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We read with interest the recent Best Evidence Topic (BET) report by L Varley and L Howard, ‘Trendelenburg position helps to cardiovert patients in SVT back to sinus rhythm.’ We are grateful that this BET highlighted the substantial benefit of using a postural modification to the Valsalva manoeuvre for re-entrant SVT. However, whist we agree with the ‘Clinical Bottom Line’, we feel the title of this BET was misleading and does not reflect current evidence.
‘Trendelenburg position’ is typically used to describe a supine patient with the bed tilted head down below the level of the pelvis. Although this position was associated with a higher rate of cardioversion in a small, uncontrolled before and after study, no physiological benefits of this position have been demonstrated and it was not used in the REVERT trial, the largest RCT of VM modification to date.
For clarification, in our study the Valsalva strain was conducted in the semi-sitting position with movement to the supine position with leg elevation, immediately at the end of the strain. There are plausible physiological reasons why this specific sequence of postural changes and timing of strain may improve Valsalva effectiveness as described in our paper. Although it is possible that Trendelenburg positioning after straining might further improve cardioversion rates, this has not been tested to date.
On behalf of the REVERT study Team
1) L Varley, L Howard BET 2: Trendelenburg position helps to cardiovert patients in SVT back to sinus rhythm EMJ 2017 page 189; 34: 189-190 DOI: 10.1136/emermed-2017-206590.2
2) Appelboam A, Reuben A, Mann C, et al; REVERT Trial Collaborators. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet 201531.;386:1747–53.
3) Willy Meyer (1854-1932), in [von Langenbeck’s] Archiv für klinische Chirurgie, Berlin, 1885, 31: 495-525.
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