Wolff-Parkinson-White Syndrome - ECG
The Wolff-Parkinson-White syndrome (WPW syndrome) is an abnormality that is caused by an extra connection transmitting electric impulses between the atria and ventricles (so-called bundle of Kent). Normal transmission of the electric impulses from atria to ventricles is possible only through the so-called AV node.
The ECG curves have a short PQ interval (below 120 ms) and QRS complexes begin with a delta wave. This is due to a faster transmission of signals to the ventricles. In addition, the patients may experience recurring bouts of regular supraventricular tachycardia (AVRT) when a pathological loop is formed. This loop has usually this mechanism of signal transmission: atrium -> AV node -> ventricles -> the bundle of Kent -> atrium.
Detail of the P wave and QRS complex including the delta wave in WPW syndrome This is an ECG with WPW syndrome. On the first sight it is not well seen but on closer look we can see P waves in a very short distance from QRS complexes containing the delta waves.
Conclusion: The calm form of the WPW syndrome has no manifestations but the paroxysms of supraventricular tachycardia are associated with palpitations and syncope. The patients with WPW syndrome have a higher risk of sudden death compared to the general population. The risk is due to more frequent ventricular fibrillation.
Acute AVRT regular supraventricular tachycardia developed on the basis of WPW syndrome can be solved by anti-arrhythmic medication or electrical cardioversion. The WPW syndrome can be finally solved by a catheter radiofrequency ablation of the bundle of Kent.