What is the primary purpose of using a phonocardiogram?

The primary purpose of using a phonocardiogram is to record heart sounds for detecting murmurs. This diagnostic tool captures the acoustic signals generated by the heart, which include normal heart sounds as well as abnormal sounds such as murmurs, gallops, or rubs that may indicate underlying cardiovascular conditions. The data collected through a phonocardiogram can help clinicians assess the functionality of the heart valves and detect any abnormalities in blood flow.

In the context of the other options, while imaging techniques and electrocardiographic monitoring are crucial for understanding heart function, they serve different purposes. Three-dimensional visualization focuses on the structural anatomy but does not provide auditory information. Monitoring electrocardiographic changes is specific to electrical activity rather than acoustic heart sounds. Measuring blood pressure is entirely a vascular assessment, unrelated to the monitoring of heart sounds. Thus, the phonocardiogram stands out as a unique tool emphasizing the auditory aspect of cardiac examination.