What is an AV block?
Atrioventricular (AV) Block happens when the electrical signals that control your heartbeat are slowed down or completely blocked as they move from the upper chambers of the heart to the lower chambers.
Normally, the heart’s natural pacemaker, called the sinoatrial node, creates electrical signals to keep the heart beating at a steady rhythm. These signals travel through a pathway that includes the atrioventricular node.
In AV block, this pathway is disrupted. If the signals are completely blocked, the ventricles take over and generate their own signals to keep the heart beating. However, these signals are much slower than those from the SA node, which can lead to a slower overall heart rate.
Depending on the severity of the blockage, AV block is classified into the following levels::
- First-degree AV block: This is the mildest form and often doesn’t cause symptoms. It happens when the electrical signals take longer than normal to pass through the AV node. If the delay lasts over 0.3 seconds, some people may feel tired or have difficulty breathing.
- Second-degree AV block: There are two types, functional block (Mobitz I or Wenckebach) and structural block (Mobitz II). In this condition, the electrical signals between the upper and lower chambers of the heart don’t flow smoothly, leading to mild irregular heartbeats.
- Third-degree AV block: This is the most serious type, where no electrical signals from the atria reach the ventricles. As a result, the heart beats very slowly, which can lead to significant or life-threatening symptoms such as heart failure or sudden death.
Is atrioventricular block dangerous?
Atrioventricular block can become extremely dangerous if it reaches stage 3. The complications of AV block can severely affect a person’s life, causing symptoms like slow heart rhythms, dizziness, difficulty breathing, or fainting.
AV block can also lead to heart stopping and circulatory failure, both of which carry a high risk of death. A stroke could also occur, potentially leading to sudden death within an hour of the condition starting.
In the early stages, AV block often shows symptoms similar to those of other health issues, which can cause patients to ignore it. However, if left untreated, the condition can worsen, significantly increasing the risk of severe complications.
Causes of an AV block
Atrioventricular block can be caused by various factors, including congenital factors or secondary causes such as medication use, high potassium levels, ischemia, fibrosis, inflammation, and vascular diseases. Some factors can increase your risk of developing AV block, such as:
- Older age.
- Diabetes.
- Excess weight.
- Preeclampsia during pregnancy.
- Chronic kidney disease.
- Overdoing physical activity.
- Regular smoking.
Common signs and symptoms of atrioventricular block
Depending on the severity of the condition, the symptoms of AV block can vary.
- Stage 1 AV block: At this early stage, patients typically do not show any specific symptoms, which is why most people don’t realize they have it unless it’s detected during a medical check-up.
- Stage 2 AV block: During this stage, patients may experience symptoms like fainting, dizziness, and fatigue. Some may also have chest pain and shortness of breath, but these symptoms usually last for only a few minutes.
- Stage 3 AV block: This is the most severe stage, where patients experience all the symptoms from stage two, but at a more intense level. Stage 3 AV block can be life-threatening if not treated promptly.
How do doctors diagnose and treat an atrioventricular block?
To diagnose atrioventricular block accurately, doctors typically use the following tests:
- Electrocardiogram (ECG) readings.
- Holter monitor for heart rate tracking.
- Echocardiogram results.
- Tilt-table test results.
For stage 1 and stage 2 AV block, where there are few or no symptoms, treatment is generally not necessary. Patients in these stages are usually advised to monitor their condition at home and have routine follow-up appointments every 1-2 years.
However, for stage 3 AV block, treatment is crucial as it can lead to life-threatening arrhythmias. In this case, doctors may prescribe medications to address underlying conditions such as hypertension or heart disease.
Additionally, doctors may recommend a pacemaker for patients with AV block to help regulate heart rhythms. Implanting a pacemaker is a straightforward and safe procedure, and patients can typically return to their normal activities after a short recovery period at the hospital.
Besides medication or pacemaker implantation, patients should focus on maintaining a healthy lifestyle to prevent the condition from worsening. It is important for patients to eat a balanced diet, limit fatty foods, and increase their intake of fruits and vegetables.
Regular physical activity, like walking every day, should be part of the daily routine. If the patient is overweight, losing weight is advisable, as obesity can contribute to the development of AV block.
However, all guidelines provided are for informational purposes only. The most effective way to identify common heart rhythm disorders early is by consulting a cardiologist when you notice any unusual symptoms. To schedule an appointment or get expert advice from top cardiologists at Hanoi French Hospital, please call our hotline at 024.3574.1111.
With a team of skilled doctors and state-of-the-art facilities, we offer a range of comprehensive heart health checkup packages, including specialized cardiovascular evaluations for athletes, designed to help identify potential heart risks early.
In conclusion, symptoms of AV block can differ among individuals and may not always show obvious signs. For this reason, it’s essential to schedule regular heart health check-ups to identify and address any heart issues early, helping to prevent serious complications.
