The heart is a four-chambered muscular organ that beats to pump blood throughout our body. It consists of two upper chambers called the atria, and two lower chambers called the ventricles. The chambers that receive blood are known as the atria, while the ventricles pump the blood to the rest of the body. During the course of daily life, it is likely that you may feel your heart beat faster than normal. While this is usually a common occurrence, the appearance of a flutter-like sensation in the chest or neck may actually be a potentially serious condition known as arrhythmia.

Arrhythmias are abnormal heartbeats that can be irregular, skipped, too fast, or too slow. Not all arrhythmias are dangerous and many people encounter them throughout their lives, but severe arrhythmias can be life-threatening.

About Arrhythmia

An arrhythmia is a medical condition characterized by an abnormal rate or rhythm of the heart. Electrical signals generated in the sinoatrial node, which is the heart's natural pacemaker that controls rhythm, cause the heart to beat rhythmically at a controlled rate as the signals travel across the heart muscles. A change in sequence or timing of these signals may cause erratic heartbeats. As a result, the heart may beat too fast or too slow.

When a person's heart rate becomes greater than 100 beats per minute, the situation is known as tachycardia, while a heart rate that is less than 60 beats per minute is known as bradycardia. Arrhythmia is when either of these conditions occurs on a regular basis.

 

Arrhythmias are caused by either a genetic defect or a malfunction in the conduction of electrical signals in the heart. A common genetic defect is Wolff-Parkinson-White syndrome, which is a condition where an extra pathway exists between the ventricles and the atria. This causes additional electrical signals to go back and forth and complicate the heart's natural signal system.

The sinoatrial node may fail or the signals sent to the rest of the heart can become blocked. This causes portions of the heart to beat out of synch with the rest of the muscle.

There can be various reasons for aberrant electrical impulses. Sometimes, the cause may not be apparent. Arrhythmias may also occur if any additional part of the heart, such as the ventricles, starts generating signals. In that case, these new signals add to the messages being sent from the sinoatrial node, which leads to an abnormal heart rate or rhythm. A heart attack is also a common cause of arrhythmias.

Other conditions that affect the heart can also influence how the heart processes electrical signals. Some of these include heart failure, high blood pressure, and an alteration in the activity of the thyroid gland, which produces hormones that can affect heart rate. Smoking, alcohol, and certain drugs like cocaine and amphetamines can also affect the heart rate because they cause the heart to speed up.

Arrhythmias generally consist of four types: premature beats, supraventricular arrhythmias, ventricular arrhythmias, and bradyarrhythmias. 

Premature Beats: The most common type of arrhythmia is one that causes a premature beat. This type of arrhythmia is one where the heart beats quicker than normal, briefly pauses, and is followed by a more forceful beat. When premature beats arise in the atria they are known as premature atrial contractions (PACs. When premature contracts occur in the ventricles, it is known as premature ventricular contractions (PVCs).

Supraventricular Arrhythmias: Another type of arrhythmia is the supraventricular arrhythmia. These can occur in two forms. The first is a paroxysmal atrial tachycardia (PAT), which is a series of early heartbeats that occur in the atria. The second form is paroxysmal supraventricular tachycardia (PSVT), which is a series of early heartbeats that occur in the ventricles. Both of these contractions speed up the heart's beating rhythm. 

In both cases, the early beats that cause this arrhythmia occur because of extra electrical signals. The normal amount of electrical signals that make the heart function help the natural pacemaker beat properly. In these cases, extra signals are produced in either the atria or ventricles and block the normal signals which confuses the natural pacemaker.

The extra signals trigger a rapid heart rate. In a healthy heart, the natural pacemaker allows the chambers of the heart to fill with blood and then pump it out to various parts of the body. The rapid heartbeats associated with this type of arrhythmia do not allow the chambers of the heart to fill with blood before it contracts. Since the heart is responsible for pumping blood to various parts of the body, any interference with how it functions can compromise blood flow throughout the body.

Ventricular Tachycardia: A third type of arrhythmia is known as ventricular tachycardia (VT), which is a fast heartbeat that occurs in the ventricles. This arrhythmia speeds up the heartbeat. In these cases, extra electrical impulses originate in the ventricles and interfere with the electrical signals coming from the body's natural pacemaker. This causes the heartbeat to rise. As a result, the ventricles do not have enough time to fill with blood before they contract, which affects the body's blood flow. 

VT usually occurs in consequence to another condition in the heart, such as a heart attack, or an abnormality in the heart muscles or in one of the valves. Exercise, emotional excitement, or a sudden change in posture can also cause VT since they speed up the body's heart rate and blood flow.

Bradyarrhythmia: The fourth type of arrhythmia is known as bradyarrhythmia, which refers to when the heart beats much slower than usual. Specifically, it generates a heart rate of less than 60 beats per minute. This is dangerous because a low heart rate causes less blood to be pumped to various parts of the body, which can negatively impact muscles and organs. It can be caused by a defect in the heart's natural pacemaker or the conduction path in the heart; these can occur due to a heart attack or another heart disease. It may also be caused by a medical condition like a low body temperature. 

Seriousness of Arrhythmias

Premature beats are not serious in most cases. These are typically common in teenagers and children and usually have no cause, nor do they require treatment.

Supraventricular tachycardia is often seen in children and women, anxious or fatigued people, and those who engage in excess smoking, alcohol, or caffeine. In these cases, the arrhythmia is not considered serious, however, in extreme cases; these types of arrhythmias can lead to unconsciousness or cardiac arrest.

A life threatening form of SVT is called Wolff-Parkinson-White syndrome. This is typically a genetic defect of the heart. In this condition, the electrical signals in the heart travel along an extra pathway from the atria to the ventricles and disrupt the timing of the usual signals.

Arrhythmias that arise in the ventricles are potentially more serious than those that arise in the atria. Ventricular tachycardia episodes that last a few seconds do not cause much of a problem, but those that last longer can result in dizziness, unconsciousness, and arrest in the heart. It may eventually turn into a ventricular fibrillation, an even more severe cardiac event that can cause unconsciousness or sudden death. This occurs when the prolonged delay of a heartbeat causes blood to not fully empty from the heart, which causes cardiac arrest.

Atrial fibrillation (AF) is a condition where disorganized abnormal electrical signals originate in the atria and cause a heartbeat of as high as 300 beats per minute. The atria cannot contract and only quiver, which negatively impacts the blood flow from the heart because the blood pools and clots. AF can cause the heart to fail and cause potential complications like stroke.

 

You may have an arrhythmia if you have felt abnormally fast, slow, or irregular heartbeats or felt as though the heart paused for a short while. You may feel anxious, dizzy, or weak, and possibly faint, sweat, or develop chest pain or shortness of breath.

To verify the type and extent of an arrhythmia, it may be required to undergo some tests. An electrocardiogram (known as either an ECG or EKG) records the heart's electrical activity. It may also be advised to wear a Holter monitor, which is a small, portable machine that is worn for a full day to continuously record a heartbeat during daily activities. You may need to run on a treadmill to enable the doctor to gauge and record the increased electrical activity that comes with physical movement. Other tests that may be done include:

 

• Tilt Table Test: a procedure used to diagnose fainting or blackout spells that can occur from lack of blood flow

 

• Event Recorder: a small, portable monitor is worn for several weeks to record EKG material

 

• Magnetic Source Imaging, a device is used to sense the magnetic fields generated by heart muscle tissue

 

Arrhythmias are typically treated with medicines, medical procedures, or surgery. Medicines called antiarrhymics restore the normal heart rate and rhythm. These medications have potential side effects that can possibly make an arrhythmia worse or even cause a different kind of arrhythmia to form.

Blood thinning medications may also be used to prevent clotting since they act to thin the blood and reduce the chance of any clotting that limits the amount of blood that gets pumped out of the heart. Any other medical conditions like high blood pressure or having an irregular thyroid may also require treatment. Some arrhythmias may need a non-natural, electrical pacemaker, which is a device that electrically stimulates the heart to beat at a normal rate. Other situations may require a quick jolt of electricity from another type of electrical device. This is called cardioversion or defibrillation. These devices are generally implanted under the skin in the chest and do not provide constant electricity like a natural pacemaker.

If medicines do not work, a thin, flexible tube may need to be threaded through vessels in the arm or upper thigh into the heart. This allows energy to be delivered through the tube to help destroy the abnormal foci that generate abnormal heartbeats. This surgery is known as catheter ablation.

Surgery may be required to treat any underlying conditions like a blocked vessel in the heart or a defective valve. Some surgeries make small cuts or burns in the unhealthy vessels to prevent the spread of disorganized signals in heart.

Even though most arrhythmias do not pose a serious problem it is a good idea to get examined if your heartbeat seems abnormal in any way. With proper treatment and precautions, you can avoid an arrhythmia and keep your heart healthy.