A normal heartbeat is initiated by an electrical signal that comes from the heart’s natural pacemaker, the sinoatrial (SA) node, located at the top of the right atrium. The electrical signal travels through the atria and reaches the atrioventricular (AV) node. After crossing the AV node, the electrical signal passes through the bundle of His. This bundle then divides into thin, wire-like structures called bundle branches that extend into the right and left ventricles. The electrical signal travels down the bundle branches and eventually reach the muscle cells of the ventricles, causing them to contract and pump blood to the body. Heart block occurs when this passage of electricity from top to bottom of the heart is delayed or interrupted.
Heart block, AV bundle, or Bundle branch block is a disease of the electrical system of the heart, as opposed to coronary artery disease, which is a disease of the blood vessels of the heart. The heart of an individual with heart block beats irregularly and more slowly than normal. In some cases the heart may actually stop for up to 20 seconds, caused by a delay, obstruction or disruption along the pathway that electrical impulses travel through to make the heartbeat.
Heart block may affect people who appear healthy. It is frequently a sign of some other underlying heart problem. Electrical impulses that make the heart beat may be slowed or blocked as a result of injury or damage to the heart muscle, or blockage of a blood vessel. Even alterations to impulses that last only a fraction of a second can cause bundle branch block (heart block).
Sometimes heart block can make it more difficult for the heart to pump blood properly through the circulatory system, meaning that muscles and organs, including the brain do not get enough oxygen to function properly.
Heart block itself does not usually require direct treatment. However, the underlying health conditions which generally accompany it, such as coronary heart disease, do.
Heart block typically causes lightheadedness, fainting (syncope) and palpitations. Coronary artery disease, on the other hand, causes chest pain (angina) or heart attack (myocardial infarction).
A healthy human heart beats at approximately 60 to 80 times per minute. A heartbeat is one contraction of the heart muscles, which push blood around the body. Every muscle contraction is controlled by electrical signals that travel between the atria (the upper chambers of the heart) and the ventricles (the lower chambers).
Partial heart block - this is when the electrical impulses are delayed or stopped. The heart does not beat
regularly.
Complete heart block - this is when the electrical signals are completely stopped. The heartbeat will drop to
about 40 times per minute.
There are three types of heart block:
First degree heart block - Generally refers to minor heartbeat disruptions, such as skipped beats. It is the least
serious type of heart block and does not generally require treatment.
Second degree heart block - Some electrical signals never get to the heart, causing drooped beats. The patient
commonly experiences dizziness and may need a pacemaker.
Third degree or complete heart block - Electrical signals do not travel between the atria (upper chambers of the heart) and ventricles (lower chambers of the heart). This type is more common in patients with heart
disease. If not treated with a pacemaker there is a serious risk of heart attack. The terms bundle branch block and
AV bundle refer to the Bundle of HIS - a bundle of cardiac muscle fibers that conduct electrical impulses that regulate
heartbeat from the right atrium to the ventricles. If there is a signal block on the right bundle branch block (the right
side of the heart) it is not usually seen as serious. However, if it occurs in the left bundle branch block (the left side of
the heart) it is often linked to an elevated risk of developing coronary artery disease, or some other heart
problem.Exposure to toxic substances and taking certain medicines—including digitalis, beta blockers, and calcium
channel blockers—also may cause heart block. Heart block is a condition where the electrical signals that control
your heartbeat are slowed down or blocked as they travel through your heart. Heart block is a type of arrhythmia,
which means an abnormal heartbeat. Your heart's job is to deliver the oxygen in your blood to your body, by pumping
blood through your blood vessels. When your heart beats too slowly, it can't pump as efficiently. The usual heart rate
for adults is between 60 and 100 beats per minute. Your heartbeat is thought to be too slow if it drops below 50 beats
per minute. This can lead to symptoms such as fainting and feeling short of breath.
Some types of heart block have been linked to genetic mutations (changes in the genes). An overly active vagus nerve also can cause heart block. You have one vagus nerve on each side of your body. These nerves run from your brain stem all the way to your abdomen. Activity in the vagus nerve slows the heart rate. Slow heartbeat (heart rate), called bradycardia, is an arrhythmia, or disorder of the heart's rhythm. Each day, a normal heart beats about 100,000 times, at a rate anywhere from 60 to 100 times a minute. Changes in heart rate caused by activity, diet, medications, and age are normal and common.
Here we are treating for blocks in a span of 7 days. After that 3 day complete rest is required.