Basic Electrocardiography

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Basic Electrocardiography
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Electrocardiogram

• ECG versus EKG
• graphical recording of the electrical activity
  of the heart

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Electrical Stimulation of the Heart

• SA node
• pacemaker
• AV junction (bridge)
• AV node
• bundle of His
• Bundle branches
• right
• left
• fasicles (small subdivisions)
• Purkinje fibers

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Electrical Stimulation of the Heart

• Mayo Clinic
• Lifebeatonline

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Electrical Stimulation of the Heart

• Normal conduction
• sinus rhythm
• Abnormal conduction
• junctional rhythm
• escape pacemaker

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Cardiac Conductivity

• Conduction speed varies throughout the heart
• Slow - AV node
• Fast - Purkinje fibers

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Example

• Sick Sinus Syndrome
• depressed SA node
• light-headedness
• syncope
• bradycardia

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Cardiac Automaticity

• Automaticity
• SA node - primary pacemaker
• Other sites

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Example

• Automaticity can increase outside the SA node
• ectopic (non-sinus) pacemaker
• a run of ectopic beats can lead to abnormal
  tachycardia

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Abnormalities

• blockage of stimuli through AV junction AV
  heart block
• disease of bundle branches bundle branch block
• damage to ventricular muscle abnormal ECG
  pattern

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Class Organization

• Understanding normal ECG and conditions that
  cause abnormal depolarization and repolarization
• Recognizing abnormal rhythms and AV conduction
  disturbances