Both my ankles have swollen in last few weeks to the size of small hams. Is this an indication of an impending coronary event, I believe I have congestive heart failure, and my ejection factor in 2009 at catheterization was 61%. I have been sleeping in a a car reclined but not prone for 3 years 7 months and 19 days.
Since you have congestive heart failure, and since you are mostly keeping your feet in a dependent position, swelling of the foot, ankle or legs is bound to occur. Try to keep the feet elevated as much as possible. Try to sleep in a flat position, then the ankle swelling will come down. Then to prevent further leg of feet swelling, please wear grade 2 compression stockings toes to knees both sides, during walking time. This will prevent foot, ankle or leg swelling.