Alex saw a patient in June who presented following a syncopal episode associated with chest radiating to the back and neck. He had an initial SBP 70/ which responded to IVT, HR 90-100, sats 95%. He had no past medical history.
Bedside echo was done promptly for the cause of hypotension:
Zoomed in subcostal view shows 1-2cm of pericardial fluid, containing some hyper echoic strands (likely clot in this case) and invagination of the RA (annotated below). Thank you Lisa for saving the images.
Given the story and the echo findings, a prompt diagnosis of type A aortic dissection was made. Cardiothoracics and cardiology attended promptly and the patient transitted rapidly to theatre from CT. He spent 1:45 minutes in ED.
Features suggestive of aortic dissection on ED cardiac ultrasound are:
dilated aortic root >3cm
hyperechoic flap which undulates independent of aortic pulsations (most sensitive)
Signs of tamponade are (in the presence of a pericardial effusion - remember it is still a clinical diagnosis):
RA invagination in systole (seen best in subcostal and apical 4 chamber: A4C views)
RV invagination in diastole (sometimes RV may be so collpased, it is difficult to visualise): seen best in subcostal and parasternal long axis.
Alternating RA and RV collapse gives the seasaw sign seen in the subcostal view
MV doppler variations >25% insp to exp (A4C)
TV doppler variations >40% insp to exp (A4C)
Left image: not much variation; right image: 23% variation inspiration to expiration
Rv and LV interdependence: ie RV collapsed on expiration and LV collapsed on inspiration (seen best in A4C or subcostal four chamber).
If there were a delay to theatre, this patient may have been temporised with intravascular volume expansion and pericardiocentesis.
The easiest technique for US guided pericardiocentesis is left parasternal or apical, with a linear transducer. This is described well in the following article (thanks George P):