As physicians who specialize in the electrical system of the heart and cardiac rhythms, we use the 12-lead electrocardiogram (ECG) as our main and most informative non-invasive tool to diagnose and differentiate arrhythmias. 

Since 1903, when it was introduced by Willem Einthoven, ECG has maintained its status as the gold standard of diagnosing all types of cardiac arrhythmias. You may have had several ECGs already, but usually we prefer to have one performed in our office, as we might use different positions for the leads or perform a longer recording, giving us a rhythm strip.

The biggest limitation of an ECG is that it represents an extremely brief period, just a glimpse of 10 seconds of your heart’s electrical activity. If the arrhythmia is present during the acquisition of the ECG, then we will be able to identify your arrhythmia. 

However, if the arrhythmia or symptoms of arrhythmia (including palpitations, dizziness or syncope) is only intermittent and not present while obtaining the ECG, then we’ll need other tools to help record arrhythmia when is happening. 

In these situations, we will perform extended or long term monitoring while you are at home and living a regular life with regular activities. 

This extended monitoring can serve 2 purposes:

  1. To detect the arrhythmia
  2. To evaluate the burden of the arrhythmia (if it has already been identified) 

Fortunately, since the 1940s there has been continuing progress in the field of ambulatory external ECGs (portable ECGs you wear for 1-30 days that help us understand the exact cause and nature of your symptoms and identify arrhythmias.)

There are two types of ambulatory ECG monitors: external (on the skin) and internal (underneath the skin) monitors. In addition, ambulatory ECG monitors can provide with continuous or intermittent monitoring.

Continuous monitors:

  • External:                        
  • Internal:                         
    • Implanted loop recorder
    • Any types of implantable cardiac devices (pacemakers or defibrillators)

Intermittent monitors: