What is the recommended initial drug of choice for stable narrow complex SVT?

Adenosine is the recommended initial drug of choice for stable narrow complex supraventricular tachycardia (SVT) due to its rapid action and effectiveness in interrupting reentrant circuits within the atrioventricular (AV) node. When administered, adenosine essentially slows conduction through the AV node, which can often restore normal sinus rhythm quickly. This makes it particularly useful in an emergency setting when a patient is experiencing episodes of stable narrow complex SVT.

The rapid onset of action can be particularly advantageous as it provides immediate results, allowing healthcare providers to manage the condition effectively and assess the patient's response. Additionally, adenosine is typically well-tolerated and has a short half-life, meaning its effects are transient, making it suitable for acute episodes without prolonged impacts.

In contrast, other options like digoxin, diltiazem, and metoprolol are generally used either for rate control or as a secondary line of treatment for SVT after adenosine has been administered or in specific situations where adenosine may be contraindicated. They are not the first-line treatment for immediate management of stable narrow complex SVT.