Catherization Results vs Echo Results

I just returned from a catherization. I am a 54 yo woman, overweight and  on meds for high blood pressure, cholesterol and diabetes.

I have been diagnosed with a subaortic membrane for about 4 years.  Last summer I started feeling tired and dizzy. The echo reports showed the following:
Dec 05 the peak gradient was 32mmHg;  
Jan 07 it was 46mmHg;
May 07 it was 62mmHg.  

The catherization I just had showed the peak gradient at 8-11,5 mmHg.

The cardiologist is thinking that my dizziness and fatigue is due to being overweight.  I do swim laps two to three times weekly, but have had more difficulty with that due to shortness of breath.

The echos also report report moderate pulmonary hypertension.  I recently had a sleep study that showed no sleep apnea and PFT was relatively normal (I think).

My cardiologist wants to send me to a major medical center for another opinion.  Any thoughts on why the peak gradient may show up differently on the echos and on the catherization.  

Thanks.

[FLBrat]

No thoughts regarding the gradients.  Just caution on the swimming if you get dizzy easily.  You may want to switch out to something like walking.  Swimming and fainting (dizziness) dont go too well together.

[Jack54]

To accurately determine pulmonary hypertension, you need a "right side" heart cath. They normally will not do one unless they really suspect it, PH that is. Good luck on losing weight :)