Hello,
Is this something that can come or go, or did the technician fail to notice it?
It could be either. Not all echo lab do routine diastolic function evaluations. Diastolic function can change depending on well your body is doing. For example, someone with severe heart failure can have severe diastolic dysfunction that improves markedly to diursis with lasix. It is possible that you just were better compensated during one of your echos.
I am scheduled for a RHC for Pulm. Hyper. and am wondering if they should do a LHC also.
If you have normal heart function, a LHC is probably not helpful. It would be helpful is they are worried about coronary artery disease or valvular disease that cannot be assessed non invasively with an echo.
What causes right atrial enlargement?
The most common cause is increased right ventricular pressure (as would be seen with pulmonary hypertension). There are many causes of pulmonary hypertension -- it is a very extensive work up, in fact at tertiary centers there are physicians that only see and specialize in pulmonary hypertension. There are some valvular problems that causes right atrial enlargement, but his would have been seen with your echo.
I hope this helps. Thanks for posting.