Heart Failure Types: Understanding Systolic vs Diastolic Dysfunction

Heart failure can be categorized into two main types: systolic heart failure and diastolic heart failure. The key difference lies in the function of the left ventricle's ejection fraction (EF), a measurement seen on echocardiogram reports. EF represents the percentage of blood the left ventricle pumps out with each contraction.

What Defines Diastolic Heart Failure?

Diastolic heart failure occurs when the ejection fraction remains normal or near normal, but the heart still struggles to meet the body's demands. This typically happens due to impaired relaxation of the heart muscle between beats. Common causes include thickened heart walls, increased stiffness, and reduced elasticity of the ventricular walls. While the heart can contract effectively, it relaxes slowly and incompletely, reducing the amount of blood filled into the ventricle for the next heartbeat.

Understanding Systolic Heart Failure

Conversely, systolic heart failure is characterized by a weakened heart muscle that cannot contract forcefully enough to eject sufficient blood. This results in an ejection fraction below 40% and causes noticeable symptoms like fatigue, shortness of breath, and fluid retention. It represents a more advanced stage of heart muscle dysfunction.

Progression of Heart Failure Stages

While these represent different types of heart failure, they often reflect different stages in the progression of cardiac disease. For example, patients with hypertension may initially develop diastolic dysfunction as the heart muscle thickens to compensate for increased pressure. If blood pressure remains uncontrolled, this can progress to systolic dysfunction over time.

Common Underlying Conditions

This pattern isn't exclusive to hypertension – similar progression occurs in patients with coronary artery disease and various cardiomyopathies. Early detection and management of diastolic dysfunction can potentially prevent the transition to systolic heart failure, emphasizing the importance of regular cardiac screening and risk factor modification.