White papers on Portable ECG Devices
From Heart Health Initiative
How to use 1-lead ECG recorders to obtain 12-lead resting ECGs and exercise ("stress") ECGs
by James W Grier
Department of Biological Sciences
North Dakota State University
Fargo, ND 58102-3400
Introduction
Although 1-lead ECG (EKG) recorders are normally used primarily for basic heart monitoring, checking for various arrhythmias, or simple educational or research purposes, they can also be used for looking at the effects of exercise on the ECG. One-lead recorders can also be used to accomplish full 12-lead recordings in a sequential manner.
New, low-priced, 1-lead handheld ECG recorders have become available for personal, home, and sports use, much as with home blood-pressure/pulse recorders or glucose testers for diabetics. They also are suitable in some emergency situations but only when used by medical or emergency personnel. Otherwise, they can be used by the general public for personal recording of information, such as for baseline information, routine monitoring, or during uncommon events, like with cardiac event recorders. The recordings can then be shown to the person's cardiologist or electrophysiologist or, for non-emergency or simple monitoring purposes, used by the person himself or herself if he or she is able to interpret them. (ECGs are complex and have a fairly steep learning curve. For a basic introduction, click here.)
One-lead ECG recorders may also be used for monitoring the heart in association with regular exercise, workouts, and sports activities. The actual recordings need to be done while the body is not moving, to avoid artifacts from the muscles. However, "resting" measurements can nonetheless be done during exercise and while the heart is responding to the exercise by briefly interrupting the activity long enough to obtain a recording or immediately after finishing the activity. Recordings can also be made while resting during the recovery period following exercise. The use of any ECG recorder for exercise, however, is somewhat akin to stress tests done in a clinic or hospital under medical supervision and should not be done at home if cardiac problems are suspected or might occur or if clear emergency or urgent situations exist (see disclaimer section below). Please consult a cardiologist if in doubt.
The purpose of this article is to explain how to use 1-lead (2 to 3 electrode contact) recorders in both exercise and 12-lead contexts. When using the recorder for exercise purposes, one might want to focus on a particular lead of the various 12 that are available, such as lead II or one of the chest leads (V1-V6). Thus, I will explain how to obtain the different 12 leads first and then one can choose which of them to use for measuring the ECG during exercise.
Important disclaimer: This information is provided for educational, sports-associated (by healthy persons), research, and non-emergency monitoring use only, not diagnostic or emergency uses by untrained persons. In the event of an emergency or suspected-emergency situation, appropriate medical help and facilities should be sought as quickly as possible. The only time that personal ECG recorders should be even considered in urgent, emergency situations would be if problems were to occur in remote locations to obtain useful information and/or while waiting for transportation and help, that is, when the use of the recorders would not delay possible help and might permit the collection of useful information for later use.
