Heart Arrhythmias

Arrhythmia which is also known as heart arrhythmia is a common disease condition that occurs when the impulses that flow through your heart and help control your heartbeat don’t flow appropriately causing your heart to either beat too slow or too fast and eventually, this will cause what is known as irregular heartbeats or irregular heart patterns.

Heart arrhythmias can be harmless at first or they may end up causing your heart to flutter and cause your pulse to speed up. However, even with the fluttering, they may still be harmless.

However, there are other times when you get heart arrhythmias and they really can become a problem and even life-threatening if care is not taken.

What does it mean to have a normal heartbeat?

Generally, your heart has four chambers namely the left atrium, the left ventricle, the right atrium and the right ventricle. The upper chambers are the atrial chambers while the lower chambers at the ventricular chambers.

Your heart also has its electrical control system which is made up of the sinoatrial node, the atrioventricular node, the Purkinje filers as well as the bundle of HIS. These elements all make up what is known as the pacemakers of the heart.

The sinoatrial node is located in the right atrium and its function is to generate electrical impulses that will then be transferred by other elements of the pacemakers. The impulses provided by the sinoatrial node causes the start of each heartbeat.

From the sinoatrial(SA) node, the electrical impulses travel through to both the right and left atrium, thereby causing the muscles present in the atria to begin contractions which therefore causes blood to be pumped into the ventricles

These impulses will then get to a pack of cells which are known as the atrioventricular node or AV node. The AV node is the only area that allows the impulses to travel from the atria to the ventricles.

The AV node then causes the electric impulses to slow down its velocity before sending these signals to the ventricles. When these impulses are slowed down, it causes a slight delay which allows the ventricles to become filled with blood.

When these impulses eventually reach the ventricles, they cause the muscles of the ventricles to contract and as such, cause blood to flow back to the lungs as in pulmonary circulation or back to the other parts of the body as in systemic circulation.

In a normally functioning heart, this cycle goes on smoothly without any hitches and the normal heartbeat is 72 beats per minute with a normal range of 60-100 beats per minute. Anything short of this will lead to a problem with the heart.

Types of Arrhythmias

Generally, there are two different types of arrhythmias and they are

1. Tachycardia

Tachycardia usually occurs when the heart tends to beat faster than usual. We have established that the normal heartbeat range is between 60-100 beats per minute. Anything above 100 beats per minute refers to tachycardia. Tachycardia is further divided into two namely

A. Tachycardia in the atria

Tachycardia in the atria refers to a fast irregular heartbeat that occurs at the level of the atrium. They include;

i. Atrial fibrillation

This is a common disease condition that is caused by uncoordinated or chaotic impulses in the heart which eventually leads to the heart rate speeding up. This occurs when the electrical impulses that are sent into the atria cause the contractions of the atria to become weak, uncoordinated, and rapid.

These uncoordinated signals will also be transmitted to the AV node causing the ventricles to begin to beat rapidly and uncontrollably leading to an irregular beat pattern in the ventricles.

Although atrial fibrillation is considered temporary, some episodes may not end until when it is appropriately treated. If it is not properly treated, they can become deadly and can lead to stroke

ii. Atrial flutter

Atrial flutter is a bit similar to atrial fibrillation. In atrial flutter, the signals that are sent to the atria are more coordinated and organised however, they are still rapid in nature.

Although these signals happen to be somewhat rhythmic in nature, the signals are still sent at a fast rate and this causes a faster heartbeat.

Atrial flutter also has the tendency to lead to life-threatening situations such as a stroke if it is not properly treated.

iii. Supraventricular tachycardia

Supraventricular tachycardia is a combination of different types of arrhythmias which begin to occur in the AV nodes or the atria just above the ventricles hence its name.

iv. Wolf-Parkinson-White syndrome

This syndrome occurs as a result of an extra electrical conduit system between the atria and the ventricles. Normally, for each person, there is only one pathway of electrical impulses between the atria and the ventricles.

However, when there is an extra which is formed at birth, this condition is known as Wolf-Parkinson-White syndrome. In this condition, you may not likely experience symptoms as a child or as a baby. You may begin to experience symptoms as you grow into adulthood.

The extra pathway allows for electrical signals to begin to pass from the atria to the ventricles, however, it bypasses the AV node and this leads to short-circuiting which in turn causes rapid heartbeats leading to tachycardia.

B. Tachycardia in the ventricles

Tachycardia in the ventricles occurs when there is a rapid heartbeat which originates in the ventricles. They include

i. Ventricular tachycardia

This disease condition is caused by abnormal electric signals which start in the ventricles and then proceeds thereby causing a rapid heart rate and an abnormal heartbeat.

