Heart block might be diagnosed as part of a routine doctor's visit or during an emergency situation. (Third-degree heart block often is an emergency.)
Your doctor will diagnose heart block based on your family and medical histories, a physical exam, and test results.
Your primary care doctor might be involved in diagnosing heart block. However, if you have the condition, you might need to see a heart specialist. Heart specialists include:
Your doctor may ask whether:
Your doctor also may ask about other health habits, such as how physically active you are.
During the physical exam, your doctor will listen to your heart. He or she will listen carefully for abnormal rhythms or heart murmurs (extra or unusual sounds heard during heartbeats).
Your doctor also may:
Doctors usually use an EKG (electrocardiogram) to help diagnose heart block. This simple test detects and records the heart's electrical activity.
An EKG shows how fast the heart is beating and its rhythm (steady or irregular). The test also records the strength and timing of electrical signals as they pass through the heart.
The data are recorded on a graph. Different types of heart block have different patterns on the graph. (For more information, go to "Types of Heart Block.")
A standard EKG only records the heart's activity for a few seconds. To diagnose heart rhythm problems that come and go, your doctor may have you wear a portable EKG monitor.
The most common types of portable EKGs are Holter and event monitors. Your doctor may have you use one of these monitors to diagnose first- or second-degree heart block.
A Holter monitor records the heart's electrical signals for a full 24- or 48-hour period. You wear one while you do your normal daily activities. This allows the monitor to record your heart for a longer time than a standard EKG.
An event monitor is similar to a Holter monitor. You wear an event monitor while doing your normal activities. However, an event monitor only records your heart's electrical activity at certain times while you're wearing it.
You may wear an event monitor for 1 to 2 months, or as long as it takes to get a recording of your heart during symptoms.
For some cases of heart block, doctors may do electrophysiology studies (EPS). During this test, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records your heart's electrical signals.
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Heart Block, visit www.clinicaltrials.gov.
When a heart attack happens, any delays in treatment can be deadly.
Knowing the warning symptoms of a heart attack and how to take action can save your life or someone else’s.
The NHLBI has created a new series of informative, easy-to-read heart attack materials to help the public better understand the facts about heart attacks and how to act fast to save a life.
Click the links to download or order the NHLBI's new heart attack materials:
“Don’t Take a Chance With a Heart Attack: Know the Facts and Act Fast” (also available in Spanish)
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.