Heart virus usually refers to myocarditis, or an inflammatory condition of the heart muscle caused by a viral infection. In most cases this is an asymptomatic condition and many of us go through it at least once. Some individuals, however, have a more pronounced inflammatory response which leads to heart damage and subsequent heart failure. Of those people only a few recover their heart function. Heart failure may be a very debilitating potentially leading to all those complications that you mentioned, but leg weakness isn't typical. I am wondering if there was something else going on.
Infection of heart valves.
Is there a posibility that it was a virus that affected the heart? Hea was told that the legs wre not functioning because the heart was not pumping correctly