Final answer:
An echocardiogram is a diagnostic ultrasound test of the heart that is useful for detecting abnormalities in heart valves, muscles, and other structures, differentiating from an ECG which detects electrical activities. It is particularly helpful when a valvular or septal disorder is suspected.
Step-by-step explanation:
An echocardiogram is an ultrasound examination of the heart which is used to assess the heart's functions and structures. It can demonstrate any abnormal valvular activities, muscle function, and other cardiac conditions. For example, conditions such as valve disorders, Myocardial Infarction (MI), and other pathologies can be detected. The echocardiogram is different from an Electrocardiogram (ECG or EKG), which is used to study the electrical activity of the heart to identify any abnormalities in the heart's rhythm or damages such as infarcts that reflect electrical waves in different lead potentials of the ECG.
Importantly, while an ECG can provide a wealth of information about the heart's electrical functionality, it may not reveal the effectiveness of the heart pumping, which is better assessed with an echocardiogram. An echocardiogram can also help to detect subtle changes in the heart by visualizing the structure and movement, which may not be evident on an ECG. This test is usually ordered when a clinician suspects or detects valvular or septal disorders through auscultation, which is the technique of listening to heart sounds, a proven, safe, and inexpensive diagnostic method dating back to the ancient Egyptians.