Atrioventricular Block

The three types of AV block, classified on the extent of impairment in the electrical conduction between the atria and the ventricles of the heart, are: 

• First-degree AV block:  This atrioventricular block type is the mild form, in which the electrical impulses reach the ventricles late yet reach with interruption.
• Second-degree AV block: This AV block happens when some of the electrical impulses from the Atria fail to reach the ventricles, which leads to missed heartbeats. 

Third-Degree AV block: This atrioventricular block type is the severe form of this condition. It causes complete blockage of the Electrical impulses between the atria and ventricles. As a result, the ventricles develop their electrical signals to maintain an independent heartbeat, which leads to a decline in the heart's ability to pump blood. 

The AV block symptoms vary depending on the extent of the blockage and the underlying causes. These symptoms are: 

• Dizziness 
• Fatigue or weakness
• Fainting 
• Chest pain 
• Palpitation or uneven heartbeat
• Memory problems in severe cases 

It's important to know that some AV patients may not face all the symptoms. However, if you are experiencing any AV block symptoms, you must seek medical attention immediately. 

AV block causes include: 

• Ageing: The majority of AV block cases are caused by ageing; as we grow, the heart's electrical conduction system may sink, leading to AV block. 
•  Heart disease: Diseases such as coronary artery disease, heart attack, myocarditis and cardiomyopathy can lead to damage to the heart muscles and disrupt the electrical impulses between the atria and ventricles
• Medications: Beta-blockers, calcium channel blockers, and digoxin can slow down the heart rate, which can cause AV block.
• Inherited conditions:  Some heart conditions are rare genetic disorders inherited from the family, such as Lenegre disease and Lev disease, which can cause AV block. 

Other factors: AV block condition can be caused by conditions that impact the autonomic nervous system, such as sleep apnoea, carotid sinus hypersensitivity or by electrolyte imbalances, such as low potassium and magnesium level. 

Some factors that may increase the risk of AV block include certain medications, such as beta-blockers, calcium channel blockers, and digoxin, which can lead to this condition. 

Some rare genetic disorders, such as Lenegre disease and Lev disease, can also increase the risk of developing AV block. An imbalance in Electrolytes, such as Low levels of potassium or magnesium in the blood, can be caused by AV block. Autonomic nervous system disorders, conditions that affect the autonomic nervous system, such as sleep apnoea or carotid sinus hypersensitivity, can increase the risk of developing AV block.  

It's important to note that having one or more risk factors for AV block does not necessarily mean that a person will develop the condition. However, suppose you have any risk factors for AV block. In that case, it's important to discuss your concerns with a healthcare provider and take steps to manage your overall health and reduce your risk of developing the condition.

Atrioventricular block management is not always preventable, mainly if it's caused by factors such as ageing or genetic conditions. However, some steps can reduce or control the risk of developing this condition.  

These are:

• Maintaining a healthy lifestyle, such as regular exercise, following a balanced diet, and avoiding alcohol and tobacco intake, can keep your heart healthy and reduce the risk of developing heart disease.
• If you have underlying conditions that can increase the risk of this condition, such as heart disease, high blood pressure, and diabetes. It would help if you worked with the Doctor that can help you with these conditions.
•  If you are taking medications that can be the risk factor in developing AV block, such as beta-blockers, calcium channel blockers, or digoxin, it's essential to take your Doctor's advice and monitor your heartbeat regularly.  
• Being overweight can increase the risk of developing heart disease and other conditions leading to AV block. 
• Regular check-ups by visiting your Doctor can help detect early symptoms of heart problems, including AV block, and it will enable immediate treatment for the condition.

Preventing AV block conditions is not always possible, but you can maintain a healthy lifestyle to control the risk of developing this condition. 

AV block diagnosis involves a medical history, physical examination and diagnostic tests. Some of the tests that a doctor can perform to diagnose AV block are: 

• Electrocardiogram (ECG) is a test that calculates the electrical activity of the heart. It can detect abnormalities in a heartbeat, including AV block. 
• Holter monitor: this portable ECG device is worn for 24-48 hours to continuously record the heart's electrical movement. It can help in detecting any irregular or frequent episodes of AV block. 
•  Event monitor: this portable device is worn for weeks or months to record the heart activity if the patient feels any symptoms related to this condition. 
• Echocardiogram: This imaging test uses sound waves to create images of the heart's function and structure. It can help in detecting structural abnormalities that can be the cause contributing to AV block.  
• Electrophysiology study (EPS): is an invasive test that involves threading a flexible thin wire through a vein into the heart to measure the heart's electrical activity and identify the location of the blockage. 

The detailed diagnostic test used to analyse AV block cause varies depending on the severity and type of blockage, as well as other symptoms and history. So, it's essential to talk to your Doctor for better analysis and treatment. 

