Diagnostic Tests at the Electrophysiology Section
Physicians use diagnostic testing to evaluate how blood flows through the heart's chambers and major blood vessels. Diagnostic procedures used at the Electrophysiology Section measure the electrical conduction of the heart, abnormal heartbeats, arrhythmia episodes, heart and blood pressure changes and electrical images of how your heart is working. These tests include:
An electrophysiology study assesses the electrical conduction system of the heart and any abnormal heartbeats. The study can measure:
- How fast the electrical signals in the heart travel
- How well the electrical impulses are pacing your heart rhythm
During the study, physicians may artificially cause an abnormal heart rhythm in patients to see how these respond, and how effectively these respond, to a particular drug. Physicians may also perform tests to see how a pacemaker is working, where a pacemaker should be installed, what caused the abnormal heart rhythm and whether or not more studies are needed.
You will be asked to lie on a table with a large X-ray camera above and a television, heart monitors and other instruments nearby. Everyone will be dressed in sterile gowns, gloves and masks.
You will undergo cardiac catheterization so wires can be positioned in the chambers of your heart. You may feel pressure when the catheters are inserted but you should not feel pain. It may become tiring and uncomfortable to lie in the same position so long. Once the wires are in place, electrical signals from your heart are monitored and recorded. Your doctor may artificially increase your heart rate to cause any abnormal rhythm disturbances. Drugs may be given to you through a needle and tube inserted in your arm. The entire study takes up to three hours.
At Cedars-Sinai's Electrophysiology Laboratory, specially trained doctors conduct these tests. Electrophysiology experts read and interpret the recording of the heart's action and provide a full report to the patient's doctor. The heart specialist can then use this information in planning the best treatment plan.
Click here for instructions for preparing for cardiac catheterization, angiography and electrophysiology studies.
This painless test requires that you lie still while the technician puts electrodes (which can record the electrical activity of your heart and are attached by sponge pads) on your arms, legs and chest. In some cases, shaving chest hair may be needed so there is better contact between the electrodes and the skin. The electrodes are connected by wires to an electrocardiogram (ECG) monitor, which looks like a television. The test takes about five minutes.
Some of the things an electrocardiogram can tell your physician are your heart rate, how regularly your heart is beating as well as the size and position of your heart's chambers, any damage to your heart and the effects of any drugs or devices used to regulate your heart. An electrocardiogram can also show whether a coronary artery is blocked and where the block is located. Other types of conditions including high blood pressure, thyroid disease and some types of malnutrition may appear on an electrocardiogram.
Click here for more information about electrocardiograms.
A longer monitoring period may be necessary to properly record and diagnose arrthymia episodes. Your doctor may order a Holter or extended event monitor, a small, portable device worn continuously to record your arrthmia events during your daily activities. Patients may need to wear the monitor for as long as one month to properly diagnose the arrthymias.
Further testing may be ordered, depending on the results of these recordings.
A tilt-table study is used to check for changes in heart rate and blood pressure when your body's position is changed. This test is most commonly done when a person has periods of losing consciousness or nearly fainting.
When the table is upright, blood collects in the legs and lower part of the body. Less blood returns to the heart to be pumped. This may cause the blood pressure to drop. Normally the nerves that control the heart and blood vessels keep your blood pressure at a steady level. A tilt table study will show the heart slowing as the blood pressure falls.
A nurse prepares you before the procedure by inserting an intravenous (IV) line in your arm. He or she will also connect you to an electrocardiogram and a blood pressure cuff.
At first, you will lie flat for 20 to 30 minutes. Then, the tilt bed will be changed to a nearly vertical (80 degrees) position for 30 to 45 minutes. In this position, you might feel lightheaded, dizzy or as if you might faint. It is important that you tell the doctor or nurse of any symptoms you may be feeling. Finally, the tilt bed will be put in a horizontal position and you will be observed for another 20 to 30 minutes.
You may also be given a drug to increase you heart rate through your IV as part of this test. The drug may make your heart feel like it is pounding. The doctor will decide if this is needed at the time of the study. During this portion of the test, your position will be changed from vertical to flat several times. Depending on your body's response, the test may last up to three hours.
Click here for information on preparing for a stress test.