It shows lots of heart problems to a trained person. I have been grounded for 4 years due to a regular ECG
I have no knowledge of the poster's case of course, but in the past, pilots have been grounded - indeed to the point of loss of license - only to find out that something they were taking affected their ECGs.
In the 60s, at least one British Eagle pilot, and I think 3 others, lost their licenses due to a failed ECG. These particular cases turned out to be caused by excessive coffee drinking. The anomaly in the readout became well known, and presumably in the worst cases, the subjects can now be re-tested after cutting back. I recall the start of their protests to get their licenses back, but heard no more.
So, no pills for colds or the like, especially 'Night remedies'. No booze, and not too much caffeine, would all be a good start to passing the medical.