Which rhythm is characterized by irregular atrial rhythm with P waves varying in morphology and a slower ventricular rate, typical of wandering atrial conduction patterns?

• A. Wandering Atrial Pacemaker
• B. Multiform Atrial Tachycardia
• C. Atrial Fibrillation
• D. Atrial Flutter

Answer: (A)

Wandering atrial pacemaker occurs when the impulse origin shifts among several atrial sites rather than staying at the SA node. This causes P waves to vary in morphology from beat to beat because each atrial focus produces a differently shaped P wave. The ventricular rate tends to be slower or normal, and the rhythm is irregular because the atrial firing site keeps changing. This pattern fits the description of irregular atrial rhythm with changing P wave shapes and a slower rate, reflecting wandering conduction through the atria.

This helps distinguish it from other rhythms: a faster, irregular tachycardia with multiple P morphologies would point to multiform atrial tachycardia; atrial fibrillation shows no distinct P waves and a chaotic, irregular baseline; atrial flutter produces a sawtooth flutter pattern with typically a faster rate unless there is high-grade block. The key is the combination of irregular rhythm with variable P wave morphology and a relatively slow ventricular response.