Background: The REVERT Randomized Controlled Trial demonstrated the superiority of the modified valsalva maneuver (MVM) over the standard valsalva maneuver (VM) in re-establishing normal sinus rhythm (NSR) in patients with PSVT (Appelboam 2015). MVM exaggerates venous return to the heart and increases vagal outflow by elevating the patient’s legs. However, the success rate of the MVM is still significantly lower than that of intravenous adenosine, the first-line pharmacological therapy for treating PSVT, which establishes NSR by transiently slowing electrical conduction through the AV node.
Given that these two treatment options operate via different physiologic mechanisms, the author of this study postulates that MVM and IV adenosine could be combined synergistically to convert PSVT with better success rates than either treatment individually and with better safety profiles.
Article: Xiao, L., Ou, X., Liu, W., Lin, X., Peng, L., Qiu, S., & Zhang, Q. (2024). Combined modified Valsalva maneuver with adenosine supraventricular tachycardia: A comparative study. The American Journal of Emergency Medicine, 78, 157–162. PMID: 38281376.
Clinical Question:
Does simultaneously performing the modified valsalva maneuver and administering intravenous adenosine, compared to either treatment alone, have greater success in achieving normal sinus rhythm in patients presenting to the ED with PSVT?
What they did:
Prospective randomized controlled trial, unblinded, multicenter study
Conducted from January 2017 to December 2022
Patients with confirmed PSVT were randomly assigned to receive MVM, IV Adenosine, or combined therapy.
Modified Valsalva Maneuver (MVM) Group:
Patient’s were instructed to exhale into a syringe for 15 seconds
Then rapidly were moved into a supine position with legs elevated
Technique was repeated once more if NSR was not achieved after 5 minutes of performing MVM
IV Adenosine Group:
IV Adenosine was administered in a stepwise fashion with escalating doses of 6 mg, 12 mg and 18 mg.
Combination Therapy Group:
Patient began the MVM protocol by exhaling into a syringe
At the beginning of exhalation, IV Adenosine was administered
At 15 seconds patients were rapidly repositioned into a supine position with legs elevated
Population:
Inclusion Criteria:
Patients aged 14 to 70 presenting to the ED with PSVT
Exclusion Criteria:
New York Heart Association III and IV
Hemodynamically unstable (SBP <90mmHg)
Unstable angina
Myocardial infarction within 3 weeks
Patients with atrial fibrillation or atrial flutter
Patients who received antiarrhythmic therapy within 1 week
Patients allergic to adenosine
Patients contraindicated for MVM (aortic coarctation, glaucoma, retinopathy) or patients unable to tolerate MVM
Patients who achieved successful cardioversion but PSVT recurred within 5 minutes after success
Outcomes:
Success Rate Outcomes:
Successful rate with first attempt
Successful rate with second attempt
Total success rate
Average adenosine doses needed (mg)
Duration it took for cardioversion (seconds)
Risk Profile Outcomes:
Longest RR interval (seconds)
Heart rate 1 minute after cardioversion (beats per minute)
Adverse effects
Arrhythmia
Palpation/Chest tightness
Lightheadedness/Nausea and Vomiting
Others
Results:
Study Participants:
135 patients diagnosed with pSVT
13 excluded
122 were randomly assigned to three groups.
4 patients were considered as failure to antiarrhythmic for recurrence within 5 min of conversion,
3 of them were converted with verapamil and one with amiodarone.
The study included 118 patients, distributed as follows:
MVM group: 38 patients
Adenosine group: 44 patients
Combination therapy group: 36 patients
Success Rates on First Attempt:
MVM group: 24% (9/38)
Adenosine group: 30% (13/44)
Combination group: 50% (18/36)
The differences were not statistically significant (p = 0.043)
Total Success Rate:
MVM group: 42% (16/38)
Adenosine group: 75% (33/44)
Combination group: 86% (31/36)
The differences were statistically significant (p <0.001)
Average Adenosine Dose Needed:
No significant difference in the average dose required across groups (p = 0.718).
The difference in duration among groups was statistically significant (p < 0.001).
Adverse Effects:
No significant difference in RR interval length was observed between the MVM and IV Adenosine groups.
No significant differences in heart rate 1 minute after cardioversion were observed between the three groups.
Strengths:
The study addresses clinically relevant questions, enhancing its practical significance.
The study was conducted at multiple centers, increasing the data’s generalizability.
It is the first research paper to explore the synergistic effects of combining MVM and IV Adenosine in treating PSVT.
The primary outcomes are patient-centered and objectively measured, potentially ensuring relevance and reliability.
Limitations:
The study was conducted in a single country, raising questions about whether the findings apply to other populations.
The small sample size diminishes the study’s statistical power, making it difficult to draw reliable conclusions and detect meaningful differences between treatment groups.
The study lacks detailed information on recruitment and the randomization process, such as whether it was computer-generated or if patients were enrolled consecutively. This absence of detail leaves the study open to bias.
The unblinded nature of the study could influence outcomes due to observer bias.
The requirement for patients to exhale forcefully for 15 seconds and the mobility needed in executing MVM may not be suitable for all patients with PSVT.
Using a specialist cardiologist to confirm PSVT via a 12-lead ECG does not reflect standard emergency practices, potentially limiting the study’s findings’ practicality and applicability.
