Heart Ejection Fraction of 35% - What Stage of Heart Failure Does It Indicate?

Having an ejection fraction (EF) of 35% does not directly indicate a specific stage of heart failure. While EF is a crucial measurement of heart function, it is not the sole factor used to classify heart failure stages. Heart failure is typically categorized based on functional classifications established by the New York Heart Association (NYHA). These classifications focus on the physical limitations experienced by patients and are more closely related to symptoms than EF values alone.

Understanding Heart Function Classification

The NYHA classification divides heart failure into four functional classes based on the severity of symptoms and limitations during physical activity:

Class I – Normal Heart Function

Patients experience no limitations in their daily activities and can perform even strenuous physical tasks without experiencing symptoms such as shortness of breath or fatigue.

Class II – Mild Limitations

Individuals may feel symptoms like breathlessness or fatigue during intense physical exertion, but they can manage routine daily tasks without difficulty. This class indicates a slight limitation in physical capacity.

Class III – Moderate Limitations

Shortness of breath or fatigue may occur with minimal physical activity such as climbing stairs, shopping, or light housework. Patients in this category often need to pace themselves during daily activities to avoid discomfort.

Class IV – Severe Limitations

This is the most advanced stage of heart failure, where symptoms occur even at rest. Individuals may feel breathless or fatigued while sitting or lying down, and physical activity is severely restricted.

What Does an Ejection Fraction of 35% Mean?

The ejection fraction measures how much blood the left ventricle pumps out with each contraction. A normal EF ranges between 50% and 70%. An EF of 35% is considered significantly reduced and indicates that the heart is not pumping as efficiently as it should. However, this number alone cannot determine the exact heart failure classification.

Patients with an EF of 35% may fall into Class II, III, or IV, depending on the presence and severity of symptoms during activity and rest. Therefore, EF should be interpreted alongside other clinical assessments, including symptom evaluation and physical examination, to determine the true stage of heart failure.