What is the primary purpose of an EKG?

The primary purpose of an EKG, or electrocardiogram, is to monitor the electrical activity of the heart. This test records the heart's electrical impulses, allowing healthcare professionals to assess the rhythm and the health of the heart muscle. By analyzing the waveform patterns produced by the EKG, clinicians can identify abnormalities such as arrhythmias, signs of heart disease, or previous heart attacks.

In contrast, the other choices do not relate to the core function of an EKG. Diagnosing lung disease and evaluating kidney function involve different diagnostic tools such as pulmonary function tests and blood tests, respectively. Blood pressure assessment is done using a sphygmomanometer and does not provide insight into the electrical activity of the heart. Therefore, monitoring the heart's electrical activity is the definitive purpose of an EKG.