An electrocardiogram (ECG) is a medical test that records the heart’s electrical activity. While traditionally performed in a clinical setting, technology has led to wearable devices like the ECG patch. This is a small, adhesive cardiac monitor worn on the chest to continuously track heart activity over an extended period. This allows for remote monitoring as a person goes about their daily life, enabling the capture of data that a brief, in-office ECG might not detect.
How an ECG Patch Works
An ECG patch is a self-contained biosensor that adheres directly to the skin of the chest using a medical-grade adhesive. Its function relies on built-in electrodes that detect the heart’s electrical signals, the same ones measured by a standard ECG machine. The patch is designed to be small and lightweight, keeping it in place for the duration of the monitoring period.
Inside the housing, the patch contains a battery and a memory chip to store the collected data. This allows it to record the heart’s rhythm continuously, often for up to 14 days. By capturing every heartbeat over this timeframe, the patch can identify sporadic electrical patterns. Some patches also include an accelerometer to record physical activity, providing additional context for the heart data.
Conditions Monitored by an ECG Patch
Doctors prescribe an ECG patch to investigate symptoms that are infrequent or unpredictable. These devices are useful for detecting or ruling out various types of arrhythmias (irregular heartbeats) that may not occur during a short medical appointment. The extended monitoring period increases the chances of capturing evidence of an underlying heart rhythm disorder.
Among the most common conditions an ECG patch helps diagnose is Atrial Fibrillation (AFib), a rapid and irregular heartbeat that can increase the risk of stroke. The patch is also used to investigate unexplained palpitations, which patients describe as a fluttering or racing sensation. It can also be a diagnostic tool for syncope (fainting) by helping determine if a cardiac issue is the cause.
Comparing the ECG Patch to a Holter Monitor
For many years, the Holter monitor was the standard for ambulatory cardiac monitoring. A Holter monitor consists of a small box connected via multiple wires to several electrodes on the chest. This setup records the heart’s activity, but its use is limited to a 24 to 48-hour period. The network of wires can be cumbersome, and the device is not water-resistant, meaning patients cannot shower while wearing it.
The ECG patch offers a different patient experience. As a single, self-contained unit, it has no external wires, making it more discreet and comfortable. An advantage is that most patches are water-resistant, allowing patients to shower without interrupting the monitoring process. The duration of monitoring is also a distinction; an ECG patch can record data for up to two weeks, compared to the shorter Holter monitoring window.
The Patient’s Role During Monitoring
A patient’s active participation helps improve the quality of the diagnostic data. Many patches feature a button that the patient can press if they experience a symptom like dizziness, shortness of breath, or palpitations. This action creates a time-stamped mark in the data log. Patients are also asked to keep a diary to note the time and nature of their symptoms, which allows the physician to correlate the recorded heart rhythm with the patient’s sensations.
Patients are encouraged to continue with their normal daily routines, including light to moderate exercise. Following the specific instructions provided with the device is important, such as avoiding submerging the patch in water and being mindful not to dislodge it. Adhering to these guidelines ensures the device collects a complete and accurate record.
After the Monitoring Period
Once the prescribed monitoring period is complete, the patient removes the adhesive patch from their chest. Most monitoring services provide a pre-paid envelope, and the patient is instructed to place the used device inside and mail it back to a data analysis center.
Upon its return, trained technicians download the stored electrocardiogram data from the device’s memory. A cardiologist or a specialized heart rhythm physician interprets the findings and prepares a final report. This report is then sent to the patient’s own doctor, who will schedule a follow-up appointment to discuss the results and determine the next steps.