What are the causes of left heart failure?

Causes of left heart failure

Original author: Dr. Yu Li

Heart failure is a serious stage of the development of various heart diseases, and left heart failure is one of the common types of heart failure. Understanding the causes of left heart failure is of great significance for prevention and early intervention.

Left heart failure is mainly due to impaired function of the left ventricle, which causes the heart to be unable to pump blood effectively, resulting in a series of symptoms and signs. The following are some common causes of left heart failure:

1. Myocardial disease

1. Coronary heart disease: Coronary atherosclerosis leads to myocardial ischemia, hypoxia, and even myocardial infarction. Long-term myocardial ischemia can cause myocardial cell death and fibrosis, affecting the contraction and relaxation function of the left ventricle.

2. Cardiomyopathy: such as dilated cardiomyopathy and hypertrophic cardiomyopathy. Dilated cardiomyopathy is characterized by the expansion and thinning of the myocardium, and weakened contractility; hypertrophic cardiomyopathy is characterized by the thickening of the myocardium and the shrinking of the ventricular cavity, which leads to obstruction of blood outflow and increases the burden on the left ventricle.

2. Overload of the heart

1. Excessive pressure load: Common in diseases such as hypertension and aortic valve stenosis. In hypertension, peripheral vascular resistance increases, and the left ventricle needs more force to pump blood. Long-term excessive pressure load can lead to myocardial hypertrophy and strain. In aortic valve stenosis, left ventricular ejection is blocked, and pressure increases, which can also cause left ventricular hypertrophy and failure.

2. Excessive volume load: such as mitral regurgitation, aortic regurgitation, etc. When the mitral valve is incompetent, blood will flow back to the left atrium during the contraction of the left ventricle, resulting in an increase in the volume load of the left ventricle; when the aortic valve is incompetent, blood in the aorta during diastole will flow back to the left ventricle, also increasing the volume load of the left ventricle. Long-term excessive volume load will gradually expand the left ventricle and eventually lead to heart failure.

3. Arrhythmia

Severe arrhythmias, such as rapid atrial fibrillation and ventricular tachycardia, can lead to a rapid ventricular rate, shorten ventricular filling time, and reduce cardiac output, thereby inducing left heart failure.

IV. Infection

Respiratory tract infection is one of the common causes of left heart failure. Infection increases the burden on the heart and may activate the body's inflammatory response, impairing myocardial function.

V. Other factors

1. Drugs: Certain drugs, such as anti-tumor drugs, antiarrhythmic drugs, etc., may be cardiotoxic. Long-term use can damage the myocardium and lead to left heart failure.

2. Endocrine and metabolic diseases: such as diabetes, hyperthyroidism or hypothyroidism, etc., can cause left heart failure by affecting myocardial metabolism and function.

3. Bad living habits such as alcoholism and long-term smoking will also increase the risk of left heart failure.

In short, the causes of left heart failure are varied and often the result of multiple factors working together. For people with high-risk factors for heart disease, such as hypertension and coronary heart disease, they should actively control their condition, improve their lifestyle, and undergo regular heart examinations to detect and treat left heart failure early. At the same time, once symptoms of left heart failure such as dyspnea, fatigue, cough, and sputum occur, they should seek medical attention in a timely manner, make a clear diagnosis, and take appropriate treatment measures to delay the progression of the disease, improve the quality of life, and prolong life.