Heart block is a condition of blocking the pathway that electrical impulses travel to make your heartbeat. It can be because of the Atrioventricular bundle or Bundle branch block, but it does not fall under the coronary artery disease that affects the heart’s blood cells.
In the heart block, the pathway that sends electrical impulses to the left or right side of the bottom chambers of the heart gets blocked or delayed resulting in injury and damage to the heart muscles or heart valves.
A healthy heartbeat rate is estimated to be 60 to 100 times per minute, during which the heart muscles push the blood all around the body. This contraction and relaxation of the heart muscles are controlled by the electrical impulse that travels from atria(upper chambers) to the ventricles(lower chambers).
A heart block occurs when these impulses get delayed or blocked, preventing the heart from regular beating and will drop to 40 times per minute. This makes a considerable difference where only a change of even a fraction of a second can cause heart block.
The heart function is to pump blood to different parts of the body to provide oxygen sufficiently. When a heart blocks, it becomes difficult for it to pump oxygenated blood to different types/organs of the body. As a result, the muscles and organs, including the brain, will not function efficiently due to lack of oxygen.
It can also lead to lightheadedness, fainting, and palpitations. Heart block is harmful to health, and it can become more dangerous depending on the severity of the heart block. Like, a third-degree heart block will worsen pre-existing conditions, such as heart failure. It can also cause loss of consciousness and sudden cardiac arrest. It may also cause severe chest pain.
Whereas coronary heart disease occurs when a waxy substance known as plaque gets built up in the coronary arteries causing chest pain, known as angina or heart attack or myocardial infarction(MI).
Heart Block Types
Here is a description of the types of heart block:-
- First-degree heart block: It is the initial or minor heartbeat disruption similar to a skipped heartbeat. It is a minor type of heat block and usually does not require any medical treatment.
- Second-degree heart block: It is a type of heart block in which the electrical impulse does not reach the part of the heart, resulting in dropped or skipped heartbeat. In such a situation, the impulse generated by the atrial portion of the heart did not reach the ventricles that cause dizziness, and the patient may need a pacemaker.
- Third-degree or complete heart block: It is a type of heart block where the electrical impulse does not travel between the upper and the lower chamber of the heart. It usually occurs with patients suffering from heart disease, and such patients are at serious risk of a heart attack.
What Causes The Heart To Block?
In a healthy heart, the electrical impulse that is present inside the heart muscles to signal them to contract and beat. These impulses move along a pathway through the atrioventricular (AV) node from the upper heart chambers to the lower chambers.
This pathway also consists of a cluster of cardiac fibers known as the bundle of HIS, “bundle branch block,” or the “AV bundle.” These bundles are divided into two branches, right and left bundles present at each ventricle and are responsible for the conduction of electrical impulses to the heart ventricles.
Damage to any of the branch bundles can lead to uncoordinated ventricular contractions and abnormal heartbeat. A blockage on the right side of the heart walls is not usually severe, but blockage on the left side can develop a high risk of coronary artery disease or other heart problems.
How will I Get To Know About Heart Block?
A person having a heart block will experience general heart block symptoms of it which includes:-
- Irregular or slow heartbeats or palpitations
- Shortness of breath
- Lightheadedness and fainting
- Pain or discomfort in the chest
- Difficulty in physical exercise due to lack of oxygenated blood being pumped around the body
People suffering from heart block might appear healthy, but they may have an underlying heart problem.
Is There Any Risk Factor Associated With Heart Block?
Heart block is usually caused due to scarring of the heart tissue with older age. Few people are born with heart block, but some people have a history of heart disease or develop the risk of heart blocking by smoking habit.
Below are the conditions that increase the risk of having a heart block:-
- Coronary thrombosis
- Myocarditis or the inflammation of the heart muscles
- Endocarditis or swelling of the heart valves
- Scar tissue in the heart, if not treated can lead to heart attack
The chance of developing heart block increases after a heart attack or a heart operation and may also occur as a complication of Lyme disease.
How To Diagnose Heart Block?
If you consult a physician for a heart block treatment, he may ask your medical history, age, and will examine your heartbeat. If the physician suspects something dangerous, he will refer you to either cardiologist or a heart specialist for better medical treatment.
Today medical science has discovered several diagnostic tests for heart block. One of them is an electrocardiogram(ECG), the most common test for diagnosing heart block by recording heart activity. It involves probes that are attached to the skin of the chest to continually record the electrical impulses throughout the heart in the form of waves.
The waves recorded as a result of the test indicates your heartbeat. The doctor will examine the waves to know if you are suffering from a heart block. It can also show the side of the heart that is affected by the heart block.
Another technique is known as Holter tape, which is a portable device that records the electric impulses of the heart. The patient needs to wear it under his clothes that will record information about the electrical impulses while the person is busy with their normal activities for 1 to 2 days.
The best thing about such a device is whenever the person experiences a severe symptom, and he presses a button of the portable device to record the heart moment.
An echocardiogram is a type of ultrasound that scans the heart muscles and the valves.
The electrophysiology test is also used to test with the help of tiny electrical shocks to determine the cause of the abnormal rhythm and the place where it occurred.
Another test is a tilt-table test where the patient lies on a bed that keeps changing its position and provokes arrhythmia, or abnormal heartbeats.
How Is Heart Block Treated?
There is not any specific test to deal with heart block. Heart block treatment depends on the situation of the patient. Some people having bundle branch block show no symptoms and do not require treatment. But treatment will be needed if a person also has hypertension.
Another treatment is known as reperfusion therapy for people with left bundle branch block and has a heart attack to restore blood flow through blocked arteries. This can be achieved with the help of an anti-clotting agent, such as streptokinase, that dissolves the blood clotted and increases the blood flow rate of the heart. On the other hand, anti-clotting drugs increase the risk of bleeding.
A pacemaker can also be helpful in such treatment, a small battery-operated device that may be imparted under the skin in a patient with a fainting record in his medical history. It is placed near the collarbone during a surgical procedure of 1 to 2 hours under local anaesthesia.
Some pacemakers can also be used by setting the electric impulse only when needed. Some of the pacemakers can sense when the heart stops beating and produces an electrical impulse to restart it.
Note that pacemakers are not affected by cell phones, personal stereos, or household appliances, but a person using a pacemaker should not undergo a magnetic resonance imaging(MRI) scan.
Complications Associated With Heart Block
The risk of complications increases with the people having a left side bundle branch block than those with a right side bundle block. These complications include:-
- Arrhythmia, or irregular heartbeat
- Bradycardia, or low heart rate
- Insufficient contraction
- Cardiac arrest and circulatory failure
- Sudden cardiac death that can be fatal within one hour of starting symptoms
Heart block cannot be avoided, but the risk of developing heart disease can be reduced by consuming a healthy diet, regular exercising, minimizing alcohol consumption, and a good habit of not consuming tobacco.