What is the initial treatment for persistent symptomatic SVT?

The initial treatment for persistent symptomatic supraventricular tachycardia (SVT) is cardioversion. When a patient is experiencing persistent symptomatic SVT, it typically means that they are exhibiting significant symptoms such as palpitations, dizziness, or chest pain, which warrants an immediate and effective intervention.

Cardioversion, particularly synchronized electrical cardioversion, is considered first-line treatment in these urgent situations because it aims to restore normal sinus rhythm quickly. This intervention is specifically designed for cases where the patient presents with hemodynamic instability due to the rapid heart rate. By delivering a controlled electric shock to the heart, cardioversion can effectively reset the heart's rhythm and alleviate the symptoms.

In contrast, other treatments like adenosine may be used in stable patients or during an acute SVT episode as a potential first-line treatment, especially when there are no significant symptoms. However, if the symptoms are persistent and the patient is unstable, immediate cardioversion is the more appropriate choice. Anti-arrhythmic medications or calcium channel blockers are generally considered in cases where immediate cardioversion is not feasible or necessary, but they do not serve as the first-line treatment when the patient demonstrates significant symptoms.