Parasternal Long-Axis Echocardiogram View


Parasternal Long-Axis Echocardiogram View, PLAX View, E-point Septal Separation, EPSS, Aorta Diameter Measurement on PLAX View, Aortic Dissection on PLAX View

  • Background
  1. Improved window (bring heart closer to transducer and reduce rib shadowing)
    1. Patient positioned in left lateral decubitus position (if possible)
    2. Start along sternal border near the 3rd interspace and check several interspaces inferiorly and laterally (to left)
    3. View improves when patient breathes out
    4. More difficult view in COPD or Asthma
    5. Preferred view in Obesity, pregnancy or Ascites (increased abdominal pressure pushes the heart upward into the chest)
  2. Transducer orientation
    1. Transducer 3-5 cm to the left of the left sternal border at the 3rd to 5th intercostal space
    2. Transducer indicator pointed towards patient's right Shoulder (10:00 position) in cardiac mode
  • Technique
  1. Images
    1. UltrasoundHeartPLAXAndPSAX.jpg
    2. ultrasoundProbePositionEchoPLAX.jpg
    3. ultrasoundBMP_cvPLAX2.jpg
  2. Landmarks
    1. Right ventricle or right ventricular outflow tract
    2. Left ventricle, aortic valve and proximal aorta
    3. Mitral valve and left atrium
    4. Descending Aorta
  • Interpretation
  • General
  1. Visualizes the positions of the parasternal short axis cross sections (see below)
  2. Wall motion abnormalities (especially apex and septum)
  3. Valvular insufficiency (Mitral Regurgitation or Aortic Insufficiency) with color doppler
  4. Aortic root dilation (best imaged with same probe orientation but at the 3rd intercostal space)
  1. Decreased contractility of left ventricle
    1. Normal
    2. Depressed or severely depressed
    3. Hyperdynamic
  2. Decreased ejection fraction
    1. Gross Estimate
      1. Estimate visually what percentage difference is seen between the left ventricle volume in systole and diastole
      2. M-mode compare end-systolic (ESD) and end-diastolic (EDD) diameters
    2. Linear calculation: Ultrasound calc package
      1. In M-Mode, measure end-diastolic (EDD) and end systolic (ESD) diameters
      2. Ejection fraction = 100 * (EDD^3 - ESD^3) / EDD^3
  3. Dilated left ventricle (end diastolic diameter >56 mm)
    1. Measure across widest point between septum and posterior wall
    2. Chordae tendinae may obscure true posterior wall
  4. E-point Septal Separation (EPSS) on M-Mode or cine
    1. Distance between the septum and the mitral valve leaflet when maximally open
    2. Normal is <8-10 mm (>13 mm is correlated with an EF<30%)
  5. Aorta Diameter Measurement on PLAX View (for Aortic Dissection)
    1. Evaluate for Thoracic Aortic Dissection (Type A)
    2. Obtain Parasternal Long-Axis Echocardiogram View (PLAX View)
    3. Measure the maximal distance between anterior and posterior walls of aorta
      1. Probe should be perpendicular to the two aorta walls
      2. Distance >4 cm is concerning for Aortic Dissection
      3. Other suggestive findings: Pericardial Effusion, flap within the aorta
  • Interpretation
  • Other findings
  1. Mitral valve stenosis
    1. Vitral valve will have a hockey stick appearance at flap distal end (curving away from septum)
    2. Incomplete opening of the mitral valve septum
  • Resources
  1. Parasternal Long Axis View Video (Sonosite)
    1. http://www.youtube.com/watch?v=4qerzEW_ASU
  2. Echocardiographer
    1. http://echocardiographer.org/
  • References
  1. Mateer and Jorgensen (2012) Introduction and Advanced Emergency Medicine Ultrasound Conference, GulfCoast Ultrasound, St. Pete's Beach
  2. Noble (2011) Emergency and Critical Care Ultrasound, Cambridge University Press, New York, p. 61-88
  3. Orman, Dawson and Mallin in Majoewsky (2013) EM:Rap 13(1): 4-6
  4. Reardon (2011) Pocket Atlas Emergency Ultrasound, McGraw Hill, New York, p. 61-106