Other cardiovascular diagnostic tests

• Resting Echocardiogram:

  • ultrasound to provide moving images of heart
  • provides information about
  • size of hearts chambers
  • thickness and motion of the ventricle walls
  • competence of values
  • presence of thrombus in ventricles
  • Left ventricle function & ejection fraction (EF)
  • equal to/more than 50% = good left ventricle function
  • 35 to 49% = moderate left ventricle function
  • less than 35% = poor left ventricle function
• Echocardiogram pt1:

  • can also be used to see if valves are working correctly to ensure blood is pumped around the myocardium in the correct path
  • this echocardiogram shows the mitral valve open, allow blood to flow from the left atrium to the left ventricle, representing diastole

  
• Echocardiogram pt2:

  • this echocardiogram shows the mitral valve closed, preventing blood to flow from the left atrium to the left ventricle, representing systole

  
• Stress Echocardiography:

  • Exercise echo
  • resting echo performed
  • exercised on treadmill or bike
  • when peak heart rate reached echo reoeated
  • ultrasound image is taken to determine whether myocardium is getting enough blood and oxygen during exercise
  • ischaemic myocardium will be stiff and less flexible
  • Dobutamine echo
  • dobutamine injected - increases heart rate and increases contraction
  • used for this unable to exercise or to:
  • produce high quality images with no interference from deep breathing or muscle tremors caused by exercise
• Diagnostic Criteria for Stress Echocardiography:

  • summarised into 4 equations centred on regional wall function and describing the fundamental response patterns:
  • normal
  • ischemic
  • necrotic
  • viable
• Nuclear Imaging - Myocardial Perfusion Scans:

  • inject radio isotope (thallium) picked up on xray
  • determine evidence of ischaemia
  • scan below shows evidence of ischaemia during exercise (dark image) that returns to normal when the heart is at rest demonstrating reversible ischaemia

  
• Cardiac MRI (Magnetic Resolution Imaging)

  • gold standard non-invasive investigation which shows both still and moving pictures of the heart:
  • structure - differentiate cardiomyopathy types
  • pumping ability - left ventricle function
  • valve competency
  • stress induced myocardial ischaemia
  • cant be used with patients who have large metallic implants
• Chest X-ray:

  • patient has to remove all clothes and jewellery from the waist
  • the xray machine sends a beam of ionising radiation through an xray tube
  • the energy passes through the chest and is absorbed on film to create a picture
  • bone and other dense areas show up as light shades of grey
• Chest X-ray - heart failure:

  • can look at the size of the myocardium in relation to the mediastinum
  • if the heart is enlarged it could indicate heart failure