What should be done if rhythm fails to convert after Adenosine in stable SVT?

The correct response involves administering Cardizem (diltiazem), which is a calcium channel blocker used to help control heart rate in patients experiencing stable supraventricular tachycardia (SVT). After administering Adenosine and observing that the rhythm fails to convert, Cardizem provides an alternative therapeutic approach to manage the patient's heart rate effectively.

The initial dose of 10 mg IV push (IVP) over 2 minutes is appropriate for rapid control of the heart rate. If, after 5 minutes, the heart rate remains elevated (greater than 120 beats per minute), an additional dose of 15 mg IVP can be given. This sequential dosing strategy allows for careful monitoring of the patient's response to the medication while minimizing the risk of hypotension or other adverse effects.

The other options would not be appropriate in this situation. Immediate defibrillation is reserved for unstable rhythms or if the patient were in a life-threatening condition, which does not apply to stable SVT. Increasing the dose of Adenosine is unnecessary as the standard dosing protocol for adenosine generally does not exceed 12 mg; thus, an additional increase to 20 mg is not standard practice and may not yield the desired result. Lastly, although vagal