30 April 2020 Author : Rui Campante Teles The mitral valve is one of the four heart valves and separates the left atrium from the left ventricle. When the left atrium contracts (atrial systole), the mitral valve opens and blood flows to the left ventricle. Then, when the left ventricle contracts (ventricular systole) and pumps blood through the aortic valve to the aortic artery, the mitral valve closes to prevent blood from refluxing into the left atrium. What is mitral regurgitation and what are its symptoms In mitral regurgitation , there is an abnormal reflux of blood from the left ventricle to the left atrium during ventricular systole, when the closing of the mitral valve should prevent this movement of blood. The reflux of mitral regurgitation increases the volume of blood in the left atrium and the pressure in this location, also causing an increase in pressure upstream in the pulmonary veins. As a result, the lungs can become “drenched” in blood, which causes shortness of breath and tiredness. Also, less blood will be pumped into the systemic circulation through the aortic artery. Mitral regurgitation is a common valve disease and its prevalence increases with age. The severity and symptoms of the disease are variable, from asymptomatic, in less severe cases, or even cause heart failure. There are several causes for mitral regurgitation, for example: Hereditary weakness of the valve tissue; Myocardial infarction or heart attack; Other diseases of the heart muscle, for example cardiomyopathies or infections. How is the diagnosis made The diagnosis of mitral regurgitation is based on the auscultation of the characteristics of the heart murmur caused by reflux of blood through the mitral valve. Electrocardiogram and chest radiography can be used to confirm or estimate increases in left ventricular volume. Cardiac echocardiography, or echocardiogram, is essential to assess the increase in volume of the left atrium and left ventricle and the amount of blood that is refluxing, in order to assess the severity of the disease. What is the treatment for mitral regurgitation The treatment of mitral regurgitation is based on medications and, in some cases, with surgery of the mitral valve to repair or replace the damaged heart valve or, in other cases, implantable cardiac devices that help the heart to contract better. It is important to know that about half of the patients referred for surgery are not operated, due to concomitant diseases, left ventricular dysfunction or old age. In recent years, important innovations have been developed in the field of treatment of diseases associated with mitral regurgitation and there are already several devices for percutaneous placement in Portugal. The choice of the most appropriate treatment for each patient involves a multidisciplinary team made up of physicians from various specialties - cardiology, cardiac surgery, anesthesiology, and internal medicine, together with the patient attending physician. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
