Understanding Wolff-Parkinson-White Syndrome

A young adult male is bought to the emergency room due to signs of distress while playing basketball. Sound familiar? It might. You may even think of some cardiac conditions that might be associated with this scenario. But, only certain diagnostic measures can determine the actual cause of the problem. The Portland Tribune covered a story in which the 2006 NBA second draft pick, LaMarcus Aldridge had this experience. The forward for the Portland Trail Blazers was diagnosed with Wolff-Parkinson-White Syndrome (WPW) after experiencing a rapid heartbeat which forced him to leave a game against the L.A. Clippers.

Wolff-Parkinson-White is an abnormality in cardiac rhythm. However, to appreciate the problem in WPW or any heart condition it is important to have an understanding of how the heart works. According to the New York-Presbyterian Hospital, the heart conducts electrical signals from the sinoatrial (SA) node which is located in the upper right chamber of the heart. The SA node has automaticity, meaning it independently sets the rhythm for the heart. The sinoatrial node has specialized cells making it the heart's natural pacemaker. The electrical impulse then moves to the right and left atria resulting in a simultaneous contraction. The impulse will move toward the atrioventricular (AV) node. The AV node is located at the junction between the atria and ventricles, which are the upper and lower heart chambers respectively. The atrioventricular nodes transmit the signal down specialized tissue found within the ventricular septum and separates into a right and left bundle branch. The impulse is conducted across the ventricles resulting in the simultaneous contraction and release of oxygen-rich blood to the body.

In Wolff-Parkinson-White Syndrome, individuals have an abnormal connection known as the accessory pathway. The pathway develops as a result of incorrect signals during fetal heart development. It connects the atria and ventricles providing a second route for electrical impulses. This extra pathway is dangerous because it conducts impulses faster than the normal pathway. Although the problem occurs during fetal development, individuals do not present with symptoms until adolescence or adulthood. While some may remain asymptomatic, most experience rapid heart rates, lightheadedness, dizziness and fainting. These patients will undergo an electrocardiogram (ECG) which will pinpoint WPW as the cause for their symptoms.

The American Heart Association reports that while medications can be prescribed to control WPW's rapid heart rates, most people have chosen a one time procedure called catheter ablation. Catheter ablation is the same procedure Aldridge underwent and usually replaces the need for patients to continue taking medication for this condition. Not all patients are considered for this procedure. Cardiac surgeons determine candidates for catheter ablation by taking factors such as symptomatic severity, frequency and risk for more incidents of tachycardia into consideration. The procedure involves positioning a catheter in the bundle of Kent and using radiofrequency energy to destroy the accessory path. Catheter ablation remains the most common method for treating WPW.

Sources: Kerry Eggers, "Caution guides Aldridge's care", The Portland Tribune, "Wolff-Parkinson-White Syndrome", New York-Presbyterian Hospital, "Wolff-Parkinson-White Syndrome", American Heart Association