Thank you very much for the useful information.
There are few important possibilities i would consider in your case.
First, this can be due to a Neurological problem (neuropathy developing after Legionnaire's disease). Although this is not a common clinical presentation, but this is documented long term effect of legionnaire's disease.
Then circulation issue to the affected leg/muscle might be the problem.
This can lead to reduced exercise capacity of the muscles as well as weakening.
Then we also have to consider any joint related issues in the leg such as arthritis affecting the knee or hip joint (but this remains a least likely possibility).
As you mentioned that your EKG was not good; therefore this needs to be evaluated further by a cardiologist, but i personally do not feel that these current symptoms are directly from your heart.
You should see your doctor, discuss all the details i have mentioned and get a management plan chalked out that suits best to your needs.
An Internist would be of best help for you in this situation and if deemed necessary, he can involve another doctor (such as a Neurologist for Nerve Conduction Studies) in the treatment plan.
And off-course, you would require a cardiologist's consultation as well, for your heart.
I hope this clarifies and answers your question.
I would have been worried too if I were at your place, but let me reassure you that this is a treatable condition and carries a good prognosis with appropriate management.
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