Hell Kiran - thanks for your question. Sounds like you are frustrated - can't say I blame you.
The first thing you might do is to go back to your cardiologist. Make certain all due diligence is being done. If you are not happy still you can always find a second opinion. I fyou need help finding a doctor you migh try our locator information.
As well, if you feel aniety may be playing a role in this, you mig htbe intersted in reading our sister site AnxietyConnection.com
hope this helps, all the best, sue