Electrophysiology (EP) Study

An electrophysiology or EP study is a minimally invasive procedure to monitor and test electrical activity in the heart in cases where an arrhythmia or irregular heartbeat may be suspected.

The very nature of a cardiac arrhythmia is unpredictable. Especially in their earlier stages, arrhythmias, including the most common heart rhythm abnormality atrial fibrillation or AFib, can be sporadic (paroxysmal). Often, therefore, a typical in-office EKG will not be sufficient to diagnose the disorder. Electrophysiology studies allows for a more comprehensive understanding of the heart’s electrical signals and to determine the exact location of the misfiring heart signals, if they exist.

Electrophysiology studies are conducted in a catheterization (Cath) Lab or electrophysiology (EP) lab. During the procedure, a small incision is made in the thigh and a catheter is threaded up to the heart. The tip of the catheter contains specialized hardware to record and map the heart’s electrical activity. These signals are then translated by specialized software to form a comprehensive mapping of the heart and its electrical signals.

In some cases, an EP study may be used to induce AFib in patients that have been complaining of severe, but intermittent heart rhythm problems. By inducing the arrhythmia, we can accurately map the problematic areas of the heart.

Ultimately, the diagnostic goals of the EP study are to

• Understand more about the cause and the exact location of the arrhythmia
• Learn more about whether medication is functioning as expected
• Understand if further treatment may be necessary including a pacemaker, ICD or curative catheter ablation
• Understand potential risk factors for heart attack or syncope (unexplained fainting)

If the conditions are appropriate for treatment, a cardiac catheter ablation may also be performed during the EP study. This is a procedure whereby misfiring heart tissue is ablated or destroyed to eliminate the improper electrical activity. Cardiac catheter ablations are relatively low risk, highly effective, often curative procedures that can significantly improve the patient’s lifestyle very soon after the procedure is performed.

A diagnostic EP study my last for an hour or more depending on the comprehensiveness of the test as well as the feedback that your electrophysiologist receives. If a follow-up procedure is performed, additional time will be necessary.

Risks of an EP study

Fortunately, EP studies are relatively low risk when performed by an experienced electrophysiologist. Some of the most common concerns and risks during EP study include:

• An EP study can induce arrhythmia in some patients. Your electrophysiologist may also induce an arrhythmia. This may be an uncomfortable situation that could require electroshock cardioversion to correct
• There is a small chance that the catheter can damage the blood vessel through which it is threaded as well as heart tissue, requiring a corrective procedure
• It is possible for small blood clots to form around the catheter requiring blood thinning
• medication if the patient is not already on it
• Pain, bruising and swelling around the incision site in the groin
• A small chance of infection at the incision site

Risks specific to your condition will be discussed during consultation.