While electrocardiograms (EKGs) are non-invasive, an EP study is considered a minimally invasive diagnostic test. The study is performed after the patient is given a local anesthesia and conscious sedation with medicine through an IV to keep him or her as comfortable as possible. The procedure involves inserting one or more catheters—narrow, flexible tubes attached to electricity-monitoring electrodes—into a blood vessel, often through a site in the groin or neck, and passing the catheter wire up into the heart.
The journey from entry point to heart muscle is navigated by images created by a fluoroscope, an x-ray-like machine that provides continuous, live images of the catheter and heart muscle.
Once the catheter reaches the heart, electrodes at its tip gather data and a variety of electrical measurements are made. These data pinpoint the location of the faulty electrical site. During this electrical mapping, an electrophysiologist, may instigate, through pacing (the use of tiny electrical impulses), some of the very arrhythmias that are the crux of the problem. These induced events are safe, given the range of experts and resources close at hand, and they are necessary to ensure the precise location of the problematic tissue.
Once the damaged site or sites are confirmed, the specialist may administer different medications or electrical impulses to determine their ability to halt the arrhythmia and restore normal heart rhythm. Based on this data, as well as information gathered before the study, the specialist may choose to place an implantable cardioverter device (ICD) or a pacemaker or will perform radiofrequency ablation.
Throughout the procedure, the patient is sedated but awake and remaining still. Patients rarely report pain, more often describing what they feel as discomfort. Some patients watch the procedure on monitors and occasionally ask questions. Other patients sleep. The procedure usually takes about 2 hours. The patient remains still for 4 to 6 hours afterward to ensure that the entry point incision begins to heal properly. Once mobile again, patients may feel stiff and achy from lying still for so long.
Who Performs the Test and Where
Since potentially dangerous arrhythmias may be provoked during an EP study, specialized staff and equipment are present to handle all situations. An electrophysiologist, a physician who has trained in internal medicine and cardiology and then received advanced training in the diagnosis and treatment of heart rhythm problems, performs the EP study. The electrophysiologist leads a team of specially trained health care professionals, technicians, and nurses, who assist during the procedure. The team performs the EP study in our state-of-the-art electrophysiology laboratories, well-equipped, controlled clinical environment here at Strong. As a result, the test is quite safe and complications are rare.