Transthoracic cardiac pacing
Transthoracic cardiac pacing
Indications
- Patient with symptomatic bradycardia and a palpable pulse who has not responded to pharmacological therapy.
- High-grade AV blockade
- Cardiac arrest with ventricular standstill, but atrial activity present.
Contraindication
- Asystolic cardiac arrest.
Procedural Technique
- Provide supplemental oxygen and gain IV access
- Some patients may require sedation to tolerate the discomfort associated with pacing, especially if higher currents are needed.
- Ensure skin is clean, dry and shaven to allow electrical contact.
- Sandwich the heart between an anterior electrode (placed over the precordium to the left of the sternum) and a posterior electrode (placed between the left scapula and the vertebral column). Ventricular pacing can also be done using standard pad placement as per defibrillation.
- Set the defibrillator to ‘Pacing’ mode—once the pacing option is activated, ensure the monitor is sensing any intrinsic QRS complexes, signaled by a marker on the monitor.
- Select the pacing rate: usually 60–80 beats/min.
- Select current: start at 5 mA and increase in increments of 5 mA until electrical capture is visible on the ECG monitor. Capture generally occurs at 50–80 mA.
- As the current rises and electrical capture with a ventricular contraction occurs, the monitor will start to show QRS–T complexes after each pacing spike.
- Check that mechanical capture is also occurring by palpating the patient’s pulse.
- Set the current at least 5 mA above the minimum current at which capture occurs.
Complications
- Failure to capture.
- Patient discomfort, so ensure adequate analgesia and sedation.
- Failure to recognize fine VF because of the size of pacing artefact on the ECG screen. Palpate the pulse and or look for loss of signs of life.
- Induction of other arrhythmias.
- Potential for local cutaneous injury with prolonged use.
Date implemented – 05/2009
Review date – currently being revised
Author – Mike Cadogan