The rapid heart rate which is caused by ventricular tachycardia gives no time at all for the ventricles to fill up with blood before a contraction begins.

Recall that the signals sent from the SA node to the AV node cause a slight delay which in turn allows the ventricles to fill up before contractions of the ventricles begin.

However, in the case of ventricular tachycardia, the fast rate at which the electrical signals are generated and sent causes the ventricles to contract quickly hence the ventricles will not be able to send an adequate amount of blood either to the lungs or to the other body parts.

Often, ventricular tachycardia constitutes a real medical emergency because asides the rapid heartbeat, the body is not getting enough blood in circulation and as such the body will tend to break down.

Without immediate medical treatment, there is a huge tendency that this situation will worsen into ventricular fibrillation.

ii. Ventricular Fibrillation

Ventricular fibrillation is often caused by rapid, uncoordinated electrical impulses which in turn causes the ventricles to begin to quiver rapidly rather than performing its primary function which is to ensure an adequate pumping of blood to either the lungs or to the body.

This condition can become fatal if the heart is not brought back to its normal rhythm within minutes. Research has shown that most people who suffer this kind of Arrhythmia have a serious underlying heart condition or have had am intense traumatic experience such as a person who has been previously struck by lightning.

iii. Long QT syndrome

Long QT syndrome occurs when there is an increased chaotic heartbeat which in turn causes a severe heart disorder. The rapid or increased heartbeats which are caused by changes in the electrical circuit of the heart can cause the patient to keep losing consciousness and as such lead to fainting.

This condition can be very severe and life-threatening. In so,e cases, the rapid and chaotic beating of the heart can cause sudden death.

This condition, however, can be due to an abnormal genetic mutation which means that you can be born with it or you can develop it as a complication of taking some drugs for a long time.

There are some medical conditions that can as well lead to the development of these diseases. Such medical conditions include congenital heart defects, and so on.

2. Bradycardia

Bradycardia is a condition that is caused as a result of a decreased heart rate. It is possible and normal for a person to a person to experience bradycardia at rest. When a person has a heartbeat that is below 60 beats per minute, the person is considered to have bradycardia.

A patient must note that a low resting heart rate doesn’t always indicate that there is an underlying condition. There are sometimes whereby the medications that are being used may be the cause of your bradycardia.

Medications that are used in managing high blood pressure(hypertension) can cause bradycardia. However, when your heart isn’t pumping enough blood into the systemic or pulmonary circulation and you also have a reduced heart rate, you can, therefore, be considered to have any of the following types of bradycardia.

A. Conduction block

Conduction block occurs when there is an obstruction in the flow of electrical impulses at the AV node or somewhere near to it. The AV node lies in between the atria and the ventricles. Another block can likely occur along the pathways that lead to each of the ventricles.

The rate of impulses between the upper portion of the heart (The atria) and the lower portion of the heart(the ventricles) can be reduced or completely stopped and this depends on the location as well as the type of ventricular block it is.

Once the signals or electric impulses are completely blocked, some cells that are present in the AV node can transmit electrical impulses at a much slower but steady rate. I’m some blocks, there may be no symptoms, however in others, there will be symptoms of bradycardia and also the patient will experience skipped heartbeats.

B. Sick sinus syndrome

Sick sinus syndrome occurs when the sinoatrial (SA) node which is responsible for conducting and setting the pacemakers of the heart begins to malfunction by not sending these impulses properly or adequately hence causing bradycardia.

There are times when the improper transportation of these impulses can cause the heart to slow down and go rapidly at intervals. Sick sinus syndrome can be caused by the scarring of the cells near the SA node which will, in turn, lead to the blocking or the slowing down of electrical impulses.

There are other types of arrhythmias that can occur asides bradycardia and tachycardia and these sets of arrhythmias are termed as premature heartbeats.

Premature heartbeats occur when there is an extra heartbeat. Sometimes, it may feel like a missed or skipped heartbeat, however, in the real sense of it, it actually occurs as a result of an additional heartbeat.

It is not unusual to have a premature heartbeat intermittently, and it rarely leads to the development of a serious heart problem. Premature heartbeats are mostly due to intense stress, the use of some certain drugs and stimulants such as caffeine and nicotine as well as strenuous exercises.

