ECG Question #1
The nurse is caring for a client on telemetry, which reveals normal sinus rhythm with a heart rate of 74. This finding indicates a normal cardiac electrical conduction, which follows:
- AV node—bundle of HIS—SA node –Bundle Branches –Purkinje fibers
- SA node—AV node—Bundle of HIS –Bundle Branches—Purkinje Fibers
- Purkinje fibers – AV node—Bundle of HIS –Bundle Branches –Purkinje fibers
- SA—Node—Bundle of HIS – Purkinje Fibers, AV node, Bundle of HIS
The electrical impulse originates in the SA node, which is in the right atrium. It then travels through the atria through intermodal pathways, causing atrial contraction. The impulse then travels through the AV node, which allows time for the atria to contract and fill the ventricles. The impulse travels down the ventricles by way of the Bundle of His to the right and left bundle branches before it reaches the Purkinje fibers, which results in contraction of the ventricles. Normal cardiac conduction does not originate in the AV node and travel to the bundle of HIS, the SA node, bundle branches to the Purkinje fibers. Normal cardiac conduction does not begin in the Purkinje fibers and then travel to the AV node, Bundle of HIS, to the bundle branches and finally to the Purkinje fibers. Normal cardiac conduction does originate in the SA node, however it does not travel to the Bundle of His, the Purkinje fibers, and then to the AV node and Bundle of His.