SVT: Less than Adequately Perfused / Unstable (Adult)
 
Status
SVT with Systolic BP >100, (AV nodal rhythms or AVRT)
         
Is Pt hypotensive SVT (AV nodal rhythms or AVRT) or Unstable/rapidly deteriorating, SVT, AF, Atrial Flutter?
           
• SVT (AV nodal rhythms or AVRT)
• Systolic BP <100
           
Abdominal valsalva manoeuvre
           
Did SVT revert?
Yes     No
BLS
 
 
 
 
• If greater than 30 minutes transport time and SOB with crackles or chest pain
• Metaraminol 0.5mg IV given over 1 minute
- Repeat 0.5mg IV 2 until minutely either:
- Arrhythmia reversion
- BP > 00
- max. Metaraminol 5mg IV delivered
• If systolic BP increases to >100
- Consider Verapamil as per SVT: Adequate Perfusion
 
 
       
Rapidly deteriorating, altered conscious state (includes AF, Atrial Flutter)
           
Synchronised cardioversion
Midazolam 2.5mg IV
- Repeat Midazolam 2.5mg IV, 2 minutely until Pt does not respond to verbal stimuli but does respond to pain
- Cardioversion: Biphasic 75J (Monophasic 100J)
- If unsuccessful repeat using Biphasic 150J (Monophasic 200J then 360J) if required
       
Loss of output
Mx per appropriate CPG
   
Reversion
BLS
             
Special Notes
A Pt eye opening to pain but not to voice commands would also be likely to be making incomprehensible sounds and making purposeful movements in response to pain. i.e. a GCS of 9, (E2, V2, M5). Sedation should be used cautiously in these Pts.
The effectiveness of the Pt’s respirations should be continuously monitored.
 
General Care
If wide complex QRS or unsure of diagnosis treat as for CPG A0404 Ventricular Tachycardia.
Treat Pt symptomatically in accordance with appropriate Guideline and transport for further assessment and treatment CPG A0404 Ventricular Tachycardia.
If Pt is unconscious or becomes unconscious at any time during treatment, perform immediate synchronised cardioversion.
Valsalva instruction

- Evidence suggests a greater reversion rate with an abdominal valsalva manoeuvre with the following 3 elements:
1. Position - Supine
2. Pressure - At least 40mmHg for max. vagal tone. Best achieved with Pt blowing into a 10ml syringe hard enough to move the plunger to create this pressure.
3. Duration - At least 15sec. if tolerated by Pt

Ref. G Smith, A Morgans, and M Boyle Emerg Med J 2009; 26: 8-10. doi:10.1136 emj.2008.061572