Hello! Thank you for asking on HCM! Seems that your dad actually is suffering form decompensated chronic heart failure, at least on class III. I recommend you to consult his cardiologist for a comprehensive medical re-evaluation, as his life expectancy, facing disease severity, is not promising in short and long terms as well. A careful physical examination, a cardiac ultrasound, and possible additional tests (chest X ray study, some blood tests like complete blood count, BUN, creatinine, electrolytes, etc) are necessary to review and optimize his therapy. Perhaps, a few days hospitalization would be helpful to manage the situation. Hope to have been helpful. Greetings! Dr. Iliri.