ELECTROPHYSIOLOGY
Electrophysiology studies, or EPS, use cardiac catheterization techniques to study patients with irregular heartbeats (called arrhythmias). EPS shows how the heart reacts to controlled electrical signals. These signals can help doctors find out where in the heart the arrhythmia starts and determine which medicines are most effective at stopping it. EPS also can help doctors identify other catheter techniques that could be used to stop the arrhythmia.
During an electrophysiology study, doctors perform a cardiac catheterization procedure in which a long, thin tube (called a catheter) is inserted into a leg artery and threaded into the heart. This catheter can be used to send electrical signals into the heart to recreate in a controlled setting the patient’s arrhythmia. Doctors can then study the arrhythmia and test certain medicines to see which will stop it.
Holter and event monitors are used to record a patient's ECG for a prolonged period of time on an outpatient basis. Called ambulatory monitoring, their purpose is to look for evidence of heart problems that come and go, and that are not apparent when a standard ECG is performed. Ambulatory monitoring is particularly useful in diagnosing heart arrhythmias and cardiac ischemia.
With the Holter monitor, electrode leads are applied to the skin (similar to the leads used in recording a standard ECG), and attached to a tape recorder. The patient is sent home and resumes normal activities while the tape recorder records a continuous ECG tracing for 24 or 48 hours.
Event recorders use a circular tape that stores only approximately 30 seconds of a patient's heart rhythm.
At any given time while a patient is wearing them, event recorders will have the most recent 30 seconds of the patient's ECG. When the patient experiences a symptom, he or she presses a button that freezes the recording, which is then transmitted by telephone to an interpreting center.
