Your doctor will begin the procedure by choosing veins in your legs, arms or neck for catheter entry. It is possible that both legs and an arm will be used.
The number of catheters used during EPS depends on the type of study being done. Usually 3 to 5 catheters are used. Once the entry sites are chosen, the areas are shaved, scrubbed, and then painted with a special disinfectant to make sure they are absolutely clean. Then, one or more shots of numbing medicine are given in that area. As with your IV, this is done with a small needle and it may feel slightly uncomfortable, like a small pinch. You may also experience a slight tingling or burning sensation.
Once the areas are numb, you may feel some pressure or slight discomfort as a needle guides an introducer into your vein. The introducer provides a pathway for the catheters to be put in. Your doctor will then begin the process of guiding the catheters into place, while watching them on a special x-ray screen, like a TV screen. Sometimes placing the catheters is slow and takes a long time. You will not feel the catheters as they move through your blood vessels. You may feel a "skipped" heartbeat, a fluttering or a pounding in your chest when the catheters move through your heart. This is because the catheter is actually tickling your heart.
When in place, the catheters will sense the electrical signals in different areas of your heart. Your doctor will view these signals on EKG monitors.
Since it is common for abnormal heartbeats to come and go, your doctor may try to trigger them during the procedure under controlled conditions. By doing this, your doctor can study your abnormal heart rhythm, or arrhythmia, and identify the location in your heart that may be causing it.
After locating this area, your doctor will determine which treatment method is possible. The decision is based on the location and type of the abnormal beat.
One possible treatment that uses radio waves is called Radiofrequency Ablation or just ablation. During ablation, your doctor will guide a special catheter to the area in your heart causing the problem. The catheter tip heats up and gives a small burn to the area, which safely scars it so it cannot send the abnormal signals. In doing so, ablation usually stops the abnormal heart rhythm without damaging the heart. You may feel some discomfort during ablation, but the procedure is not considered painful. After ablation, your doctor will try to re-trigger the abnormal heartbeat. If the abnormal beat cannot be triggered, the ablation is considered successful.
Another possible treatment is drug therapy. Different drugs can be given through your IV to affect your heart rhythm. Your doctor will observe your heart's reaction to different drugs and discover which drug best corrects your abnormal heartbeat.
When the procedure is complete, you may feel some discomfort as the catheters are removed and pressure is applied to the entry sites.