A case of palpitations
Case: You have a 37 y.o male who presents with palpitations. He is alert and generally well-appearing. You obtain an initial set of vitals—BP 150/70, HR 210, RR, 16, T 99F. You immediately obtain an EKG and find a regular, narrow, tachycardia at a rate of 203.
What is the diagnosis? And what is your first move?
Question: What is the modified valsalva maneuver?
The “Modified Valsalva Maneuver” has been shown to be a very effective method for SVT termination. In patients with stable SVT, this should be the first maneuver attempted to convert SVT. It is simple, zero cost, well tolerated, and with zero serious adverse events.
How to: In a semi-recumbent position patients blow into a syringe for 15-20 seconds and then are immediately repositioned into a supine position with a passive leg raise.
See the original REVERT Trial or read the RebelEM commentary.
See this RebelEM commentary on a meta-analysis on this topic.
JAMA has a great video that demonstrates this procedure:
Question: What about diltiazem for SVT?
If you are reaching for adenosine…fine. It’s been the standard first line agent for some time. But consider diltiazem–stop torturing your patients with adenosine!
A 2017 Cochrane systematic review of 7 RCTs (622 patients) found similar conversion rates to sinus rhythm with adenosine or calcium channel blockers (90% versus 93%) and no significant difference in significant adverse events.
So why torture our patient with adenosine? The primary side effect of adenosine is the sensation of “impending doom” due to the sinus pause. Other side effects include headache, dizziness, facial flushing, and dyspnea. Sounds pretty terrible.
There is a slightly longer time to conversion to NSR for diltiazem (~6.5 minutes) compared to adenosine (~1.5 minutes).
Diltiazem can be given as a slow IV infusion of 2.5mg/min or an IV push of 0.25-0.3mg/kg.
Caution in those patients with hypotension or heart failure. Though…these patients would probably benefit from electricity anyway.
Diltiazem for stable SVT is supported by 2020 AHA Guidelines
Cheers,
Dillon
