Electrocardiogram

• Electrocardiogram

  • also known as ECG or EKG
  • test that records the electrical activity of the heart
• Electrocardiography

  • produces an Electrocardiogram
• Electrocardiogram

  • recording of the heart’s electrical activity through cycles
• Sinoatrial node ( 60 - 100 )

  • the heart’s upper chamber
  • conducts electrical impulse
• Atrioventricular node ( 40 - 60 )

  • delays impulse
  • transmits to the ventricles
• Bundle of His ( 40 - 60 )

  • impulse from AV to the ventricles
• Bundle branches ( 20 - 40 )

  • impulse through the interventricular septum
• Purkinje fibers ( 20 - 40 )

  • impulse through the ventricles
  • cause the ventricles to contract
• Inherent rates

  • heart rate generated by cardiac cells and sends impulse
• P - wave

  • atrial depolarization
• Depolarization

  • contract or systole
• QRX complex

  • ventricular depolarization
• T - wave

  • ventricular repolarization
• Repolarization

  • relax or diastole
• P - R interval

  • start of P - wave to QRS
  • conduction through the AV node
• ST interval

  • interval between depolarization and repolarization
• QT interval

  • time taken for ventricular depolarization and polarization
• Rhythm

  • R - R intervals
• Heart rate

  • 1500 / small boxes between 2Rs
  • # of R in between x 10
• 6 second strip method

  • # of R in between x 10
• P - waves

  • present and upright
• P - R interval

  • # of boxes from the start of the p - wave to the start of QRS x 0.04
• QRS complex

  • number of boxes in the QRS x 0.04