Parasternal Long Axis

PLAX

The parasternal long axis view (PLAX) is excellent for assessing the posterior pericardium, where very early effusions will be identified. The left atrium (LA), mitral valve (MV), left ventricle (LV), left ventricular outflow tract (LVOT) and aortic valve (AV) are all seen very clearly. The right ventricular outflow tract (RVOT) is closest to the transducer.

The movement of the mitral valve leaflets should be dynamic and energetic and the anterior leaflet should almost touch the interventricular septum in diastole. If not the myocardial motility is sub-optimal. Similarly if the movement of the mitral valve leaflets are hyper-dynamic and the left ventricle completely collapses each cycle, then this suggests the patient is hypovolaemic and would benefit from an urgent fluid challenge.