What wave is septal depolarization?
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What wave is septal depolarization?
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 does the septum depolarize 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).
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 does the Q wave on an ECG represent?
Electrocardiogram Interpretation Q waves represent the initial phase of ventricular depolarization. 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 happens when the heart Depolarizes?
Depolarization of the heart leads to the contraction of the heart muscles and therefore an EKG is an indirect indicator of heart muscle contraction. The cells of the heart will depolarize without an outside stimulus. This property of cardiac muscle tissue is called automaticity, or autorhythmicity.
How do you identify a pathological Q wave?
Q waves are considered pathological if:
- > 40 ms (1 mm) wide.
- > 2 mm deep.
- > 25% of depth of QRS complex.
- Seen in leads V1-3.
What ECG wave or segment is a negative deflection and represents interventricular septal depolarization?
Q wave
The second wave is the QRS complex. Typically this complex has a series of 3 deflections that reflect the current associated with right and left ventricular depolarization. By convention the first deflection in the complex, if it is negative, is called a Q wave.
What is a septal Q wave?
Abstract. 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.
What is depolarization of the ventricles?
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 leads are Q waves normal?
Q Waves. Q waves are normally seen in the inferior and left lateral precordial leads in pediatric patients.
What is depolarization and hyperpolarization?
Hyperpolarization is when the membrane potential becomes more negative at a particular spot on the neuron’s membrane, while depolarization is when the membrane potential becomes less negative (more positive).
What does septal infarct mean?
Septal infarct is a patch of dead, dying, or decaying tissue on the septum. The septum is the wall of tissue that separates the right ventricle of your heart from the left ventricle.
What does the Q wave represent and why does it follow a downwards direction opposite to main QRS complex )?
QRS wave complex The rule is: if the wave immediately after the P wave is an upward deflection, it is an R wave; if it is a downward deflection, it is a Q wave: small Q waves correspond to depolarization of the interventricular septum. Q waves can also relate to breathing and are generally small and thin.
What does positive and negative deflection in an ECG represent?
A wave of depolarization traveling toward a positive electrode results in a positive deflection in the ECG trace. A wave of depolarization traveling away from a positive electrode results in a negative deflection. A wave of repolarization traveling toward a positive electrode results in a negative deflection.
Which wave on the ECG represents ventricular depolarization?
QRS wave complex
QRS wave complex The three waves of the QRS complex represent ventricular depolarization.
What is ventricular depolarization?
What are the septal leads?
The septum is represented on the ECG by leads V1 and V2, whereas the lateral wall is represented by leads V5, V6, lead I and lead aVL. To make things more complicated, sometimes the LAD “wraps around” the cardiac apex, which is a common anatomic variant.
