable pathway starts with documentation, referral and temporary protection, followed by targeted investigation, specialist risk assessment, treatment and a written decision. The record should include the event timeline, resuscitation data, ECG and imaging files, medication list, device information, family history and emergency arrangements. For elite athletes, the Australian Institute of Sport and current WADA requirements can be engaged early so treatment does not create an avoidable anti-doping issue.

Follow-up should be scheduled around symptoms, medication changes, device checks and meaningful changes in training. Remote reviews can support athletes living outside metropolitan centres, but the local doctor or club should know when to call an ambulance and where the emergency plan is kept. Shared records, with the athlete’s consent, reduce repetition and help a new cardiologist or club medical officer understand prior decisions.

Clinicians, clubs and athletes should act on one agreed plan: document the event, refer promptly where indicated, and keep the athlete out of competition until the specialist review is complete and formal clearance has been given. Use current evidence, involve the people who manage training and emergencies, and revisit the plan as the athlete’s health changes. When risk can be controlled, returning to sport should be recognised as a carefully prepared medical decision rather than a simple declaration of fitness.