All depends on the individual. Some people feel they can't get up out of a chair, while others go for walks. I think it depends mainly if there is any permanent damage to the heart from necrosis etc.
I'm not sure you are asking what life is like for someone with a 28% efficiency (Ejection Fraction) or what lifestyle changes are necessary to raise the Ejection Fraction, also called EF. The EF can be and often is raised, but the cause of the low EF rating needs to be known to even begin a conversation. Can you provide more information?
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