Final answer:
A mid to late systolic click followed by a late systolic murmur most easily detected over the left clavicle can indicate mitral valve prolapse. Murmurs are the result of turbulent blood flow and are detected using auscultation techniques.
Step-by-step explanation:
The abnormal heart sound referred to in the question is most likely caused by mitral valve prolapse, a condition where the mitral valve bulges into the left atrium during systole. This causes a mid to late systolic click and can be followed by a late systolic murmur.
The murmur is best detected over the left clavicle area during auscultation. Heart sounds, including the "lub" of atrioventricular valves closing and the "dub" of semilunar valves closing, can be heard via auscultation with a stethoscope.
The unusual sound called a murmur results from a turbulent flow of blood and can range in severity from grade 1 to grade 6. In the case of mitral valve prolapse, if the murmur is present, it may become more apparent during certain respiratory maneuvers.
Listening for these sounds involves the use of a stethoscope and possibly asking the patient to modify their breathing to amplify the murmurs. Deep inhalation increases blood flow into the right side of the heart, possibly increasing right-sided murmurs, while expiration may increase left-sided murmurs. The auscultation technique is crucial for detecting these murmurs accurately.