Certified Cardiographic Technician (CCT) Practice Exam 2026 - Free CCT Practice Questions and Study Guide

The QRS duration specifically indicates the time taken for ventricular depolarization, which is a critical phase in the cardiac cycle. During this phase, the electrical impulses travel through the ventricles, leading to their contraction and subsequent pumping of blood to the lungs and the rest of the body. By measuring the QRS duration on an electrocardiogram (ECG), healthcare professionals can assess the electrical activity of the heart and identify any abnormalities that may indicate conditions such as bundle branch blocks or other forms of ventricular conduction delay.

The time taken for atrial depolarization primarily corresponds to the P wave on the ECG, which reflects the electrical activity leading to atrial contraction. Various components of the cardiac cycle are represented in the ECG, but the total duration encompasses more than just the intervals of depolarization and repolarization that are measured individually. An understanding of QRS duration is vital for interpreting an ECG and diagnosing potential heart issues efficiently.