People who may have arrhythmias need to receive a thorough cardiac examination, which may include one or more of the following testing procedures:

History and physical examination. These are the first steps the doctor will take.

Electrocardiogram (ECG or EKG). This test records the heart's rate and rhythm. The doctor will place disks on your chest and connect them to a recording machine. This machine will draw lines across a strip of paper, allowing the doctor to look for any changes in the heart's normal rhythm.

Signal-average ECG. This computer-enhanced analysis of small electrical signals may predict arrhythmic events.

Echocardiography. This test is used to assess the structure, function and blood flow of your heart. During the test, a small instrument called a Doppler probe will send sound waves (ultrasound) through the portion of the body where it is applied, allowing for the blood flow to be heard and images of it recorded.

Exercise stress testing. Stress testing will measure what happens to your heart during exercise. You will exercise on a treadmill or bicycle while connected to the ECG machine, which will indicate if exercise causes arrhythmias or makes them worse.

Tilt-table evaluation. This test measures your heart rate and blood pressure while lying flat, then monitors them as the table is tilted up. Position changes exert stress on the part of the nervous system responsible for maintaining heart rate and blood pressure, so physicians can observe the cardiovascular response under controlled conditions. The tilt-table evaluation, which takes between 20 and 45 minutes, is helpful for patients with syncope (blackout).

Arrhythmia monitoring devices. You may be asked to wear a Holter monitor, which records your heart rate and rhythm continuously for up to 24 hours at a time. Long-term monitoring - up to a month - may be performed with an event monitor, which records an infrequent arrhythmia and provides a way for your doctor to retrieve and save the data via computer recording.

Electrophysiology (EP) studies. During an EP study, which can be performed at the Texas Heart Institute at St. Luke's Episcopal Hospital's Cardiac Catheterization Laboratories, doctors insert one or more small wires through a vein in the leg or upper extremity and then guide them to the heart. Programmed electrical stimulation then reproduces your arrhythmia, allowing physicians to determine the nature and location of the rhythm disturbance. When drug therapy is begun or revised, EP studies allow doctors to gauge the heart's reaction to certain medications.

For more information about The Center for Arrhythmias and Electrophysiology, call (832) 355-6567 or (800) 238-4212.