Wolff-Parkinson-White syndrome resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alonso Alvarado, M.D. [2]; Hilda Mahmoudi M.D., M.P.H.^[3]; Alejandro Lemor, M.D. [4]

Wolff-Parkinson-White Syndrome Resident Survival Guide Microchapters
Overview
Causes
FIRE
Diagsis
Treatment Initial Long-term
Do's
Don'ts

Overview

Wolff-Parkinson-White (WPW) syndrome is a condition of pre-excitation of the ventricles of the heart due to the presence of an accessory pathway known as the Bundle of Kent through which the electrical impulses bypass the AV node. The difference between WPW pattern and WPW syndrome is that WPW pattern is characterized by the presence of characteristic ECG findings, such as a short PR interval and a delta wave, whereas WPW syndrome is the occurrence of tachycardia with or without associated symptoms in a subject with existing WPW pattern. The treatment of WPW syndrome is targeted towards the restoration of the sinus rhythm, usually by the administration of either ibutilide or procainamide. The most common type of arrhythmia in WPW syndrome is AV reentrant tachycardia. Atrial fibrillation in a patient with WPW is life threatening and should be managed urgently. Atrial fibrillation in a patient with WPW should be suspected when there is ECG findings suggestive of atrial fibrillation in the context of a heart rate higher than 220 beats per minute.

Causes

Life Threatening Causes

Wolff-Parkinson-White syndrome can be a life-threatening condition and must be treated as such irrespective of the underlying cause.

Common Causes

• Congenital

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
Boxes in red signify that an urgent management is needed.

Abbreviations: AF: atrial fibrillation; AVRT: AV reentrant tachycardia; BP: blood pressure; ECG: electrocardiography; HF: heart failure; LVH: left ventricular hypertrophy; WPW: Wolff-Parkinson-White pattern

Identify cardinal findings that increase the pretest probability of Wolff-Parkinson-White syndrome ❑ Baseline ECG findings suggestive of WPW pattern (pre-excitation) ❑ PR interval (<120 ms) ❑ Delta wave     AND ❑ Tachyarrhythmia ECG findings suggestive of orthodromic AVRT ❑ Ventricular rate usually 200–300 bpm ❑ Regular, narrow QRS complex (usually <120 ms unless pre-existing bundle branch block or aberrant conduction) ❑ P waves may be buried in the QRS or retrograde ❑ Delta wave may be lost during NSR in case of participating concealed bypass tract ECG findings suggestive of antidromic AVRT ❑ Ventricular rate usually 200–300 bpm ❑ Regular, wide QRS complex ❑ Delta wave is observed during NSR ECG findings suggestive of AF with WPW ❑ Ventricular rate usually >200 bpm ❑ Irregularly irregular, wide QRS complex with varying morphology ❑ Absence of P waves

Does the patient have any of the following findings that require urgent cardioversion? ❑ Hemodynamic instability ❑ Hypotension ❑ Cold extremities ❑ Peripheral cyanosis ❑ Mottling ❑ Altered mental status ❑ Chest discomfort suggestive of ischemia ❑ Decompensated heart failure

YES

NO

Perform electrical cardioversion

Continue with the complete diagnostic approach below

❑ Irregular wide QRS complex ❑ Unsynchronized, biphasic 120–200 J OR ❑ Unsynchronized, monophasic 360 J ❑ Irregular narrow QRS complex ❑ Synchronized, biphasic 120–200 J OR ❑ Synchronized, monophasic 200 J ❑ Regular wide QRS complex ❑ Synchronized, biphasic or monophasic 100 J ❑ Regular narrow QRS complex ❑ Synchronized, biphasic or monophasic 50–100 J

After stabilizing the patient, continue with the complete diagnostic approach below

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.

