The treatment process of a case with dilated cardiomyopathy, severe mitral insufficiency, and coaptation defect in the context of decompensated clinical condition with left ventricular assist device placement.

Heart failure in children is a clinical and pathophysiological syndrome arising from ventricular dysfunction and pressure or volume overload of the circulatory system. Features of paediatric heart failure include feeding problems, poor weight gain, exercise intolerance, or dyspnoea. The aetiology of heart failure in children is complex, with the primary causes being CHD and cardiomyopathies. Cardiomyopathies occur at an incidence of 1.13-1.24 cases per 100,000 children. The prevalence of cardiomyopathy is estimated to be 7.8-8.3 cases per 100,000 infants, particularly common in patients under one year of age presenting with severe heart failure symptoms. Mitral valve insufficiency is a significant source of morbidity in children with dilated cardiomyopathy. Severe mitral insufficiency can lead to a decrease in cardiac output, independent of the left ventricular ejection fraction, exacerbating the clinical course of heart failure in patients with dilated cardiomyopathy. As ventricular systolic function deteriorates, the options for treating mitral insufficiency decrease, leading to a loss of surgical intervention opportunities and making heart transplantation the only viable option. Close monitoring of mitral valve insufficiency in children with dilated cardiomyopathy is essential, as it may lead to decompensated heart failure. In patients who have lost the chance for valve surgery due to decompensation, the application of left ventricular assist device can help improve the decompensatory state and contribute to the reduction of left ventricular diastolic and systolic dimensions, consequently leading to improvements in the dilation of the mitral annulus and severe mitral insufficiency findings. Further studies are needed to determine the optimal timing for surgery in patients who have not missed the chance for valve surgery due to a decrease in ejection fraction.