Chronic heart failure

Chronic heart failure, or CHF, refers to the gradual onset and persistent presence of symptoms and signs of heart failure (such as dyspnea, fatigue, and limb edema) based on pre-existing chronic heart disease. According to the primary affected cardiac chamber, it can be divided into left-sided heart failure, right-sided heart failure, and biventricular heart failure. According to changes in systolic and diastolic function during heart failure, it can be divided into systolic dysfunction heart failure and diastolic dysfunction heart failure, i.e., systolic heart failure and diastolic heart failure. If both types of dysfunction are present simultaneously, it is classified as mixed type.