What sound is indicative of a mitral regurgitation that intensifies in the left lateral position?

The sound indicative of mitral regurgitation that intensifies in the left lateral position is a holosystolic, high-pitched blowing sound. This characteristic sound is produced due to the backflow of blood from the left ventricle into the left atrium during systole, as the mitral valve fails to close properly.

Positioning the patient in the left lateral decubitus position brings the heart closer to the chest wall, enhancing the transmission of this sound and making it more pronounced. The holosystolic nature of the murmur means it occurs throughout the entirety of systole, typically starting with the first heart sound and continuing until the second heart sound. The high pitch and blowing quality are critical descriptors that help differentiate it from other types of murmurs, such as those seen in aortic stenosis or pericardial friction rubs.

Other sounds described in the choices do not correspond with the typical presentation of mitral regurgitation. Understanding these attributes helps in correctly identifying the pathology associated with the murmur.