Understanding EKG and Heart Activity

Introduction to EKG

• Definition: An EKG (Electrocardiogram) is a graphical representation of the electrical activity of the heart.

Key Components of EKG

• QRS Complex: Represents ventricular depolarization.

  • Function: This is when the ventricles contract, pumping blood out of the heart.

• T Wave: Represents ventricular repolarization.

  • Note: Atrial repolarization is not visible on an EKG. This is because it occurs during the QRS complex.

Electrodes and Leads

• Electrode Placement: A typical EKG uses 10 electrodes placed strategically:
  • Limb Electrodes:
  • Right Arm
  • Left Arm
  • Right Leg
  • Left Leg
  • Chest Leads (Precordial Leads):
  • V1: Right side of the chest.
  • V2: Typically the next position on the left side of the chest.

Importance of EKG

• Gold Standard: EKG is considered the gold standard for determining the true heart rate.
  • Reason: It accurately depicts the heart's electrical activity, making it the best method for monitoring heart rate.

Measuring Heart Rate

• To determine heart rate from an EKG:
  • Identify two consecutive R waves (the tall peaks in the EKG waveform).
  • The intervals between these R waves can be used for calculating heart rate.

Understanding EKG Waves

• The peaks on the EKG are outlined by golden lines indicating larger box sizes, which help in measuring intervals and heart rate accurately.