Modified Valsalva Maneuver: A Realist Evaluation

Cardiac arrhythmia, specifically paroxysmal supraventricular tachycardia (SVT), accounts for a substantial proportion of emergency medical services resources utilization. Restoring a normal sinus rhythm (reconversion) should be done quickly and effectively. Reconversion requires increasing the atrioventricular node's refractoriness, which can be achieved by vagal maneuvers, pharmacological agents, or electrical cardioversion. The Valsalva Maneuver (VM) is a commonly used non-invasive reconversion method. It increases myocardial refractoriness by increasing intrathoracic pressure for a brief period, thus stimulating baroreceptor activity in the aortic arch and carotid bodies, resulting in increased parasympathetic (vagus nerve) tone. The effectiveness of conventional vagal maneuvers in terminating SVT, when correctly performed, shows a considerable variation ranging from 19.4% to 54.3%. To improve the effectiveness of the Valsalva Maneuver, the Modified Valsalva Maneuver (MVM) was introduced. While the standard VM is performed when the patient is in a sitting position (45°-90°), the modified VM involves having the patient sit up straight and perform a forced expiration for about 15 seconds, after which the patient is brought into a supine position with the legs raised (45°) for another 15 seconds. This modification should increase relaxation, phase venous return, and vagal stimulation. A recent meta-analysis demonstrated a significantly higher success rate for reconversion to sinus rhythm when using the MVM compared to the standard VM in patients with an SVT (Odds Ratio = 4.36; 95 percent c.i. 3.30 to 5.76; P \< .001). More adverse events were reported in the MVM group, although this difference is not significant (Risk Ratio = 1.48; 95 percent c.i. 0.91 to 2.42; P = .11). The available evidence suggests that medication use was lower in the MVM group than in the standard VM group. However, medication use could not be generalized across the different studies. None of