During the modified Valsalva maneuver, how long should the patient be positioned flat with raised legs?

The modified Valsalva maneuver is a technique used primarily in the context of treating certain types of supraventricular tachycardia (SVT). When a patient is positioned flat with their legs raised during this maneuver, the recommended duration is 15 seconds. This specific timing is important because it allows enough time for the increased venous return to the heart, which can help restore normal heart rhythm by increasing the pressure in the thoracic cavity and influencing autonomic nervous system responses.

Positioning the patient flat with their legs elevated promotes venous return to the heart and can potentially enhance the effectiveness of the maneuver in re-establishing a normal heart rate. Other durations, such as 5 seconds or 30 seconds, may not provide the optimal conditions needed to achieve the desired cardiovascular effects, while prolonging it to 1 minute may cause unnecessary discomfort or complications without additional therapeutic benefit.