70 y.o female with past medical history of hypothyroidism and COPD, presenting with chief complaint of “heart racing”. Symptoms began earlier that day. Patient denies any chest pain or shortness of breath.
Initial Vital Signs: HR 112, BP 112/74, RR 18, O2 Sat 100%
Exam: Remarkable only for tachycardia and irregular rhythm
Irregular, no clear P waves
PR – do you see any P waves? QTc – normal ~ 400ms
- Irregularly irregular rhythm
- No P waves
- Irregular “fibrillatory” waves – best seen in V1
Atrial Fibrillation with rapid ventricular rate
+ Why is this important?
Atrial Fibrillation increases your risk of thrombus formation and of embolic stroke!
+ What should be your next step in mangement
Is the patient Stable or Unstable?
Unstable = Cardioversion!
Stable? o Diltiazem: dose = 0.25 mg/kg IV over 2 min followed by a 2nd bolus of 0.35mg/kg IV over 2 min o OR 5mg slow push (max of 50mg) followed by a drip 5-15mg/hr o Metoprolol: dose 5mg IV Q5min up to 15mg
Recent prospective randomized double blinded study by Fromm C et al comparing diltiazem vs metoprolol in decreasing HR <100 data-preserve-html-node="true" in w/in 30 min showed diltiazem had a more rapid rate control
o Esmolol: dose = 0.5mg/kg bolus over 1 min, followed by a drip 0.05-0.2mg/kg/min
o Digoxin: loading dose of 0.5mg then repeat
o Amiodarone: dose = 150mg IV over 10 min followed by drip
+ Additional resources
EMCrit: http://emcrit.org/emnerd/the-case-of-the-irregular-irregularity/ o Tips on what to do when cardioversion doesn’t work http://emcrit.org/podcasts/crashing-a-fib/
Life in the Fast Lane: http://lifeinthefastlane.com/ecg-library/atrial-fibrillation/
Diltiazem vs. Metoprolol in the Management of Atrial Fibrillation or Flutter with Rapid Ventricular Rate in the Emergency Department. http://www.ncbi.nlm.nih.gov/pubmed/25913166