Through cardiac pacing a pacemaker delivers an electrical impulse to a chosen part within the myocardium with the aim of causing depolarisation. This leads to the spreading of the action potential to all parts within the heart.
Pacemakers are able to monitor the natural pacemaker of the heart (SA Node). If this is fully functioning, the pacemaker lets it work uninterrupted, but if or when needed, the pacemaker paces.
Pacemakers are considered to be anti-bradycardia devices. They are individually programmed so as not to fall below a certain heart rate, allowing a low heart rate momentarily so that it is recorded into the patient’s device statistics.
Some pacemakers are also able to defibrillate so as to restart the electrical rhythm of the heart to a sinus rhythm.
Cardiac pacing is used in the case of:
- 2nd and 3rd degree AV blocks
- AV blocks with chronic atrial fibrillation
- SA Node disease
- Heart failure
- Genetic-related long QT syndrome
- Anterior Myocardial Infarction with AV block
- Drug-induced blocks (eg. digoxin intoxication)
- Atrial fibrillation prevention
- Hypertrophic Cardiomyopathy (thickened heart muscle)
Cardiac Pacing Sites
RA Appandage = paced P-wave resembling normal activity P-wave
RV Apex = paced QRS complex that is usually prolonged with a following wider looking T-wave
CSL Coronary Sinus Lead = implanted into the LV. A third lead benefits cardiac output by correcting and syncronising both left and right ventricles
Temporary Cardiac Pacing
Temporary pacing is used in emergency settings such as on patients experiencing ventricular bradyarrhythmias, post cardiac surgery (when the patient is susceptible to tachyarrhythmias so temporary pacing can be available immediately on demand with low sensitivity), and whilst undergoing evaluation for a permanent pacemaker.
Pacemakers are able to:
- pace – at a fixed rate (asynchronous) independently of intrinsic cardiac rhythm OR on demand – only if intrinsic cardiac rhythm is absent
- sense – they are considered to be anti-bradycardia devices since they can sense if the heart rate falls below their programmed lower rate, and in that case, pace
NOTE: a TPM (temporary pacemaker) malfunction, including battery failure, falls under the responsibility of the nurse! Thus, ensure proper checking of equipment, battery, threshold, and that leads and connection points are secured well.
Transcutaneous Cardiac Pacing (Temporary)
Transcutaneous pacing = used in emergency settings as a short term pacing method, easily set up by nurses with an AED device. A spike can be captured to mechanically function the heart temporarily. Although it’s quite a quick pacing method, it is not always tolerated by the patient, and may also be unstable.
Transvenous Cardiac Pacing (Temporary)
Transvenous pacing = a reliable pacing method that is more tolerated than the transcutaneous method by patients, established within 10-30 minutes by a physician. Transvenous pacing is done via the axillary-subclavian vein or the femoral vein in Endocardial Pacing, or via the axillary-subclavian vein in Epicardial LV Pacing.
- may induce ventricular tachycardia
- abdominal twitching (voltage should be checked and possibly lowered)
- infection may be possible especially if wire is left more than 48 hours in situ (transparent dressings should be used for possible infection monitoring)
- perforation of the myocardium whilst advancing wire into the heart
- pneumothorax – puncturing of the lungs (may be confirmed by x-ray)
Permanent Cardiac Pacing
Permanent pacing = a fully programmable device implemented through elective surgery.
The NGB Code
Pacemaker Nursing Management
- note pacemaker settings and compare with ECG recordings
- ensure that all spikes are followed by a P and/or QRS complex
- monitor for pacemaker malfunction – ensure it is both capturing and sensing as it should
- monitor route of insertion for bleeding, haematoma formation, and signs of infection – measure the patient’s body temperature every 4 hours
- monitor white blood cell count which should be within normal range (5000-10000/mm3)
NOTE: report to cardiologist if malfunction is noted.
Patient Education
When using a temporary pacemaker, patient should remain in bed. Area from where the lead has been inserted should remain immobilised, as if mobilised, lead may become easily displaced. Patients should also restrict activity on the implantation side. Mobile devices should be used on the opposite side of the pacemaker implantation. Patients should keep their 6 monthly or yearly appointments as required. A pacemaker’s battery life is usually between 6-20 years, depending on its use.
Prior to being discharged, ensure that the patient knows how to look for signs and symptoms of infection and when to seek medical attention, and is aware of how to avoid electromagnetic interference.
Whilst nursing a patient with a pacing box, it is important to check the wires for any loose points and to monitor the battery.
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