Page 3 : Focussed cardiac ultrasound - Based on the views acquired using a BSI level 1 Echo

 Cardiac Ultrasound 

Focussed Cardiac Ultrasound describes echocardiography performed  by non cardiologist , non echocardiographer . There are various protocols , FELS , RACE, EGLS FEEL   etc . In my opinion, the most recognisable across specialties is the BSE level 1 echo .  This is a 17 image protocol using the standard views ( PSLAX , PS short axis x 3 , apical 4 and 5 chamber views and subcostal / IVC ) .The echo taught here is based on the BSE level one echo, but will be called Focussed cardiac Ultrasound 

The indications for focussed cardiac ultrasound include the following 

1) shock ? cause 

2) Shortness of breath ? cause 

3) haemodynamic status ( ie ? hypovolaemia vs vasodilation vs systolic dysfunction  vs diastolc dysfunction ) - useful in deciding whether an unwell patient needs inotropes or fluids 

4) ? pericardial effusion ( also ? tamponade physiology) 

5) Is there obvious valvular dysfunction that might be contributing to patients clinical presentation 

Often one single view can be misleading and several views need to be looked at to put together and useful interpretation 

Tips and tricks 

The PSLAX is the 'cardiologist view '

It gives the most information about the LV , including 

- LV End diastolic diameter LVEDD - the upper limit of normal is about 5 ( 5.1-6.0 depending on BMI , sex  ) For focussed Echo a rough estimate of  normal is acceptable. Normal ranges can be looked up later 

This is best measured at the tips of the MV ( anterior leaflet ) during diastole or the widest you can see on scrolling back the still image.  Another option is to  save it a M mode cut through this level ( anterior leaflet ) 

The wall thickness of the septum can be measured ( avoiding measuring the “knuckle” at the base of the septum and and also the lateral wall.  The upper limit of normal  LV wall and septum is about1 cm ( 0.9 mm in a female and 1.1 in a male . 

EF can be estimated by looking at the “squeeze” , although this can be inaccurate. The End point separation from the septum EPSS is the nearest the tip of the anterior leaflet of the mitral 

This can be measured by taking a “B mode” or normal still ( see images below ) and measuring directly on the B mode still or creating an M mode and measuring . 

The values to remember are as follows 

1) normal EPSS < 7 

2) EPSS > 7 mm = reduced EF 

3) EPSS > 14 = severely reduced 

- RV  : Assessing the RV on the pslax involves eye balling the diameter of the rv and seeing if it lines up with the aortic outflow tract and la , meaninf the diameter of each should be about 3.5 cm or less and in a 1:1:1 rario  of the rv appears bigger ( and im particular bigger than 3.5 cm ,then this probably represents right heart strain ( acute if no increase in rv free wall thickness ,more than half a cm, and chronic if there is evidence of rv wall thickening) 

If you think there is right heart strain there is often flattening of the septum that appears as a flat side to the otherwise oval round shape seen on the parasternal short axis view 

The pressure in the right side of the heart also translates to the ivc making it “ plethoric “ with a diameter of >2.1 cm 

The way in which the rv is “stunned” and is essentially akinetic everywhere except the apex is call mconnells sign

If you were to put a cw doppler through the triscupid valve and measure the velocity of the TR jet, this would be greater than 2.8 m/s ( but also no greater than 3.9 m/sec as this can only get that high in chronic processes) 

Not all PEs have reliable echo findings but the majority of submassive PEs  will !

The best app for resourcing normal values is “ECHOQUICK’’

The PSAX ( parasternal short axis view is the second view ) it is actually made of of three views ( see the next post on the BSE level 1 echo . The PSAX is used ( in the Basic echo    ) to look at the Aortic valve and Mtiral valve and LV in cross section . This latter view can also be used for measuring wall thickness and assessing contractility as well as regional wall abnormality . The following images show how you might measure LV wall thickness and assess EF by measuring fractional shortening  

Measuring thickness of LV wall ( not shown but easy to put callipers edge to edge of LV septum and free wall. This image shows how to work out fractional shortening ( normal range 25-45 , this equivalent to EF of 55-70 % ) 

Below is an image of the LV showing the distribution of the RCA, LAD and Cx across the regions of the LV , specifically ( and in order to) inferior wall , septum ,anterior wall and lateral