Final answer:
Blood leaks backward from the left ventricle into the left atrium during mitral valve prolapse, potentially reducing stroke volume and, over time, decreasing cardiac output. A heart murmur may be detected via stethoscope due to turbulent blood flow. Mitral valve disorders are common and can require various treatments.
Step-by-step explanation:
During mitral valve prolapse, if one of the cusps of the valve is forced backward by blood, this is known as a prolapsed valve. This can occur due to damage or breakage of the chordae tendineae, which are responsible for keeping the mitral valve closed. When the mitral valve fails to close properly, it leads to a condition known as mitral regurgitation or mitral insufficiency, where blood flows backward from the left ventricle into the left atrium during systole.
In terms of stroke volume and cardiac output, mitral regurgitation typically results in a decrease in stroke volume, because some of the blood that should be pumped out into the aorta during ventricular systole leaks back into the atrium. However, the heart may initially compensate by increasing the heart rate, which could maintain cardiac output in the short term. Over time, though, persistent mitral regurgitation can lead to a decrease in cardiac output due to the heart's reduced efficiency and potential enlargement and weakening of the left ventricle (ventricular dilation and heart failure).
Auscultation with a stethoscope may reveal a heart murmur, an abnormal sound indicating turbulent blood flow due to the faulty valve. Also, the mitral valve is the most commonly affected valve in valvular heart diseases, which can vary from benign to lethal conditions necessitating close monitoring or interventions ranging from medications to surgery.