Identify the false statement about the bundle of Kent

Correct Answer: A. It is slower than AV nodal pathway

The bundle of Kent is an accessory pathway in Wolff-Parkinson-White (WPW) syndrome that conducts impulses faster than the normal AV nodal pathway. This is the fundamental pathophysiological feature of WPW. The AV node has inherent slow conduction velocity (_{0.05 m/s) due to small-diameter cells and decremental conduction properties, whereas the bundle of Kent is composed of ventricular muscle fibers with rapid conduction velocity (}1 m/s), similar to normal ventricular tissue. Therefore, stating that the bundle of Kent is "slower than AV nodal pathway" is false—it is actually faster. This faster conduction through the accessory pathway is what causes the characteristic ECG findings in WPW: a short PR interval (because the impulse bypasses the AV nodal delay) and a prolonged QRS duration (due to the delta wave, representing early ventricular depolarization from the accessory pathway insertion site). The clinical significance in Indian practice is that WPW patients are at risk for atrioventricular reentrant tachycardia (AVRT), which can degenerate into atrial fibrillation with rapid ventricular response—a potentially life-threatening arrhythmia. Recognition of WPW on ECG is critical for risk stratification and management decisions regarding catheter ablation versus medical therapy.

Why the other options are wrong

B. Leads to prolonged QRS duration — This statement is true, not false. The bundle of Kent causes early ventricular depolarization at its insertion site, producing the characteristic delta wave (slurred upstroke of QRS). This delta wave merges with normal AV nodal conduction, resulting in a prolonged QRS complex (>0.12 s). This is a hallmark ECG finding in WPW and is correctly associated with the accessory pathway. C. Leads to short PR interval — This statement is true, not false. Because the bundle of Kent conducts faster than the AV node, the atrial impulse reaches the ventricle earlier, bypassing the normal AV nodal delay. This results in a PR interval <0.12 s (short PR interval), which is a defining ECG criterion for WPW. This is a well-established pathophysiological consequence of accessory pathway conduction. D. It is faster than AV nodal pathway — This statement is true, not false. The bundle of Kent has conduction velocity of _{1 m/s (similar to ventricular muscle), whereas the AV node conducts at} 0.05 m/s. This faster conduction is the defining feature of the accessory pathway in WPW. The question asks for the false statement, so this correct physiological fact cannot be the answer.

High-Yield Facts

Mnemonics

WPW ECG Triad Short PR + Delta Wave + Prolonged QRS = Bundle of Kent is FAST (not slow). Remember: Kent is a speedway, not a slowway. AV Node vs Kent AV Node = Slow (0.05 m/s, decremental conduction). Kent = Fast (1 m/s, muscle fiber conduction). Think: 'Node is a bottleneck, Kent is a bypass'.

NBE Trap

NBE pairs "bundle of Kent" with "slower conduction" to trap students who confuse the accessory pathway with the AV node itself. The question specifically asks for the false statement, and many students reflexively associate "accessory pathway" with "abnormal/slow" rather than recognizing that WPW pathophysiology is driven by faster conduction through Kent.

Clinical Pearl

In Indian emergency departments, a young patient presenting with palpitations and an ECG showing short PR interval + delta wave should immediately raise suspicion for WPW-related AVRT. Catheter ablation of the accessory pathway is now the gold standard definitive treatment in Indian tertiary centers, offering cure rates >95% and eliminating the risk of sudden cardiac death from rapid AF conduction.

_Reference: Harrison Ch. 226 (Arrhythmias); Guyton & Hall Ch. 12 (Cardiac Electrophysiology); KD Tripathi Ch. 8 (Cardiac Arrhythmias)_