What defines Lown-Ganong-Levine syndrome?

What defines Lown-Ganong-Levine syndrome?

• A. Bypass of the AV node by the James tract
• B. Increased interval between impulses
• C. Normal AV conduction pathway function
• D. Absence of any conduction anomalies

Answer: (A)

Lown-Ganong-Levine syndrome is characterized by a bypass tract that allows electrical impulses to travel from the atria to the ventricles, circumventing the normal conduction pathway through the atrioventricular (AV) node. This bypass tract, known as the James tract, can lead to a reentrant tachycardia due to the alternative route for impulse conduction.

In this syndrome, the conduction through the AV node is modified, often resulting in a shorter PR interval on an EKG but normal QRS duration, distinguishing it from other conditions like Wolff-Parkinson-White syndrome, where there is an accessory pathway leading to a delta wave and wider QRS complexes.

Understanding this pathway's role in Lown-Ganong-Levine syndrome is crucial for EKG interpretation and recognizing the potential for arrhythmias stemming from this abnormal conduction mechanism.