A Holter monitor is a non-invasive, painless test that records your heart’s electrical activity on
a continuous basis for 24 to 48 hours. It is an extended form of an electrocardiogram (ECG).
This type of test helps doctors diagnose and monitor myocardial ischemia (reduced blood
supply to the heart muscle and cardiac arrhythmias (abnormal heartbeats).

A Holter monitor can identify unusual heartbeats and other abnormal ECG activity that a
regular ECH might miss. A regular ECG only records the electrical activity of the heart for short time period. The detection of heart abnormalities that occur on a periodic basis are more likely
detectable with a continuous Holter monitor.

Reasons to Perform a Holter Monitor Test

In order to more thoroughly evaluate the health of your heart, your doctor may recommend
a cardiac Holter monitor test. This test reveals important information about your heart in
connection with your medical history, physical exam, age, and other tests. Although a Holter
test cannot alone diagnose every type of heart condition, it can detect potential future heart issues.

A Holter monitor may be used to identify, determine the extent of, and direct treatment for these conditions:

• Coronary artery disease (CAD) – This condition involves plaque buildup on the walls of the coronary arteries that send blood to the heart. CAD can cause ischemia which can include chest pain (referred to as angina) and inadequate blood flow to the heart muscle.
  When there is no chest pain or other symptoms, a Holter monitor can be effective
  at diagnosing ischemia.
• Cardiac arrhythmias – This condition involves heartbeats that are irregular, too slow, or too fast, particularly arrhythmias that only occur at certain times.

An ECG Holter monitor can help determine if some of the symptoms a patient is experiencing are related to a heart issue. These symptoms may include shortness of breath, dizziness, chest pain, palpitations, weakness, irregular or racing heartbeat, pounding feeling, fatigue, or passing out.