ECGs

• electrocardiography

  • used to monitor and investigate electrical activity in the heart
  • electrons are placed on skin and produces an electrocardiogram(ECG)
  • shows the number of electrical waves produced by activity of the heart
• waves


  p wave=depolarisation of atria/atrial systole

  QRS complex=depolarisaton of ventricles/ventricular systole - largest wave due to largest muscle mass

  T wave=repolarisation of ventricles

  U wave= uncertain of cause

  • the bigger the wave, the greater the electrical activity passing through region of the heart= STRONGER contractions
• tachycardia

  • heart beats too fast
  • over 100BPM
• bradychardia

  • hear beats too slow
  • less than 60 BPM
• ectopic heartbeat

  • early heartbeat folllowed by a pause
  • earlier contractions of the atria or ventricle
• fibrillation

  • heartbeat is irregular so rhythm is lost
  • atria and/ or ventricles stop contracting properly