Wolff-Parkinson-White Syndrome (WPW Syndrome) is a congenital cardiac anomaly that leads to disruption of the heart rhythm. WPW syndrome often occurs with other anomalies, both cardiac and noncardiac. Patients with Wolff-Parkinson-White Syndrome have extra conducting tissues, called accessory pathways, that connect the atria and the ventricles. Since cats with this anomaly may not have various signs, it is most often diagnosed based on electrocardiogram (ECG) findings.
The heart's natural timekeeper is a small mass of specialized cells called the sinus node. It iniates and maintains the heart's normal rhythm, which is referred to as normal sinus rhythm. However, the sinus node can malfunction and develop an abnormal rate or rhythm of electrical impulse initiation. Because all heart tissue not only propagates the normal rhythm of the heart, but is also capable of initiating a beat, any part of the heart muscle can interrupt the normal sinus rhythm, or even take over as the heart's pacemaker, setting off an abnormal heartbeat. When one of these events interrupts the heart's normal beat, either short-term or prolonged arrhythmias can occur.