What is a common distinguishing feature of systolic heart failure?

Systolic heart failure is primarily characterized by a reduced ability of the heart to contract effectively, leading to a decrease in the ejection fraction. The ejection fraction is a measurement that expresses the percentage of blood that is pumped out of the ventricles with each heartbeat. In systolic heart failure, this value is often less than 40%, indicating that the heart is not able to pump sufficient blood to meet the body's demands.

In contrast, impaired diastolic filling, cardiac hypertrophy, and increased stroke volume are features that are more commonly associated with other cardiac conditions or different types of heart failure. For instance, impaired diastolic filling is a hallmark of diastolic heart failure, where the heart has difficulty relaxing and filling with blood. Cardiac hypertrophy can occur in both forms of heart failure but does not specifically distinguish systolic heart failure. Increased stroke volume is typically not seen in systolic heart failure; rather, it is often associated with conditions where the heart's pumping ability is enhanced.

Thus, the key defining feature of systolic heart failure is the reduced ejection fraction, which underscores its impact on the heart's pumping efficacy.