Under construction.
Normal parasternal long axis view (PLAX)
Notice:
The LV diameter in diastole is less than 6cm in men and 5.3 in women (look at the centimetre marks on the side).
The RV (outflow tract) is smaller in diameter than the LV and also contracts. There’s a centimetre or 2 between probe and RV.
The RVOT, Aortic root and LA are of similar diameter in this view usually – some suggest a rule of thirds.
The LV walls move AND thicken (concentric contraction), reducing the distance between them by about 25-30% (fractional shortening) and increasing wall thickness by about half.
The base and apex remain still and the MV annulus moves towards the apex (longitudinal function). The actual apex should not be in this view and you should be able to drop a line down the middle of the screen and catch the open AV leaflets.
Both MV and AV should be in perfect profile. The valve leaflets aren’t thick (2mm max) and move freely with the anterior MV leaflet almost colliding with the septum.
There is a bounce to the rhythm, caused by the 2 phases of diastole – the passive filling E wave and active atrial contraction, the A wave. This is also evident in the ‘double flap’ of the MV leaflets.
The AV leaflets in young people are thin, almost invisible, and open right out into the Sinus of Valsalva.
The descending aorta lies against the LA.