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.; Hilda Mahmoudi M.D., M.P.H.^[2]; Alejandro Lemor, M.D. [3]

Synonyms and keywords: WPW syndrome; WPW pattern

Wolff-Parkinson-White Syndrome Resident Survival Guide Microchapters
Overview
Causes
FIRE
Diagnosis
Treatment Initial WPW with AF 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

The aim of FIRE is to identify urgent conditions that require immediate intervention in suspected Wolff-Parkinson-White syndrome based on the 2003 ACC/AHA/ESC and the ACLS guidelines.
Boxes in red signify that an urgent management is needed.

Identify cardinal findings that increase the pretest probability of Wolff-Parkinson-White syndrome ❑ Palpitsations ❑ Chest discomfort ❑ Regular rhythm ❑ Rate over 150 bpm ❑ Orthodrome AVRT: narrow QRS complex preceded by a p-wave ❑ Antidrome AVRT: wide QRS complex followed by a retrograde p-wave

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

❑ Assess airway, breathing, and circulation (ABC)

Continue with the diagnostic approach below

❑ Perform urgent sychronized electrical cardioversion ❑ Narrow regular rhythm: 50-100 Joules ❑ Narrow irregular rhythm: 120-200 Joules biphasic or 200 Joules monophasic ❑ Wide regular rhythm: 100 Joules ❑ Wide irregular rhythm: defibrillation

❑ Administer oxygen if necessary

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

Complete Diagnostic Approach

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

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

Characterize the symptoms: ❑ Asymptomatic ❑ Palpitations ❑ Dyspnea ❑ Fatigue ❑ Chest discomfort ❑ Lightheadedness ❑ Polyuria Characterize the timing of the symptoms: ❑ Onset ❑ Sudden ❑ Duration ❑ Frequency ❑ First episode ❑ Recurrent episodes

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 (bpm)) ❑ Rhythm ❑ Regular (most of the cases) ❑ 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 searching for: ❑ Hypertrophic cardiomyopathy ❑ Ebstein's anomaly of the tricuspid valve

WPW with AF Suspect when AF appears with heart rates of 220 to 360. EKG findings ❑ Irregularly irregular rhythm ❑ Rapid ventricular response (over 220 bpm) ❑ Wide QRS complex ❑ No P wave

Orthodromic AVRT The anterograde conduction (from the atrium to the ventricle) passes through the AV node and the retrograde conduction (from the ventricle to the atrium) passes through the accessory pathway. It apprears in 90 to 95% of WPW. EKG findings: ❑ Regular rhythm ❑ Narrow QRS complexes ❑ P wave before QRS

Antidromic AVRT The anterograde conduction (from the atrium to the ventricle) passes through the accessory pathway and the retrograde conduction (from the ventricle to the atrium) passes through the AV node. It apprears in less than 10% of WPW. EKG findings: ❑ Regular rhythm ❑ Wide QRS complexes ❑ P wave after QRS

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

No

Yes

❑ Urgent electrical cardioversion (Class I, Level of Evidence C) And/Or ❑ Catheter ablation (Class I, Level of Evidence B)

❑ Assess the ECG

Orthodromic AVRT

Antidromic AVRT

❑ 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- or third-degree A-V block (except in patients with a functioning artificial pacemaker 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 (systolic pressure less than 90 mm Hg) or cardiogenic shock If not effective ❑ Administer procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 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: complete heart block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes

Avoid the use of av blocking agents such as digoxin, verapamil or diltiazem ❑ 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 procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 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: complete heart block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes Or ❑ Administer adenosine 6 mg IV (bolus) ❑ If initial dose is not effective, administer a second dose of 12 mg, repeated a second time if required ❑ Should be used with caution because may produce AF Contraindications: second- or third-degree A-V block (except in patients with a functioning artificial pacemaker

Wolff-Parkinson-White Syndrome with Atrial Fibrillation

Atrial fibrillation in a patient with WPW should be suspected when the the heart rate of a patient with WPW is between 220 and 360 bpm. Shown below is an algorithm summarizing the managment of Wolff-Parkinson-White syndrome with atrial fibrillation according to the ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation.

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

No

Yes

❑ Urgent electric cardioversion (Class I, Level of Evidence B) And/Or ❑ Catheter ablation (Class I, Level of Evidence B)

Avoid the use of AV node blocking agents such as digoxin, verapamil or diltizem ❑ Restore sinus rhythm (Class I, Level of Evidence C) ❑ 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 procainamide 100 mg infusion diluted to 100mg/ml at a rate of 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 to administer new dosage Contraindications: complete heart block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes Or ❑ Administer amiodarone 15 mg/min in 10 minutes (Class IIb, Level of Evidence B) ❑ Then, 1mg/min for 6 hours ❑ Then 0.5 mg/min for 18 hours Contraindications: cardiogenic shock, severe sinus-node dysfunction

Long-Term Treatment

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

Long Term management

Single or infrequent episodes ❑ No treatment (Class I, Level of Evidence C) And ❑ Vagal maneuvers (Class I, Level of Evidence B) Or ❑ Single dose treatment (pill-in-the-pocket): verapamil, dialtizem or beta blockers (Class I, Level of Evidence B) Or ❑ Catheter ablation (Class IIa, Level of Evidence B) Or ❑ Sotalol or amiodarone (Class IIb, Level of Evidence B) Or ❑ Flecainide or propofenone (Class IIb, Level of Evidence C) ❑ Avoid AV blocking agents such as: digoxin, verapamil, dialtizem(Class III, Level of Evidence C)

Recurrent episodes ❑ Catheter ablation (Class I, Level of Evidence B) Or ❑ Class IC 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)

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

Do's

• Perform catheter ablation of the accessory pathway if possible (class I, level of evidence B).
• Electrical cardioversion can be performed in cases of WPW with AF with rapid ventricular response (class II, level of evidence A).
• In asymptomatic patients, either no intervention (class I, level of evidence C) or catheter ablation (class IIb, level of evidence B) could be performed.
  
• Prescribe propafenone over flecainide for the prevention of recurrence orthodromic AVRT as 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).

Don'ts

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

References

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