Page 85 - Critical Care Notes

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■ Pacing to prevent tachycardia
■ Congenital heart disease
Contraindications
■ Local infection at implantation site
■ Active systemic infection with bacteremia
■ Severe bleeding tendencies (relative contraindication)
■ Active anticoagulation therapy (relative contraindication)
■ Severe lung disease and positive end-expiratory pressure ventilation
(relative contraindication for internal jugular and subclavian access.
Procedure
■ Performed in an electrophysiology (EP) lab or in a cardiac catheterization
lab. Usually done using local anesthesia.
■ Small incision is made at the insertion site (usually right or left subclavian); a
sheath or introducer is inserted into the subclavian vein; a lead wire is thread-
ed through the introducer into the vessel; and the lead wire is then advanced
into the atrium, ventricle, or both (depending on the type of pacemaker).
■ Once the lead wire is in the proper position, it is tested to verify proper
location and to make sure it is functioning properly. The number of leads
placed (1, 2, or 3) depends on the type of pacemaker.
■ Once the lead wires are tested, an incision is made under the clavicle. The
pacemaker generator is slipped under the skin through the incision after the
lead wire is attached to the generator. An ECG is obtained to verify the
pacer is working correctly.
■ The incision is then closed with sutures, adhesive strips, or surgical glue; a
dry sterile dressing is then applied.
Postoperative Care
Patients are not always admitted or returned to the ICU post procedure; a
telemetry floor may be appropriate.
■ Continuous cardiac monitoring. A pacemaker-generated impulse should
appear as a spike on the ECG. The spike indicates the pacemaker has fired.
Pacemaker rhythm:
■ Rate: Varies according to the preset pacemaker rate and patient’s native
heart rate.
■ Rhythm: Irregular for demand pacemaker unless patient is 100% based
with no native beats.
■ P wave: None for ventricular pacemaker. P waves may be seen but unre-
lated to QRS. Atrial or dual chambered pacemakers should have P wave
after each atrial spike.
■ PR interval: None for ventricular pacing. Atrial or dual chambered pacing
should produce constant PR intervals.
■ QRS: Wide (>0.10 sec.) after each ventricular spike in a paced beat.
Patient’s native QRS will look different from paced QRS. Atrial pacing
only, QRS may be normal.
CV