Electrical signals control the beating of the heart. When this electrical signal is partially or fully blocked, it is known as heart block or AV block. As a result, the heart might beat slowly or skip beats and cannot pump blood adequately. Complete heart block usually refers to a third-degree block wherein the heart's pumping ability is severely compromised. If left untreated, this condition could lead to an abrupt cardiac arrest.
Alternate Names
Atrioventricular block or AV block; AV nodal block or AVB; Conduction disorder
Complete Heart Block Causes
-
A malfunction with the heart's electrical signals, which controls the heart rate and rhythm, causes heart block.
-
Other causes include heart muscle disease (cardiomyopathy), heart valve dysfunction, and structural abnormalities in the heart.
-
Damage during open-heart surgery, as an adverse event of some drugs or exposure to toxins, can also induce heart block.
Signs and Symptoms of Complete Heart Block
-
Extreme exhaustion
-
Breathing problems
-
Pain in the chest
-
Dizziness
-
Nausea
-
Fainting
-
Irregular heartbeat
Risk Factors of Complete Heart Block
-
Advancing age
-
Deranged sodium and potassium levels
-
Coronary artery disease (CAD) or a heart attack
-
Hypertension
-
Cardiomyopathy – a condition involving improper functioning of the heart muscles
-
Neuromuscular illnesses that are hereditary
-
Sarcoidosis – an inflammatory condition that also affects the heart
-
Medicines that reduce the pace of the heart
-
Lyme disease – a type of tick-borne illness that affects the heart
-
A renal disease that has progressed to an advanced stage
-
Hypothyroidism – a condition in which the thyroid gland does not function properly
-
As an after-effect of a heart surgery
Stages of Heart Block
Depending on the extent of the impairment of the electrical signal, heart block might be of first, second, or third-degree as discussed:
-
First-degree heart block – although the electrical impulse reaches the ventricles, it travels via the AV node more slowly than usual. There is a delay in the impulses.
-
Second-degree heart block – intermittent disruption of the impulses, which gradually becomes more frequent
-
Mobitz type 1 block- a less severe second-degree heart block wherein symptoms include mild dizziness.
-
Mobitz type 2 block – a more severe second-degree heart block wherein symptoms are more prominent and need pacemaker intervention.
-
Third-degree heart block – the electrical transmission between the atria and ventricles is completely disrupted.
Epidemiology
-
0.5-2 % of otherwise healthy persons suffer from a first-degree or a Mobitz type 1 second-degree heart block.
-
One in every 30 persons with heart failure, for example, is thought to develop Mobitz type 2 heart block.
-
Congenital third-degree heart blockages are extremely uncommon, occurring in about one out of every 20,000 newborns.
-
Acquired third-degree heart block, on the other hand, is a common consequence of cardiac disease, especially in elderly people.
-
5-10% of adults over the age of 70 with a history of cardiac abnormalities usually have a third-degree heart block.
Pathophysiology
The electrical signals that generally pass from the atria to the ventricles are disrupted.
-
Conduction is slowed without missing beats for a first-degree block. QRS complexes follow all regular P waves; however, the PR interval is greater than usual (> 0.2 sec)
-
Second-degree AV block occurs when the ECG shows more P waves than QRS complexes, but there is still a link between the P waves and QRS complexes.
-
The P wave rate is bigger than the QRS rate, and there is no correlation between P waves and QRS complexes in a third-degree block.
Diagnosis and Tests
A cardiologist will first check the following:
-
Medications (both prescribed and over-the-counter ones) being currently used
-
Certain lifestyle choices relating to smoking and substance use
-
The heart rate and the blood pressure
-
Accumulation of fluid in the legs and feet
Recommended Tests Include
-
An electrocardiogram (ECG) measures the electrical impulses in the heart.
-
Holter or an event monitor to track the heart's rhythm over a length of time
-
A Loop recorder, a little gadget that can be implanted, is injected beneath the skin of your chest and can track.
-
An electrophysiology checkup involves inserting a long, thin catheter into a blood vessel and guiding it to the heart to assess and record electrical activity.
Complete Heart Block Treatment and Prevention
The treatment is generally dependent on the extent of blockage in the heart. The therapeutic options available are:
-
The prescriptions might need to be adjusted, or related underlying illnesses may need to be treated.
-
Generally, no therapy is advised in case of a first-degree heart block. Tweaking lifestyle choices and taking preventive medications usually helps.
-
In the case of second-degree heart block, medications are given but under observation. If severe symptoms appear, pacemaker therapy could be advised.
-
In the case of a third-degree heart block, most certainly, a pacemaker should be installed.
Preventive measures primarily include the management of risk factors as follows:
-
A healthy lifestyle is beneficial to overall health, as well as heart health.
-
Avoid smoking, exercise regularly and eat a well-balanced diet.
-
Medicine-induced heart block can be reduced by understanding the hazards of your medications and discussing them with your healthcare provider.
-
Before using any herbal supplements or new medicines, consult your doctor, especially if you have heart block risk factors.
Possible Complications
Life after a Heart Block
Most people with extensive heart block can live a normal life with the help of pacemaker therapy. However, the need to abide by a few rules:
-
Avoid circumstances where the pacemaker could be disturbed
-
Avoiding electrical equipment that produces powerful magnetic fields
-
Carry a card that identifies the type of pacemaker installed
-
Check the pacemaker regularly to ensure it is in good operating order
-
Maintain a healthy level of activity while avoiding contact sports
Our BLK-Max Medical Experts
If you are facing any similar signs or symptoms please contact the BLK-Max team to schedule an appointment at : +91-11-30403040
Give Feedback
.jpg?v=1)
JCI Accredited
