text: Since your question id very specific so I presume here that you have clear idea about what is Edema...Now here I shall be explaining the relationship of edema and heart diseases.\n\nEdema is basically a condition which develops when there is leakage of clear fluid(plasma) out of our blood vessels(veins) and their collection/stagnation in the interestitial space(which is the space in between the veins and the tissues)...In short anything that increases the pressure in veins(thus forcing more fluid to move out and collect) makes edema which is apparent as swelling of our body parts, specailly dependent part eg legs, ankle(its so because due to gravity these fluid try to settle down)..\n\nNow lets discuss what kind of heart diseases makes edema...Diseases of the heart which has anything to do with increasing the back-pressure in the veins (which are draining inthe heart) makes the increased pressure in veins ....like if there is congestive heart failure then the heart functions less than what it should ideally do, which means that all the blood which is trying to enter heart is not able to enter fully and this makes inceasing back-pressure in these big veins which leads to sepage of fluids into interestitial space leading to Edema..........\n\n\nNow my dear friends, there are plenty of reasons of edema...and also different diseases of heart has different mechanism of edema making ....but its difficult to explain all of them here.....but if there is any particular disease then you can simply ask me..I hope I could answer your query.But since I guess you have posted 3 similar questions ..but my answer is common..In case you find my answer reasonably good then  I  hope that I might gain 10 points each from 3 questions..lol.Take care