An electrophysiology study (EPS) is a specialised cardiac investigation carried out in a catheterisation laboratory to assess the electrical system of the heart in detail. It is used to identify the cause of arrhythmias, evaluate the risk of dangerous heart rhythms, and guide treatment decisions.
What happens during the procedure
The patient lies on an X-ray table and the procedure is usually performed under local anaesthesia with sedation. Thin, flexible wires (catheters) are inserted through a vein in the groin (and sometimes the arm or neck) and guided through the veins into the heart chambers. These catheters both record the electrical signals within the heart and, when required, deliver tiny electrical pulses to stimulate (provoke) arrhythmias in a controlled setting.
What it can show
An EPS can:
- Map the electrical pathways of the heart and identify abnormal circuits
- Determine whether an arrhythmia can be provoked, and if so, how easily
- Assess the function of the sinus node and AV node
- Identify the origin of a tachycardia
- Guide catheter ablation when treatment is performed in the same session
Why it might be recommended after cardiac arrest
After a cardiac arrest, particularly where the underlying cause has not been identified, an EPS may be recommended to investigate whether a provokable arrhythmia exists. It can also be used to assess whether a particular tachycardia is amenable to ablation. In some patients, the EPS leads directly to ablation treatment in the same procedure.
Recovery
The procedure typically takes one to three hours. Patients usually return home the same day or after an overnight stay. The puncture sites in the groin should be kept clean and dry, and patients are usually advised to avoid strenuous activity for a day or two.
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