Causes of Arrhythmias

The causes of arrhythmias include

  1. Heart attack
  2. Previous heart attack which caused scarring of the heart cells
  3. Cardiomyopathy can lead to changes in the structure of the heart.
  4. Coronary heart diseases which are caused by the blocked arteries
  5. Hypertension
  6. Overactive thyroid gland causing hyperthyroidism
  7. An underactive thyroid gland causing hypothyroidism
  8. Excessive smoking
  9. Excessive intake of caffeine
  10. Excessive intake of alcohol
  11. Drug abuse
  12. Severe stress
  13. The intake of some medications as well as supplements.
  14. Sleep apnea
  15. Genetic anomalies
  16. Diabetes

Risk factors associated with arrhythmias

There are certain risk factors that are associated with arrhythmias. These factors can increase the chances of you developing any type of Arrhythmia and they include

1. Heart problems, coronary heart diseases, or previous heart surgery

Having a previous heart surgery, or a previously clogged or narrowed arteries, cardiomyopathy, heart failures, abnormal heart valves, previous heart surgery of any kind can definitely increase your chances of developing cardiac arrhythmias.

2. Hypertension

High blood pressure will increase the chances of you developing coronary heart disease which in turn may cause the walls of the ventricles of the heart to become stiffen and This will affect how the electrical impulses travel across the heart. It can also ultimately change the pathway of electrical impulses.

3. Congenital Heart disease

When a baby is born with congenital heart defects, it can affect the electrical pathways of the heart and ultimately result in arrhythmias.

4. Thyroid Problems

When you have hyperthyroidism or hypothyroidism, there are increased chances of you developing heart arrhythmias.

5. Drugs and some supplements

Some over the counter drugs and supplements will cause the short-circuiting of the heart hence causing the development of arrhythmias.

6. Diabetes

One of the risks that are associated with the development of diabetes is high blood pressure as well as coronary heart disease. Developing any of these will definitely increase your chances of developing cardiac arrhythmias.

7. Electrolyte imbalance

There are certain substances in the blood which includes sodium, potassium, calcium, magnesium, and so on. These substances are known as electrolytes. These substances help in the triggering and the conduction of electrical signals in the heart which is important for the heartbeat.

When there is an abnormally high or low level of these electrolytes will affect the conduction of these signals and can definitely lead to the development of Arrhythmia.

8. Intake of too much alcohol

The intake of alcohol into your body system can affect so many things in your body. It can cause electrolyte imbalance and as such cause arrhythmias. It can also tamper with the conduction of the electrical impulses of the heart and as such lead to atrial fibrillation.

9. The use of nicotine and other hard drugs

Intake of nicotine, as well as cocaine or the use of stimulants such as caffeine, will cause your heart to begin to beat rapidly hence contributing to the development of Arrhythmia.

Some illegal drugs such as amphetamines can affect the heart seriously and can even lead to ventricular fibrillation.

10. Obstructive sleep apnea

When your breathing is interrupted while you are sleeping, you are said to have sleep apnea. Once this occurs constantly, it can cause an obstruction and as such cause bradycardia leading arrhythmia.

Complications

There are certain conditions that can develop as a result of arrhythmias and these conditions include

1. Stroke

We have established that the essence of the electrical impulses being transported around the heart is for the pumping out of the blood through the ventricles either into the pulmonary circulation or into the systemic circulation.

Once there is any disruption in this which is not treated immediately, it can cause the blood to begin to gather and as such cause the clotting of blood.

If a clot breaks, it can immediately pass through the blood vessels from the heart to the brain. Note that the blood vessels in the brain are thinner and as such when these clots get to the blood vessels in the brain, they can cause the vessels to become clogged causing a blockage of blood flow which in turn causes a stroke.

Some medications such as blood thinners can help reduce the risk of your blood forming clots and as such reduce the risk of you developing stroke.

2. Heart failure

Once the muscles of the ventricles don’t pump out blood as they are supposed to for a prolonged period which may be caused as a result of atrial fibrillation, there is a tendency for a heart failure to occur.

Prevention

In order to prevent heart arrhythmias from occurring, it is necessary to live a heart-friendly lifestyle. This means that the kind of lifestyle you decide to adopt should be one that helps you reduce the risk of developing heart disease.

Examples of a heart-friendly lifestyle that you can decide to adopt should include the following:

  1. The intake of a diet that helps improve the functionality of your heart
  2. Increase your physical workout. However, be careful not to go overboard with it.
  3. Reduce smoking to the barest minimum
  4. Maintain a healthy weight scale
  5. Avoid the intake of caffeine and also avoid taking alcohol. If you must take, ensure that you take in very little.
  6. Avoid stress and any stressful situation that can push your heart into overdrive.
  7. Avoid any over the counter drugs. If you must take them, ensure that you take them with caution. Also, avoid taking over the counter cough and cold drugs. This is because some of them contain stimulants which can cause your heartbeats to speed up hence causing an arrhythmia to occur.

Sources;

  1. Heart arrhythmia; Mayo Clinic
  2. Introduction to Arrhythmia; Medicine Net