Wolff-Parkinson-White (WPW) syndrome is a very rare congenital heart disorder that causes abnormal heartbeat rhythms (arrhythmias) and faster than normal heartbeats (tachycardia). This occurs due to an abnormal alternate electrical pathway (accessory pathway) between the atrium and the ventricle of the heart. The extra electrical pathway is called a bypass tract as it bypasses the AV node and it could not control the heartbeat making it beat very fast.
WPW is a type of supraventricular tachycardia called atrioventricular reciprocating tachycardia (AVRT).
The disorder is usually not life-threatening, but can cause serious heart problems. That is why further evaluation is recommended before children with WPW pattern participate in high-intensity sports.
Cause of WPW syndrome
Although there is no exact cause known for the development of extra pathway but an abnormal gene is found to be the cause of WPW in a small percentage of people. It may be inherited in some cases. It is also associated with some forms of congenital heart disease, such as Ebstein’s anomaly.
Symptoms of Wolff-Parkinson-White (WPW) syndrome
Most of the person’s with WPF usually do not feel any fast heartbeat. Although the symptoms most often appear for the first time in the teenagers but people of all ages, including infants, can experience its symptoms. The symptoms may come as an episode of rapid heartbeat that may begin suddenly. The episode can occur during exercise or while at rest and may last for few seconds or several hours. It can be triggered by caffeine or other stimulants including alcohol.
The most commonly found symptoms of WPW syndrome include:
- Chest pain
- Chest tightness
- Shortness of breath
- Difficulty breathing
A person with WPW can have a heart rate of 160 to 220 beats per minute. They can also have atrial fibrillation or atrial flutter resulting in heartbeat to cross more than 250 to 300 times per minute. This may result in syncope or cause sudden death.
It can also trigger ventricular fibrillation that can be life-threatening, although this is extremely rare.
Symptoms of WPW syndrome in infants
- Rapid breathing
- Ashen color
- Poor feeding
- Evidence of congestive heart failure if the episode has been untreated for several hours
Physical findings of WPW syndrome
- Mostly normal cardiac examination
- During tachycardia, the patient is cool, diaphoretic, and hypotensive
- Pulmonary vascular congestion (during or following an SVT episode)
- Clinical features of associated cardiac defects like:
- Ebstein anomaly
- Hypertrophic cardiomyopathy
Diagnosis of WPW
WPW syndrome is usually discovered by chance during a heart exam for any other problem. A 12-lead electrocardiogram (ECG) is the best diagnostic tool for WPW syndrome. The classic ECG features include:
- A shortened PR interval
- A slurring and slow rise of the initial upstroke of the QRS complex (delta wave)
- A widened QRS complex (total duration >0.12 seconds)
- ST segment–T wave (repolarization) changes, generally directed opposite the major delta wave and QRS complex, reflecting altered depolarization
The ECG morphology in WPW syndrome varies widely and it is not easy to diagnose WPW syndrome. But the team of Tricog has achieved this rare success by diagnosing WPW syndrome in a 24 year old male patient with his ECG interpretation only.
Management of WPW syndrome
In almost 25 percent of people with WPW syndrome, symptoms disappear on their own. In the rest of persons, following techniques may manage the disorder:
- Vagal maneuvers like coughing, bearing down or putting an ice pack on face etc. to slow a rapid heartbeat.
- Medications like injection of an anti-arrhythmic medication.
- Cardioversion i.e. use of paddles or patches over chest to electrically shock heart and restore a normal rhythm.
- Radiofrequency catheter ablation to permanently correct the heart-rhythm problems.