ECG%20Practice%20Cases:%20Part%202%20Arrhythmias

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ECG Practice CasesPart 2 Arrhythmias

• Megan Chan, PGY-1
• UHCMC 2015

ttp//thepracticalpsychosomaticist.com/2013/04/01/
qtc-interval-prolongation-and-antipsychotics-by-el
ysha-elson-pharm-d-mph/
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71 y/o female with SOB
DIAGNOSIS?
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What Can Cause AFIB?
Afib with RVR (HR 140) Nonspecific ST T wave
changes
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Atrial Fibrillation

• Etiology
• HTN
• CAD
• Valvular heart disease
• Thyrotoxicosis
• ETOH abuse
• Pericarditis
• Post-operative state
• Treatment
• Medication
• Rate control beta blockers, diltiazem, digoxin
• Rhythm control amiodarone, quinidine,
  procainamide
• DC-Synchronized Cardioversion
• Esp if associated with MI, hypotension, or
  pulmonary edema

http//www.riversideonline.com/source/images/image
_popup/hb7_afib.jpg
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43 y/o female in clinic for follow up
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Her ECG 2 years ago
DIAGNOSIS?
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Her ECG 2 years ago
Sinus tach (HR 100) with RBBB and a PVC
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DIAGNOSIS?
Her Current ECG
New Aflutter with 21 conduction Old RBBB
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AFLUTTER
http//www.medicine-on-line.com/html/ecg/e0001en_f
iles/08.htm
http//www.learntheheart.com/ecg-review/ecg-topic-
reviews-and-criteria/atrial-flutter-review/
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Atrial Flutter

• Etiology
• Pulmonary diseasee.g. pulmonary HTN, PE
• Valvular/ischemic heart disease
• ETOH abuse
• Pericarditis
• Treatment
• Cardioversion
• Medicationssimilar to Afib tx but dont use
  quinidine or procainamide as these can decrease
  atrial conduction to 11
• DC cardioversion
• Ablationesp if sawtooth is down-going

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67 y/o female with palpitations
DIAGNOSIS?
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SVT with LVH (Narrow complex tachycardia, HR
165) (R in I gt 14, R in aVL gt 12, S in V2 R in
V6 gt 35)
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Supraventricular tachycardia

• Pathophysiology
• AV nodal reentrant tachycardia (AVNRT)
• 2 pathways (1 fast, 1 slow) within the AV node
• Common slow-fast AVNRT anterograde conduction
  via slow pathway, retrograde conduction via fast
  pathway
• ECG no discernible P waves (inverted P buried
  within QRS complex) because the atria and
  ventricles activate simultaneously. Pseudo R
  waves in V1 or V2.
• Uncommon fast-slow AVNRT anterograde
  conduction via fast pathway, retrograde
  conduction via slow pathway
• ECG inverted P wave that falls after the QRS
  because the atria activation is delayed
• Orthodromic AV reentrant tachycardia (AVRT)
• An accessory pathway between the atria and
  ventricle that conducts retrogradely
• ECG P waves may or may not be discernable
  depending on the rate. Accessory pathway is far
  enough from the AV node that there is a
  difference in timing of activation of the atria
  and ventricles.

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AVNRT vs AVRT
Accessory pathway between atrium and ventricle
2 pathways within the AV node
http//en.wikipedia.org/wiki/FileAV_nodal_reentra
nt_tachycardia.png
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Common AVNRT
No pseudo R waves during sinus rhythm
Pseudo R waves in V1
Uncommon AVNRT
P waves in yellow falling after QRS
http//lifeinthefastlane.com/ecg-library/svt/
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http//imgarcade.com/1/avrt-vs-avnrt-ecg/
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What Type of SVT is this?
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What Type of SVT is this?
Pseudo R waves
Common AVNRT
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Supraventricular tachycardia

• Etiology
• Ischemic heart disease
• Digoxin toxicity
• Excessive caffeine/amphetamine
• Excessive ETOH
• Atrial flutter with RVR

What is your Next Step in Management?
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Supraventricular Tachycardia

• Treatment
• Maneuvers to increase vagal tone and delay AV
  conduction to block reentry
• Valsalva maneuver
• Carotid sinus massage
• Breath holding
• Head immersion into cold water
• Pharmacotherapy
• IV adenosine agent of choice
• Decreases sinoatrial and AV nodal activity
• IV verapamil, IV esmolol/propranolol/metoprolol,
  digoxin
• DC cardioversion if unstable or meds ineffective
• Prevention
• Digoxin drug of choice
• Verapamil, Beta-blockers
• Radiofreqency ablation

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http//www.emedu.org/ecg/images/ans/2adeno_1a.jpg
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http//www.emedu.org/ecg/images/ans/2adeno_2a.jpg
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Atrial Tachycardia with Adenosine
P waves with blocked AV conduction
http//www.heartpearls.com/tag/adenosine
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72 y/o female with palpitations
DIAGNOSIS?
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What is your Next Step in Management?
NSR with PVC (PVC resembles LBBB because
originating from right tract)
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Premature Ventricular Contractions

• Etiology
• Variation of normal
• Excessive caffeine
• Anemia
• Anxiety
• Organic heart disease (ischemic, valvular,
  hypertensive)
• Medications (e.g. epinephrine, digitalis
  toxicity)
• Metabolic abnormalities (hypoxia, hypokalemia,
  acidosis, alkalosis, hypomagnesemia)
• Treatment
• None if asymptomatic.
• ? mortality if treated. However, gt10 PVCs per
  hour ? risk of death in those with heart
  disease.
• If symptomatic, treat with beta-blockers and
  possibly ablation.

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85 y/o female admitted for falls
DIAGNOSIS?
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DIAGNOSIS?
Sinus Bradycardia (HR 50) with PAC
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Premature Atrial Contractions

• Pathophysiology
• Early beat fires on its own from a focus in the
  atria
• Etiology
• Variant of normal
• Adrenergic excess
• ETOH/Tobacco
• Electrolyte imbalances
• Ischemia
• Infection
• No significance in a normal heart, but may be a
  precursor of ischemia in a diseased heart.

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REFERNCES

• Agabegi SS, Agabegi ED. Step up to Medicine, 3rd
  ed. 2013. Lippincott Williams Wilkins.
  Philadelphia, PA.
• Gomella LG, Haist SA. Basic EKG reading. In
  Clinicians Pocket Reference. McGraw-Hill 2007.
  http//flylib.com/books/en/2.569.1.27/1/.
  Accessed Nov 18, 2014.
• Longo DL, Fauci AS, Kasper DL, et al.
  Electrocardiography. In Harrisons Principles of
  Internal Medicine, 18th ed. 2012. McGraw Hill.
  New York, NY.
• University of Illinois at Chicago. Online ICU
  Guidebook. 2013. http//chicago.medicine.uic.edu/U
  serFiles/Servers/Server_442934/Image/1.1/residentg
  uides/final/icuguidebook.pdf. Accessed December
  1, 2014.