Abnormal Heart Rhythm Diagnosis

Overlake’s heart rhythm experts (electrophysiologists) use a wide range of diagnostic tools to expertly pinpoint the cause of heart arrhythmias, from atrial fibrillation (AFib) to less-common arrhythmias.

Our doctors always start with the simplest, least invasive test. But we have a state-of-the-art electrophysiology lab for more advanced testing, when needed. Our testing takes place at the Bob and Patty Edwards Arrhythmia Center at Overlake—one of the region’s most advanced and comprehensive arrhythmia centers.

Tests to diagnose heart arrhythmias

You may need multiple tests to determine the heart arrhythmia type and cause. Heart arrhythmia testing at Overlake includes:

Echocardiograms and electrocardiograms (ECGs)

An echocardiogram (echo) is an ultrasound tool that uses sound waves to produce images of the heart. It can detect heart valve problems and other structural abnormalities that cause arrhythmias.

An electrocardiogram (ECG, formerly known as an EKG) uses painless electrodes placed on the chest and arms to monitor the heart’s electrical activity. 

Learn more about echocardiograms and ECGs.

Heart event monitors

These small, wearable or implantable ECG monitors record your heart rhythm as you go about daily activities. The devices record and transmit around-the-clock information about your heartbeat to our dedicated device clinic, which alerts your doctor to any issues.

We offer a lightweight, wearable ECG patch that sticks to the skin over your heart for up to two weeks. Unlike other ambulatory monitoring devices, you can wear our selected heart event monitor while you sleep, shower and exercise for 24/7 data capture. This enables the patch to detect heart rhythm changes other devices often miss.

If you faint frequently or have infrequent arrhythmias, your doctor may implant a loop recorder device under the skin over the heart. This flat ECG device is about the size of an AAA battery. It can stay in place for up to three years to help find hard-to-detect arrhythmias that increase your risk of stroke.

Exercise stress test

Also called a treadmill test, an exercise stress test checks for changes in heart rhythm, heart rate, breathing, and blood pressure that occur during physical exertion. Our team monitors your heart via an ECG machine while you run on a treadmill or ride a stationary bike.

Tilt-table test

This test measures changes in heart rate and blood pressure as you lie on a table that rotates your body from prone (flat on the back) to standing up. Your doctor may use this test to diagnose arrhythmias that cause fainting spells.

EP study (heart mapping)

An EP study creates a cardiac map of electrical signals as they travel through your heart. This information helps doctors determine where faulty electrical signals are coming from, so they can select the most effective treatments. Our electrophysiologists perform this test in our state-of-the-art cardiac catheterization laboratory. Overlake has two dedicated EP labs and a hybrid operating room for combined catheter-based and open-chest procedures.

Our doctors thread catheters (thin tubes) with electrodes on the tip through blood vessels to reach the heart chambers. Mild electrical pulses travel through the electrodes to map the electrical activity. Your doctor may also use the electrodes to trigger an arrhythmia and pinpoint its starting location in the heart. Depending on the findings, you may undergo an arrhythmia treatment at the completion of the EP study.  

Cardiac catheterization

This test can determine if coronary artery disease (a buildup of plaque) is causing an arrhythmia. Our doctors thread catheters through blood vessels to reach the heart. An X-ray machine takes pictures of the heart and blood vessels as a safe dye injected through the catheters travels through the coronary arteries, heart chambers and heart valves.