Abnormal Heart Rhythm

Wolff-Parkinson White (WPW) Syndrome

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Wolff-Parkinson White (WPW) syndrome is an extra electrical pathway in the heart, which is an abnormal bridge of heart muscle fibers that connects the upper chambers of the heart to the lower chambers, called the ventricles. This extra pathway may allow electrical impulses to travel rapidly in the heart causing an abnormally fast heartbeat, a form of supraventricular tachycardia (SVT). The extra electrical pathway may be seen on an electrocardiogram (ECG), causing an abnormal pattern known as a delta wave. In rare cases, the heart rhythm can be extremely rapid and potentially dangerous.

WPW Sinus Rhythm

In this diagram, the extra connection is shown during normal sinus rhythm, or the normal transmission of impulses through the heart.

WPW Orthodromic Reciprocating Tachycardia-Common

In this diagram, the electrical impulse flows down the normal atrioventricular (AV) node from the atrium to the ventricle, and then returns back to the atrium via the extra pathway, which acts as a "short circuit" perpetuating the arrhythmia.

The "normal" number of heartbeats per minute, called pulse rate varies with age. The heart beats about 140 times a minute in a newborn, compared to 70 times a minute in an older child at rest. Heart rate is not constant, changing in response to many factors, such as activity, fever and fear. In WPW -- when the heart beats too quickly, up to 280 beats per minute -- the heart cannot fill completely with blood, preventing the body from receiving the blood volume it needs to function properly.

Wolff-Parkinson White (WPW) may cause the following symptoms:

• Palpitations, which can be skipping, fluttering or pounding in the chest
• Fatigue
• Chest pressure or pain
• Shortness of breath
• Fainting, also known as syncope, or near-syncope
• Lightheadedness or dizziness

It is important to note that during an episode of WPW, children may not know how to describe what they are feeling. They may have trouble keeping up with other children or realize they are having "spells" and want to sit down and rest. Sometimes, children do not experience any symptoms at all.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007