I had normal ecg echo and tmt durinh first week of april. Yesterday while sleeping i felt nausea and after that chest pressure, specially while lying down and it was going off after sitting. I am perplexed. 2 echo and tmt in last 6 months, both okay. Travelled 12 kms this week down from vaishno devi without any issue. But this feeling has frightened me badly. I had gas also last night, burping frequently. Don't know whether it is cardiac issue or gastric. I have started feeling imbalance while sitting, not while walking, running and hiking. Pl guide