Abbreviations: AF: atrial fibrillation; AVRT: AV reentrant tachycardia; BP: blood pressure; ECG: electrocardiography; HF: heart failure; LVH: left ventricular hypertrophy

Characterize the symptoms: ❑ Asymptomatic ❑ Palpitations ❑ Dyspnea ❑ Fatigue ❑ Chest discomfort ❑ Lightheadedness ❑ Polyuria Characterize the timing of the symptoms: ❑ Onset ❑ First episode ❑ Recurrent ❑ Duration ❑ Frequency ❑ Termination of the episode ❑ Spontaneous ❑ Medication use ❑ Not terminated

Identify possible triggers: ❑ Infection ❑ Caffeine ❑ Alcohol ❑ Nicotine ❑ Congenital heart disease ❑ Congestive heart failure ❑ Valvular disease ❑ Hypovolemia ❑ Acidosis ❑ Hyperthyroidism ❑ Hypoxia ❑ Anxiety ❑ Hypokalemia ❑ Hyperkalemia ❑ Hypoglycemia ❑ Hypothermia ❑ Toxins ❑ Stress ❑ Pulmonary embolism ❑ Coronary thrombosis ❑ Trauma

Examine the patient: Appearance of the patient ❑ Cool and diaphoretic Vitals ❑ Heart rate ❑ Tachycardia (150-250 beats per minute) ❑ Rhythm ❑ Regular (most of the cases) ❑ Irregularly irregular (suggestive of AF) ❑ Blood pressure ❑ Hypotension ❑ Normal BP Cardiovascular ❑ Normal heart examination in most cases ❑ Tricuspid regurgitation characterized by a holosystolic murmur heard best along the left lower sternal border (suggestive of Ebstein's anomaly) ❑ S4 (suggestive of LVH) Respiratory ❑ Rales (suggestive of HF)

Order studies: ❑ ECG ❑ Echocardiography screening for: ❑ Hypertrophic cardiomyopathy ❑ Ebstein's anomaly of the tricuspid valve

WPW with AF ❑ Suspect when AF appears with heart rates of 220 to 360 ❑ Irregularly irregular, wide QRS complex with varying morphology ❑ Absence of P waves

Orthodromic AVRT ❑ Ventricular rate usually 200–300 bpm ❑ Regular, narrow QRS complex (usually <120 ms unless pre-existing bundle branch block or aberrant conduction) ❑ P waves may be buried in the QRS or retrograde ❑ Delta wave may be lost during NSR in case of participating concealed bypass tract

Antidromic AVRT ❑ Ventricular rate usually 200–300 bpm ❑ Regular, wide QRS complex ❑ Delta wave is observed during NSR

Treatment

Initial Treatment

Shown below is an algorithm summarizing the initial approach to Wolff-Parkinson-White syndrome according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.

Does the patient have any of the following findings that require urgent cardioversion? ❑ Hemodynamic instability ❑ Hypotension ❑ Cold extremities ❑ Peripheral cyanosis ❑ Mottling ❑ Altered mental status ❑ Chest discomfort suggestive of ischemia ❑ Decompensated heart failure

Yes

No

❑ Direct current cardioversion (Urgent) Check FIRE for details

What is the type of tachycardia according to the ECG findings?

WPW + AF (Stable)

Orthodromic AVRT (Stable)

Antidromic AVRT (Stable)

Avoid the use of AV node blocking agents such as digoxin, calcium channel blockers, beta blockers and adenosine. ❑ Administer procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 25-50 mg/min every 5 minutes (Class I, Level of Evidence C) ❑ Administer until the arrhythmia is suppressed or until 500 mg has been administered ❑ Wait 10 minutes or longer to administer new dosage Contraindications: third degree AV block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes OR ❑ Administer ibutilide 1 mg IV infusion over 10 minutes (Class I, Level of Evidence C) ❑ Repeat the dosage if the tachycardia continues Contraindications: hypersensitivity to ibutilide or any component of the formulation, QTc >440 msec OR ❑ Administer flecainide 50 mg every 12 hours (Class IIa, Level of Evidence B) ❑ Increase 50mg BID every four days until efficacy is achieved ❑ Maximum dose recommended for SVT is 300 mg/day Contraindications: pre-existing second degree AV block or third degree AV block , right bundle branch block associated with a left hemiblock unless a pacemaker is present, cardiogenic shock, hypersensitivity to the drug

