How To Obtain This View:
The PLAX view is often the first view to be obtained during the FCU scan.
Patient Position:
Left lateral decubitus, with left arm under patients head.
The transducer is placed in the left parasternal 3rd or 4th intercostal space, with the marker facing the patients right shoulder or 10 o’clock position.
Useful For Assessment Of:
Left Ventricle:
Simple eyeballing can be used to determine LV systolic function. This view is also used for many of the measurements of LV diameter and LV wall thickness. The inferolateral and anteroseptal LV walls are seen.
Right Ventricle:
The right ventricular outflow tract is seen. Its size should be similar to that of the aortic root or left atrium in the normal heart.
Left Atrium:
The left atrium should be assessed for size and presence of clot or masses.
Aortic Root & Ascending Aorta:
The aortic root is normally equal in size to the left atrium in the normal heart. Measurements of left ventricular outflow tract diameter (LVOTd) aortic valve annulus diameter, and aortic root diameter are made in end-diastole. Look for evidence of dilatation or dissection.
Aortic Valve:
The right and non-coronary cusps are seen. Look for valve thickening, calcification, mobility of leaflets or leaflet prolapse. Color doppler can be added to detect aortic regurgitant jets.
Mitral Valve:
The normal mitral valve should open well in diastole and close in systole. Leaflet thickening, calcification, mobility and presence of vegetations should be noted. Any leaflet tissue that appears above the annulus in systole suggests leaflet prolapse or flail leaflet. Color doppler can be used to detect regurgitation.
Pericardial Space & Pleural Space:
Pericardial effusions will be seen as a rim of fluid anterior to the descending aorta. The size of the effusion can be measured with calipers.
Pleural effusions will appear to pass posterior to the descending aorta. See video in interpretation section.
Descending Thoracic Aorta:
This can be seen posterior to the left atrium, and should be evaluated for size and presence of a dissection flap.
Ideal Image Characteristics
- Apex is not seen in the PLAX view
- The LV walls should be perpendicular
- Fan the probe until the largest diameter of the LV is obtained
- Mitral valve and aortic valve are seen
- Minimal angle between LV septal wall and aortic root
- Descending thoracic aorta should be seen posterior to the LA
