Effectiveness of the modified Valsalva manoeuvre in adults with supraventricular tachycardia: a systematic review and meta-analysis

Background and importance Cardiac arrhythmia, specifically paroxysmal supraventricular tachycardia (SVT), accounts for a substantial proportion of emergency medical services resources utilisation. Reconversion requires increasing the atrioventricular node's refractoriness, which can be achieved by vagal manoeuvres, pharmacological agents or electrical cardioversion. There are multiple variants of vagal manoeuvres, including the Valsalva manoeuvre (VM). While the effectiveness of the standard VM has already been systematically reviewed, there has been no such analysis for the modified VM. Objective(s) Compare the effectiveness of the modified VM versus the standard VM in restoring the normal sinus rhythm in adult patients with supraventricular tachycardia. Design Systematic review with meta-analysis of published randomised controlled trials. Outcome measures The primary outcome was the reconversion to a sinus rhythm. Secondary outcomes included: medication use, adverse events, length of stay in the emergency department and hospital admission. Main results Five randomised controlled trials were included, with a combined total of 1181 participants. The meta-analysis demonstrated a significantly higher success rate for reconversion to sinus rhythm when using the modified VM compared to the standard VM in patients with an SVT (odds ratio = 4.36; 95% confidence interval, 3.30-5.76; P < 0.001). More adverse events were reported in the modified VM group, although this difference is NS (risk ratio = 1.48; 95% confidence interval, 0.91-2.42; P = 0.11). The available evidence suggests that medication use was lower in the modified VM group than the standard VM group. However, medication use could not be generalised across the different studies. None of the included studies showed a significant difference in length of stay in the emergency department. Only one study reported on hospital admission, with no significant difference between the two groups. Conclusions The available evidence is highly suggestive to support the use of the modified VM compared to the standard VM in the treatment of adult patients with SVT. Meta-analysis showed a higher success rate, required less medication use, and resulted in an equal number of adverse events. However, these results cannot be regarded as definitive in the absence of higher-quality studies.