Since my pacemaker implant last December for Trifasicular Block I have been feeling very unwell, with nausea,heartburn,fluctuating blood pressure, lethargy, occasional light headedness, short term memory loss, + aches + pains in chest + back. I had been back to ER on 5 occasions with the usual heart/pacemaker checks + blood tests. Nothing was found + they suggested psychological issues. As a psychologist I felt that this could only be a part contributor. In frustration I went back over my last 6 blood tests + noted elevated blood calcium levels. I then researched this + pursued this with my GP. He referred me for an ultra sound which was followed by a nuclear medicine scan. The scans found a 15mm tumour on one of my parathyroid glands. This was producing large amounts of parathyroid hormone which in turn was increasing the levels of blood calcium. Blood calcium is very impotant to the electrical transmission in your body + is related to heart problems, particularly Brachycardia + Arrythmia's. Who knows how long I have had this tumour. There is a suggestion that had this been diagnosed earlier It may have prevented the necessity for a pacemaker. I will have the tumour-also called parathyroid Adenoma surgically removed. These tumours are very common particularly in women over 50. If you have similar symptoms please insist on having your blood calcium + parathyroid hormone levels checked. Even a slight increase should be followed up.