Bradycardia resident survival guide

Jump to navigation Jump to search
Bradycardia Resident Survival Guide Microchapters
Overview
Causes
FIRE
Diagnosis
Treatment
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]: Associate Editor(s)-in-Chief: Ogheneochuko Ajari, MB.BS, MS [2]; Vidit Bhargava, M.B.B.S [3]

Overview

Bradycardia is defined as a sinus rhythm with a rate < 60 beats per minute. A heart rate of < 50 beats per minute is used as a working definition of bradycardia causing symptoms.[1] The evaluation of bradycardia includes assessment of heart rhythm, symptoms and associated medical conditions. The management of symptomatic bradycardia typically involves treating the underlying causes, the use of medications (e.g. atropine) or insertion of temporary or permanent pacemaker. Nevertheless, some asymtomatic bradycardias may require treatment to prevent complications.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

Click here for the complete list of causes.

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The initial rapid evaluation is based on the 2005 AHA guidelines for cardiopulmonary resuscitation and emergency cardiovascular care.[2]
Boxes in red signify that an urgent management is needed.

Abbreviations: IV: Intravenous; ECG: Electrocardiogram

 
 
 
 
Identify cardinal findings that increase the pretest probability of bradycardia
Heart rate < 50 beats/min
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Does the patient have any of the following findings of hemodyanamic instability that require urgent treatment?
Shock
Altered mental status
Hypotension
Hypothermia
Oliguria
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Yes
 
No
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Initial Stabilization
Do the following simultaneously without delaying the treatment

❑ Maintain patent airway
❑ Assist breathing if required
❑ Place patient on cardiac monitor
❑ Give supplemental oxygen
❑ Monitor blood pressure and evaluate oxyhemoglobin saturation
❑ Establish IV access
❑ Obtain ECG to define rhythm
❑ Evaluate clinical status and identify reversible causes simultaneously
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Is there an AV block?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
No
 
 
Yes
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Second degree AV block/Third-degree AV block
 
First degree AV block
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
First Line Treatment Option
❑ Administer atropine 0.5 mg IV bolus and repeat every 3-5 mins with a maximum dose of 3 mg

Second Line Treatment Options

❑ Administer Dopamine infusion (2-10 mcg/kg/min)
OR
❑ Administer Epinephrine infusion (2-10 mcg/min)
OR

❑ Proceed with transcutaneous pacing
(Class IIa, level of evidence B)
 
DO NOT GIVE ATROPINE
❑ Proceed with transcutaneous pacing
 
First Line Treatment Option
❑ Administer atropine 0.5 mg IV bolus and repeat every 3-5 mins with a maximum dose of 3 mg

Second Line Treatment Options

❑ Administer Dopamine infusion (2-10 mcg/kg/min)
OR
❑ Administer Epinephrine infusion (2-10 mcg/min)
OR

❑ Proceed with transcutaneous pacing
(Class IIa, level of evidence B)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Are the signs of poor perfusion or shock persisting?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Yes
 
No
 
 
 
 
 
 
 
 
 
 
 
 
❑ Consult a cardiologist and
❑ Prepare patient for transvenous pacing
 


Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.[1][3]

Abbreviations: CK-MB: Creatine kinase myocardial type; ECG: Electrocardiogram; TSH: Thyroid stimulating hormone

 
 
 
Characterize the symptoms:

Lightheadedness or dizziness
Dyspnea
Chest pain
Altered mental status
Syncope
Fatigue
Exercise intolerance
Obtain a detailed history:
Age (bradycardia is commonly seen in the elderly)
❑ Use of negative chronotropic medications

Beta blockers
Calcium channel blockers
Digoxin

❑ Past medical history

Disease in the sinus node
AV nodal disease
❑ Age-related fibrosis and sclerosis
Infection
Increased intracranial pressure
Electrolyte disturbance
Exposure to toxins
Surgery
Heart transplant
Sleep apnea
Myocardial infarction
Hypothyroidism
 
 
 
 
 
 
 
 
 
 
 
 
Examine the patient:

Vitals
Pulse

❑ Rate
Heart rate < 60/min
❑ Rhythm
❑ Slow regular
❑ Irregular pulse of varying intensity (suggestive of the 2nd and 3rd degrees of AV block)

Respiration

Tachypnea

Blood pressure

Hypotension in some cases

Skin
❑ Inspection

❑ Dry or coarse skin
❑ Dry or coarse hair
Pallor
❑ Facial edema (not common)

❑ Palpation

❑ Cool lower extremities (due to poor cardiac output)

Neck

Jugular venous distension (suggestive of heart failure)
Cannon a waves in jugular venous pulse (suggestive of complete heart block)

Respiratory examination
❑ Assessment of respiratory effort movement

❑ Intercostal retractions
❑ Suprasternal retractions

❑ Auscultation

Rales (uncommon)

