Heart defect caused by GERD

My cardiologist wants to put a defibrillator/pacemaker in to help slow beating heart (30-35).  Had every test available except MRI or CT scan of heart and stomach/esophogus.  Had gastric stapling in 1982 with severe problems eating, bloating, pressure and pain since then.  This has gotten worse and causes pain in center of chest down past waist.  

Is it possible my GERD problem is causing pressure and not allowing my heart to have enough chest area to have an increased heart output?

Would a MRI or CT scan be advised?  If so, what types of tests?  Should this be performed before insertion of defibrillator/pacemaker?

I have not mentioned my diagnosis to Cardiologist as doctors tend to dislike self-diagnosis.  I feel I know my body better than a doctor I see for short office visits.

[CCF HeartMD3]

I am sorry to hear about your recent troubles. Patients such as yourself with reduced heart function are at increased risk of having sudden cardiac death from abnormal heart rhythms (such as ventricular tachycardia or ventricular fibrillation). Defibrillator's are effective in preventing sudden cardiac death by monitoring your heart rate and shocking your heart back into rhythm should it go into an abnormal rhythm.

I would doubt that your previous surgery would be causing the decreased function of your heart; however, I would discuss your recent chest discomfort with your physician to ensure that these pains are not something that need to be explored further.