A resting electrocardiogram is taken lying down, in a few minutes, with no sedation

What exactly happens?

MedlinePlus describes it this way: you are asked to lie down, a technician will clean several areas on your arms, legs, and chest, and then will attach small patches called electrodes. The patches connect to a machine that prints the tracing.

Fonasa's 2026 MLE fee schedule is precise about the acceptable minimum: service 17-01-001 is called E.C.G. de reposo and includes at least 12 leads and 4 complexes per lead.

Is any preparation needed?

Very little, and that is part of the trap. MedlinePlus advises telling the team about every medicine you take, and adds a concrete instruction: do not exercise or drink cold water immediately before an ECG because these actions may cause false results.

It generally asks for no fasting, though each centre may have its own instruction, especially when the ECG sits inside a pre-operative package.

Which of the three electrocardiograms did my doctor order?

• E.C.G. de reposo, code 17-01-001. The one on this page: lying down, minutes, no exertion.
• Electrocardiograma de esfuerzo, code 17-01-003. That is the cardiac stress test, with a treadmill and a doctor in the room.
• E.C.G. continuo, test Holter o similares, code 17-01-006. That is the Holter monitor, worn for a full day.

All three share the word in the catalogue and consume completely different resources. An order saying only electrocardiogram, with no surname, is an order the scheduler has to interpret.

Why does such a simple order get lost?

It rarely fails on its own. It fails as a prerequisite. The ECG is the gate into a pre-operative workup, a cardiology specialist referral or an occupational check, and what people book is the consultation rather than its requirement. The patient reaches the specialist without the tracing, and the visit is spent reordering it.

The second reason is economics in reverse: it is so cheap and so quick that nobody builds follow-up around it. No slot sits empty when an electrocardiogram goes undone, so the centre's calendar never misses it.

What should I do if I am holding one?

1. Check whether the order says reposo, esfuerzo or continuo. That word decides which unit to go to.
2. Ask whether your centre takes it on a walk-in basis. Many do, and you need no appointment.
3. If the ECG is a prerequisite for another consultation, book it first and with margin.
4. Take the physical order even if the system already has it. It saves an argument at the desk.
5. Confirm when and how you collect the report, because a tracing with no reading helps nobody.

Being told you are missing the electrocardiogram before your specialist appointment rather than after already works. If you want to know whether your centre does this, ask about Surface next time you go.