Final answer:
The ejection fraction of the left ventricle in patients with heart failure is generally below 40 percent, which indicates a reduced capacity to pump blood compared to the normal range of approximately 55-70 percent in healthy individuals.
Step-by-step explanation:
The ejection fraction (EF) of the left ventricle is an important parameter used in the diagnosis and assessment of heart failure (HF) in patients. In healthy individuals, EF typically ranges from about 55-70 percent, with a mean of 58 percent. However, in patients with heart failure, the EF is usually reduced. Specifically, an EF below 40 percent is generally classified as a reduced ejection fraction, which is often an indicator of heart failure, with different degrees of severity based on how much lower the EF is than the normal range.