Breathing issues! Is he suffering from?

My father age 79 is experiencing breathing difficulty. Symptoms: After lunch, during his afternoon nap, he wakes up with trouble breathing. This improves with his inhaler and doesn’t recur in the evening or next morning. Since the past 7-8 days, mild breathlessness is also seen around 12:30 pm after his bath, but it resolves on its own. Diet: Breakfast: Oats, boiled egg, banana (sometimes idli). Lunch: Steamed rice, catla fish curry, dal, ripe mangoes. Medicines: Fostera 5, Lopez MD 2, Syndopa Plus, Losar H, Atorva 10, Lipicard 200, Ecosprin 150, Stemlo 10, Raplif D 8 mg. History: Bypass surgery 20 yrs ago. Sedentary lifestyle. There is no feeling of heaviness in his chest. Attaching his Echocardiograhy report. What is he suffering from?