Thanks for your question on HCM. I can understand your situation and problem. In my opinion, your father is having aspiration pneumonia mostly. He is having following risk factors for aspiration. 1. Old age 2. Difficulty in swallowing 3. History of choking 4. Non functioning epiglottis Anaerobic infection is most common cause for Aspiration pneumonia. So better to get done sputum culture and sensitivity to identify causative organism and start appropriate antibiotic therapy. Just make sure that his antibiotic regimen contain anaerobic coverage. So discuss all these with his treating doctor and start proper treatment.