Cardiac Event Monitors | MedStar Health

Long-term monitoring of irregular heartbeats with a portable device

An event monitor, also known as a cardiac event recorder or monitor, is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but whereas an electrocardiogram takes place over a few minutes, an event monitor measures heart rhythms over a much longer time.

What to expect from an event monitor

Your doctor will give you an event recorder and show you how to use it. The recorder will include patches called electrodes that you’ll stick to your chest. You’ll typically wear the electrodes for about 30 days, taking them off only during showers or baths.

Unlike another portable heart rhythm monitoring device called a Holter monitor , an event monitor only measures heart rhythms when you feel an irregular heartbeat or other symptoms. You may need to press a button on the device when you feel these symptoms. You’ll then send the recording over the phone to your doctor, who will review the recorded heart rhythm.

Event monitors shouldn’t have any effect on your daily activities. The tests aren’t painful, and the only side effect you may notice is a slight rash where the electrodes stick to your skin. This rash usually goes away on its own.


Arrhythmia treatments (heart rhythm)

Treatments for arrhythmias, or heart rhythm disorders, such as minimally invasive procedures, implantable devices, and surgery, vary based on the type and severity of your condition.

Cardiac ablation

Cardiac ablation uses heat or cold to destroy heart tissue causing abnormal heart rhythms known as arrhythmias.

Catheter ablation for atrial fibrillation

Catheter ablation is a minimally invasive procedure that uses heat or cold to destroy heart tissue causing atrial fibrillation, a type of abnormal heart rhythm.

Convergent (maze) procedure

A convergent maze procedure is a procedure that aggressively treats atrial fibrillation (AFib). Maze procedures create a pattern, or maze, of scar tissue in the heart to disrupt faulty electrical signals causing your abnormal heart rhythm.

Electrical cardioversion

Electrical cardioversion uses electrical shocks to treat heart rhythm disorders.

Heart surgery for atrial fibrillation (maze)

A surgical maze procedure treats atrial fibrillation (AFib) by creating a pattern, or maze, of scar tissue in the heart to disrupt faulty electrical signals causing your abnormal heart rhythm.

Implantable cardioverter defibrillator (ICD)

An implantable cardioverter defibrillator (ICD) is a device implanted below your collarbone that monitors your heart’s rhythm. When it detects an abnormal rhythm, it delivers an electrical impulse or shock to the heart to correct it.

Leadless pacemakers

A leadless pacemaker is a small capsule placed in the heart’s right ventricle that delivers an electric pulse to regulate the heartbeat.

Left atrial appendage closure

Closing the left atrial appendage can decrease the risk of dangerous blood clots and stroke for patients with atrial fibrillation.


A pacemaker is a device that helps control various types of heart rhythm disorders.

Pulmonary vein isolation

Pulmonary vein isolation creates scar tissue to disrupt electrical signals coming from the pulmonary veins that cause atrial fibrillation (AFib), a type of abnormal heart rhythm.

Radiofrequency ablation for atrial fibrillation

Radiofrequency ablation uses extreme heat to destroy heart tissue causing an abnormal heart rhythm known as atrial fibrillation.

Subcutaneous implantable cardioverter defibrillator (S-ICD)

Subcutaneous implantable cardioverter defibrillators (S-ICD) deliver electrical shocks to regulate your heart during ventricular arrhythmias.

WATCHMAN™ device (left atrial appendage closure)

We can implant a WATCHMAN device to permanently seal off the left atrial appendage (LAA), which is a small pouch in the top left chamber of the heart that is the site of almost all stroke-causing blood clots in people with atrial fibrillation (AFib).

Wearable cardioverter defibrillator

A vest that contains a device that monitors your heart and, if an abnormal heart rhythm is detected, delivers a shock to restore a normal heartbeat.

Our providers

Cardiologist taking EKG test of senior patient

Expert cardiology care

Getting the care you need starts with seeing one of our cardiologists.

Additional information

Electrophysiology program

We are leaders in developing and using the latest procedures and technologies to treat heart rhythm disorders, and our cardiac electrophysiology laboratory is one of the most sophisticated in North America.

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