Electrophysiology

Sometimes the source of the heart's problem lies, not in the arteries or the muscles of the heart, but in its electrical system. Many people have arrhythmias — electrical glitches in the heartbeat. For example, the heart may beat too fast (tachycardia) or too slow (bradycardia), or it may be throwing in extra heartbeats. In that case, the electrophysiology laboratory at Bridgeport Hospital can provide information for a diagnosis.

Electrophysiology Tests

Electrophysiology tests are performed by an electrophysiologist with the help of a radiology technician and a surgical scrub technician who administers medications, monitors the status of the patient, and operates special computer systems during the procedure.

An electrophysiology study is a two-to-four-hour procedure designed to test the heart's electrical system. Patients are awake during the test, which begins with placement of electrocardiogram (EKG or ECG) pads so that EKGs can be taken throughout the procedure. An intravenous line (IV) is placed in an arm to give fluids and medications, if needed. Blood pressure and the level of oxygen in the blood are continuously monitored. Small catheters are passed through tiny openings in groin or shoulder veins, and up to the heart where they are positioned to record the heart's electrical signals.

Normal EKG

During the study, the heart is stimulated to beat at different rates, or in different patterns. It's a bit like an electrical "test drive" to see if the heart has the tendency to go into potentially dangerous rhythms, either slow or fast, that require treatment. (If an abnormal heartbeat does occur, the rhythm can be regulated back to normal).

Treatments for rhythm disorders include:

• medications
• pacemakers
• defibrillators
• radioablations

Fainting disorders

A tilt-table test can help unveil the causes of certain fainting disorders. Many otherwise healthy people of all ages have a reflex that, under certain conditions, their heart rate may slow and/or their blood vessels may dilate. This reflex of blood vessel (vaso) expansion is caused by the vagus nerve and the fainting that it may cause is caused vasovagal syncope. It is the most common form of fainting, or near-fainting. It often occurs when people are frightened (when getting an injection, for example) or when they stand still for long periods (for instance, in church or on a long movie line). A tilt-table test is intended to study these reflexes. The information obtained may help physicians determine how to prevent such fainting spells. During the test, the patient lies on a special table. An intravenous line (IV) is placed in an arm to give fluids and medications as needed. Adhesive EKG electrodes are placed on the chest to monitor the heart rate, and blood pressure is measured throughout the test.

A tilt-table test is intended to bring out these reflexes, and may make the patient faint. By learning what causes the syncope, the electrophysiologist can determine how to prevent such fainting spells.

During the test, the patient lies on a special table in the electrophysiology lab. An intravenous line (IV) is placed in an arm to give fluids and medications, if needed, and continuous EKG and blood pressure monitoring is done.

The table is then tilted up to about 60 to 80 degrees for as long as 30 minutes while the patient is continuously monitored. Head-up tilting causes blood to collect in the legs, which causes the blood pressure to drop. The brain compensates by signaling the heart to speed up and the blood vessels to constrict. If these reflexes are unable to cope properly with this situation, or if the reflex becomes too powerful during the test, the patient may become faint. Returning the table to the flat position restores normal blood pressure and ends the symptoms. Treatments for vasovagal syncope may include increasing fluid and salt intake, medications, and even pacemakers in rare cases.

Radioablation
If an EP study reveals certain arythmias, radioablations may permanently cure the arrhythmia.

In the radioablation procedure, which can last between 2-6 hours, a special catheter is used that delivers radio frequency energy to the precise area of the heart that is causing the abnormal heartbeat. The tip of the catheter heats up and painlessly destroys the surrounding tissue, interrupting the abnormal circuit.