Fibrillation of the Atria and Common ECG Abnormalities

1
Atrial Fibrillation

• An Overview For Electrocardiogram Technicians

2
What is Fibrillation?

• A rapid and uncoordinated muscular contraction
• Results in decrease cardiac output in the heart
• Severity depends on the chamber affected
• Cause by aberrant electrical impulses
• Leads to predictable abnormalities on the EKG

3
Cardiac Structure

• The heart contains four chambers
• Two smaller chambers on the top known as atria
• Two larger chambers on the bottom called
  ventricles
• Fibrillation can occur in either the atria or
  ventricles
• Ventricular fibrillation is more severe

4
Atrial Function and Fibrillation

• Primary purpose is to force blood into the
  ventricles
• Right chamber contains a sinoatrial node that is
  responsible for regulating electrical stimuli
• Fibrillatory impulses originate from tissue near
  the pulmonary veins
• Allowed to wonder aimlessly through the atria
• Sustained by re-entry circuits

5
Atrial Function and Fibrillation

• Irregular and uncoordinated contractions result
  in less blood being pushed into the ventricles
• Decreases cardiac output
• Less oxygen and nutrients delivered to the body
• Can cause signs and symptoms
• Electrical stimuli usually do not enter the
  ventricles

6
EKG Changes

• Absent P waves
• Fibrillatory waves
• Loss of the isoelectric baseline
• QRS abnormalities
• Ventricular rate variations
• Irregular rhythms

7
Medical Evaluation

• To be performed by nurses and physicians
• May order additional studies such as
  echocardiogram and Holter monitoring
• Ensure test quality
• Identify obvious abnormalities
• Diagnosis and treatment can be complex

8
Resources

• Atrial Fibrillation ECG
• www.ekgtechniciansalary.org