What condition is associated with a reduced ejection fraction (EF) of less than 50%?

A reduced ejection fraction (EF) of less than 50% indicates that the heart is not pumping blood effectively during systole. This measurement is primarily associated with left-ventricular systolic dysfunction, which refers to the impaired ability of the left ventricle to contract and eject blood into the circulation. In this condition, the heart muscle becomes weakened, leading to a decrease in the percentage of blood that is pumped out with each heartbeat, resulting in a lower EF.

Understanding that left-ventricular systolic dysfunction specifically describes this reduction in contractility helps clarify its direct relationship to the ejection fraction. Other conditions listed may contribute to heart issues but do not primarily define or correlate with a reduced ejection fraction in the same way. For example, left-ventricular hypertrophy involves thickening of the heart muscle but doesn't necessarily indicate reduced contractility unless it progresses to dysfunction. Congestive heart disease encompasses various forms of heart failure but is a broader term that can refer to cases with preserved ejection fraction as well. Similarly, coronary artery disease can lead to reduced EF due to ischemia but does not inherently define a reduction in EF on its own.