Rosh Internal Medicine Boost Practice Exam

Given the patient's condition, what method is primarily employed to restore normal heart rhythm?

1. Administration of calcium channel blockers

2. Administration of adenosine

3. Implementation of mechanical ventilation

4. Introduction of diuretics

The correct answer is: Administration of adenosine

The primary method employed to restore normal heart rhythm in certain tachyarrhythmias, particularly in cases of paroxysmal supraventricular tachycardia (PSVT), is the administration of adenosine. This medication acts rapidly by briefly blocking the conduction through the atrioventricular (AV) node. This effect allows for the interruption of reentrant pathways that may be causing the rapid heart rhythm, effectively restoring a normal sinus rhythm. Adenosine is especially effective because it has a very short half-life, which makes it suitable for acute situations in a clinical setting. Following administration, it can cause a transient heart block that often results in a return to a normal rhythm. This mechanism is particularly crucial in emergency medicine where swift action is necessary to alleviate symptoms associated with atrial or junctional reentrant tachycardias. In contrast, calcium channel blockers, while utilized in certain arrhythmias and for rate control, do not have the immediate effect characteristic of adenosine. Mechanical ventilation and diuretics are not interventions aimed primarily at restoring heart rhythm; they serve different roles in managing respiratory failure and fluid overload, respectively.