Norm of His Bundle Electrography
Atrial-to-His (A-H) interval = 50–120 msec; His-to-ventricular (H-V) activation = 35–55 msec.
Usage of His Bundle Electrography
Antidysrhythmic drug evaluation, precise location of bundle branch block, bypass tract physiology evaluation, decision-making about pacemaker implant, syncope evaluation, and differentiation of true AV (atrioventricular) block from concealed AV extrasystoles.
Description of His Bundle Electrography
His bundle electrography is the use of a bipolar catheter electrode system during right-sided heart catheterization for recording activity of rhythm and conduction in the bundle of His located in the heart. This test provides information on intra-atrial and intraventricular conduction that is not available with regular electrocardiography.
Professional Considerations of His Bundle Electrography
Consent form IS required.
Dysrhythmias, phlebitis, pulmonary emboli, thromboemboli, and hemorrhage.
Clients with coagulopathy and acute pulmonary embolism.
- Have emergency medication available for use in case a dysrhythmia develops.
- See Client and Family Teaching.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- A catheter is introduced through the femoral vein and guided by fluoroscopy to the right ventricle.
- Leads I, II, and III placed on the limbs are recorded simultaneously with two intracardiac bipolar electrograms. One is in the high right atrium (HRA), and the other is over the septal leaflet of the tricuspid valve to record the bundle of His (HBE). The first deflection of the HBE represents right atrial activity. The second deflection represents His bundle activity. The third deflection represents ventricular activation.
- Monitor vital signs and lower extremity pulses and observe and palpate for hematoma at the catheter site every 15 minutes × 4 and then hourly × 4.
- Maintain the extremity in extension until the frequent monitoring period has passed.
- Assess the catheter site for bleeding every 30 minutes for 4 hours.
Client and Family Teaching
- Fast from food and fluids for at least 6 hours.
- The test takes 1–3 hours.
- Results are available immediately.
Factors That Affect Results
- Poor catheter positioning.
- See also Cardiac catheterization for other care required.