The electrophysiological study (EPS) is a test that allows the study of cardiac rhythm disturbances. The EPS consists of two parts: the first is diagnostic (the mechanism that causes the arrhythmia is determined) and the second part is therapeutic (in which the mechanism that sustains the arrhythmia is destroyed). The heart has electrical activity, with “foci” that generate this electricity and connections that transmit it. Arrhythmias are alterations in the electrical activity of the heart.
Diagnosis of arrhythmia
EPS is performed in a cardiac catheterization laboratory. One or more catheters are inserted through the patient’s groin and accessed via the femoral vein to the heart. Occasionally it may be necessary to puncture through other vessels. These catheters are usually visualized by X-rays. During EPS, the catheters are used to record electrical activity in different areas of the heart to determine what type of arrhythmia the patient has and where it originates. Once the problem that generates the arrhythmia has been identified, it is destroyed during EPS. This is called therapeutic EPS and with this technique many of the existing arrhythmias can be cured.
Ablation of the arrhythmia
The destruction of the mechanism that sustains the arrhythmia is called ablation. Different energy sources can be used to ablate (“destroy”), the most frequent being radiofrequency (which destroys by heating) and secondly cryotherapy (destroys by freezing). The end of the ablation catheter rests on the area where the arrhythmia is generated and energy is applied to eliminate it.
Most therapeutic EUS is performed under local anesthesia and with light sedation of the patient, allowing the patient to communicate with the room staff. In some cases it may be necessary to use general anesthesia. Therapeutic EPS can cure most arrhythmias originating in the different areas of the heart (atria and ventricles). Many of these arrhythmias significantly reduce the patient’s quality of life and some may even be life-threatening.
Definitive treatment
Thanks to therapeutic EPS, the patient can definitively get rid of his arrhythmia, thus avoiding hospitalization and drugs (none of which are curative and may have significant undesirable effects). The duration of EES is approximately two hours, although in complex cases it can be considerably longer. The patient is usually discharged home within 24 hours, unless a complication occurs. EPS must be performed by electrophysiologists who are cardiologists specialized in the management of arrhythmias, for which they have had to obtain specific accreditation after a very demanding training period.