can you please shed some light?

I recently went to cardiology because of chronic orthostatic hypotension and they performed a transthoracic echo and found 2 ASD's, they then did a TEE which was inconclusive because I was pulling out tube! they then did a bubble echo which showed the saline shunting straight across.  Then they sent me for an MRI to determine more detail. This is where it gets confusing.  The next letter I received said the MRI was normal!!!???.  So I have no idea if I have holes or not.  Is it posible to see clear shunting on a bubble echo and then have no holes? I understand that shunting can be intermittant but not the holes surely.  What could this mean, is it possible for the first two echo's to be wrong or for the MRI to be wrong?  and should they have done the MRI with contrast to see shunting?

I would really appreciate an answer to these questions or possibilities as I appreciate it will be difficult to know specifics.  Thank you

[Mukesh Garg, MD]

Shunts can be intermittent at times and are best evaluated by using various manuovers to change intracardiac pressures (like Valsalva) during TEE with bubble study