Which of the following is classified as an irregular rhythm?

Which of the following is classified as an irregular rhythm?

• A. Wandering pacemaker
• B. Sinus bradycardia
• C. Ventricular tachycardia
• D. First-degree AV block

Answer: (A)

The wandering pacemaker is characterized by an irregular rhythm due to the variation in the site of impulse generation in the atria. This condition occurs when the dominant pacemaker shifts from the sinoatrial (SA) node to other areas of the atria. As a result, the P waves in the electrocardiogram (ECG) change morphology, and the intervals between the heartbeats can be inconsistent, leading to an irregularly irregular rhythm. This variability contributes to the diagnosis of wandering pacemaker, making it a classic example of an irregular rhythm.

In contrast, sinus bradycardia presents as a regular rhythm albeit at a slower rate, while ventricular tachycardia typically demonstrates a consistent, rapid heart rate. First-degree AV block involves a prolongation of the PR interval but still maintains a regular rhythm throughout. Hence, wandering pacemaker stands out as the primary example of an irregular rhythm due to its unique characteristics.