Difference between revisions of "ACLS: Bradycardia"

Line 87: Line 87:
  
 
==References==
 
==References==
(references/>
+
#Semelka, M et al. Sick Sinus Syndrome: A Review. Am Fam Physician. 2013 May 15;87(10):691-696.http://www.aafp.org/afp/2013/0515/p691.html#afp20130515p691-t2.

Revision as of 15:39, 23 August 2014

Background

  • Only intervene if pt is symptomatic (hypotension, AMS, chest pain, pulm edema)

Categories

  1. Sinus node dysfunction
    1. Sinus bradycardia
    2. Sinus arrest
    3. Tachy-brady syndrome (sick sinus)
    4. Chronotropic incompetence
  2. AV node dysfunction
    1. 1st degree AV block
    2. 2nd degree AV block Mobitz I/Wenckebach
    3. 2nd degree AV block Mobitz II
    4. 3rd degree AV block (complete heart block)

Differential

  1. Ischemia/Infarction
    1. Inferior MI (involving RCA)
  2. Neurocardiogenic/reflex-mediated
    1. Increased ICP
    2. Vasovagal reflex
    3. Hypersensitive carotid sinus syndrome
    4. Intra-abdominal hemorrhage (i.e. ruptured ectopic)
  3. Metabolic/endocrine/environmental
    1. Hyperkalemia
    2. Hypothermia (Osborn waves on ECG)
    3. Hypothyrodism
  4. Toxicologic
    1. B-blocker
    2. Ca-channel blocker
    3. Digoxin toxicity
    4. Opioids
    5. Organophosphates
  5. Infectious/Postinfectious
    1. Chagas dz
    2. Lyme dz
    3. Syphilis

Sick Sinus Syndrome

  1. Collection of bradyarrhythmias with or without tachycardia[1]
    1. 50% have alternating bradycardia and tachycardia
    2. Causes include:
      1. Intrinsic: degenerative fibrosis, infiltrative disease process, ion channel dysfunction, SA node remodeling
      2. Extrinsic: pharmacologic, metabolic/electrolyte disturbance, autonomic, OSA
    3. Clinical manifestations related to end-organ hypoperfusion
      1. Syncope/pre-syncope (50%)
    4. Dx - ECG identification, inpatient telemetry, outpatient Holter monitoring, event monitoring, loop monitoring
      1. ECG frequently negative for findings early in disease course
    5. Tx - remove extrinsic factors and/or pacemakers
      1. Pacemakers do not reduce mortality, only decrease symptoms
    6. Complications
      1. (50%) Tachy-brady syndrome with atrial fibrillation or atrial flutter
      2. (50%) AV block

Treatment

  1. Atropine
    1. Can be used as temporizing measure (while awaiting pacing and/or chronotropes)
    2. Use cautiously in pts w/ ongoing ischemia (tachycardia may worsen ischemia)
    3. 0.5mg q3-5min (max 3 mg or 6 doses)
      1. may not work in 2nd/3rd deg HB, heart transplant
  2. Chronotropes
    1. Dopamine 2-10mcg/kg/min
    2. Epinephrine 2-10mcg/min
  3. Transcutaneous Pacing
  4. Transvenous Pacing


Antidotes for toxicologic causes

See Also

References

  1. Semelka, M et al. Sick Sinus Syndrome: A Review. Am Fam Physician. 2013 May 15;87(10):691-696.http://www.aafp.org/afp/2013/0515/p691.html#afp20130515p691-t2.
    1. Semelka, M et Al. Sick Sinus Syndrome: A Review. Am Fam Physician. 2013 May 15;87(10):691-696. http://www.aafp.org/afp/2013/0515/p691.html