What happens in Lown-Ganong-Levine syndrome regarding electrical impulses?

What happens in Lown-Ganong-Levine syndrome regarding electrical impulses?

• A. Impulses are delayed significantly
• B. Impulses sent directly to the bundle of His
• C. Impulses are completely interrupted
• D. Impulses do not affect heart rhythm

Answer: (B)

In Lown-Ganong-Levine syndrome, the primary characteristic is that electrical impulses are conducted directly from the atria to the ventricles via an accessory pathway that bypasses the normal delay in the AV node. This results in a shorter-than-normal PR interval on an electrocardiogram (ECG), as the impulses reach the ventricles more quickly than they would through the standard conduction pathway. The presence of this accessory conduction pathway allows the impulses to travel more rapidly, which can lead to episodes of paroxysmal supraventricular tachycardia.

This is distinct from the options regarding delayed impulses, complete interruption of impulses, or impulses having no effect on heart rhythm, as these do not accurately describe the underlying mechanism of Lown-Ganong-Levine syndrome. The focus is on the alteration of the conduction pathway that enables quicker transmission of electrical impulses, which contributes to the abnormal heart rhythms associated with the syndrome.