JBL Cardiology Practice Test

Heart failure with preserved ejection fraction (HFpEF) is characterized primarily by the inability of the ventricles to relax properly during the filling phase of the cardiac cycle. This impaired relaxation leads to increased filling pressures and congestion, even though the ejection fraction, which measures the percentage of blood ejected from the heart during contraction, remains normal (or preserved) at 50% or greater.

In HFpEF, the issue arises from diastolic dysfunction, where the heart muscle can contract effectively but struggles with its ability to fill adequately. This is often due to a stiffened ventricular wall, which does not allow for proper diastolic filling, leading to symptoms of heart failure such as shortness of breath, particularly during exertion, despite the ejection fraction being normal.

Other options are not representative of HFpEF. For instance, the heart muscle does contract effectively in this condition, making any reference to it not contracting inaccurate. The ejection fraction remains preserved, which is contrary to what is suggested by the notion of a reduced ejection fraction. A faster heart rate is not a defining characteristic of HFpEF; while heart rate can vary, it does not define the underlying dysfunction seen in this condition.