Checked-out
After some check-ups including a stint on the treadmill machine, the conclusion was that my Dad probably had a touch of reflux. With his background history, taking those tests were sensible precautions. He was worried that he would have to wait for tests if he were to go to UMMC and at his age, he could do without all that.
He was given medicine and is now settling back at home. He said, he would probably be having a lie-in all afternoon and I wouldn't blame him. Thank Allah that everything checked out OK.