There are a number of tests that can be performed to determine if someone is in a group that is at high risk for cardiac arrest. These include:

1. Echocardiogram – a painless test in which sound waves are used to create a moving picture of the heart. The test can measure the pumping ability of the heart and identify other problems that may increase a person’s risk for SCD.
   
   
2. Electrocardiogram – A painless test in which electrodes are attached to the patient’s chest to record the electrical activity of the heart in order to identify abnormal heart rhythms. Certain arrhythmias could point to an increased risk of SCD.
   
   
3. Holter monitor – A Walkman-size recorder that patients attach to their chest for one to two days, recording a longer sampling of their heart rhythm. After the recorder is removed, the tape is analyzed for signs of arrhythmia.
   
   
4. Event recorder – a pager-sized device that also records the electrical activity of the heart over a longer period of time. Unlike a holter monitor, it does not operate continuously. Instead, patients turn on the device whenever they feel their heart beating too quickly or chaotically.
   
   
5. Electrophysiology study (EPS) – This test is performed at a hospital or clinic. A local anesthetic is used to numb areas in the groin or neck and thin flexible wires called catheters are snaked up to the heart to record its electrical signals. During the study, the electrophysiologist studies the speed and flow of electrical signals through the heart, identifies rhythm problems and pinpoints areas in the heart that may be the sources of abnormal electrical signals that trigger arrhythmias. The physician can also determine if a patient has had a prior heart attack or evidence of prior heart damage without knowing it. All of this information can help determine whether the patient is in a group at higher risk for SCD.