Severe mitral regurgitation in 1-year-olds does not usually improve with development, and mitral regurgitation tends to produce symptoms of cardiac insufficiency such as nocturnal paroxysmal dyspnea and sedentary breathing. Severe regurgitation is often seen in patients with organic heart disease and requires prompt treatment. 1. If mitral or tricuspid regurgitation is caused by heart disease or other reasons, it is important to see if it is combined with other pathologies. 1 year olds with mitral regurgitation that is combined with tricuspid regurgitation are in serious trouble, and will not improve as they develop. 2. In 1-year-olds with arrhythmia, severe regurgitation of the mitral and tricuspid valves may be detected on ultrasound. At this time, if the arrhythmia is recovered or the heart function is improved, the mitral and tricuspid regurgitation may be reduced or disappear. This situation is not called post-developmental improvement, but it refers to the different performance of the valve function in a certain heart function condition. Therefore, it is recommended that patients seek timely medical attention and reasonable diagnosis and treatment under the guidance of specialized physicians.