What is ventricular depolarisation and Repolarisation?
Ventricular depolarization and activation is represented by the QRS complex, whereas ventricular repolarization (VR) is expressed as the interval from the beginning of the QRS complex to the end of the T wave (QT interval). VR is a complex electrical phenomenon which has been studied in detail[2,3].
How does depolarization and repolarization occur in the heart?
Each deflection (wave) of the ECG represents either depolarization or repolarization of the specific parts of the heart. Because depolarization occurs before mechanical contraction, the waves of depolarization can be associated with contraction and relaxation of the atria and the ventricles.
What is polarization of nerve?
In biology, polarization pertains to the act or process of producing a positive electrical charge and a negative electrical charge such that between a nerve cell internal electrical charge, which is negative, and the surrounding environment of a nerve cell, which is positive.
Which wave represents repolarization of ventricles?
The T wave represents ventricular repolarization. Generally, the T wave exhibits a positive deflection. The reason for this is that the last cells to depolarize in the ventricles are the first to repolarize.
What happens ventricular repolarization?
Following ventricular repolarization, the ventricles begin to relax, and pressure within the ventricles drops. When the pressure falls below that of the atria, blood moves from the atria into the ventricles, opening the atrioventricular valves and marking one complete heart cycle.
What is the difference between polarization and depolarization?
The main difference between depolarization and repolarization is that the depolarization is the loss of resting membrane potential due to the alteration of the polarization of cell membrane whereas repolarization is the restoration of the resting membrane potential after each depolarization event.
What are the causes of polarization?
Causes. There are various causes of political polarization and these include political parties, redistricting, the public’s political ideology, and the mass media.
What does QRS mean on ECG?
The QRS complex represents the electrical impulse as it spreads through the ventricles and indicates ventricular depolarization. As with the P wave, the QRS complex starts just before ventricular contraction.