What is the primary purpose of an electrocardiogram (EKG)?

The primary purpose of an electrocardiogram (EKG) is to measure the electrical activity of the heart. This diagnostic tool provides a graphical representation of the heart's electrical impulses, allowing healthcare professionals to assess various aspects of heart function. By analyzing the EKG waveforms, clinicians can identify abnormalities in heart rhythm, detect issues such as arrhythmias, and evaluate heart conditions including ischemia or myocardial infarction. The ability to visualize the heart's electrical conduction is crucial in diagnosing and managing cardiovascular health.

The other options do not align with the function of an EKG. Assessing heart valve functionality typically involves imaging techniques like echocardiography rather than electrical measurement. Diagnosing lung diseases generally requires pulmonary function tests or imaging, while monitoring blood pressure levels is done using sphygmomanometers or similar devices, not through EKGs.