Cardiac electrophysiology study is an invasive examination conducted in patients in whom a superficial 12-lead ECG and other non-invasive (painless) examination do not provide sufficient information to diagnose and treat heart rhythm disorders.
Electrophysiology study is performed at a specially equipped and specialized laboratory (electrophysiology laboratory – EP lab). The procedure can last 1-4 hours. After local anaesthesia is given in the groin area, 2 to 5 thin introducers (plastic tubes) are inserted and through the introducers electrophysiology catheters are placed in the femoral vein. Catheters can be introduced through the left and/or right femoral vein, and rarely through subclavian and/or jugular vein to the right heart (the choice is up to the cardiologist). The catheters are further introduced to the heart and placed in the heart under X-ray control. At the tip of each catheter an electrical signal coming from the heart is recorded.
Electrophysiology study is performed to clarify the nature of the arrhythmic disturbances and to determine where arrhythmia occurs. During the EP study the doctors want to cause the arrhythmia experienced by the patient in his life. The arrhythmia may be caused by the electrical impulses produced over the catheter tip and managed by doctors.
In most cases, the arrhythmias caused during the EP study are interrupted by the same impulses that caused them. However, there are times when one electroshock is needed to cease the arrhythmia. In accordance with the determined arrhythmia and its mechanism, the doctor will decide on antiarrhytmic therapy, ablation and/or prevention. In some cases, it is possible to completely cure clinical arrhythmia with radiofrequency ablation by ablating in the area where arrhythmia occurs. (see: Radiofrequency cardiac ablation).