What is the term for the part of the EKG that measures heart muscle contraction?

The portion of the EKG that measures heart muscle contraction is known as the QRS complex. This complex reflects the depolarization of the ventricles, which leads to ventricular contraction and is a critical component of the cardiac cycle. During this phase, the electrical signal that originates in the atria moves through the bundle of His and the Purkinje fibers, resulting in the simultaneous contraction of both ventricles.

Understanding the function of the QRS complex is essential for diagnosing various cardiac conditions. Abnormalities in the QRS complex can indicate issues such as ventricular hypertrophy, bundle branch blocks, or other forms of ventricular dysfunction. The timing and morphology of this complex can reveal a great deal about the electrical conduction system of the heart and the overall health of the myocardium.

In contrast, the PR interval measures the time it takes for the electrical impulse to travel from the atria to the ventricles, the ST segment indicates the period between ventricular depolarization and repolarization, and the P wave represents atrial depolarization. Each of these components serves a specific function, but it is the QRS complex that primarily corresponds to the contraction of the heart muscle.