Final answer:
The first intervention for a patient in SVT without severe symptoms and with normal blood pressure typically involves vagal maneuvers or the administration of adenosine, following ACLS guidelines. Supervised medical treatment may progress to beta blockers and other interventions if needed.
Step-by-step explanation:
The question concerns a patient presenting with palpitations and diagnosed with Supraventricular Tachycardia (SVT), observed via a normal blood pressure reading. The priority is to determine the first intervention for a patient in SVT without chest pain, shortness of breath, or lightheadedness. The immediate treatment for SVT, especially in a stable patient with a blood pressure of 120/78, would typically involve vagal maneuvers, such as the Valsalva maneuver, to slow the heart rate or the administration of adenosine if vagal maneuvers are ineffective. A vagal maneuver can be an initial effort to convert SVT to a normal sinus rhythm non-invasively. If unsuccessful, intravenous adenosine can be administered in a rapid IV push, which may interrupt the reentrant pathways in the heart and restore normal rhythm. It's essential to follow the Advanced Cardiac Life Support (ACLS) guidelines for the treatment of SVT. Other treatments, such as beta blockers or calcium channel blockers, and further interventions like cardioversion or ablation, may follow depending on the patient's response to initial therapy. Supervision by a healthcare professional is crucial during these interventions due to potential complications.