Which of the following is a characteristic of atrial fibrillation?

Which of the following is a characteristic of atrial fibrillation?

• A. Presence of P waves
• B. Regular ventricular rhythm
• C. Irregular ventricular rhythm
• D. Consistent atrial spikes

Answer: (C)

Atrial fibrillation is characterized by an irregular ventricular rhythm. In this condition, the electrical impulses originating in the atria are disorganized, leading to ineffective atrial contraction and causing the ventricles to respond in an irregular fashion. This results in an unpredictable and chaotic heart rhythm, which can be visualized on an EKG as varying intervals between EKG complexes, often described as "irregularly irregular."

In contrast, other characteristics that might be presented in the choices, such as the presence of distinct P waves or consistent atrial spikes, are not indicative of atrial fibrillation. In this condition, P waves are typically absent or replaced by fibrillatory waves, and the rhythm is anything but regular, thus supporting why the irregular ventricular rhythm is the correct characteristic to identify atrial fibrillation.