Click on the button below to go to the main page:

Cardiac US

Click on the button below to go to the previous page:

PSax

APICAL FOUR CHAMBER

This view allows you to see all the chambers of the heart at once. However, it is also the most difficult view to get on axis in the supine patient, Advanced assessment of LV (LVOT VTI and Simpsons') and RV (TAPSE) systolic function is best assessed in this view.

Probe placement:

  • Over apex beat or 5th IC space anterior to mid axillary line
  • If the patient is supine, the apex is more medial than expected
  • Probe marker to 3 o'clock; Probe held almost horizontally
  • Fanning towards the patient's R shoulder

A4C probe marker at 3 o'clock

ideal A4C: note the crus of the heart is nice and vertical. At the apex LV walls are clapping, not bowing towards the MV

The ideal on axis A4C is with the probe at the LV apex, fanning up towards the base of the heart. Thus, the heart should be vertical (on its head and the LV walls should come together like they're clapping.

You may have to push into the intercostal space to define the LV walls. In this view, the IV and IA septa and the mitral and tricuspid valves should have an inverted cross shape. You should angle and manoever the probe until the heart looks as long as possible. This means you are right at the apex. When the heart looks fat and baggy, it means you are slicing above or medial to the apex: thus the heart will look foreshortened. A foreshortened A4C will give the appearance of systolic dysfunction.  

Sometimes in may not be possible to get both the RV and LV in view and you may need to look at one side and then the other. Held expiration or inspiration may also help make the imaging better. 

And if all else fails, get the patient to turn to the left lateral position with their arm above their head. This moves the apex closer to the chest wall. 

In the A4C look at all chambers and assess for size relative to each other. 

LV

Long conical shape. LV walls come in together like clapping hands.

MV

opens fully, thin, coapt at the end of diastole

LA and RA

Equal in size, IA septum usually straight

RV

V shaped. Smaller than the LV. Tapers at the apex, Lateral wall moves up and down with systole. 

APICAL 5 CHAMBER

Fanning anteriorly on the A4C view will reveal the ascending aorta emerging from the left ventricle. This is called the A5c and is used to to measure the LVOT VTI. Often people forget whether the probe marker should be at 3 or 9 o'clock for A4C. Checking which chamber the aorta originates from is a good way to confirm which chamber is the LV.

A5C view

The heart is a bit foreshortened (note apex of LV seems rounded). Sometimes this is necessary to get a view of the ascending aorta and make it parallel to the pw doppler line of sight.

APICAL 2 CHAMBER

This view gives you just the LV and LA. It is important because the LV walls are made up of the true anterior and inferior walls. This is important for vascular territory: anterior wall (LAD) and inferior wall (RCA). If you're not sure which wall is which, rotate anticlockwise a tiny bit more and you will see the aorta emerge from the LV. The side of the aorta is the anterior wall. Then rotate clockwise back to the 2 chamber to save a clip.  

To get this view, rotate the transducer anticlockwise 90 degrees from the perfect A4C. Once the transducer marker is at 9 o'clock, fan slightly to the patient's right shoulder. This closes off the RV and RA from the A4C. 

APICAL 3 CHAMBER

This view also gives you the ascending aorta which is important when measuring VTI and AR. From the A2C, if you rotate a further 20-30 degrees, you will see the ascending aorta and LVOT.  It's a useful view for the VTI when you can't get a good angle with the five chamber view. 

TROUBLE SHOOTING FOR A4C

FORESHORTENED HEART

When the transducer is more medial than the true apex of the heart, the heart will seem baggy and round and the apex will fold into the LV cavity. To fix this, sweep/ slide your transducer laterally and more caudally. Especially in the elderly, the apex is more lateral and inferior than you may think. 

CORONARY SINUS IS VISIBLE

The main vein of the heart - the coronary sinus - sits posteriorly between the atria and ventricles. This is visualised as an anechoic stripe between the atria and ventricles when the transducer is angled to posteriorly. Just fan a tiny bit anteriorly and you will close this off and see the RV and MV again. 

RV CLOSING OFF 

If the RV looks like a tiny triangle next to the LV, it maybe because the LV is really dilated and dominating the view or it could be off axis imaging. To fix your imaging technique and open up the RV rotate slightly clockwise. 

If the RV if closing off rotate clockwise

HEART IS ON ITS SIDE

This happens if you've accidentally rocked the transducer too laterally. Rock medially or sweep a bit more laterally and then rock medially to fix this, 

LV ON THE LEFT OF SCREEN

This happens when the marker on the transducer is at 9 o'clock instead of 3 o'clock with the echo preset or because you have accidentally chosen the abdo preset on the echo transducer and the probe marker on the screen is on the left rather than the right. 

The easiest way to figure out which side is the LV is to angle the transducer anteriorly and get an A5C, see which chamber the aorta arises from and adjust you transducer/ preset accordingly. 

Other features to help differentiate LV and RV (which persist even in cases with pathology) are:

RV has trabeculations, has a moderator band and no papillary muscles.

TV is closer to apex than the MV

LV has papillary muscles. 

Click on the button below to go to the next page:

subxyphoid