Final answer:
The first intervention indicated for a 35-year-old woman presenting with palpitations and normal blood pressure is vagal maneuvers. Medications like beta blockers or adenosine are not the first line of treatment and are used after other interventions like vagal maneuvers have been tried.
Step-by-step explanation:
A 35-year-old woman presents with palpitations but no other symptoms, and her blood pressure is 120/78 mm Hg. The appropriate first intervention to consider would be vagal maneuvers. These are simple techniques that can be done to try to slow down the heart rate and do not require any medication. In the case of tachycardia, where the heart rate is above 100 bpm, these maneuvers may help to restore a normal rhythm.
Using medications right away is not indicated unless the patient shows more serious symptoms or if vagal maneuvers fail to alleviate the condition. Beta blockers, such as metoprolol, are often used as a first-line treatment for various cardiac issues, including high blood pressure and tachycardia, after non-pharmacological methods have been attempted. Adenosine may be employed in certain cases of arrhythmias but is typically administered in acute settings and often after other interventions have been considered. It is also not administered as a slow push in the initial management of tachycardia.
It's important to note that beta blockers and adenosine are typically used as per specific tachycardia protocol and require continuous monitoring of the patient's heart rate and rhythm. Initial non-invasive and non-pharmacological strategies like vagal maneuvers are preferred since they pose minimal risk and can be easily performed. Always, medical intervention should be guided by the patient's specific symptoms and vital signs, and follow established clinical guidelines.