II. Technique: Transducer

  1. Transducer orientation
    1. Transducer placed at PMI or approximately xiphoid level (6th intercostal space) in mid-clavicular line or nipple line
      1. Identify heart apex with other views (e.g. PLAX)
    2. Transducer indicator pointed towards patient's left (3:00 position)
    3. Align energy toward right Shoulder along heart's long axis
    4. Hand holding transducer is pushed with knuckles into the bed to get best angle through heart
    5. Four chamber apical view will appear bullet shaped, oriented vertically
    6. Five chamber view obtained by then angling the transducer slightly anterior toward the chest wall
  2. Images
    1. UltrasoundHeartApical.jpg
    2. ultrasoundProbePositionEchoApical.jpg
    3. ultrasoundBMP_cvApical.jpg

III. Technique: Landmarks - Four chamber heart view

  1. Right ventricle
    1. Triangular appearance
    2. Does not extend to the apex
  2. Left ventricle
    1. Extends to apex (unlike right ventricle)
  3. Tricuspid valve
    1. Appears higher on the screen, closer to probe, more inferior in chest
  4. Mitral valve
    1. Trace regurgitation is common
  5. Right atrium, left atrium and descending aorta

IV. Interpretation: General

  1. Pericardial Effusion (best view for Pericardiocentesis)
  2. Apical thrombus (decrease depth to see, apex is closest to probe in this location)
  3. Systolic Dysfunction
  4. Wall motion abnormalities

V. Interpretation: Stroke Volume (Velocity-Time Integral or VTI)

  1. Precautions
    1. Inaccurate in moderate to severe Aortic Regurgitation or dynamic LVOT obstruction
  2. View: Apical 5 Chamber View
    1. Start with 4 chamber apical view (see above)
    2. Angle the transducer slightly anterior toward the chest wall
  3. Measurement of Velocity-Time Integral (VTI) of the Left ventricular outflow tract (LVOT)
    1. Set Ultrasound machine to Pulse Wave doppler (PWD)
    2. Place cursor in Left ventricular outflow tract (LVOT)
      1. Place cursor as close to aortic valve without including it
    3. Capture Pulse Wave doppler (PWD) wave form and freeze the image
      1. PWD wave form will appear as a sharks fin
    4. Measure the area under the curve of the PWD wave form (LVOT VTI)
      1. Choose LVOT VTI from the Ultrasound calculation menu
      2. Manually trace the wave with the cursor
      3. Machine calculates the area under the curve (VTI in cm)
  4. Interpretation of Velocity-Time Integral (VTI in cm)
    1. Normal adult VTI = 18 to 22 cm (when Heart Rate 55 to 95 beats/min)
  5. References
    1. Blanco (2015) J Ultrasound Med 34(9): 1691-700 [PubMed]

VI. Interpretation: Fluid responsiveness based on Velocity-Time Integral (VTI in cm)

  1. Technique
    1. Obtain initial VTI measurement (as above)
    2. Perform Passive Leg Raise Maneuver (PLR Maneuver)
    3. Repeat VTI measurement (as above)
  2. Interpretation
    1. Increase in Velocity-Time Integral (VTI in cm) of 15% with passsive leg raise suggests fluid responsive
  3. References
    1. Blais (2009) Crit Care 13(6): R195 [PubMed]

VII. Resources

  1. Apical 4-Chamber View Video (SonoSite)
    1. http://www.youtube.com/watch?v=_eHZz-OCc_M
  2. Echocardiographer
    1. http://echocardiographer.org/

VIII. 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
  5. Stowell, Kessler and Lotz (2017) Crit Dec Emerg Med 31(8): 13-22

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