As a medical professional with expertise in cardiology, I can explain the QRS wave in detail. The QRS complex is a fundamental component of the electrocardiogram (EKG or ECG), which is a test that measures and records the electrical activity of the heart. The QRS complex represents the electrical activity that occurs when the ventricles of the heart begin to contract. It is a series of three waves, labeled as the Q wave, R wave, and S wave, which are seen on the ECG tracing. The QRS complex is typically the most prominent and recognizable part of the ECG waveform. It signifies the rapid depolarization of the ventricular muscle fibers, which is the process by which the ventricles prepare to pump blood out to the body. The individual waves have specific meanings: 1. Q wave: This is the first negative deflection (downward) after the P wave and before the R wave. It represents the initial depolarization of the ventricles. 2. R wave: This is the first positive deflection (upward) following the Q wave. It signifies the peak of ventricular depolarization. 3. S wave: This is the negative deflection that follows the R wave. It indicates the completion of ventricular depolarization. Abnormalities in the QRS complex can indicate various heart conditions, such as bundle branch block, ventricular hypertrophy, or myocardial infarction (heart attack). read more >>

The QRS complex is a name for the combination of three of the graphical deflections seen on a typical electrocardiogram (EKG or ECG). It is usually the central and most visually obvious part of the tracing. It corresponds to the depolarization of the right and left ventricles of the human heart.read more >>