Certified Registered Nurse Anesthetist (CRNA) Practice Exam

In diastolic heart failure, what is typically observed?

1. Increased stroke volume

2. Decreased ejection fraction

3. Normal ejection fraction

4. Enlarged heart

The correct answer is: Normal ejection fraction

Diastolic heart failure, also known as heart failure with preserved ejection fraction (HFpEF), is characterized primarily by the heart's inability to relax and fill adequately during diastole. In this condition, the ejection fraction, which measures the percentage of blood ejected from the heart during each contraction, remains normal (typically around 50% or more). This is a critical distinction; patients with diastolic heart failure have a preserved ejection fraction because the left ventricle is able to contract effectively but struggles with the filling phase due to stiffness or other issues affecting the myocardium. Normal ejection fraction in diastolic heart failure helps differentiate it from systolic heart failure, where the ejection fraction is typically decreased due to impaired myocardial contractility. Other features of diastolic heart failure may include symptoms of heart failure such as shortness of breath and fatigue, which arise due to the ventricle's inability to accommodate the returning blood volume, leading to fluid retention and increased pressures in the heart and lungs. It's important to note that while diastolic heart failure may present with an enlarged heart due to various compensatory mechanisms or underlying conditions, in itself, an enlarged heart is not a defining feature specifically attributed to di