Some pain can be normal but I recommend that you return to the physician who performed the catheterization for further evaluation.
If she had a major bleeding ulcer in the past it may prudent to stop it. I would discuss the risks and benefits of taking it versus stopping it with her primary care doctor (someone who knows all of her medical conditions)--that is the safest way to figure this out from a risk to benefit perspective.
the heart pauses are concerning. generally, when pauses hit the 3-second duration the patient gets a pacemaker (unless it is being induced by something, such as medications-- sometimes we will re-evaluate off the medication). Regarding your mitral valve I cannot comment on who is "the best in the country." You need to discuss this with your cardiologist.