I had heart surgery 1 month ago. I have been re-examined 4 times already. The last few times I went for a follow-up checkup, my heart rate decreased from 9m to 6mm and 4mm. But the last time it increased to 10/5 and 6mm. The doctor told me after heart surgery if the cardiac output decreased and then increased again? I'm so worried, can you give me advice on how to eat and what foods to avoid? Is there any way to reduce cardiac fluid? Thank you doctor.