Wolff-Parkinson-White syndrome resident survival guide

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

Wolff-Parkinson-White Syndrome Resident Survival Guide Microchapters
Overview
Causes
Diagnosis
Treatment Initial Treatment WPW with AF Long-term Treatment
Do's
Don'ts

Overview

Wolff-Parkinson-White syndrome (WPW) it is a condition of pre-excitation of the ventricles of the heart due to an accessory pathway known as the Bundle of Kent. The diagnosis is made when a patient with pre-existing WPW pattern develops an arrhythmia which involves the accessory pathway. The difference between WPW pattern and WPW syndrome is that, the WPW pattern caracterices by the appearance of a delta wave on the EKG and the WPW syndrome appears when arrhytmya symtoms develope. The treatment is focused on recovering sinus rhythm, usually acquired with ibutilide or procainamide. Atrial fibrillation in a patient with WPW is life threatening and should be managed urgently and should be suspected when the heart rate is above 220 bpm.

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

• The presence of the accessorry pathway is a congenital anomaly
• Atrial fibrillation

Diagnosis

Shown below is an 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 ventricle 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: ❑ Tachycardic (150-250 beats per minute (bpm)) ❑ Rhythm: ❑ Regular (most of the cases) ❑ Irregular (suggestive of AF) ❑ Blood pressure ❑ hypotensive ❑ Normal BP Cardiovascular ❑ Normal heart examination in most cases ❑ Tricuspid regurgitation 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

Orthodromic AVRT The impulse travels from the atrium to the ventricle through the AV node and returns to the atrium through the accessory pathway. 90-95% of WPW EKG findings: ❑ Narrow QRS complexes ❑ Ventricular rate between 150-250 bpm (or more) ❑ Usually regular ❑ PR interval less than one half of the tachycardia RR interval

Antidromic AVRT The impulse travels from the atrium to the ventricle through the accessory pathway and from the ventricle to the atrium through the AV node. Less than 10% of WPW EKG findings: ❑ Wide QRS complexes ❑ Ventricular rate between 150-250 bpm (or more) ❑ Usually regular ❑ PR interval more than one half of the tachycardia RR interval

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.

Determine if the patient has any unstable signs or symptoms ❑ Chest pain ❑ Congestive heart failure ❑ Hypotension ❑ Loss of consciousness ❑ Seizures

Stable patient

Unstable patient

❑ Assess the ECG

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

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 given as a rapid intravenous 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

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.

Determine if the patient has any unstable signs or symptoms ❑ Chest pain ❑ Congestive heart failure ❑ Hypotension ❑ Loss of consciousness ❑ Seizures

Stable patient

Unstable patient

❑ 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

❑ Urgent electric cardioversion (class I, level of evidence B) ❑ Catheter ablation (class I, level of evidence B)

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) ❑ Vagal maneuvers (class I, level of evidence B) ❑ Catheter ablation (class IIa, level of evidence B) ❑ Avoid the use of digoxin (class III, level of evidence C)

Recurrent episodes ❑ Catheter ablation (class I, level of evidence B) ❑ Class IC antiarrhythmic agents such as: flecainide, propafenone 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) ❑ 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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