ECG Cardiovascular Investigations

• Electrocardiography:

  • Electrocardiography (ECG) is a transthoracic interpretation of the electrical activity of the heart over a period of time, as detected by electrodes attached to the outer surface of the skin an recorded by a device external to the body
  • provides a simultaneous snapshot of the hearts electrical activity
  • provides information about:
  • the heart rate and rhythm (regular or irregular)
  • whether electrical activity in the atria and ventricle are normal
  • presence or absence of good teamwork between the atria and ventricles
• Electrocardiography:

  • analysing the ST segment can determine whether has angina or myocardial infarction

  
• ECG - Stable Angina:

  • fixed coronary artery disease
  • chest pain/tightness on exertions - relieved by rest/nitrates
  • ST segment depression on ECG

  A) stable angina

  
• ECG - Myocardial Infarction:

  • atheroma/thrombus in coronary artery -> necrosis (scar tissue)
  • ST segments elevation or depression on ECG
  • plus elevated troponin (blood marker showing theres necrotic myocardial tissue)
  • plus symptoms
  • ST segment elevated myocardial infarction will have elevated troponin and symptoms
  • ST segment depression myocardial infarction will have have elevated troponin, which is how you differentiate it from stable angina

  A) elevated myocardial infarction

  B) depressed myocardial infarction