A patient presents with racing palpitations with a heart rate of 160. Is this supraventricular tachycardia? You are waiting for the EKG. In the meantime you wonder about all those vagal maneuvers. You tried them early in your career and they didn’t work. Is it worth a second look?
The human dive reflex was reviewed this month in the Emergency Medicine Journal.(Smith EMJ 2012) In pediatric populations it was 90-100% effective but in adult populations for paroxysmal supraventricular tachycardia it was 5-20%. The authors note that heterogeneous studies with a low sample size limit conclusions. Until better evidence is found they recommend:
-Immerse the entire face, not just part of it (with cold packs)
-Employ augmentation techniques of a deep breath followed by breath holding, as well as calming measures)
-Duration of the treatment should be 30-40 seconds before abandoning it
Think back to your previous attempts. Did you use optimal methods? If not, maybe give it a try using the above techniques, and let me know how it goes.
Take Home Points
-Full face coverage
-Augmentation with deep breath, breath hold, calming techniques
-Wait 30-40 seconds before abandoning the effort