Chordae Tendineae: The tendinous cords that connect each cusp of the two atrioventricular HEART VALVES to appropriate PAPILLARY MUSCLES in the HEART VENTRICLES, preventing the valves from reversing themselves when the ventricles contract.Heart Rupture: Disease-related laceration or tearing of tissues of the heart, including the free-wall MYOCARDIUM; HEART SEPTUM; PAPILLARY MUSCLES; CHORDAE TENDINEAE; and any of the HEART VALVES. Pathological rupture usually results from myocardial infarction (HEART RUPTURE, POST-INFARCTION).Mitral Valve: The valve between the left atrium and left ventricle of the heart.Mitral Valve Insufficiency: Backflow of blood from the LEFT VENTRICLE into the LEFT ATRIUM due to imperfect closure of the MITRAL VALVE. This can lead to mitral valve regurgitation.Mitral Valve Prolapse: Abnormal protrusion or billowing of one or both of the leaflets of MITRAL VALVE into the LEFT ATRIUM during SYSTOLE. This allows the backflow of blood into left atrium leading to MITRAL VALVE INSUFFICIENCY; SYSTOLIC MURMURS; or CARDIAC ARRHYTHMIA.Rupture: Forcible or traumatic tear or break of an organ or other soft part of the body.Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.Papillary Muscles: Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.Rupture, Spontaneous: Tear or break of an organ, vessel or other soft part of the body, occurring in the absence of external force.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.