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 Alavarado, MD

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

Overview

Wolff-Parkinson-White syndrome (WPW) its 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 patern in the ECG developes an arrythmia which involves the accessory pathway. The treatment is focused on recovering sinus rythm. Atrial fibrillation in a patient with WPW is life threatening and should be managed urgently.

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.

• Atrial fibrillation

Common Causes

• Atrial fibrillation

Diagnosis

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.

Abbreviations: AVRT: AV reentrant tachycardia; BP: Blood pressure; AF: Atrial fibrilation HF: Heart failure LVH: Left ventricle hypertension; ECG: Electrocardiography

Characterize the symptoms: ❑ Asymptomatic ❑ Palpitations ❑ Dyspnea ❑ Fatigue ❑ Chest discomfort ❑ Lightheadedness ❑ Polyuria Characterize the timing of the symptoms: ❑ Onset ❑ Duration ❑ Frequency

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: ❑ Rhytmic (most of the cases) ❑ Arrhythmic (suggestive of AF) ❑ Blood pressure: hypotensive or normal BP Cardiovascular ❑ Normal heart examination in most cases ❑ Tricuspid regurgitation murmur (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

Management

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 sign or symptom ❑ 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

Treatment ❑ 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 given as a rapid intravenous bolus (class I, level of evidence A) ❑ If initial dose not effective, administer a second dose of 12 mg, repeated a second time if required Contraindications: second- or third-degree A-V block, sinus node disease If not effective ❑ Administer verapamil, boluses of 5 mg to acumulate 15 mg. (class I, level of evidence A) Contraindications: hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock, patients with known hypersensitivity to verapamil hydrochloride If not effective ❑ Administer procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 50 mg per minute 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 Contraindications: complete heart block, lupus erythematosus, idiosyncratic hypersensitivity, torsades de pointes

Treatment ❑ Administer: ❑ Ibutilide IV infusion of 1 mg given 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 ❑ Procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 50 mg per minute every 5 minutes (class I, level of evidence B) ❑ Give untilln 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 ❑ Adenosine should be used with caution because may produce AF ❑ 6 mg given as a rapid intravenous bolus ❑ If initial dose not effective, administer a second dose of 12 mg, repeated a second time if required. Contraindications: second- or third-degree A-V block, sinus node disease

Long-term Management

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)

Prevention of recurrent AVRT ❑ Catheter ablation ❑ 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)

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.

Initial approach ❑ Control ventricular response ❑ If possible: terminate AF ❑ If possible: catheter ablation of the accessory pathway (class I, level of evidence B)

Stable patient

Unstable patient

❑ Restore sinus rythm (class I, level of evidence C) ❑ Ibutilide IV infusion of 1 mg given 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 ❑ Procainamide, 100 mg infusion diluted to 100mg/ml at a rate of 50 mg per minute 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 ❑ Amiodarone, loading dose 15mg/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 ❑ Avoid AV blocking agents (class III, level of evidence B), such as: ❑ Digoxin ❑ Nondihydropyridine calcium channel antagonists: verapamil, diltizem

❑ Urgent electric cardioversion (class I, level of evidence B) ❑ Catheter ablation (class I, 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 intervantion (class I, level of evidence C) or catheter ablation (class IIb, level of evidence B) could be performed.
❑ Prescribe propofenone over flecainide for the prevention of recurrence orthodromic AVRT as it has also a mild beta blocking activity.
❑ Schedule exccercise 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).

References

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