Cardiovascular examination
❑ Auscultation

Heart sounds
S3 (uncommon)

Abdominal examination
❑ Percussion

Ascites - suggestive of heart failure (uncommon)

Extremities
❑ Inspection/palpation

❑ Lower extremity edema - suggestive of heart failure (uncommon)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Order tests:
First initial test

12-lead ECG (to determine rhythm)

12-lead ECG showing sinus bradycardia

Other initial tests
Holter monitoring- to evaluate

❑ Severe sinus bradycardia
❑ Sinus pauses
❑ Sinus arrest
❑ Second-or third-degree AV block

Exercise stress testing (for diagnoses of sick sinus syndrome and ischemic heart disease)
Carotid sinus massage (to evaluate carotid sinus hypersensitivity)
Echocardiogram (to evaluate valvular heart disease)
Laboratory tests
Thyroid function tests (elevated TSH in hypothyroidism)
Basic metabolic panel (to determine electrolyte disturbances)
Cardiac enzymes (creatine kinase, CK-MB and troponin)
Serum creatinine (elevated in renal impairment)
❑ Serum digoxin (for junctional bradycardia)
Other Investigations
Tilt-table testing (to evaluate autonomic system and diagnosis of neurocardiogenic syncope)

Electrophysiologic testing (to evaluate bradyarrhythmias)
 

Treatment

Shown below is an algorithm depicting the treatment of bradycardia based on the 2010 AHA guidelines for cardiopulmonary resuscitation and emergency cardiovascular care.[1]

 
 
 
Bradycardia/Bradyarrhythmia with heart rate
< 60/min
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Determine signs and symptoms of hemodynamic instability
Hypotension
❑ Acutely altered mental status
❑ Signs of shock
Ischemic chest discomfort
❑ Acute heart failure
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Unstable
 
 
 
Stable
 
 
 
 
 
 
 
 
 
 
 
 
 
 

❑ Close follow up and monitoring
❑ Identify and treat underlying causes
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Sinus node dysfunction

❑ Treat underlying cause

❑ Withdrawal of medication
❑ Administer electrolytes to correct for imbalance
❑ Correction of thyroid dysfunction
❑ Correction of hypoglycemia
❑ Give Theophylline 200-400mg PO twice daily for fatigue and/or dizziness
Temporary pacing for severe symptoms
Permanent pacing for irreversible causes with severe symptoms (e.g. Sinus node dysfunction with AV block or Afib
 
AV Block
Acquired or Congenital
❑ Treat underlying cause
Temporary pacing if indicated
❑ Reassurance for irreversible causes without indication for pacing
Permanent pacing for symptomatic irreversible causes
 
Carotid sinus hypersensitivity
Permanent pacing
 
Neurocardiogenic syncope

❑ Lifestyle modification

❑ Adequate salt and fluid intake
❑ Elevation of legs, lying down and tensing maneuvers
❑ Avoid precipitating factors

Fludrocortisone 0.1-0.2mg PO once daily
OR
Midodrine 2.5-10mg PO tid
OR
Fluoxetine 20mg PO once daily
OR

Permanent pacing
 

Do's

Don'ts

  • Do not treat asymptomatic or minimally symptomatic patients, unless the rhythm is likely to progress to symptoms or become life threatening.[1]
  • Do not delay pacing if the rhythm is Mobitz type II second degree block or third-degree AV block even if the patient is asymptomatic.
  • Do not use atropine in hypothermic patients with either bradycardia or Mobitz type II second degree AV block.
  • Do not use atropine to treat bradycardia in cardiac transplant patients as the transplanted heart lacks vagal innervation.[1]
  • Do not use atropine to treat type II second degree and third degree heart blocks since their management requires transcutaneous/transvenous pacing.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Neumar, RW.; Otto, CW.; Link, MS.; Kronick, SL.; Shuster, M.; Callaway, CW.; Kudenchuk, PJ.; Ornato, JP.; McNally, B. (2010). "Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care". Circulation. 122 (18 Suppl 3): S729–67. doi:10.1161/CIRCULATIONAHA.110.970988. PMID 20956224. Unknown parameter |month= ignored (help)
  2. "Part 7.3: Management of Symptomatic Bradycardia and Tachycardia". Circulation. 112 (24_suppl): IV-67–IV-77. 2005. doi:10.1161/CIRCULATIONAHA.105.166558. ISSN 0009-7322.
  3. "Part 7.3: Management of Symptomatic Bradycardia and Tachycardia". Circulation. 112 (24_suppl): IV-67–IV-77. 2005. doi:10.1161/CIRCULATIONAHA.105.166558. ISSN 0009-7322.

Template:WH Template:WS

Cardiology