What Is the Difference Between Systolic and Diastolic Heart Failure
What Is the Difference Between Systolic and Diastolic Heart Failure Heart failure is a complex condition that affects millions worldwide, but understanding its nuances can significantly impact management and outcomes. One key aspect of heart failure is distinguishing between its two primary forms: systolic and diastolic heart failure. While they share common symptoms such as fatigue, shortness of breath, and fluid retention, their underlying mechanisms differ, influencing treatment strategies.
Systolic heart failure, also known as heart failure with reduced ejection fraction (HFrEF), occurs when the heart’s ability to pump blood effectively is compromised. In this condition, the heart’s left ventricle—the main pumping chamber—becomes weakened and cannot contract forcefully enough to eject an adequate volume of blood into the circulation. As a result, less oxygen-rich blood reaches the body’s organs and tissues, leading to symptoms like fatigue, weakness, and pulmonary congestion. The hallmark of systolic failure is a reduced ejection fraction, which is a measure of the percentage of blood ejected from the ventricle with each heartbeat. A normal ejection fraction typically ranges from 55% to 70%, but in systolic heart failure, this value falls below 40%, indicating impaired contractile function.
In contrast, diastolic heart failure, also called heart failure with preserved ejection fraction (HFpEF), involves the heart’s inability to relax and fill properly during the diastolic phase—when the heart muscle relaxes and prepares for the next contraction. Despite maintaining a normal or near-normal ejection fraction, the ventricles become stiff or less compliant, limiting the amount of blood they can hold. Consequently, blood backs up into the lungs and other tissues, causing symptoms similar to systolic failure. Patients might experience shortness of breath during exertion or when lying down, but their ability to pump blood out remains intact. The preservation of ejection fraction distinguishes diastolic failure from systolic failure, although the symptoms and clinical management may overlap.
Understanding the differences between these two forms of heart failure is crucial because they often require tailored treatment approaches. For systolic failure, therapies focus on improving heart contractility, reducing preload and afterload, and preventing further deterioration through medications such as ACE inhibitors, beta-blockers, and diuretics. Diastolic failure management emphasizes controlling blood pressure, managing comorbid conditions like diabetes or obesity, and reducing fluid overload, often with diuretics.
The underlying causes also differ somewhat. Systolic heart failure is frequently linked to ischemic heart disease, myocardial infarction, or dilated cardiomyopathy, which weaken the heart muscle. Diastolic failure often results from conditions that make the heart stiff, such as hypertension, hypertrophic cardiomyopathy, or infiltrative diseases like amyloidosis.
In summary, while both types of heart failure share common symptoms and can coexist, their fundamental differences lie in how the heart’s pumping and filling functions are affected. Recognizing these distinctions enhances diagnosis, guides appropriate treatment, and ultimately improves patient outcomes.
