Is Q wave depolarization?
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Technically, a Q wave indicates that the net direction of early ventricular depolarization (QRS) electrical forces projects toward the negative pole of the lead axis in question. Although prominent Q waves are a characteristic finding in myocardial infarction, they can also be seen in a number of noninfarct settings.
What is septal depolarization?
In normal depolarization, the septum depolarizes before the bundle branches. The septum depolarizes from left towards right. Normal V1. In a normal V1 pattern, the QRS begins with a small initial “r” wave, indicating depolarization of the septum towards the lead.
Why does the septum Depolarize from left to right?
The electrode placement represents lead II. 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).
What is a septal Q wave?
Background: Small Q waves in the left lateral leads are termed septal q waves, and their response to exercise has been reported to be a marker of septal ischemia in coronary artery disease.
Why is Q wave downward?
As septal depolarization moves from left to right, the depolarization vector is directed towards the – electrode of lead II (RA), and therefore a negative-going deflection (Q-wave) is produced.
Why are Q and S waves negative?
What happens during Q wave?
This is known as a Q wave and represents depolarisation in the septum. Whilst the electrical stimulus passes through the bundle of His, and before it separates down the two bundle branches, it starts to depolarise the septum from left to right.
What is septal Q wave response to exercise in hypertrophic cardiomyopathy?
The septal q wave response to exercise is a useful marker of septal ischemia in HCM with asymmetric septal hypertrophy. Septal Q wave as a marker of septal ischemia in hypertrophic cardiomyopathy
What is a Q wave on the electrocardiogram?
By definition, a Q wave on the electrocardiogram (ECG) is an initially negative deflection of the QRS complex. Technically, a Q wave indicates that the net direction of early ventricular depolarization (QRS) electrical forces projects toward the negative pole of the lead axis in question.
What does it mean when Q waves are pathologic?
They are pathologic if they are abnormally wide (>0.2 second) or abnormally deep (>5 mm). Q waves that are pathologically deep but not wide are often indicators of ventricular hypertrophy.
What causes absence of small septal Q waves in leads v5-6?
The absence of small septal Q waves in leads V5-6 should be considered abnormal. Absent Q waves in V5-6 is most commonly due to LBBB.