What is Heart Block?
What is Heart Block?Heart block is a type of arrhythmia, a heart rhythm disorder that disrupts how the heart beats, which affects how well the heart can pump blood throughout the body. Electrical signals control your heartbeat, telling the muscle when to contract. When the signal generated in the heart's upper chambers (the atria) is delayed or blocked before reaching the lower chambers (the ventricles), this is called a heart block.
Types of Heart Block
TypesDoctors categorize heart block by how severely the electrical signals between the upper and lower chambers of the heart have been impeded. There are three degrees of heart block:
- First-degree heart block - The mildest form of heart block, where the electrical impulse still reaches the ventricle but is delayed
- Second-degree heart block - This type of heart block is characterized by even slower electrical impulses than first-degree heart block. Signals are also intermittently dropped. There are two subdivisions of second-degree heart block.
- Mobitz Type I - Electrical signals gradually slow down, eventually getting to the point where your heart skips a beat
- Mobitz Type II - Some signals reach the ventricles, and some do not, leading to a more irregular heartbeat
- Third-degree heart block - Also called a complete atrioventricular block. In this type of heart block, one of the electrical signals from the atria reaches the ventricles. The ventricle often tries to beat on its own, but this causes a slow and unreliable heartbeat that affects the heart's ability to pump blood. Usually, implantation of a pacemaker is indicated.
Signs & Symptoms of Heart Block
SymptomsThose with first-degree heart block may not have any symptoms. For more severe forms of heart block, symptoms include:
- Dizziness
- Chest discomfort
- Nausea
- Lack of energy
- Shortness of breath
- Fatigue
What Causes Heart Block?
CausesHeart block is usually caused by other heart issues. Damage to the pathway of electrical signals from the top to the bottom of the heart can cause heart block. The most common causes of heart block include:
- Heart attack - Occurs when part of the heart does not receive enough blood or oxygen
- Coronary artery disease - Narrowing of the arteries is usually caused by plaque buildup
- Cardiomyopathy - A disease of the heart muscle that makes it more difficult for the organ to pump blood, which can lead to a heart attack
- Lyme disease - Damage to the heart's tissue from the bacteria that causes Lyme disease can lead to heart block
- Thyroid disease – A more rare cause of heart block
Risk Factors
Risk FactorsHeart block can happen in anyone, but several factors may put you at a higher risk of developing the condition. These include:
- Older age
- High potassium levels
- Lyme disease
- Recent heart surgery
- Medicines that slow heart rate (including beta-blockers and calcium channel blockers)
- Hypothyroidism
Prevention
PreventionIn some cases, heart block may be present at birth or have an unpreventable cause. However, you can make lifestyle changes that reduce your chances of developing heart block and other heart diseases. A healthy diet, regular exercise, and avoiding smoking can help keep your heart healthy. If you and your doctor are aware of the factors that put you at risk of heart block, it's more likely that you can address the problem early and before it increases in severity.
Trust NewYork-Presbyterian for Heart Block Care
At NewYork-Presbyterian, our cardiac experts can identify the signs of heart block and create a comprehensive treatment plan based on your individual case and lifestyle. Our physicians can help you maintain a proactive approach to heart health by monitoring risk factors and preventative efforts.