What is Electrophysiology?

Cardiac Electrophysiology, is the study of the electrical activities of the heart, specifically for the purposes of diagnosing and treating heart rhythm disorders.

Diagnosing Heart Rhythm Disorders

The process of making an accurate diagnosis starts with an office evaluation. Taking the time with our patients early on is definitely worthwhile, an investment that minimizes expensive, unnecessary testing and charts the shortest path toward diagnosis and treatment of the problem. There are various types of heart rhythm disorders. Some are associated with symptoms. Others are asymptomatic. Some are life-threatening, most are not. There are times when only reassurance is all that is needed. Other times, diagnosis leads to a curative procedure. Medications remain an important part of treatment. Devices like pacemakers and defibrillators are often used as well.

The initial diagnosis starts with assessing the overall health of the heart. An echo cardiogram to assess muscle strength and valve function is often needed. A stress test to assess coronary risk may also be attained early on in the evaluation. Dr. Kedia often orders an EKG monitor to record a patient’s heart rhythm at the time that the patient is symptomatic. Some patients’ symptoms are infrequent, thus, necessitating long-term monitoring. The device, implanted under the skin, may be needed if long-term monitoring is desired. An electrophysiology study (EP study) is an outpatient procedure that may be needed to establish diagnosis in a more efficient manner. This is especially important if a dangerous rhythm disorder is suspected. An EP Study is a low-risk procedure. The rhythm problem could be eliminated by ablation during the procedure, as well.

EP Study

An EP study is a low-risk outpatient procedure. Once the patient is made comfortable, 3 catheters (insulated wires) are placed into the femoral vein at the right groin, and are advanced into the heart chambers and placed at strategic locations. Electrical signals are then transmitted from the heart and fed into a computer (mapping system) for analysis. The heart is stimulated by the catheters in order to elicit the abnormal rhythm. Once the rhythm is brought on it can be pinpointed and eliminated.

Elimination of rhythm disorders is performed during EP study with a process called ablation. During ablation, energy is applied to the source of the abnormal rhythm to extinguish it. Traditionally, the energy source used is radio frequency energy, which heats up the tissue and destroys it. Freezing energy can also be used. This type of ablation is called cryoablation. It can be done with a freezing catheter or a balloon. The latter is used typically to ablate the circumference of the pulmonary veins that attach to the back of the heart, a common source of abnormal rhythms. Other ablation sources are being investigated, such as laser, high frequency ultrasound and microwave energy.

All of these modalities have their pluses and minuses. Radiofrequency energy is still the most commonly used modality because of its flexibility and speed of application. Dr. Kedia may employ more than 1 modality in any given procedure, if necessary. He believes the perfect energy source that suits every patient has not yet been invented. The search goes on.

Rhythm disorders vary in location and level of complexity. They are typically divided into upper versus lower chamber rhythms (supraventricular versus ventricular tachycardia). Some come from a single site; others are caused by multiple active sites. Rhythm disorders that come from multiple sites are more difficult to eradicate. Multiple sites generating abnonnal electricity in the upper chamber of the heart create a common rhythm disorder called atrial fibrillation (AF). AF has been the focus of Dr. Kedia’s attention for the last 15 years because it is the most common rhythm problem and it is the most challenging one.