Helth Cover

Back in april my husband went to the local gp for patches to stop smoking. while he was there his general health was discussed,he complained about feeling a bit tired but he is 77. Blood tests were run also an ecg. Nothing more was heard and as far as we were concerned there was no problems. In july I booked a holiday to usa, and of course took out Travel insurance. Two weeks ago we had a telephone call from the local hospital, cardiology department, they were doing a clinic for the overflow of backlog patients. We went to the appointment to be told that my husband had atrail fibrillation. Went to see a different gp in the practice, explained we had booked a holiday to the usa without being aware of a heart condition,she said you can complain.I rang the travel insurance company today to make them aware of my husbands condition and they said they would not charge because I was not aware of the condition at the time of taking out insurance. If I had to make a claim, going back into my husbands medical notes the referal was already done before I booked the holiday, and we knew nothing about it. Help this is driving me around the bend?
The point I am trying to make if the doctor had made us aware there was a problem,we wouldn’t have booked the holiday,and also a doctor is suppose to give a patient a choose of hospitals when making a referal.