Ryan Ernst and I recently had a conundrum of a patient: she was chronically in A fib, and came to the ED after dialysis (she got a full run) because her heart rate was high. Like really high. Low 200s. The problem was that her blood pressure was really low. Like 70s/50s. So what do you do?
Shock her, right? She has an arrhythmia and is unstable, based on her BP. The thing was though that she was totally asymptomatic, had no complaints (not even palpitations) and is in no distress. We looked back in her records and saw that her blood pressure tends to run on the low side, although not typically that low.
So we decided to give her a little Cardizem (5mg) and see what happens. We were hoping that if we slowed down her rate, her BP would go up because her heart would have more time to fill. So we gave 5mg, and her rate came down a little. So we gave 5mg more. Then 5 mg more. Then started her on a drip. Her heart rate improved (was bouncing between 100-140ish), blood pressure came up marginally (and then would intermittently drop back down). We called CTO and MICU and let them deal with it. We were out of ideas.
So I’ve gone into the FOAM world to try to get some ideas about this problem. I found a good podcast from EMCrit (http://emcrit.org/podcasts/crashing-a-fib/) although I can just see the looks on the nurses faces when I ask them for phenylephrine, or ask to run a Cardizem drip at 2.5 mg/min and keep a very close eye on the patient.
One thing that’s particularly interesting from that podcast is that apparently, you can shock these patients, but if they’re chronic Afib patients, it’s usually not going to work. This was news to me. So Weingart recommends maybe trying some amiodarone, and if that doesn’t work, use some push-dose phenylephrine to get the BP up so that you can start them on a more aggressive Cardizem drip without tanking their pressure. I’d be curious what you all think of this strategy.
This also got me thinking about calcium channel blockers vs beta-blockers for regular old AF with RVR (in a non-hypotensive patient). There is an AWESOME blog called emlyceum (emlyceum.com) that is from Bellevue hospital and overseen by Dr Anand Swaminathan. All of their monthly posts are very evidence-based and provide links to all of their references. The put up a post a few years back on this very question of BBs vs CCBs, you can find the answer here: http://emlyceum.com/2014/01/17/medication-comparisons-answers/. I would highly encourage you all to check out this very good blog.
That’s it for now, please share your thoughts/experiences, that’s what makes this fun!