December 2007
Question: In the still image, what are the chambers labeled 1 and 2 and the structures labeled 3 and 4? Refer to the two animations that follow.

Answer: 1 and 2 are both the right atrium, 3 is a Chiari network, and 4 is the tricuspid valve. Many readers mistook the Chiari network for the interatrial septum, but the bubbles enter the RA on either side of the Chiari network simultaneously.

The Chiari network is a remnant of the right valve of the sinus venosus. Briefly, in the development of the RA, there are 2 portions: the auricular portion, or rough RA, and the sinus venosus or smooth RA. The sinus venosus is initially made up of right and left horns. The right valve of the sinus venosus separates the rough and smooth portions, in essence creating “2 RA chambers”. With fetal development, the left horn becomes the coronary sinus, and the right becomes the SVC and IVC and the remainder of the smooth RA. The right valve regresses, and persists as the crista terminalis (the ridge separating the smooth and rough portions), the thebesian valve (the entry to the coronary sinus) and the eustachian valve (the entry to the IVC). The Chiari network is a membrane that pathologically persists, and joins these 3 structures. It is often fenestrated or strand like, and rarely causes problems although it may obstruct flow or become infected.

November 2007
Question: The 2D and colour Doppler clips, and the 2 figures are taken from a 57 year old male who was 2 weeks status post MVR for mitral valve prolapse, and was admitted to the hospital in extremis. What do these clips & figures suggest is going on?

Answer: The 2D clip shows a bioprosthetic valve in the mitral position; the 2 leaflets that are seen are coated with a substance that resembles the large mass in the left atrium (Answer picture 1). The mean gradient of 22 mmHg leaves no doubt that there is mitral stenosis. The colour Doppler shows an intense inflow jet which aliases; I omitted the aliasing scale which is set at 55. Given the time sequence, it was obvious that the masses in the LA and on the mitral bioprosthesis were thrombus; the surgeon is seen holding the LA mass (Answer picture 2). Subsequent workup showed the patient to be HIT positive (heparin induced thrombocytopenia). A mechanical mitral valve was placed and the patient recovered uneventfully.

October 2007
Question: What is the pathology seen in the video clip, and what structures do the arrows indicate in the still?

Answer: There has been a penetrating aortic ulcer, and the blood has tracked down to fill the media of the whole ascending aorta. The 2 structures are:

1. pericardial recess filled with fluid (Right hand frame), and
2. the left main coronary artery (left hand frame).

September 2007
Question: These 2 echos are from an exam of an 18 year old woman with no previous medical history except for IVDU. How are the 2 echos related?

Answer: The first clip shows the mitral valve with a vegetation attached, and as well a mass in the dome of the left atrium which also proved to be vegetation. The second clips show a lateral wall defect, more pronounced in the right hand panel. A piece of the vegetation embolized down the circumflex artery (Sept answer A),with subsequent myocardial ischemia and infarction. Later on, on followup TTE, a cystic mass was seen in the lateral wall of the LV in an apical 4 chamber view (Sept answer B)-angiography confirmed the presence of a coronary aneurysm, presumably mycotic. (Sept answer C).

August 2007
Question: In clip#1 and still#1, a right ventricular assist device (RVAD) outflow cannula is seen in the right pulmonary artery. An intervention was performed. In clip#2 in the left hand panel, the 4 chamber view was taken before the intervention, and the right hand panel after the intervention. What do the clips indicate, and what was done at the intervention?

Answer: The first clip and still show an RVAD outflow cannula ("outflow" refers to the fact that the flow is coming out of the device) which is sitting in the right main PA, and in fact the flow abuts on the wall of the PA. This is clearly not a satisfactory situation, and resulted in very low flow from the device. This is manifest in clip 2 left hand panel is which there are clear signs of RA hypertension-the RA is full, and the IAS bows towards the LA. The outflow cannula was repositioned in the main PA, and the right hand panel of clip 2 shows decompression of the RA.

July 2007
Question: Examine the 2 clips, the 2 stills, and describe the pathology in each, and how they are interrelated. (The Doppler tracing is taken from video clip number 2)

Answer: Clip #1 shows the right side of the heart; the RA is massively dilated, and the tricuspid leaflets do no coapt. This patient had rheumatic tricuspid valvular disease. Still #1 shows a transgastric view of both ventricles; there is RVH and a “D” shaped septum indicative of RV pressure overload. These clips indicate the likelyhood of high RV pressure, and this is confirmed when examining the clip#2 and the still#2; the pulmonic valve is seen to open partway through diastole, and the PW tracing shows a diastolic signal below the baseline indicative of PR, and then forward flow during the later half of diastole. At surgery, the pulmonic and tricuspid valves were replaced, with good results.