Mild mitral regurgitation

The mitral valve belongs to the left ventricular valve. The ventricle is a particularly important part. It affects our vital signs and effectively protects our heart. However, many problems often occur in this area, including mild mitral regurgitation. This situation can be explained by certain reasons. So what is mild mitral regurgitation?

The mortality rate of surgical treatment depends on the patient's hemodynamic and clinical condition, especially the left ventricular function and the liver, kidney and lung function and the proficiency of the surgical team. In most medical research centers, the mortality rate of mitral valve replacement for patients with mitral regurgitation is between 2% and 7%, and the mortality rate of repair is even lower, at 1% to 2%.

Most patients can achieve improved clinical symptoms and quality of life after surgery, reduced pulmonary hypertension, reduced heart size and left ventricular weight, and significantly improved survival rate compared with medical treatment. However, for patients with a long preoperative medical history and poor heart function, postoperative improvement in cardiac function is not as satisfactory as after mitral stenosis and aortic valve replacement. In conclusion, patients who underwent surgery for mitral regurgitation had a lower survival rate than those who underwent surgery for mitral stenosis. However, observational studies have found that any time surgical treatment is performed improves long-term survival.

It is worth noting that the survival rate of patients with cardiac function level I and II during surgery is not only higher than that of patients with severe symptoms before surgery, but also has no difference with the expected survival rate of the corresponding age and gender in the general population. The most common cause of death after surgical correction of mitral regurgitation is left ventricular dysfunction caused by long-term irreversible myocardial damage. The incidence of postoperative congestive heart failure increases over time (38% at 10 years in survivors), with the majority (2/3) often being residual left ventricular dysfunction after surgery. Valvular or surgical dysfunction can explain heart failure in nearly one-third of patients. Postoperative congestive heart failure has a poor prognosis and should be prevented whenever possible, including early correction of mitral regurgitation.

Among patients who have successfully undergone valve replacement surgery, the EF of most patients decreases, which may be due to the combined effect of several factors: myocardial damage caused by excessive volume load before surgery; persistent myocardial damage sometimes caused during surgery; changes in load status after surgery. When mitral regurgitation occurs, the afterload of left ventricular ejection decreases, and increases after surgery compared to the original level, while the preload after surgery is significantly lower than before surgery, resulting in a decrease in left ventricular ejection fraction; in addition, changes in the connection between the papillary muscles and the valve ring after removal of the subvalvular device during valve replacement surgery also affect the improvement of left ventricular function. The use of vasodilators is very effective in improving cardiac function and increasing EF. Foreign studies on the relationship between left ventricular function before and after surgery and the relationship between preoperative left ventricular function and postoperative survival have shown that EF may decrease by nearly 10% in the early stage after valve replacement.

However, there are significant individual differences, and a greater decrease in postoperative EF may be seen in patients with a significant increase in LV end-systolic dimension, volume, or wall stress, or in those with severe symptoms, prolonged mitral regurgitation, or coronary artery disease. The best surgical results are for patients with no symptoms or mild symptoms and an EF of no less than 60%. A significantly lower EF before surgery (<50%) is associated with a higher mortality rate in the late postoperative period. Even a critical EF (50%-60%) is accompanied by an increased mortality rate in the late period. Therefore, preoperative EF is an independent predictor of postoperative usefulness and survival. Nevertheless, surgical treatment is still advocated for these patients because it still provides better prognosis than medical treatment.