Arrhythmias

Arrhythmia, an abnormal heart rhythm, is a broad term that describes either a fast or a slow heart rate. There are a variety of heart conditions that can cause arrhythmias. This one area of cardiology is called electrophysiology. Electrophysiologic testing is an invasive diagnostic study of the electrical circuitry of the heart. It may be used for diagnosing fast or slow heart rhythms.

Electrophysiology studies are usually used in patients to determine the need for either a pacemaker or an implantable cardioverter-defibrillator. As well, electrophysiology studies are also used to discover the presence of an arrhythmia that is amenable to radiofrequency ablation.

Electrophysiology studies are performed in a hospital. It requires an overnight fast and the patient is consciously sedated in the electrophysiology laboratory, which is in the same laboratory as the cardiac catheterization. Large IVs are placed in the femoral vein, the large vein in the patient’s groin. Thin pacemaker wires are placed through the IVs up to the right side of the heart. The pacemaker wires themselves are attached to an external computer, which is used for monitoring and studying the electrical system of the heart. The patient does not feel any discomfort during this procedure. Occasionally, palpitations are felt if the heart rate is going fast. After the physician finishes making measurements of the electrical system, a technique called programmed stimulation is then performed. Programmed stimulation requires pacing the heart at a variety of rates to look for underlying arrhythmia mechanisms. After the test is completed, the wires are removed from the heart and the sheaths are taken out of the groin. The patient can expect to lie on their back for a four-hour period. If no procedures are required, the patient usually goes home the same day.