Advanced Cardiovascular Life Support (ACLS) Practice Exam

Which rhythm requires synchronized cardioversion?

1. Atrial fibrillation

2. Stable ventricular tachycardia

3. Unstable supraventricular tachycardia

4. Bradycardia

The correct answer is: Unstable supraventricular tachycardia

Synchronized cardioversion is a procedure used to restore a normal rhythm in patients experiencing certain types of arrhythmias, particularly when they are unstable. Among the listed rhythms, unstable supraventricular tachycardia is correctly identified as requiring synchronized cardioversion because the patient may exhibit signs of instability, including low blood pressure, altered mental status, or chest pain. In such cases, immediate intervention is necessary to prevent further deterioration and potential cardiac complications. Synchronized cardioversion utilizes a timing mechanism to deliver a shock that is synchronized with the R wave of the QRS complex, allowing for the restoration of normal rhythm without causing more harm, such as triggering ventricular fibrillation. This is particularly important in cases of unstable rhythms where rapid intervention is critical for patient safety. In contrast, while other rhythms like atrial fibrillation and stable ventricular tachycardia might also be candidates for cardioversion, they are generally managed differently based on stability factors. Atrial fibrillation is usually addressed in a more controlled manner unless symptomatic, while stable ventricular tachycardia is often treated with antiarrhythmic medications rather than immediate cardioversion unless the patient becomes unstable. Bradycardia typically does not require cardioversion and is often