Question

In a patient with unstable tachycardia, with a narrow regular QRS complex, what is the first line drug to give?

1) Adenosine
2) Amiodarone
3) Lidocaine
4) Procainamide

Answer 1

Adenosine is the first-line medication for unstable tachycardia with a narrow regular QRS complex, as it is effective in converting SVT to a normal sinus rhythm.

Step-by-step explanation:

In a patient with unstable tachycardia that features a narrow regular QRS complex, the first-line drug to administer is Adenosine. This medication is known for its effectiveness in converting supraventricular tachycardia (SVT) to a normal sinus rhythm. Adenosine briefly blocks the AV node's conduction, which can interrupt the re-entrant circuit involved in SVT. Other medications such as Amiodarone and Procainamide may be used for other types of arrhythmias, but they are not the first choice for acute narrow complex tachycardias. Additionally, procedures like cardioversion or defibrillation may be necessary in severe cases where medications do not lead to the restoration of a normal heart rhythm.