A patient with sudden onset palpitations and an ECG shows a rapid heart rate. What is the best initial treatment for this patient?

The Valsalva maneuver is considered the best initial treatment for a patient experiencing sudden onset palpitations accompanied by a rapid heart rate as seen on an ECG. The maneuver is a simple physical technique that helps to stimulate the vagus nerve, which in turn can slow down the heart rate and restore a normal rhythm, particularly in cases of supraventricular tachycardia (SVT).

The maneuver involves the patient taking a deep breath and then forcefully exhaling against a closed mouth and nostrils, creating pressure in the chest cavity. This action can lead to increased intrathoracic pressure, which may interrupt the tachycardia by affecting the conduction in the atrioventricular (AV) node.

In practice, this is often tried first because it is non-invasive, quick to implement, and carries minimal risk compared to medications or electrical interventions. If the Valsalva maneuver is unsuccessful and the arrhythmia persists, then medical therapy like adenosine or electrical cardioversion may be considered as subsequent steps.