In a 14‑year‑old with long QT syndrome (prolonged QT interval on electrocardiogram) and a family history of premature death, should competitive sports be restricted and a non‑selective beta‑blocker initiated?

Restrict Competitive Sports and Initiate Beta-Blocker Therapy

In this 14-year-old with electrocardiographically manifest Long QT Syndrome and a concerning family history of premature sudden death, competitive sports must be immediately restricted and beta-blocker therapy initiated without delay. The correct answer is B: Restrict sport and give beta blocker.

Immediate Management Algorithm

Step 1: Immediate Sports Restriction

• All competitive sports participation must cease immediately until comprehensive evaluation is completed, appropriate treatment is initiated, and the patient remains asymptomatic on therapy for at least 3 months 1, 2
• This is a Class I recommendation from the American Heart Association/American College of Cardiology 1
• The combination of long QT on ECG, family history of sudden death at age 40, and age 14 creates a high-risk profile demanding immediate intervention 2, 3

Step 2: Initiate Beta-Blocker Therapy

• Beta-blocker therapy is a Class I recommendation for all patients with electrocardiographically documented LQTS 1, 2, 4
• Beta-blockers reduce adverse cardiac events by >75% in LQTS patients 2, 4, 3
• Nadolol is the preferred agent, with propranolol as an acceptable alternative; metoprolol should be avoided due to lower effectiveness 3, 5
• Treatment should begin immediately regardless of symptoms, as 12% of untreated symptomatic LQTS patients experience sudden death as their first manifestation 3

Step 3: Comprehensive Evaluation Required

• Genetic counseling and mutation-specific genetic testing (Class I recommendation) to identify the specific LQTS subtype, which determines trigger-specific restrictions 2, 4, 3
• Echocardiography to exclude structural heart disease (the murmur must be evaluated) 2, 4
• Exercise stress testing to assess QTc response and monitor beta-blocker adequacy 3
• 24-hour Holter monitoring to detect non-sustained ventricular tachycardia 4

Why Other Options Are Incorrect

Option A (Continue sport with annual ECG) is dangerous:

• Untreated LQTS patients face high mortality risk during competitive sports 3
• Annual monitoring without treatment and restriction ignores the Class I recommendation for immediate sports restriction 1, 2
• The family history of sudden death at age 40 significantly elevates this patient's risk profile 2

Option C (Minimal sport with pacemaker consideration) is inappropriate:

• Pacemakers do not prevent sudden death from ventricular arrhythmias in LQTS 4
• The mechanism of sudden death in LQTS is torsades de pointes and ventricular fibrillation, which require defibrillation, not pacing 4
• ICD (not pacemaker) is only indicated if syncope or ventricular tachycardia occurs despite beta-blocker therapy, or for cardiac arrest survivors 4, 3

Option D (Low exertion sport only) is premature:

• While low-intensity activities may eventually be permitted, no sports should occur until the 3-month treatment and evaluation period is completed 1, 2, 3
• The patient must first undergo comprehensive evaluation, initiate treatment, and remain asymptomatic on therapy 1, 2

Critical Additional Management Requirements

Mandatory Precautions:

• Strict avoidance of QT-prolonging medications (check www.crediblemeds.org) 1, 2, 3
• Electrolyte monitoring and aggressive hydration management to prevent dehydration 1, 2, 4
• Avoidance of hyperthermia from febrile illness or heat-related conditions 1, 2
• Energy drinks must be strictly avoided as they increase catecholamine release and heart rate, which are dangerous triggers for LQTS 2

Future Sports Consideration (Only After Initial Management):

• After 3 months of asymptomatic treatment, sports participation "may be considered" with shared decision-making (Class IIb recommendation) 1
• This requires expert assessment by a cardiac channelopathy specialist 1
• If permitted, only low-intensity activities (Class IA sports: bowling, golf, brisk walking) are reasonable 1, 3
• High-intensity burst activities remain strictly contraindicated even after treatment 1, 3
• Swimming is specifically contraindicated, particularly for LQT1 genotype 1, 2
• Personal automated external defibrillator (AED) and emergency action plan required if any sports permitted 1, 2, 3

Common Pitfalls to Avoid

• Do not assume asymptomatic status equals low risk: up to 25% of genotype-positive patients have normal QTc intervals on resting ECG 2
• Do not use beta-blockers as justification for immediate sports participation: beta-blockers cannot be regarded as a means of affording safety to retain eligibility in vigorous competitive sports 1
• Do not consider ICD or AED availability as justification for unrestricted sports: these should not be regarded as prospectively designed treatment strategies allowing participation in otherwise restricted activities 1
• Age 14 represents a high-risk period for sudden cardiac death in LQTS patients 2