89 Years. Have Aortic Stenosis. Shortness Of Breath, Swollen Legs And Feet, Confused, Low Appetite, Seizure. Common?

Can you tell me if seizures are common in people with aotic stenosis, and heart failure? My father, aged 89, has aortic stenosis, and, I suspect (heart failure although this has never been talked about )and over the past 6 months has become increasngly frail and "disabled" - shortness of breath swollen legs and feet, very confused, eats very little, limited ability to weight bear. He lives in another country so I am not fully aware of his condition. It appears that he has just had a seizure. Is this typical inpeople with heart failure? Thanks,