The normal EF is around 50 to 75%. Heart failure happens when cardiac output at < 29% as the amount of output usually does not meet the system's demand for blood/oxygen and an individuals has symptoms that require treatment.
However, it is estimated about 24% of the heart population do not know nor have any symptoms at heart failure range. The system compensates.
It depends on the underlying reason to answer the question of how bad is this condition. Do you have an enlarged left ventricle? Do you have heart muscle damage from virus, congenital disorder, coronary artery blockage, certain medication can contribute, as well as drugs, alcohol abuse.
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