What's on this Page
First Degree Atrioventricular Block
What is atrioventricular block?
Atrioventricular (AV) block, also called heart block, is a problem with the system that controls how often the heart beats (heart rate) and the pattern of heart beats (heart rhythm). In this condition, the signals that travel from the heart’s upper chambers (atria) to its lower chambers (ventricles) move too slowly or are interrupted. There are several types of heart block:
- First-degree.
- Second-degree.
- Third-degree or complete.
What is First Degree Atrioventricular Block?
First-degree AV block is the least serious type of heart block. In this condition, the signals that control heart rate move too slowly. As a result, the heart may beat more slowly than normal. First-degree AV block can increase your risk of developing a type of irregular heartbeat called atrial fibrillation.
What are the causes?
This condition may be caused by:
- Any condition that damages the system that controls the heart’s rate and rhythm, such as a heart attack.
- Overstimulation of the nerve that slows down heart rate (vagus nerve). This cause is common among well-conditioned athletes.
- Some medicines that slow down heart rate, such as beta blockers or calcium channel blockers.
- Surgery that damages the heart.
Some people are born with this condition (congenital heart block), but most people develop it over time.
What increases the risk?
The risk for this condition increases with age. You are also more likely to develop this condition if you have:
- A history of heart attack.
- Heart failure.
- Coronary heart disease.
- Inflammation of heart muscle (myocarditis).
- Disease of heart muscle (cardiomyopathy).
- Infection of the heart valves (endocarditis).
- Infections
or diseases that affect the heart. These include:
- Lyme disease.
- Sarcoidosis.
- Hemochromatosis.
- Rheumatic fever.
- Muscle disorders including Lev disease and Lenegre disease.
Babies are more likely to be born with heart block if:
- The mother has an autoimmune disease, such as lupus.
- The baby is born with a heart defect that affects the heart’s structure.
- A parent was born with a heart defect.
What are the signs or symptoms?
This condition usually does not cause any symptoms.
How is this diagnosed?
This condition may be diagnosed based on:
- A physical exam.
- Your medical history.
- A measurement of your pulse or heartbeat.
- Tests.
These may include:
- An electrocardiogram (ECG). This test is done to check for problems with electrical activity in the heart.
- A Holter monitor or event monitor test. This test involves wearing a portable device that monitors your heart rate over time.
- An electrophysiology (EP) study. This test involves having long, thin tubes (catheters) placed in the heart. This test records electrical signals in the heart.
How is this treated?
Usually, treatment is not needed for this condition. In some cases, treatment involves:
- Treating an underlying condition, such as heart disease.
- Changing or stopping any heart medicines that can cause heart block.
Follow these instructions at home:
- Take over-the-counter and prescription medicines only as told by your health care provider.
- Work
with your health care provider to control lifestyle choices that increase
your risk for heart disease. You may need to:
- Get regular exercise. Each week, try to get 150 minutes of moderate-intensity activity (such as walking or yoga) or 75 minutes of vigorous activity (such as running or swimming). Ask your health care provider what type of exercise is safe for you.
- Eat a heart-healthy diet with fruits and vegetables, whole grains, low-fat dairy products, and lean proteins like poultry and eggs. Your health care provider or diet and nutrition specialist (dietitian) can help you make healthy choices.
- Maintain a healthy weight.
- Limit alcohol intake to no more than 1 drink per day for nonpregnant women and 2 drinks per day for men. One drink equals 12 oz of beer, 5 oz of wine, or 1½ oz of hard liquor.
- Do not use any products that contain nicotine or tobacco, such as cigarettes and e-cigarettes. If you need help quitting, ask your health care provider.
- Keep all follow-up visits as told by your health care provider. This is important.
Contact a health care provider if:
- You feel like your heart is skipping beats.
- You feel more tired than normal.
- You have swelling in your hands, feet, or lower legs.
Get help right away if:
- Your symptoms change or they get worse.
- You develop new symptoms.
- You
have chest pain, especially if the pain:
- Feels like crushing or pressure.
- Spreads to your arms, back, neck, or jaw.
- You feel short of breath.
- You feel light-headed or weak.
- You faint.
Summary
- First degree AV block is the least serious type of heart block. In this condition, the signals that control heart rate move too slowly. As a result, the heart may beat more slowly than normal.
- Usually, treatment is not needed for this condition. In some cases, you may need to change or stop medications that may be making the condition worse.
- Healthy lifestyle choices such as exercising regularly, eating a healthy diet, and limiting alcohol are good for your heart.