When the pacemaker delivers ventricular pacing, the pacing spike is followed by a wide QRS complex, which looks similar to which of the following?
A)Left bundle branch block
B)Right bundle branch block
C)Atrial fibrillation
D)First-degree AV block

Question

Quizplus · Accepted Answer

The wide QRS complex seen after a ventricular pacing spike resembles a left bundle branch block pattern because the pacing impulse is being delivered directly to the ventricles rather than through the normal conduction pathway. This causes the ventricles to depolarize in an abnormal pattern. Right bundle branch block would not be a correct choice as it presents as a wide QRS complex with a characteristic QRS morphology different from left bundle branch block. Atrial fibrillation and first-degree AV block would not be correct choices as they are not associated with widened QRS complexes.

When the Pacemaker Delivers Ventricular Pacing, the Pacing Spike Is