Wolff-Parkinson-White syndrome

Disease Description (Causes and Symptoms)

• Definition·Causes: Wolff–Parkinson–White (WPW) syndrome is a condition in which an abnormal conduction pathway that is congenitally present between the atria and ventricles (an accessory pathway, most commonly the bundle of Kent) causes the ventricles to be excited prematurely faster than through the normal atrioventricular (AV) node pathway.
• Pathophysiology: When antegrade conduction through the accessory pathway and retrograde conduction through the AV node occur simultaneously, an electrical reentry loop forms, causing paroxysmal supraventricular tachycardia (AVRT). In addition, if the accessory pathway rapidly transmits the electrical signals of atrial fibrillation (AF) to the ventricles, the ventricular rhythm may become very rapid and irregular, potentially increasing the risk of sudden death.
• Main symptoms: Palpitations (sudden, rapid pulse), dizziness, fainting (or a feeling of impending fainting), chest pain, and shortness of breath. Some people have no symptoms and are discovered incidentally during testing. Symptoms may appear in adulthood after being absent during adolescence, or the conduction ability of the accessory pathway may disappear over time.

Treatment Methods and Precautions

• Asymptomatic patients: Observation is generally recommended when the patient is asymptomatic and at low risk (with no high-risk findings on a normal exercise stress test and EP evaluation). In children, spontaneous resolution is also possible.
• Symptomatic·high-risk patients (recurrent paroxysmal tachycardia, history of syncope, possible accompanying AF, or high-risk conduction characteristics): Percutaneous catheter ablation (radiofrequency ablation or cryoablation) is recommended as the first-line treatment. The success rate is high and the recurrence rate is low.
• Drug treatment:
  • For acute conversion of paroxysmal supraventricular tachycardia (AVRT), vagal maneuvers such as the Valsalva maneuver are attempted, and adenosine may be administered at the physician’s discretion if necessary (only for typical AVRT).
  • When AF is present in WPW (or when the rhythm is irregular and rapid and the typical electrical pattern is not certain), AV nodal blockers (beta-blockers, calcium channel blockers, digoxin, and adenosine) are contraindicated — these drugs block the AV node and may promote rapid conduction through the accessory pathway, which can be fatal. Instead, intravenous procainamide may be recommended, and unstable patients should undergo immediate synchronized electrical defibrillation (synchronized cardioversion). Amiodarone is controversial and should be used depending on the situation.
• Lifestyle management·Precautions: Avoid substances that can trigger palpitations, such as smoking, excessive caffeine, amphetamines, and cocaine. Visit the emergency room if syncope, chest pain, or persistent palpitations occur. Consult the treating physician about restrictions related to pregnancy, driving, and strenuous exercise.
• Risk of complications: If untreated, the risk of sudden death increases when AF is present. Complications of ablation include vascular complications, ventricular or atrial perforation, and, rarely, AV block requiring lifelong cardiac pacing.
• Prognosis: Prognosis varies depending on symptoms and risk findings. Prognosis is generally favorable after successful ablation. The risk of sudden death is low in asymptomatic, low-risk patients.

Checkpoints Before an Outpatient Visit (Items and Records to Prepare and Example Questions)

• Required materials to bring:
  • A list of all currently used medications and supplements (including doses and dosing times)
  • Copies, if available, of previous electrocardiograms (ECGs), Holter (24-hour) recordings, exercise stress test results, echocardiography results, and electrophysiology (EP) study results
  • Symptom diary: date and time of symptom onset, duration, triggering circumstances (exercise, stress, caffeine, etc.), and accompanying symptoms (dizziness, syncope, chest pain)
  • Family history: similar heart disease or a history of sudden death
• Status check before the outpatient visit: Whether you have recently experienced syncope, severe dizziness, or persistent rapid heartbeat; whether you are pregnant; and which medications should be stopped before testing (confirm the physician’s instructions).
• List of materials to show the physician during the visit: Most recent ECG, recordings of symptoms (phone audio/video recordings or symptom screenshots, if possible), and medication list.

Examples of General Questions to Ask the Physician

• "My ECG shows findings suggestive of WPW. Do I need treatment right away?"
• "In my case (symptoms and test results), what are the success rate and risks of catheter ablation?"
• "If drug treatment is needed, which medications would be used and what are their side effects?"
• "Are there any restrictions on daily activities (driving, exercise, and pregnancy) after treatment?"

Examples of Disease-Specific Questions

• "How can we determine whether my accessory pathway is high risk (has rapid conduction ability)? Do I need an EP study (provocation test)?"
• "When AF occurs together with WPW, could you explain specifically which medications should be avoided in an emergency (e.g., beta-blockers and calcium channel blockers) and what emergency treatment should be provided?"

Urgent notice: If you experience syncope, persistent or extremely rapid irregular palpitations, severe chest pain, or symptoms preceding syncope, go to the emergency room immediately.