science

Transcutaneous pacing

Transcutaneous pacing is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Transcutaneous pacing rather than just read about it. In short: Transcutaneous pacing (TCP), also called external pacing, is a temporary means of pacing a patient's heart during a medical emergency. It should not be confused with defibrillation (used in more serious cases, in ventricular fibrillation and other shockable rhythms) using a manual or automatic defibrillator, though some newer defibrillators can do both, and pads and an electrical stimulus to the heart are used in tr…

Key takeaways

Transcutaneous pacing belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Transcutaneous pacing to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Transcutaneous pacing from memory before moving on to harder problems.

Reference excerpt

Transcutaneous pacing (TCP), also called external pacing, is a temporary means of pacing a patient's heart during a medical emergency. It should not be confused with defibrillation (used in more serious cases, in ventricular fibrillation and other shockable rhythms) using a manual or automatic defibrillator, though some newer defibrillators can do both, and pads and an electrical stimulus to the heart are used in transcutaneous pacing and defibrillation. Transcutaneous pacing is accomplished by delivering pulses of electric current through the patient's chest, which stimulates the heart to contract. The most common indication for transcutaneous pacing is an abnormally slow heart rate. By convention, a heart rate of fewer than 60 beats per minute in the adult patient is called bradycardia. Not all instances of bradycardia require medical treatment. Normal heart rate varies substantially between individuals, and many athletes in particular have a relatively slow resting heart rate. In addition, the heart rate is known to naturally slow with age. It is only when bradycardia presents with signs and symptoms of shock that it requires emergency treatment with transcutaneous pacing.

Some common causes of hemodynamically significant bradycardia include myocardial infarction, sinus node dysfunction and complete heart block. Transcutaneous pacing is no longer indicated for the treatment of asystole (cardiac arrest associated with a "flat line" on the ECG), with the possible exception of witnessed asystole (as in the case of bifascicular block that progresses to complete heart block without an escape rhythm).

Process During transcutaneous pacing, pads are placed on the patient's chest, either in the anterior/lateral position or the anterior/posterior position. The anterior/posterior position is preferred as it minimizes transthoracic electrical impedance by "sandwiching" the heart between the two pads. The pads are then attached to a monitor/defibrillator, a heart rate is selected, and current (measured in milliamps) is increased until electrical capture (characterized by a wide QRS complex with tall, broad T wave on the ECG) is obtained, with a corresponding pulse. Pacing artifact on the ECG and severe muscle twitching may make this determination difficult. It is therefore advisable to use another instrument (e.g. SpO2 monitor or bedside doppler) to confirm mechanical capture. Transcutaneous pacing may be uncomfortable for the patient. Sedation should therefore be considered. Before pacing the patient in a prehospital setting sedation is recommended by administering an analgesic or an anxiolytic. Prolonged transcutaneous pacing may cause burns on the skin. According to the Zoll M Series Operator's Guide," Continuous pacing of neonates can cause skin burns. If it is necessary to pace for more than 30 minutes, periodic inspection of the underlying skin is strongly advised." It is meant to stabilize the patient until a more permanent means of pacing is achieved. Other forms of cardiac pacing are transvenous pacing, epicardial pacing, and permanent pacing with an implantable pacemaker. In addition to synchronized transcutaneous pacing offered by newer cardiac monitor/defibrillators, there is also an option for asynchronous pacing. Sometimes in the prehospital setting a situation may arise where ECG electrodes are not available or something interferes with their adhesion to the patient's skin. In these rare situations where the patient must be paced and there are no other alternatives, asynchronous pacing may be used. Again, this setting should only be used as a last resort due to possible adverse cardiac effects it could cause.

See also Implantable cardioverter-defibrillator Defibrillation Heart rate variability Palpitations

References

Bledsole, B., Porter, R., and Cherry, R. "Paramedic Care: Principles & Practice: Volume 3". Third Edition, Pearson, 2009. ISBN 978-0-13-513702-4 Urden, L., Stacy, K., and Lough, M. Thelan's Critical Care Nursing: Diagnosis and Management. Fourth Edition, Mosby, 1998. ISBN 0-323-01461-5 Handbook of Emergency Cardiovascular Care for Healthcare Providers. Editors Hazinski, M., Cummins, R., and Field, J. 2004. ISBN 0-87493-448-6

Illustrations

Transcutaneous pacing: True electrical and mechanical capture — True electrical and mechanical capture

Worked examples

Example 1 — a first encounter with Transcutaneous pacing

Start with the simplest possible case. Write down what Transcutaneous pacing claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Transcutaneous pacing before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Transcutaneous pacing ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Transcutaneous pacing

In research: Transcutaneous pacing appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Transcutaneous pacing in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Transcutaneous pacing is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cardiac electrophysiology, Emergency medical procedures, so understanding it makes those chapters shorter.
In everyday life: Look for Transcutaneous pacing outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Transcutaneous pacing” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Transcutaneous pacing in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Transcutaneous pacing means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Transcutaneous pacing out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Transcutaneous pacing in simple terms?

Why does Transcutaneous pacing matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Transcutaneous pacing?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Transcutaneous pacing.