The parasternal long axis view

PLAX is often the first and most useful bedside echo view: it shows the right ventricle, septum, left ventricle, mitral and aortic valves, left atrium and the descending aorta in one slice.

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Probe position

Phased-array probe just left of the sternum in the 3rd–4th intercostal space, marker toward the right shoulder. Slide up or down a rib space and rotate slightly until the LV is long and the mitral and aortic valves are both in plane.

What to look at

Squeeze: do the septum and posterior wall thicken and move inward? Eyeball normal, reduced or severely reduced.
Effusion: black band anterior to the descending aorta.
RV size: roughly equal to the aortic root and LA in normal hearts.

Real scans

Normal parasternal long axis (PLAX) (clip). Normal heart in parasternal long axis: right ventricle at the top, then the septum, left ventricle, mitral and aortic valves. Has a small EchoPedia credit line. CardioNetworks: Vdbilt · CC BY-SA 3.0 · source

Dilated LV with poor function (reduced EF) (clip). Parasternal long axis of a dilated left ventricle that barely contracts: severely reduced ejection fraction. Has a small EchoPedia credit line. CardioNetworks: Secretariat · CC BY-SA 3.0 · source

Learn this with your hands. Sonoduck gives you a 3D patient, a probe and a coach that tells you what to do. Free to start, no signup.

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FAQ

Which way does the marker point for PLAX?

Toward the patient’s right shoulder.

How do I get the short axis from PLAX?

Rotate about 90° clockwise so the marker points to the left shoulder; the LV becomes a ring.

Related guides

The apical four-chamber viewHow to find the apical four-chamber echo view, what normal looks like, and how to assess the RV and LV — with an interactive simulator.
Pericardial effusion and tamponade on ultrasoundHow to see a pericardial effusion on bedside echo (subxiphoid and parasternal views) and the ultrasound signs of tamponade. Interactive beating-heart simulator.
The IVC on bedside ultrasoundHow to scan the inferior vena cava, what IVC size and respiratory collapse suggest about right atrial pressure, and the big caveats.

Educational content for learners; follow local protocols and supervision. Simulated images are generated by Sonoduck’s physics model; real images are credited individually.