Pre-excited atrial fibrillation in a young athlete — case discussion

Presentation

Practice case (not a real patient). A 23-year-old man collapses briefly while playing basketball and is brought to a regional emergency department with palpitations. His ECG shows an irregular, rapid, wide QRS tachycardia with a varying QRS morphology.^[1] His blood pressure is 76/44 mm Hg and he is drowsy.^[1]

Step 1 — What is the rhythm?

ESC 2019 says the differential diagnosis of an irregular wide QRS tachycardia is pre-excited AF, polymorphic VT, or AT with variable block in the context of aberrancy.^[1] Pre-excited AF manifests itself by irregularity, a varying QRS morphology and a rapid ventricular rate.^[1] ANZCOR Guideline 11.9 says an irregular broad-complex tachycardia is most likely AF with bundle branch block, lists AF with ventricular pre-excitation and polymorphic VT as other possible causes, and advises seeking expert help.^[9]

Step 2 — Immediate treatment

He is haemodynamically unstable. ESC 2019 recommends synchronized DC cardioversion in haemodynamically unstable patients with pre-excited AF (Class I, Level B).^[1] ACC/AHA 2023 says patients with preexcited AF and hemodynamic instability should be treated with electrical cardioversion (COR 1, LOE B-NR).^[5] ANZCOR Guideline 11.9 says that if pre-excited AF is suspected, adenosine, digoxin, verapamil and diltiazem should be avoided, and that electrical cardioversion is usually the safest treatment option.^[9]

Step 3 — The drugs that would have harmed him

In its AVRT table, under chronic therapy, ESC 2019 says digoxin, beta-blockers, diltiazem, verapamil and amiodarone are not recommended and are potentially harmful in patients with pre-excited AF (Class III, Level B).^[1] ACC/AHA 2023 calls verapamil, diltiazem, amiodarone, digoxin, adenosine or beta blockers contraindicated, due to the risk of precipitating VF or hemodynamic deterioration (COR 3: Harm, LOE B-NR).^[5] ESC 2019 says conduction can occur preferentially via the AP "due to its shorter RP compared with the AVN", and that any AV node-modulating agents should be avoided in pre-excited AF because they may contribute to a risk of ventricular fibrillation.^[1]

Step 4 — After cardioversion

In sinus rhythm his ECG shows a short PR interval, a delta wave and a wide QRS complex, the typical resting pattern that ESC 2019 describes.^[1] With pre-excitation and an arrhythmia, he now meets the ESC 2019 description of WPW syndrome: an overt (manifest) AP in combination with usually recurrent tachyarrhythmias.^[1] ACC/AHA/HRS 2015 says SCD may be the first presentation of patients with undiagnosed WPW.^[2]

Step 5 — Definitive treatment

ESC 2019 says the treatment of choice for patients with symptomatic and recurrent AVRT, or pre-excited AF, is catheter ablation.^[1] ACC/AHA 2023 recommends catheter ablation of accessory pathways for patients with preexcited AF (COR 1, LOE B-NR), and says EP study and AP ablation can be offered as first-line therapy.^[5] ESC 2019 says AP ablation by an experienced operator has a high cure rate (>95%) and a low risk (<0.5%) of major complications.^[1] It says major complications include cardiac tamponade (0.13–1.1%) and complete AV block (0.17–2.7%) in patients in whom ablation of septal APs is attempted.^[1]

Step 6 — Sport and family

ESC 2020 sports cardiology says ablation of the AP is recommended in competitive and recreational athletes with pre-excitation and documented arrhythmias.^[8] It says competitive sport is possible 1–3 months after ablation, with ECG follow-up at 6 months and 1 year.^[8] For competitive athletes, the 2025 AHA/ACC scientific statement on competitive sports participation gives a different timing (no class or level given).^[16] The statement says that after WPW ablation, competitive sports participation can resume after vascular access site healing, taking into consideration the risk assessment of the pathway and the success of the procedure.^[16] ESC 2019 gives the prevalence of a WPW pattern as 0.15–0.25% in the general population, increasing to 0.55% among first-degree relatives of affected patients.^[1]