The study recommended an adenosine dosing strategy of 6 mg, 12 mg, and 18 mg, which may differ from some emergency physicians who start with 12 mg.
The groups have different number of attempts at the procedure (MVM = 2, adenosine = 3).
Employing P-values to compare demographics between groups could mislead interpretations of the data’s relevance to the primary outcomes.
Demographic differences, such as age and prior history of PSVT, particularly in the combination therapy group, could confound the results, especially considering the studies’ small sample size.
The study’s short follow-up period of only 5 minutes post-treatment may not adequately capture recurrence rates of arrhythmias or delayed adverse effects, limiting the understanding of the interventions’ durability and safety.
Most secondary outcomes were disease-oriented with an unclear clinical significance.
The success rates for adenosine seem much lower than in actual clinical practice.
Discussion:
Methodology:
This paper addresses an interesting and innovative topic but lacks crucial information, making the findings difficult to implement practically. Important details, such as the number of study sites involved, how patients were selected, and the randomization process used to allocate patients, are missing. The study’s unblinded nature also compromises the reliability of the data. Additionally, the relevance of the first attempt success rate of cardioversion is unclear since successive adenosine attempts occur simultaneously and only slightly extend the time to cardioversion. Furthermore, the small sample size raises concerns that any observed differences between groups might simply be due to chance alone. Consequently, the study’s results are largely clinically unusable.
Safety:
The safety concerns regarding adenosine appear overstated. Generally, adenosine has a favorable safety profile, with mostly minor side effects (Holdgate 2006). Given adenosine’s rapid and transient effects, the clinical relevance of the disease-oriented secondary outcomes, such as the RR interval and heart rate one minute after cardioversion, is questionable. Additionally, serious adverse effects associated with adenosine are rarely reported. Furthermore, it is unclear whether combining the MVM with adenosine would reduce these side effects or the feeling of impending doom experienced by patients as they convert to NSR.
Medications:
The study reported unusually low success rates of 30% for the initial 6 mg dose and 61% for the 12 mg dose. These rates are significantly lower than those in other research (Holdgate 2006). Evidence suggests that a weight-based dosing approach (0.1 mg/kg) or starting at 12 mg might be more effective for certain populations (Deck 2023, Cabalag 2010). Additionally, robust evidence supports using calcium channel blockers, which may have a more favorable side effect profile (Holdgate 2006).
The Maneuver:
Evidence suggests that the MVM may outperform standard Valsalva techniques and is relatively safe (Appelboam 2015). Using MVM in parallel while establishing IV access or preparing medications is practical. However, once medications are ready, this paper does not provide strong evidence to support additional attempts with MVM.
Author’s Conclusion: “The combination of MVM and Adenosine has a higher success rate in the treatment of paroxysmal supraventricular tachycardia. There are no significant adverse events from the combination therapy.”
Our Conclusion:
This study presents a novel topic but is riddled with methodological flaws. The sample size is small, and any difference in outcomes may be due to chance alone. Additionally, the risks associated with adenosine are overstated. While it is reasonable to use the MVM instead of other Valsalva maneuvers while waiting for medications, the evidence is insufficient to justify adopting the combined treatment protocol involving both MVM and adenosine.
References:
Appelboam A, Reuben A, Mann C, Gagg J, Ewings P, Barton A, et al. Postural modification to the standard Valsalva maneuver for emergency treatment of supraventricular tachycardias (REVERT): a randomized controlled trial. Lancet. 2015;386(10005):1747–53. PMID: 26314489
Holdgate A, Foo A. Adenosine versus intravenous calcium channel antagonists for the treatment of supraventricular tachycardia in adults. Cochrane Database Syst Rev. 2006;(4):CD005154. Published 2006 Oct 18. PMID: 17054240
Deck CM, Dang B, Ashenburg N, Rice B. Improved First Dose Conversion of Supraventricular Tachycardia Using Weight-Based Adenosine. Cureus. 2023;15(3):e35995. Published 2023 Mar 10. PMID: 37041920
Cabalag MS, Taylor DM, Knott JC, Buntine P, Smit D, Meyer A. Recent caffeine ingestion reduces adenosine efficacy in the treatment of paroxysmal supraventricular tachycardia. Acad Emerg Med. 2010;17(1):44-49. PMID: 20003123
Daniel Zone, MS-3
Touro College of Osteopathic Medicine
Middletown, New York
E-mail: dzona@student.touro.edu
Laura Fil, DO
Assistant Emergency Medicine Residency Program Director
Vassar Brothers Hospital, Poughkeepsie, New York
E-mail: Laura.Fil@nuvancehealth.org
Marco Propersi, DO FAAEM Vice-Chair, Emergency Medicine
Assistant Emergency Medicine Residency Program Director
Vassar Brothers Hospital, Poughkeepsie, New York
Twitter/X: @marco_propersi
Post Peer Reviewed By: Anand Swaminathan, MD (Twitter/X: @EMSwami)
Cite this article as: Daniel Zone, MS3, "The Modified Valsalva Maneuver: Practical Treatment or Pointless Trick?", REBEL EM blog, May 27, 2024. Available at: https://rebelem.com/mvm/.
Success Rates on First Attempt:
