What type of heart failure is characterized by the heart's inability to contract sufficiently?

Systolic heart failure is characterized by the heart's inability to contract sufficiently, which means that the heart muscle is weakened and cannot pump blood effectively. This type of heart failure leads to a reduced ejection fraction, which is the percentage of blood that is pumped out of the heart with each contraction. When the left ventricle cannot contract with enough force, it can result in symptoms such as fatigue, shortness of breath, and fluid retention.

In contrast, diastolic heart failure refers to the heart's inability to relax and fill properly, which affects the diastolic phase of the cardiac cycle. Left heart failure typically encompasses both systolic and diastolic dysfunction, but in this context, it does not specify the contraction issue. Right heart failure primarily involves the right side of the heart and often occurs as a consequence of left heart failure or lung disease. Thus, the specific definition of systolic heart failure aligns directly with the notion of inadequate contraction, making it the correct choice.