Question

What is the difference in heart monitors you wear for 24 hrs, and those you wear for two weeks? I have heart palpitations and a fast heart rate, but no pain or other symptoms. Do I also need to have an echocardiogram and a stress test done?

Answer

The 24-hour monitor is called a Holter monitor, and the other is called an Event monitor. The Holter is typically worn for 24 hours, and the Event monitor for 30 days. We choose which one to use according to how often symptoms occur, or if there is a reasonable chance of 'catching' an event during a typical 24-hour period. The Holter records everything that happens during the 24 hours, and the person can add a signal at the point in time when they feel symptoms. The Event monitor runs all the time, but only records when the patient presses the 'alarm' button. The Event monitor is therefore used when symptoms are haphazard in occurrence and frequency; it's hoped that, during 30 days, some events will be signaled and 'caught' by the monitor. It records what was occurring for 30 seconds prior to hitting the alarm button, and 15 seconds afterwards. The Holter is roughly the size of a paperback book, while the Event monitor is the size of a pager.

For someone with occasional palpitations, no other workup is needed unless something is found on the monitors. The only exception may be if there are risk factors for heart disease (e.g. cardiomyopathy, a disease of the heart muscle); then an echocardiogram may be helpful in addition. Further diagnostic testing after the monitor would then depend on what was found. Fast heart rates can be caused by a number of things, but if a number of such episodes are downloaded from the monitor, and all are entirely normal, then it is less likely that an abnormal heart rhythm is occurring.