Which approach is first-line treatment for stable paroxysmal supraventricular tachycardia?

The first-line treatment for stable paroxysmal supraventricular tachycardia (SVT) is the use of vagal maneuvers. These maneuvers work by increasing vagal tone, which can help to slow down or terminate the tachycardia by promoting atrioventricular (AV) nodal block. Common vagal maneuvers include the Valsalva maneuver, carotid sinus massage, or facial immersion in cold water. These techniques are often effective because they stimulate the parasympathetic nervous system, leading to a temporary reduction in heart rate and potentially interrupting the arrhythmia.

In contrast, adenosine is often used as a second-line treatment if vagal maneuvers fail, primarily because it has a direct effect on the AV node and is effective in acute situations. Synchronized cardioversion is reserved for unstable SVT or cases where the patient presents with significant hemodynamic compromise. Beta-blockers may be used for rate control, but they are typically not the first-line intervention in the acute setting of stable SVT, given that immediate and quick action is usually necessary. Thus, vagal maneuvers are the most appropriate initial management choice for stable paroxysmal