NEW ORLEANS – , according to Jeet Mehta, MD, a resident in the combined medicine/pediatrics program at the University of Kansas, Wichita.
The 2015 American College of Cardiology/American Heart Association/Heart Rhythm Society guidelines recommended vagal maneuvers as first-line treatment of supraventricular tachycardia, but added that there was no gold standard method. Since then, the situation has changed. Two well-conducted randomized clinical trials have been published that bring clarity as to the vagal maneuver of choice, Dr. Mehta reported at the annual meeting of the American College of Physicians.
He and his coinvestigators performed a meta-analysis of the three pre-2000 randomized controlled trials that compared the standard Valsalva maneuver to carotid sinus massage plus the two newer studies, both of which systematically compared a modified Valsalva maneuver with the standard version.
The clear winner in terms of efficacy was the modified Valsalva maneuver, in which patients with supraventricular tachycardia (SVT) performed a standardized strain while in a semirecumbent position, then immediately laid flat and had their legs raised to 45 degrees for 15 seconds before returning to the semirecumbent position. The purpose of this postural modification is to boost relaxation phase venous return and vagal stimulation.
In the 433-patient multicenter REVERT trial in the United Kingdom, 43% of those assigned to the modified Valsalva maneuver returned to sinus rhythm 1 minute after completing the task, compared with 17% of those randomized to the standard semirecumbent Valsalva maneuver. This resulted in significantly less need for adenosine and other treatments. Although REVERT investigators had the patients blow into a manometer at 40 mm Hg for 15 seconds, they noted that the same intensity of strain can be achieved more practically by blowing into a 10-mL syringe sufficient to just move the plunger (Lancet. 2015 Oct 31;386[10005]:1747-53).
The REVERT findings were confirmed by a second trial conducted by Turkish investigators, in which the modified Valsalva maneuver was successful in 43% of patients, compared with 11% in the standard Valsalva maneuver group (Am J Emerg Med. 2017 Nov;35[11]:1662-5).
Extrapolating from the published evidence, including a Cochrane Collaboration review (Cochrane Database Syst Rev. 2015 Feb 18;[2]:CD009502. doi: 10.1002/14651858.CD009502.pub3), Dr. Mehta and his coinvestigators ranked the likelihood of successful conversion of SVT to sinus rhythm from a high of 48% for the modified Valsalva maneuver, descending to 43% for a supine Valsalva maneuver, 36% for a standard semirecumbent Valsalva, 21% for a seated Valsalva, 19% for a standing one, and just 11% for carotid sinus massage.
“Based on evidence of high quality, we encourage that the modified Valsalva maneuver be done due its safety and low cost,” Dr. Mehta concluded.
He reported having no financial conflicts regarding his study, conducted free of commercial support.