Wolff-Parkinson-White syndrome

Wolff-Parkinson-White Syndrome 

Definition

Wolff-Parkinson-White syndrome is an abnormality in the electrical functioning of the heart which may cause rapid heart rates. The abnormality affects the electrical signal between the atria and ventricles.

Description

Blood is circulated through the heart and body by a muscular pump and valve system involving the atria and ventricles. The right atrium receives oxygen-lacking blood returning to the heart from the body. The blood is passed from the right atrium into the right ventricle, which contracts and sends blood out to the pulmonary artery. The pulmonary artery sends the blood into the lungs, where carbon dioxide is removed, and fresh oxygen is added. The left atrium receives blood with oxygen from the lungs and passes this arterial blood to the left ventricle, where it is emptied into the aorta, the main artery of the heart.

These functions are directed by electrical signals within the heart. In patients afflicted with Wolff-Parkinson-White syndrome, an abnormal pathway exists that causes additional electrical signals to pass between the atria and ventricles, possibly causing rapid heart rate.

Causes and symptoms

Congenital heart disease may contribute to this and other arrhythmias. Ebstein's anomaly, a congenital heart defect that involves displacement of the tricuspid valve, located on the right side of the heart, is one known cause of Wolff-Parkinson-White syndrome. This anomaly allows blood to flow via the small hole to the other side of the heart. Often, there is no known cause for Wolff-Parkinson-White syndrome. Many people with the syndrome have no symptoms. On the other hand, some people experience temporary rapid heartbeat due to certain drugs, smoking, and anxiety.

Diagnosis

Electrocardiography (ECG) is used to diagnose Wolff-Parkinson-White syndrome, and other cardiac arrhythmias. A trained physician, normally a cardiologist, can recognize patterns of electrical conduction. With this syndrome, the extra pathway will show a pattern different from those of normal conduction. If no irregular patterns show on the ECG, the patient may be sent home with a 24-hour heart monitor, called a Holter monitor, which will help detect intermittent occurrences. Other studies, such as the cardiac electrophysiologic study (EPS), may be ordered to pinpoint the location of the accessory pathway, and to determine a course of treatment.

Treatment

Various drugs may be used to treat Wolff-Parkinson-White syndrome, as well as other cardiac arrhythmias. The purpose of these drugs is to slow the electrical signals and excitation of heart muscles. As some of these drugs may have side effects, including the rare production of new or more frequent arrhythmias, the patient should be carefully observed. Ablative therapies may be accomplished with radio-frequency or cardiac catheters to cut through the tissue which is causing the abnormal electrical signals.

At one time, only open heart surgery was used, but the procedure can be done now with local anesthesia in a special cardiac laboratory. In some cases, surgery may still be recommended to treat Wolff-Parkinson-White syndrome. Young people with this syndrome may be treated more successfully with surgery, rather than enduring a lifetime of drug treatments, or the possible threat of sudden cardiac death.

Alternative treatment

A provider may teach patients methods to help control heart rate. Relaxation techniques, acupuncture, botanical medicine, and homeopathy can all be helpful supportive therapies.

Prognosis

Most patients with this syndrome can lead normal lives, even with episodes of tachycardia. In many cases, the syndrome is secondary to the underlying congenital heart defect. However, Wolff-Parkinson-White syndrome can cause sudden cardiac arrest in certain instances.

Key terms

Ablative — Used to describe a procedure involving removal of a tissue or body part, or destruction of its funtion.

Arrhythmia — Irregular heart beat.

Electrocardiograph (ECG) — A test of a patient's heartbeat that involves placing leads, or detectors, on the patient's chest to record electrical impulses in the heart. The test will produce a strip, or picture record of the heart's electrical function.

Tachycardia — Rapid heart rate, defined as more than 100 beats per minute.

Prevention

If the syndrome is not due to congenital heart disease, the patient may try avoiding behaviors which lead to arrhythmia, such as elimination of caffeine, alcohol, cocaine, and smoking.

Resources

Organizations

American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300 or (800) 242-8721. inquire@heart.org http://www.americanheart.org.

National Heart, Lung and Blood Institute. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. http://www.nhlbi.nih.gov.

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Wolff-Parkinson-White syndrome (wlf-)

n.

An electrocardiographic pattern sometimes associated with paroxysmal tachycardia, characterized by a short P-R interval together with a prolonged QRS complex with a delta wave. Also called preexcitation syndrome, WPW syndrome.

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Wolff-Parkinson-White syndrome

[woo͡lf′ pär′kinsən-(h)wīt′]

Etymology: Louis Wolff, American physician, 1898-1972; John Parkinson, English cardiologist, 1885-1976; Paul Dudley White, American cardiologist, 1886-1973

a disorder of atrioventricular (AV) conduction involving an accessory pathway. This syndrome is often identified by a characteristic delta wave seen on an electrocardiogram at the beginning of the QRS complex. It is amenable to radiofrequency ablation. See also Lown-Ganong-Levine syndrome.

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Wolff-Parkinson-White syndrome

the association of paroxysmal tachycardia (or atrial fibrillation) and pre-excitation, in which the electrocardiogram displays a short P-R interval and a wide QRS complex which characteristically shows an early QRS vector (delta wave). Called also anomalous atrioventricular excitation. Occurs occasionally in dogs, horses and cats.

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Wolff-Parkinson-White syndrome

Preexcitation syndrome Cardiology A conduction disorder with ↑ susceptibility to supraventricular paroxysmal tachyarrhythmias, in which the sinoatrial impulse travels directly to the AV node or anomalously via Kent's bundle, which is more rapid, resulting in PVCs EKG Short PR interval–< 0.1 sec, a slur on the upstroke of the R or on the downstroke of an S wave or delta wave, prolonged QRS complex, often ST-T changes Management Cardioversion, procainamide, lidocaine or radiofrequency ablation of accessory AV pathway