Agree with Holly, if you really feel something is not right follow it up, see your GP for ECG.
In my husbands case he had been very breathless, and extremely tired, he would fall asleep as soon as he sat down and stopped after work, I was waking him for dinner, and then he would fall asleep again, that's why I took him to the Dr.
Blood pressure and heartbeat all OK, ECG we were told it was OK, but he did have a Left Branch Bundle Block, but that was nothing to worry about we were assured by GP, I was not happy with his opinion even though he had been our family Dr for years and asked for a referral to cardiologist, he refused to give us a referral to the public hospital, said you will have to got private, OK I said, even then he tried to put me off by saying that's going to be expensive if you don't have insurance, I still insisted.
Private specialist when we arrived for short appt, we had taken a copy of ECG tracing with us, she looked at it, raised her eyebrows and said you GP said this is normal? YES, I replied, she said he needs an immiedate echocardiogram, I am going to squeeze him in now, walked out and came back in a few minutes and said this way.
After echo was over, she sat us down and explained husband had dialated cardiomyopathy or heart failure, his ejection fraction was at 23%, way below normal, she explained that he needed an immediate angiogram, give us 24 hours I said.
Less than those 24 hrs he collapsed at home in full on congestive heart failure, I rang an ambulance, he was taken to our local small hospital, where again after treatment the Dr said nothing wrong with him, no echo done, or even x-ray, he was discharged because as I understand it his ankles were not swollen, that's all the Dr had examined other than his monitors and chart.
Nurses told me to get in the car and drive him to the big heart hospital across other side of the city, which I did, they admitted him, got a copy of echo from the private specialist, they seemed to know who the heart specialist female Dr, and were willing to listen when I told them he had already had an echo done just a couple of days previous.
He was treated for his condition, is now 7 years on and doing very well, his ejection fraction has come back to 56%, we were told that only a couple of weeks ago by specialist at heart hospital.