❑ Use vagal maneuvers (Class I, Level of Evidence B) ❑ Carotid sinus massage ❑ Valsalva maneuver If not effective initiate IV AV nodal blocking agent ❑ Administer adenosine 6 mg IV (bolus) (Class I, Level of Evidence A) ❑ If initial dose is not effective, administer a second dose of 12 mg, repeated a second time if required Contraindications: second degree AV block or third degree AV block unless a pacemaker is present If not effective ❑ Administer verapamil 5 to 10 mg (0.075 to 0.15 mg/kg body weight) IV boluses of over 2 minutes (Class I, Level of Evidence A) ❑ Give 30% of the dose in case of hepatic impairment ❑ Monitor for prolonged PR interval in case of renal impairment Contraindications: severe left ventricular dysfunction, hypotension or cardiogenic shock If not effective ❑ Administer procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 25-50 mg/min every 5 minutes (Class I, Level of Evidence B) ❑ Give until the arrhythmia is suppressed or up to 500 mg ❑ Wait 10 minutes or longer to administer new dosage ❑ Dosage should be adjusted for the individual patient in case of renal impairment Contraindications: third degree AV block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes

Avoid the use of AV node blocking agents such as digoxin, calcium channel blockers, beta blockers and adenosine. ❑ Administer procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 25-50 mg/min every 5 minutes (Class I, Level of Evidence B) ❑ Give until the arrhythmia is suppressed or until 500 mg has been administered ❑ Wait 10 minutes or longer to administer new dosage Contraindications: third degree AV block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes OR ❑ Administer ibutilide 1 mg IV infusion over 10 minutes (Class I, Level of Evidence B) ❑ Repeat the dosage if the tachycardia continues Contraindications: hypersensitivity to ibutilide or any component of the formulation, QTc >440 msec OR ❑ Administer flecainide 50 mg every 12 hours ❑ Increase 50mg BID every four days until efficacy is achieved ❑ Maximum dose recommended for SVT is 300 mg/day Contraindications: pre-existing second degree AV block or third degree AV block , right bundle branch block associated with a left hemiblock unless a pacemaker is present, cardiogenic shock, hypersensitivity to the drug

Long-Term Treatment

Shown below is an algorithm summarizing the long-term treatment of Wolff-Parkinson-White syndrome.

Does the patient with pre-excitation have symptomatic arrhythmia?

Yes

No

Is the arrhythmia poorly tolerated, OR is atrial fibrillation with rapid conduction present?

❑ No treatment (Class I, Level of Evidence C) OR ❑ Catheter ablation (Class IIa, Level of Evidence B)

Yes

No

❑ Catheter ablation (Class I, Level of Evidence B)

❑ Catheter ablation (Class I, Level of Evidence B) OR ❑ Class I C antiarrhythmic agents such as: flecainide, propafenone (Class IIa, Level of Evidence C) OR ❑ Sotalol, amiodarone or beta blockers (Class IIa, Level of Evidence C) Avoid AV blocking agents such as: digoxin, verapamil, dialtizem (Class III, Level of Evidence C)

Do's

• Perform catheter ablation of the accessory pathway if possible (Class I, Level of evidence B).
• Consider propafenone over flecainide for the prevention of recurrence of orthodromic AVRT because propafenone it has also a mild beta blocking activity.
• Schedule exercise stress test and electrophysiology tests for the sudden cardiac death stratification (Class IIa, Level of evidence B).
• Consider catheter ablation in asymptomatic patients with structural heart disease (Class IIb, Level of evidence C).
• Administer IV procainamide (Class I, Level of evidence C), ibutilide (Class I, Level of evidence C) or flecainide (Class IIa, Level of evidence B) among WPW syndrome patients who present with atrial fibrillation . Intravenous quinidine, procainamide, disopyramide, ibutilide, or amiodarone can also be considered (Class IIb, Level of evidence B).

Don'ts

• Don't administer AV blocking agents in patients with WPW and antidromic AVRT as it will promote conduction down the accessory pathway (Class III, Level of evidence C).
• Don't administer AV blocking agents in patients with WPW and AF (Class III, Level of evidence B).
  
• Don't administer AV blocking agents (such as digoxin, verapamil or diltiazem) in the chronic treatment of WPW syndrome to prevent the recurrence of tachycardia (Class III, Level of evidence B).
  

References

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