Final answer:
The structural defect in which the mitral valve leaflets prolapse into the left atrium during systole is known as mitral valve prolapse. This leads to mitral regurgitation, where blood flows backward, often producing a heart murmur detectable by a stethoscope. Mitral insufficiency due to MVP is common and its treatment varies based on severity.
Step-by-step explanation:
The medical term referring to the structural defect wherein the mitral valve (also known as the bicuspid valve or left atrioventricular valve) leaflets prolapse into the left atrium during ventricular contraction is called mitral valve prolapse (MVP). This occurs when one or both of the valve's cusps are forced backward by the force of the blood. In the case of MVP, the chordae tendineae, which attach the valve cusps to papillary muscles in the ventricle wall, may be damaged or elongated, leading to a failure in the closure mechanism of the valve. As a result, during systole, there can be mitral regurgitation, where blood backflows from the left ventricle into the left atrium. MVP can be detected by the presence of a characteristic heart murmur through auscultation with a stethoscope.
While mitral insufficiency is one of the common valvular heart diseases, representing about 2 percent of the population, the severity and treatment can vary. Some cases of MVP are benign and simply monitored, while others may require medication or surgery.