ACCS Practice Exam 2026 – Complete Test Preparation Guide

Atrial fibrillation is characterized by a rapid and irregular heartbeat due to disorganized electrical signals in the atria. This arrhythmia leads to ineffective atrial contractions and can result in a decrease in cardiac output. In atrial fibrillation, the rate of contractions in the ventricles can vary widely, and typically, the irregularity is reflected in the pulse.

Because blood is not efficiently pumped from the atria to the ventricles, there is an increased risk of blood pooling, which can lead to thrombus formation and potential complications such as stroke. The rapid and uncontrolled rhythm causes the heart to beat more quickly, which can also reduce the time the heart spends in diastole, further compromising ventricular filling and ultimately reducing overall cardiac output.

In contrast, while atrial flutter is also an atrial arrhythmia and can likewise cause rapid heart rates, it tends to have a more organized electrical conduction. Ventricular tachycardia is a much more serious condition that arises from the ventricles and can lead to compromised cardiac output as well, but the specific focus here is on the atrial focus of the arrhythmia. Bradycardia, with its slower heart rates, does not align with the rapid heartbeat described in the question