Screenings &
Diagnostic Tests

Diagnosing Arrhythmias

Diagnosing arrhythmias involves many factors, including a careful history. People with arrhythmias may not feel any symptoms at all, or they may report symptoms that can seem unrelated to the heart, such as dizziness, fainting or shortness of breath. Some arrhythmias in otherwise healthy people can be caused by factors such as medications, diseases (including thyroid problems), diet and stress.

Electrocardiogram (ECG/EKG)

This test uses a machine attached to legs, arms, and chest via ten electrodes to record the heart's electric signals that create heart rhythms.


This non-invasive imaging technique creates a videotaped image of heart structures that reveals the heart's four chambers, valves, and movements.

Holter Monitoring

To detect irregular heart rhythms that can be fleeting, a patient wears a small phone-sized device (attached to their chest by five adhesive electrode patches) which records the heart rhythm for 24-48 hours.

Event Recorder

This small, phone-sized recording device can detect and record arrhythmias with or without the patient experiencing any symptoms. It may be worn up to a month.

Tilt Table Test

This test helps evaluate blood pressure-related reasons for fainting (syncope). Heart rhythm and blood pressure are carefully monitored while a patient rests on a special table that tilts the patient upright at a 70-80 degree angle for 30-45 minutes. A fainting episode can indicate a person has vasovagal or neurocardiogenic fainting, which is not life-threatening.

Electrophysiology (EP) Study

An EP study involves inserting a catheter — a narrow, flexible tube — attached to electricity monitoring electrodes, into a blood vessel, often through a site in the groin or neck. The catheter wire is guided into the heart while the patient is sedated. An X-ray-like machine provides "live" images of the catheter and heart muscle. The catheter's electrodes gather data, and a variety of electrical measurements. During an EP study, an electrophysiologist may provoke arrhythmias and collect data about the events. This data helps the doctor assess the need for an implantable device (such as a pacemaker), predict the risk of future cardiac events, and evaluate the effectiveness of certain medications in controlling heart rhythm disorders. If a heart arrhythmia is amenable to treatment by ablation, that procedure is often performed at the time of the EP study.