heart tests Many arrhythmias come and go. The fleeting nature of arrhythmias makes it difficult to actually capture an event during any single test. Sometimes it’s necessary to monitor the heart over time. Sometimes specialists provoke abnormal rhythms in a safe environment to evaluate and diagnose a problem. Symptoms can be hard to identify. People with arrhythmias may not feel any symptoms, or they may have symptoms that seem unrelated to the heart, such as lightheadedness, fainting or shortness of breath. Electrophysiologists conduct special tests to determine if nonspecific symptoms are related to problems in the heart's electrical conduction system or other types of heart disease. Some arrhythmias are caused by factors unrelated to the heart. Medications, metabolic diseases, substances in the environment, diet and stress can contribute to abnormal heart rhythms in people who are otherwise healthy. Specialists take all of these factors into account as they select tests best able to uncover the true cause of an arrhythmia. Diagnosing heart arrhythmias can be difficult and requires special expertise as well as unique testing equipment. To diagnose the problem, a physician will carry out a thorough physical exam. Taking into account a number of factors, including symptom patterns, the physician will then order specific tests. Diagnostic Tests include: Electrocardiogram (ECG/EKG) Echocardiogram Holter Monitor Event Recorder Tilt Table Test Electrophysiology Study Radionuclide Ventriculography Cardiac Catheterization The Normal Heart Signs and Symptoms Heart Disease and Disorders    Sudden Cardiac Arrest Substances Causing Arrhythmias Risk Factors and Prevention Heart Tests Treatment An Electrocardiogram (ECG) is a safe, commonly performed heart test that rarely causes discomfort. The patient lies down and "electrodes" at the end of wires (or leads) are attached to each arm, leg and the chest. Electrodes are sticky patches that attach to the skin, or suction cups applied with conductive paste that are easily peeled off once the procedure is completed. There are no needles used and the test is painless. The ECG takes about ten minutes from start to finish, but the actual recording of the heart's electrical activity usually is done in a matter of seconds. The places where the electrodes are attached are cleaned, and in some cases, it may be necessary to shave or clip the hair. Patients are required to remain still, and are sometimes asked to hold their breath for short periods of time. An Echocardiogram is a non-invasive, safe and effective test to study the anatomy of the heart. It uses sound waves (ultrasound) to form images of the structures of the heart. The ultrasound and electrocardiography (ECG) signals are recorded on a videotape simultaneously to be reviewed by the cardiologist. The test can evaluate the size of the different chambers of the heart, the quality of the valves, measure the heart's pumping ability and identify other problems of the heart that may increase a person's risk for dangerous arrhythmias. An electrophysiologic, or EP study provides information that is key to diagnosing and treating arrhythmias. Although it is more invasive than an electrocardiogram (ECG) or echocardiogram, and involves provoking arrhythmias, the test produces data that makes it possible to: Diagnose the source of arrhythmia symptoms Evaluate the effectiveness of certain medications in controlling the heart rhythm disorder