Definition
Normal PAC (premature atrial contraction)
Normal conduction: Uninhibited conduction through AVN. Looks similar to other QRS complexes in the EKG.
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Term
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Definition
Blocked PAC
Non-conducted (blocked): Not conducted because AVN is in refractory phase.
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Definition
Aberrantly Conducted PAC
Conducted with aberrancy: Premature beat is conducted past the AVN but one or more of the conducting fascicles or bundle branches are refractory. Resulting QRS is usually wide, and is sometimes called an Ashman beat or Ashman Phenomenon. |
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Term
| What is the Etiology and Treatment of PAC? |
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Definition
Etiology:
Physiologic: Stress, fatigue
Pharmacologic: Digitalis toxicity, alcohol
Pathologic: Coronary disease, valvular heart disease, electrolyte abnormality, hypoxia
Treatment:
Discontinue participating drugs, stimulants, and toxins
Diagnose and treat the underlying cause
βB for treatment of sustained tachycardias. |
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Term
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Definition
Wandering Atrial Pacemaker
Rate: Between 60-100 bpm
Rhythm: Varies slightly, Irregular P-P interval
Conduction: 1:1
Varying PR interval
Requires at least 3 different P wave morphologies.
Often confused with PACs |
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Term
| What is the Etiology and Treatment of Wandering Atrial Pacemaker? |
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Definition
Etiology:
Physiologic: Variations in vagal tone
Pharmacologic: Digitalis toxicity
Pathologic: Valvular heart disease, hypoxia
Treatment:
Discontinue participating drugs, stimulants, and toxins
Diagnose and treat the underlying cause |
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Term
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Definition
Multifocal Atrial Tachycardia
Rate: Between 100- 180 bpm
Rhythm: Irregular
Conduction: 1:1
Requires at least 3 different P wave morphologies.
Often confused with atrial fibrillation and atrial flutter.
Carotid massage has no effect. |
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Term
| What is the Etiology and Treatment of Multiple Atrial Tachycardia? |
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Definition
Etiology:
Pharmacologic: Digoxin toxicity, methylxanthine toxicity
Pathologic: Lung disease, CAD, CHF, valvular heart disease, diabetes mellitus, electrolyte dysfunction, pneumonia, sepsis.
Treatment:
Discontinue participating drugs and stimulants
Diagnose and treat the underlying cause |
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Term
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Definition
Atrial Flutter
Rate: Ventricular rate usually 60-150 bpm in patients with healthy AVN. Atrial rate usually 250-350 bpm.
Rhythm: Typically regular. May be irregular depending on degree of AV conduction.
Conduction: Variable; often 2:1 or 4:1
“Sawtooth” appearance of P waves. (F waves)
Carotid massage increases block. |
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Term
| What is the Etiology of Atrial Flutter? |
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Definition
Etiology:
Pharmacologic: Digoxin toxicity
Pathologic: Ischemic heart disease/acute MI, CHF, valvular heart disease, post cardiac surgery, PE.
Chest trauma |
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Term
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Definition
Atrial Fibrillation
Rate: Ventricular rate usually 170-180 bpm in patients with healthy AVN. Atrial rate may be greater than 400 bpm.
Rhythm: Irregularly irregular
Conduction: Variable
Originates from multiple areas in the atrial myocardium.
Fibrillatory baseline waves replace P waves.
Carotid massage slows ventricular rate. |
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Term
| What is the Etiology of Atrial Fibrillation? |
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Definition
Etiology:
Pharmacologic: Alcohol use (Holiday Heart)
Pathologic: Ischemic heart disease/acute MI, CHF, valvular heart disease (often rheumatic), post cardiac surgery, PE, COPD, Thyrotoxicosis.
Idiopathic: “Lone AFib”
Inflammation; may be both cause and effect (limited data in humans) |
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Term
| What is the treatment of Atrial Fibrillation? |
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Definition
Treatment:
Rhythm and rate control strategies are associated with similar rates of morbidity, mortality. Rate control; elderly patients. Rhythm control; younger and/or very symptomatic pts. |
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Term
| What is the treatment of Unstable Atrial Fibrillation? |
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Definition
Unstable
<48hrs: Synchronized cardioversion (100-200J).
>48hrs: Cardioversion with TEE to rule out thrombus. |
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Term
| What is the Treatment of Stable Atrial Fibrillation? |
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Definition
Treatment:
Stable: Anticoagulation: Heparin 1mg/kg IV[image]
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