Level 2: Mid-level evidence
A randomized trial evaluated the effect of physical counterpressure maneuvers in patients with recurrent syncope (J Am Coll Cardiol. 2006;48:1652-1657). Patients (N=223, mean age 38.6 years) with recurrent vasovagal syncope and recognizable prodromal symptoms were randomized to conventional therapy plus physical counterpressure maneuvers vs. conventional therapy alone and followed for mean 14 months.
Physical counterpressure maneuvers included leg crossing (combined with tensing of leg, abdominal, and buttock muscles), hand grip (maximal voluntary contraction of a rubber ball or any other available object, taken in the dominant hand), and arm tensing (contraction of the two arms by gripping one hand with the other and abducting both arms). These maneuvers were performed for maximum tolerated time or until complete disappearance of symptoms, with progression to second or third maneuver if needed.
Patients were blinded to assignment, as all patients received educational sessions; physicians caring for patients were not blinded to randomized assignment. Fifteen patients (6.7%) dropped out and were not included in the primary analysis. Comparing physical counterpressure maneuvers vs. conventional therapy, 31.6% vs. 50.9% had syncopal recurrence (P =.005, NNT 5), and 82.7% vs. 73.6% had presyncopal episodes (not significant).