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Bradycardia: Difference between revisions
→Ventricular Conduction Block
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==Ventricular Conduction Block== | ==Ventricular Conduction Block== | ||
[[File:Intraventricular Conduction.jpg|right]] | |||
===Right bundel branch block (RBBB)=== | ===Right bundel branch block (RBBB)=== | ||
The right bundle branch is composed of one fascicle. Right bundle branch block is a unifascicular block of the right bundle and can be found in healthy people and is represented by a broad QRS complex (>120ms). However a new RBBB in a patient with a history of normal ventricular conduction warrens further cardiological investigation. The last activity is to the right and results in a RSR’ pattern in V1 where R’ > R. This results from the delayed activation of the right ventricle. In V6 a slurred S wave can be seen at the end of the QRS complex. | The right bundle branch is composed of one fascicle. Right bundle branch block is a unifascicular block of the right bundle and can be found in healthy people and is represented by a broad QRS complex (>120ms). However a new RBBB in a patient with a history of normal ventricular conduction warrens further cardiological investigation. The last activity is to the right and results in a RSR’ pattern in V1 where R’ > R. This results from the delayed activation of the right ventricle. In V6 a slurred S wave can be seen at the end of the QRS complex. | ||
===Left anterior fascicular block (LAFB)=== | ===Left anterior fascicular block (LAFB)=== | ||
The left bundle branch is composed of two fascicles. One of the fascicle has an anterior location and activates the interventricular septum and the anterior of the ventricle. Clinically this is represented by a left axis deviation and an absent or very small S and normal q in lead I and a S>R in lead II and III. QRS duration should be <120ms. | The left bundle branch is composed of two fascicles. One of the fascicle has an anterior location and activates the interventricular septum and the anterior of the ventricle. Clinically this is represented by a left axis deviation and an absent or very small S and normal q in lead I and a S>R in lead II and III. QRS duration should be <120ms. | ||
===Left posterior fascicular block (LPFB)=== | ===Left posterior fascicular block (LPFB)=== | ||
The second fascicle of the left bundle branch is the posterior fascicle. This fascicle has a posterior location and activates the posterior and lateral part of the ventricle. This fascicular block results in a right axis deviation and is represented by a deep S in I and small q in III with a QRS duration of <120ms. | The second fascicle of the left bundle branch is the posterior fascicle. This fascicle has a posterior location and activates the posterior and lateral part of the ventricle. This fascicular block results in a right axis deviation and is represented by a deep S in I and small q in III with a QRS duration of <120ms. | ||
===Left bundel branch block (LBBB)=== | ===Left bundel branch block (LBBB)=== | ||
If the two fascicles of the left bundle branch show conduction block there is a left bundle branch block, this bifascicular block is uncommon in healthy patients and further cardiologic investigations need to be performed to screen for underlying disease. Left bundle branch block causes the left ventricle to activate later then the right ventricle. This results in typical ECG characteristics, most importantly a broad QRS of >120ms. In V1 a broad monomorphic S wave can be seen (sometimes with a small r wave) representing slow left ventricular activation. In the lead V6 a broad monomorphic R wave is seen with no Q waves. | If the two fascicles of the left bundle branch show conduction block there is a left bundle branch block, this bifascicular block is uncommon in healthy patients and further cardiologic investigations need to be performed to screen for underlying disease. Left bundle branch block causes the left ventricle to activate later then the right ventricle. This results in typical ECG characteristics, most importantly a broad QRS of >120ms. In V1 a broad monomorphic S wave can be seen (sometimes with a small r wave) representing slow left ventricular activation. In the lead V6 a broad monomorphic R wave is seen with no Q waves. | ||
==Functional conduction disorders: Aberrant Conduction== | ==Functional conduction disorders: Aberrant Conduction== | ||