Advanced Cardiovascular Life Support (ACLS) Practice Exam

Which type of ventricular rhythm shows chaotic electrical activity with no effective contractions?

1. Atrial flutter

2. Fine ventricular fibrillation

3. Normal sinus rhythm

4. Third degree AV block

The correct answer is: Fine ventricular fibrillation

The correct choice is the identification of fine ventricular fibrillation as the rhythm characterized by chaotic electrical activity accompanied by ineffective ventricular contractions. In fine ventricular fibrillation, the electrical signals in the ventricles become disorganized, leading to a lack of coordinated muscular contractions necessary to effectively pump blood. This results in an erratic electrical pattern on the ECG, which is visually chaotic and does not produce a palpable pulse or effective cardiac output. In contrast, atrial flutter features a more organized electrical activity with regular reentrant circuits in the atria, leading to increased atrial contractions but not chaotic activity at the ventricular level. Normal sinus rhythm signifies a healthy heart rhythm where signals are generated in a coordinated fashion from the sinus node, leading to effective contractions. Third-degree AV block indicates a complete lack of communication between the atria and ventricles, which can lead to disorganized contractions, but it is not characterized by the same chaotic electrical activity that defines fine ventricular fibrillation.