Where does ventricular myocardial depolarization begin?
Ventricular depolarization occurs in part via an accessory pathway (AP) directly connecting the atrium and ventricle and thus capable of conducting electrical impulses into the ventricle bypassing the AV-His Purkinje conduction system.
What indicates ventricular depolarization?
The QRS complex represents the electrical impulse as it spreads through the ventricles and indicates ventricular depolarization.
Which ventricle is depolarized first?
In right bundle branch block, the left ventricle depolarizes first. The right ventricle will depolarize after the left.
What wave causes ventricular depolarization?
Atrial depolarization is reflected by the P wave, and ventricular depolarization is reflected by the QRS complex, whereas the T wave reflects ventricular repolarization, see Figure 6.10.
Which limb lead is most aligned with the direction of ventricular depolarization?
The lead with the most positive deflection is most aligned with the direction the heart’s electrical activity is travelling. If the R wave is greater than the S wave it suggests depolarisation is moving towards that lead.
Does ventricular depolarization occur from left to right?
During ventricular activation, impulses are first conducted down the left and right bundle branches on either side the septum. This causes the septum to depolarize from left-to-right as depicted by vector 1 (Panel A).
When does ventricular repolarization begin?
Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave (QT).
When does ventricular depolarization occur?
The isoelectric period (ST segment) following the QRS and ending at the beginning of the T wave is the time at which both ventricles are completely depolarized. This segment roughly corresponds to the plateau phase of the ventricular action potentials.
What is the sequence of depolarization?
Definition. Ventricular depolarization begins at apex, causing the QRS complex. Atrial repolarization occurs. Location. Term.
What is ventricular depolarization and repolarization?
Ventricular depolarization (activation) is depicted by the QRS complex, whereas ventricular repolarization is defined by the interval from the beginning of the QRS complex to the end of the T- or U-wave. On the surface ECG, ventricular repolarization components include the J-wave, ST-segment, and T- and U-waves.
Which lead is most closely aligned with the direction of ventricular depolarization?
Does ventricular depolarization proceed from right to left?
According to the data that we collected we can say that ventricular depolarization happens from the left to the right. We can confirm this because in part II most of the peaks occurred from the left side and decrease in size when moving to the right, this process repeats itself.
When a wave of depolarization travels toward a lead How is this represented on an ECG tracing?
A wave of depolarization traveling toward a positive electrode results in a positive deflection in the ECG trace. 5.
What is the first phase of ventricular depolarization?
The first phase of ventricular depolarization is of relatively brief duration (shorter than 0.04 sec) and small amplitude. It results from spread of the stimulus through the interventricular septum. The septum is the first part of the ventricles to be stimulated.
What are complex ventricular premature depolarizations (VPDs)?
Complex ventricular premature depolarizations (VPDs) in the presence of ischemic heart disease, especially in the presence of left ventricular dysfunction, are associated with an increased incidence of sudden cardiac death.
Where does the mean vector point when the ventricle depolarizes?
After another 20 milliseconds, the mean vector is pointing toward the left arm and anterior chest as the free wall of the ventricle depolarizes from the endocardial to the epicardial surface (vector 3, Panel C). This vector records a small positive voltage in lead II.
How does heart depolarization occur?
Heart Depolarization Ventricular depolarization occurs in part via an accessory pathway (AP) directly connecting the atrium and ventricle and thus capable of conducting electrical impulses into the ventricle bypassing the AV-His Purkinje conduction system. From: Essence of Anesthesia Practice (Third Edition), 2011