NO AUTHORISATION FOR SPECIALIST

I must visit my cardiologist every year for a check up on my heart.Every year Discovery is paying for the visits to my cardiologist. This year they wont pay because in the past year since my previous visit to the cardiologist I did not had an heart attack or heart failure and I am not sick so it isnt necessary for the cardiologist visit (Discovery's comment). Discovery also said that my GP can do the necessary tests on my heart so a specialist visit is not necessary. How can a GP do the test to measure the heart valves as well as the opening of the valves and the blood flow through the valves??<br> So now I would like to know must I first get a heart attack or some heart disease before they will pay for the visits?