Advanced Cardiovascular Life Support (ACLS) Practice Exam

Which arrhythmia can present similarly to atrial flutter but is usually considered more chaotic?

1. Fine ventricular fibrillation

2. Monomorphic ventricular tachycardia

3. Atrial flutter

4. Second degree AV block Type 2

The correct answer is: Fine ventricular fibrillation

The correct answer is fine ventricular fibrillation. Fine ventricular fibrillation is characterized by rapid, unorganized electrical activity in the ventricles, causing the heart to quiver instead of pumping effectively, which leads to ineffective circulation. This arrhythmia can present with a waveform that may appear somewhat similar to atrial flutter due to the presence of rapid oscillations; however, it is significantly more chaotic and disorganized than atrial flutter. Atrial flutter typically involves a more organized electrical rhythm and results in a consistent appearance on an electrocardiogram (ECG) characterized by "sawtooth" waves, particularly in the inferior leads. In contrast, fine ventricular fibrillation lacks this organization and is much more erratic, making it critical to differentiate it from other arrhythmias, including atrial flutter, because its management differs significantly, often requiring immediate defibrillation. The other responses either do not share the characteristic chaotic presentation or are not arrhythmias that are typically confused with atrial flutter. Monomorphic ventricular tachycardia has a more regular pattern, and second-degree AV block type 2 presents with a distinct pattern of paused beats, which is not similar to the rapid oscillations seen in fine ventricular fibrillation.