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The Dizzy Ranger
Simulation Case Debriefing Material
Debriefing questions
– What went right?
– What went wrong?
– How do you treat bradycardia secondary to high degree AV
block?
– What are the indications and contraindications for emergent
pacing?
– What is the proper placement of the single lumen introducer
catheter for transvenous pacing?
– What heart chamber are you trying to place the pacemaker?
– How can you confirm proper placement and capture of the
pacemaker?
– Describe the cardiac manifestations of Lyme carditis.
– How is Lyme carditis treated?
ACLS bradycardia interventions
(HR <60 with symptoms)
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Assess airway and breathing.
Establish IV, give O2 (continuous pulse oximetry)
Place on cardiac monitor (and obtain ECG) and check blood pressure
With signs/symptoms of poor perfusion:
– Prep for trancutaneous pacing (emergent use if high degree AV block
present)
– Consider atropine 0.5 mg IV and repeat to a max total dose of 3mg if
pacer is not ready
– Consider epi (2-10 micrograms/min) or dopamine (2-10
micrograms/min) infusions if pacer not ready or is ineffective
– Prepare the transvenous pacer and consider consulting cardiology
Recognizing high degree AV block
• 2nd degree AV block
– Mobitz I (Wenckebach): Progressive prolongation of the PR interval
and shortening of the R-R until the QRS is dropped.
• Not generally associated with a higher mortality EXCEPT in the
context of acute MI
– Mobitz II: Atrial beat sporadically not conducted with constant PR and
R-R intervals.
• Can progress to 3rd degree heart block and thus carries a higher
mortality
– Both can be seen with Lyme disease
• 3rd degree AV block
– See complete AV dissociation with the QRS being conducted at an
independent rate from the atrial rate
– Patient’s are generally hemodynamically unstable with bradycardia
and hypotension
Indications for pacing in the setting of
bradycardia
• Symptomatic sinus node dysfunction
• Sinus arrest, tachy/brady syndrome, sinus bradycardia
• Second or third degree heart block
• Includes Mobitz I in the setting of myocardial infarct
• Symptomatic slow atrial fibrillation
• New LBBB, RBBB with left axis deviation, bifascicular
block, or alternating BBB in the setting of acute MI
• Prior to procedures that may induce bradycardia
• Malfunction of implanted pacemaker
Contraindications to pacing in the
setting of bradycardia
• No absolute contraindications
• Hypothermia
– Bradycardia may be manageable without pacing while awaiting
rewarming
– Pacing may precipitate V Fib that is difficult to convert.
• Thrombolytic use:
– Transcutaneous pacing may be preferred
• Asymptomatic patients
– Good idea to consider placing pacing pads in case of
deterioration
Highlights for transcutaneous
pacing
• Consider pretreating with opiods and benzodiazepines prior
to initiation
• Place anterior pad at point of maximal impulses to the left
chest wall
• Place the posterior pad directly posterior to the anterior pad
• Attach the patient to the ECG monitor and make sure both
ECG leads and pacer pads are hooked up to the pacemaker
• Set the presets to rate 80 and around 40-60 mA
– May also start with lower amperage and increase dose until capture
occurs
• Confirm placement by assessing rhythm strip for consistent
pacer spike followed by QRS and improvement in patient’s
symptoms
Highlights for emergent
transvenous pacing
• If you have the time:
– Arrange for either ultrasound to confirm
placement
OR
– Attach the negative electrode the the V1 lead on
an ECG machine
• Please refer to the Pacing instructions for tips
on transvenous placement
– Figure 4
Proper location for single lumen
catheter for transvenous pacing
• Preferred locations are the right internal
jugular vein or the left subclavian vein
• These provide the straightest path to the the
right heart anatomically
• Check your institutions preference and
cardiology preference for permanent
pacemaker placement
– Avoid the most likely site of permanent
pacemaker placement if possible
Transvenous pacer:
Confirmation of placement
• Right ventricular placement is confirmed on ECG with LBBB
pattern and LAD
– Note that RBBB may indicate coronary sinus placement or
septal perforation and LV pacing
• Look for cannon waves present on exam of the neck veins
• Listen for tricuspid insufficiency murmur due to obstruction
from the catheter
• Clinically assess for improvement in vitals, mentation, cardiac
congestion
• Obtain portable CXR radiological confirmation
• May also use ultrasound to confirm that placement of the
catheter in the right ventricle
Treatment of Lyme Carditis caused
by high degree AV block
• Symptomatic support including pacing if
necessary
– Complete heart block generally resolves within
one week
• Hospitalize and give IV ceftriaxone (2g IV daily
for 2-4 weeks) or high-dose Penicillin G.
• A combination of IV and po antibiotics should
be continued for 4 weeks.
– Including amoxicillin, doxycycline, and/or
ceftriaxone
References
• Field, JM; Hazinski, MF; Gilmore, D. American Heart
Association’s Handbook of Emergency Cardiovascular Care for
Healthcare Providers. 2005.
• Roberts J.R., Hedges J.R.: Clinical Procedures in Emergency
Medicine, 4th ed. Philadelphia, PA, WB Saunders, 2003, CH
15.
• Bing OH, McDowell JW, Hantman J, et al: Pacemaker
placement by electrocardiographic monitoring. N Eng J Med
287:651, 1972
• Goldberger E: Treatment of Cardiac Emergencies, 3rd ed. St.
Louis, CV Mosby, 1982, p252.
• Fish AE; Pride YB; Pinto DS: Lyme carditis. Infect Dis Clin North
Am; 22(2): 275-88, vi; 2008