My father is still Coughing at Night six years after a Quadruple By-p Heart Operation?

He may need to see his cardiologist and let them place a Holter monitor on him to wear for 48 hours. This will monitor his heart. He may be having PVCs (post-venticular contractions) or atral-fibrilations (A-Fib) when lying down. These make the heart feel like it skips a beat and causes a "tickle" sensation in the chest causing you to cough. If this is the problem, they may put him on a beta-blocker or other heart med.