What is the name of the test that measures heart rhythm?

The test that measures heart rhythm is known as electrocardiography. This procedure involves recording the electrical activity of the heart over a period of time using electrodes placed on the skin. The resulting electrocardiogram (ECG or EKG) provides valuable information regarding the heart's rhythm, rate, and overall electrical conduction pathways, allowing healthcare professionals to identify any abnormalities in heart rhythm, such as arrhythmias.

In contrast, an echocardiogram uses ultrasound waves to create images of the heart's structure and function, focusing more on the anatomy rather than the electrical activity. A stress test evaluates how the heart performs under physical stress but does not specifically measure heart rhythm continuously. Meanwhile, a Holter monitor is a specific type of electrocardiography that continuously records the heart's rhythm over an extended period, typically 24 to 48 hours, but the term "electrocardiography" encompasses a broader range of tests, including those taken during a specific clip of time. Therefore, the most appropriate and general term used to describe the test that measures heart rhythm is electrocardiography.