The Valsalva maneuver’s effectiveness for supraventricular tachycardia is, essentially, the reason adenosine exists. With rates of non-pharmacologic cardioversion merely 5-20%, it’s not absent of value, but hardly reliable.
So, I appreciate these authors innovation in trialling a new, improved Valsalva maneuver. The comparator in this study was the “traditional” maneuver, as applied via a forced exhalation of 40 mmHg for 15 seconds. The “modified” maneuver was the same exhalation, but followed by immediately laying the patient supine and having a passive leg raise performed.
With 214 patients analyzed in the intention-to-treat population in a multi-center randomized trial, the success rate was, essentially: 43% vs. 17% in sinus rhythm one minute after Valsalva. This boiled down to only 57% of patients in the modified Valsalva group ultimately requiring any pharmacologic therapy, compared with 80% of the traditional method.
I don’t see any particular reason to suspect the modified version would be more harmful than the otherwise safe traditional method, so there shouldn’t be any reason to avoid teaching and using this new alternative. This may also be of more use to patients at home in preventing an Emergency Department visit in the first instance.
“Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial”