Heart arrhythmias is simply defined as when the heart is beating irregularly, either too fast or too slow. This happens when there is an interruption in the flow of electrical impulse that causes the heart to beat normally to pump blood throughout the body. Certain arrhythmias may increase the risk of developing conditions such as stroke and heart failure.
When the heart quivers, it’s unable to pump blood effectively, which can cause blood to pool. This can cause blood clots to form. If a clot breaks loose, it can travel from the heart to the brain. There, it might block blood flow, causing a stroke. Heart failure can also result if the heart is pumping ineffectively for a prolonged period due to an irregular heart beat. Sometimes controlling the rate of an arrhythmia that’s causing heart failure can improve the heart’s function.
Possible Causes of Heart Arrhythmias
Certain conditions can lead to, or cause, an arrhythmia, including:
- A heart attack that’s occurring right now.
- Scarring of heart tissue from a prior heart attack.
- Changes to your heart’s structure, such as from cardiomyopathy.
- Blocked arteries in your heart (coronary artery disease).
- High blood pressure.
- Overactive thyroid gland (hyperthyroidism).
- Underactive thyroid gland (hypothyroidism).
- Sleep apnea.
Other things that can cause an arrhythmia include:
- Drinking too much alcohol or caffeine.
- Drug abuse.How To Effectively Prevent Drug Abuse
- Stress or anxiety.
- Certain medications and supplements, including over-the-counter cold and allergy drugs and nutritional supplements.
How Arrhythmias are Classified
Classification of heart arrhythmias is based on two considerations. The first is on the basis of the speed of heart rate they cause. Heart arrythmias are classified into two main types based on the speed of the heart rate they cause:
- Tachycardia : This refers to a fast heartbeat — a resting heart rate greater than 100 beats a minute.
- Bradycardia : This refers to a slow heartbeat — a resting heart rate less than 60 beats a minute.
Not all tachycardias or bradycardias mean a heart disease. For example, during exercise, it’s normal to develop a fast heartbeat as the heart speeds up to provide the tissues with more oxygen-rich blood. During sleep or times of deep relaxation, it’s not unusual for the heartbeat to be slower.
The second consideration for classifying heart arrhythmias is the basis of where they originate. Some arrythmias originate from the atria whiles others originate from the ventricles.
Tachycardias in the Atria
Tachycardias originating in the atria include:
- Atrial fibrillation : Atrial fibrillation is a rapid heart rate caused by chaotic electrical impulses in the atria. These signals result in rapid, uncoordinated, weak contractions of the atria. The chaotic electrical signals bombard the AV node, usually resulting in an irregular, rapid rhythm of the ventricles. Atrial fibrillation may be temporary, but some episodes won’t end unless treated. Atrial fibrillation may lead to serious complications such as stroke.
- Atrial flutter : Atrial flutter is similar to atrial fibrillation. The heartbeats in atrial flutter are more-organized and more-rhythmic electrical impulses than in atrial fibrillation. Atrial flutter may also lead to serious complications such as stroke.
- Supraventricular tachycardia : Supraventricular tachycardia is a broad term that includes many forms of arrhythmia originating above the ventricles (supraventricular) in the atria or AV node.
- Wolff-Parkinson-White syndrome : In Wolff-Parkinson-White syndrome, a type of supraventricular tachycardia, there is an extra electrical pathway between the atria and the ventricles, which is present at birth. This pathway may allow electrical signals to pass between the atria and the ventricles without passing through the AV node, leading to short circuits and rapid heartbeats.
Tachycardia in the Ventricle
Tachycardias occurring in the ventricles include:
- Ventricular tachycardia : Ventricular tachycardia is a rapid, regular heart rate that originates with abnormal electrical signals in the ventricles. The rapid heart rate doesn’t allow the ventricles to fill and contract efficiently to pump enough blood to the body. Ventricular tachycardia can often be a medical emergency. Without prompt medical treatment, ventricular tachycardia may worsen into ventricular fibrillation.
- Ventricular fibrillation : Ventricular fibrillation occurs when rapid, chaotic electrical impulses cause the ventricles to quiver ineffectively instead of pumping necessary blood to the body. This serious problem is fatal if the heart is not restored to a normal rhythm within minutes. Most people who experience ventricular fibrillation have an underlying heart disease or have experienced serious trauma, such as being struck by lightning.
- Long QT syndrome : Long QT syndrome is a heart disorder that carries an increased risk of fast, chaotic heartbeats. The rapid heartbeats, caused by changes in the electrical system of the heart, may lead to fainting, and can be life-threatening. In some cases, the heart’s rhythm may be so erratic that it can cause sudden death.
Although a heart rate below 60 beats per minute while at rest is considered bradycardia, a low resting heart rate doesn’t always signal a problem. If physically fit, one may have an efficient heart capable of pumping an adequate supply of blood with fewer than 60 beats per minute at rest. In addition, certain medications used to treat other conditions, such as high blood pressure, may lower the heart rate. However, if their is a slow heart rate and the heart isn’t pumping enough blood, it may be one of several bradycardias, including:
- Sick sinus syndrome : If the sinus node, which is responsible for setting the pace of the heart, isn’t sending impulses properly, the heart rate may be too slow (bradycardia), or it may speed up (tachycardia) and slow down intermittently. Sick sinus syndrome can also be caused by scarring near the sinus node that’s slowing, disrupting or blocking the travel of impulses.
- Conduction block : A block of the heart’s electrical pathways can occur in or near the AV node, which lies on the pathway between the atria and ventricles. A block can also occur along other pathways to each ventricle. Depending on the location and type of block, the impulses between the upper and lower halves of the heart may be slowed or blocked. If the signal is completely blocked, certain cells in the AV node or ventricles can make a steady, although usually slower, heartbeat. Some blocks may cause no signs or symptoms, and others may cause skipped beats or bradycardia.
- Premature heartbeats : Although it often feels like a skipped heartbeat, a premature heartbeat is actually an extra beat. Even though their may be feeling of an occasional premature beat, it seldom means you have a more serious problem. Still, a premature beat can trigger a longer lasting arrhythmia — especially in people with heart disease.
Premature heartbeats are commonly caused by stress, strenuous exercise or stimulants, such as caffeine or nicotine.