Diagnosing Bradycardia

NYU Langone heart rhythm specialists diagnose and manage bradycardia, which is an arrhythmia, or heart rhythm disorder. This condition causes a slow heart rate—typically fewer than 60 beats per minute.

The sinus node, which is the heart’s natural pacemaker, generates electrical impulses that establish heart rate. Bradycardia occurs when the sinus node in the upper chamber of the heart sends signals that are either too slow or do not reach the lower chambers.

As a result, the heart does not beat fast enough to supply the body with the oxygen-rich blood it needs. Common symptoms of bradycardia include the following:

• dizziness, lightheadedness, or fainting
• weakness or fatigue
• shortness of breath
• chest pain
• confusion

Left unmanaged, bradycardia can lead to heart failure, which is when the heart doesn’t pump enough blood to the rest of the body; or syncopy, which is loss of consciousness or fainting. Bradycardia is often discovered during a routine physical exam, before symptoms become noticeable.

The risk of bradycardia increases with age. People who have had a heart attack or have received a diagnosis of coronary artery disease have a greater chance of developing the condition. Sleep apnea, hypothyroidism, and congenital heart defects are also risk factors. Some medications used to manage high blood pressure or other heart rhythm disorders can also cause bradycardia.

To diagnose bradycardia, a specialist at NYU Langone’s Heart Rhythm Center performs a physical exam. Your doctor measures your heart rate and blood pressure and uses a stethoscope to listen to your heart. He or she asks about your family history to determine whether you are at increased risk for certain heart rhythm disorders.

Our experts may also recommend an electrocardiogram, exercise stress test, echocardiogram, tilt table test, or surveillance monitoring.

Electrocardiogram and Exercise Stress Test

An electrocardiogram, or EKG, records the heart’s electrical activity by measuring electrical currents that prompt the heart to beat. This test can help determine whether you have a slow heart rhythm.

During the brief test, specialists place small, painless electrodes on your chest. These electrodes transmit information about your heart’s electrical activity to a computer. A graph is generated that shows what type of arrhythmia you have, if any.

This test might be performed while you walk on a treadmill. This version of an EKG, known as an exercise stress test, monitors the effect of physical activity on your heart rhythm.

Echocardiogram

An echocardiogram is an ultrasound examination of the heart. High-frequency sound waves produce detailed images of the heart to determine its size, shape, and the motion of its valves. This test can help your doctor evaluate the heart’s ability to pump blood and reveal any signs of heart failure.

During the test, a handheld device called a transducer is placed on your chest to send images of your heart to a computer.

Tilt Table Test

If you have experienced episodes of fainting, your doctor may order a tilt table test to observe how your body responds to changes in position.

During the test, you lie on a table while straps hold your body in place. The table is then tilted to simulate a change in position from lying down to standing up. Meanwhile, your doctor measures how your heart rate and blood pressure respond.

If there are no changes in your vital signs after 30 minutes, your doctor may give you a medication through a vein in your arm with intravenous (IV) infusion or by mouth to slightly speed your heart rate. This can trigger symptoms.

If you experience fainting, the table is brought back to a horizontal position to allow you to recover. The test takes 45 minutes, and you may return to your usual activities afterward.

Surveillance Monitoring

Your doctor may ask you to wear a Holter device or ambulatory telemetry device to monitor your heart’s activity during your normal daily activities.

The monitoring device can remain in place for either 24 hours or up to several weeks. It does not restrict your activities, and allows constant monitoring of your cardiac rhythm without any direct participation on your part. Data from the device are sent to the Heart Rhythm Center’s device clinic, where our experts review the results and use the information, in conjunction with your doctor, to help determine the best treatment for you.