Reportedly, the Valsalva maneuver has variable success rates in the
termination of supraventricular tachycardia, perhaps in part because of
variations in performance technique. Various techniques of the maneuver
have been described. Theoretically, continued pooling of blood in the
dependent limbs on breath-hold release may attenuate vagal tone
increases in Valsalva maneuvers not performed in the supine position
(semirecumbent and sitting position maneuvers). The supine with
epigastric pressure technique has been reported to increase the success
rate of supraventricular tachycardia conversion.^*10*
<http://www2.us.elsevierhealth.com/inst/serve#rs0196064403011296010>,*11*
<http://www2.us.elsevierhealth.com/inst/serve#rs0196064403011296011>
Theoretically, this and the leg-raise technique should augment the
effect of the Valsalva maneuver by promoting venous return.
Apologies for any copyright infringement for Annals, this is this
theoretical basis why passive leg elevation should improve likelihood of
successful vagal manouvres.
Andy Webster
dave.j.fletcher wrote:
> Conversion of SVT tends to be easier if the patients are reclining.
> On the paramedic courses we teach this!! So Valsalva and other
> manoeuvres work better with subjects lying. Part of mechanism thought
> to be baroreceptor reflexes and these are more active when legs are
> raised...
>
> This is well known.
>
> One recent paper:- Ann Emerg Med. 2004 Apr;43(4):477-82.
> Vagal response varies with Valsalva manoeuvre technique: a
> repeated-measures clinical trial in healthy subjects.
> Wong LF, Taylor DM, Bailey M.
>
> But described much before this!!
>
> Regards
> Dave Fletcher
>
> ----- Original Message -----
> *From:* Taffler Richard (RJ9) West Country Ambulance Services TR
> <mailto:[log in to unmask]>
> *To:* [log in to unmask] <mailto:[log in to unmask]>
> *Sent:* Wednesday, September 21, 2005 10:18 AM
> *Subject:* [ACAD-AE-MED] SVT and raised legs!
>
> Several paramedics have recently reported the conversion of SVT to
> NSR by raising the patients legs. Previous attempts (carotid
> massage/valsalva) had proved ineffective for these patients, who
> were normotensive, although displaying signs of circulatory
> compromise (pale, sweating, dizzy etc). Does any member of the
> list have any evidence (anecdotal or otherwise) that may explain
> this phenomenon please?
>
>
>
> **Richard Taffler**
>
>
>
> BSc(Hons) BEng GASI SRPara
>
> **Clinical Effectiveness Officer**
>
> Westcountry Ambulance NHS Trust
>
>
>
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