There are three stages of AV block which include: 

• First-degree AV block: in the first stage, the electrical signal which passes from the atria and ventricles delays the signal; however, all the signals are transmitted from the atria to the ventricles, due to which the heart functions normally. 
• Second-degree AV block: In this stage, some electrical signals that run from the atria to the ventricles are blocked or delayed. Depending on the extent of the blockage, Second degree AV blocks have two subtypes: 
  • Mobitz type I (Wenckebach): this type refers to an irregular heartbeat because of the progressive lengthening of the delay between the atria and ventricles until one beat is stopped. 
  • Mobitz type II: this type is characterized by periodic blockage of electrical signals from the atria to the ventricles, which can be associated with severe symptoms. 
  • Third-degree AV block: in the third-degree stage, there is a complete blockage of electrical  signals, resulting in independent beating of the atria and ventricle that can slow down the heartbeat. This Degree is a severe form of AV block. 

The treatment and symptoms for the heart electrical system blockage vary depending on the stage and type. 

Here are some treatment and management procedures used for atrioventricular block prevention:

• Observation: in some cases, the patient may only need to go through regular check-ups if the AV block is mild to ensure that the condition remains stable.  
• Medications: Such as atropine, isoproterenol, or other medicines that improve the heart's electrical condition may be used to treat more extreme cases of AV block. 
• Pacemaker: A pacemaker is a small device implanted under the chest's skin to help control the regular heartbeat when the natural conduction system is not functioning correctly.  
• Treating underlying conditions: Underlying conditions can cause developing AV block conditions such as heart disease, high blood pressure, or medication side effects, so they need to be treated to manage the blockage. 
• Lifestyle modifications: Healthy lifestyles such as regular exercise, healthy food, and no tobacco, and alcohol consumption can help keep the heart healthy and fit and reduce the risk of developing any heart condition and also complications related to AV block.  

AV block treatment may vary depending on the patient's medical history and symptoms.

The road to recovery and aftercare for AV block depends on the seriousness of the condition. Here are some tips for recovery and aftercare:

• Follow the treatment plan: Following a treatment plan prescribed by your doctor is essential such as medications and follow-ups to monitor your conditions. 
• Monitor your symptoms: Monitor your symptoms closely and watch for any changes that can occur to report immediately to your doctor. This can help in making changes in the treatment plan if needed. 
• Adopt a heart-healthy lifestyle: It is essential to adopt a heart-healthy lifestyle to reduce the risk of any heart conditions. 
• Stay informed: have a good amount of knowledge about AV block and the other causes, as understanding the condition can help better manage the symptoms. 

Attend regular check-ups: it's essential to go for regular check-ups even if you feel better to monitor your condition and detect any changes early. 

1.    What causes atrioventricular block?
Atrioventricular block (AV block) condition happens when there is a disruption in the electrical signals that control the heart rate. 

2.    What are the different types of the atrioventricular block?
There are three types of AV blocks: 
First-degree AV block is the mildest form, where the electrical signals are delayed from the atria to the ventricles but still conducted.  

Second-degree AV block: this type of block occurs when some of the electrical signals are not conducted, which results in an uneven heartbeat. 

Third-degree AV block: this form is the most severe, where the electrical signal from the atria is entirely blocked.

3.    What are the symptoms of the atrioventricular block?
The symptoms of AV block can change because of the type and severity of the block. The symptoms may be minimal or hidden in mild cases, while in severe cases, symptoms like dizziness, fatigue, shortness of breath, fainting and chest pain can occur.

 4.    How is an atrioventricular block diagnosed?
AV block is usually diagnosed through a physical exam, medical history review, and an electrocardiogram (ECG). Other tests, such as Echocardiography and Holter monitoring, may also help diagnose AV block.

5.    Can atrioventricular block be prevented?
AV block cannot always be prevented, but lifestyle changes can reduce the risk, including stopping smoking, maintaining a healthy weight, controlling blood pressure and cholesterol and avoiding certain drugs and medications. 

6.    Who is at risk of developing an atrioventricular block?
Those at risk of developing AV block include people with a family history of heart disease, diabetes, and hypertension. Also, specific medications such as beta-blockers and calcium channel blockers can increase the risk of developing AV block. 

7.    Can atrioventricular block occur in children?
AV block can occur in children, but it is much less common than in adults. Symptoms in children include Palpitations, fainting, and fatigue. 

8.    How does an atrioventricular block affect exercise and physical activity?
AV block can affect exercise and physical activity. Depending on the severity of the blockage, physical activity may need to be reduced or even avoided to minimize the risk of other heart rhythm disturbances. 

9.    What is the long-term outlook for someone with an atrioventricular block?
The long-term outlook for someone with an AV block depends on the type and severity of the blockage. The condition may not need to be treated in mild cases and can be managed with lifestyle changes. However, more severe cases may require medications or even a pacemaker to help restore the normal heart rhythm.

 10. Are there any lifestyle changes that can help manage atrioventricular block?
Some lifestyle changes can help manage AV block. These include maintaining a healthy weight, exercising regularly, and avoiding smoking, controlling blood pressure and cholesterol, and avoiding certain medications. In addition, reducing stress and getting adequate rest can also help to keep the heart rhythm regular.