The normal heart rate is 60 to 100 beats heart per minute, on a regular basis. It is also normal for the number of heartbeats to accelerate in response to physical exertion or in the event of an dysregulation of the thyroid gland, for example. A Cardiac arrythmia occurs when the heart beats irregularly or if it beats at less than 60 heartbeats or more than 100 heartbeats per minute, without justification.

Arrhythmia is the most common heart disorder. In an arrhythmic heart, the electrical impulses who control the Heart beats occur from messy way or do not go through the usual electrical circuits.

The duration of an arrhythmia varies a lot from one individual to another and also depends on the type of arrhythmia.

Remark. There are a multitude of forms of arrhythmia, and not all are described in this sheet.

The different types of arrhythmia

The arrhythmias are classified according to the place where they originate, the atrium or the ventricle and according to the effect they produce, either the acceleration or the slowing down of the heartbeat. The tachycardias correspond to an increased heart rate, the bradycardies to a decrease.

Tachycardias, or increased heart rate

We speak of tachycardia when the heart beats at a rate greater than 100 beats per minute.

Some tachycardias occur in Headsets. The most common forms are:

• Atrial fibrillation. It is the most common type ofarrhythmia. It most often occurs after the age of 60, in people with high blood pressure or a heart problem. It is usually caused by wear and tear on the conductive tissue of the heart. Up to 10% of people 80 and over suffer from it. Periods of atrial fibrillation can last from a few minutes to a few hours. Often the fibrillation is even permanent. A fibrillating atrium can contract at the rate of 350 to 600 times per minute (luckily the ventricles don’t beat as quickly because some of those messy impulses get blocked along the way). This type of arrhythmia can be dangerous. The blood is no longer circulating adequately. If it stagnates in the atrium, a blood clot can form, migrate to the brain and risk causing a stroke;
• Atrial flutter. This type of arrhythmia is similar to atrial fibrillation, although the heartbeat is more structured and a little slower in this case, at around 300 per minute;
• Tachycardia supraventricular. There are several forms. It usually causes 160 to 200 contractions per minute and can last from a few minutes to a few hours. It occurs more in young people and is generally not life threatening. The most common is supraventricular tachycardia paroxysmal ou Bouveret’s disease (a kind of short circuit is created and stimulates the ventricles very quickly and regularly). the Wolff-Parkinson-White syndrome is another form. It occurs when electrical impulses pass from the atrium to the ventricle without passing through the atrioventricular node;
• Sinus tachycardia. It is characterized by a increased heart rate beyond 100 beats per minute. Sinus tachycardia is normal in a healthy heart after physical exertion, dehydration, stress, consumption of stimulants (coffee, alcohol, nicotine, etc.) or certain drug treatments. However, it can sometimes be a sign of a major health problem in the heart, such as pulmonary embolism or heart failure;
• Atrial extrasystole. An extrasystole is a premature contraction of the heart, usually followed by a longer pause than normal. The extrasystole sometimes slips between the normal pulsations, without altering their succession. It is normal to have a few a day. With age, they are more frequent, but often remain harmless. However, they can be caused by a health problem (heart or other). Atrial extrasystole starts in the atrium, while ventricular extrasystole (see below) originates from the ventricles.

Other tachycardias occur in ventricles, that is, in the lower chambers of the heart:

• Ventricular tachycardia. This is a regular, but very rapid beat of the ventricles, ranging from 120 to 250 contractions per minute. It often occurs at the site of a scar left by previous surgery or weaknesses due to heart disease. When the periods last several minutes, they may degenerate into ventricular fibrillation and require emergency response;
• Fibrillation ventricular. These rapid and disorganized contractions of the heart ventricles constitute a medical emergency. The heart can no longer pump and the blood is no longer circulating. Most people lose consciousness immediately and require immediate medical assistance, including cardiopulmonary resuscitation. The heartbeat must be restored with a defibrillator, otherwise the person dies within a few minutes;
• Syndrome du QT long. This problem refers to the length of the QT space on an electrocardiogram (ECG), which is the time between electric charge and discharge of the ventricles. It is often caused by a genetic disorder or a congenital malformation of the heart. In addition, the side effects of several drugs can lead to this syndrome. It causes the heart to beat faster and irregularly. It can lead to unconsciousness and even cause sudden death;
• Ventricular extrasystole. Premature contraction can occur in the ventricles. Ventricular extrasystole is more frequent than that of atrial origin. As with the atrial extrasystole, it can be harmless in a healthy heart. However, it is necessary to explore further when it is very common.

Bradycardias, or decreased heart rate

Bradycardia occurs when blood is circulated through less than 60 heartbeats per minute. a slower heart rate that normal is not necessarily life threatening. It can even be a sign of excellent heart health. Some athletes, for example, have a resting heart rate of 40 beats per minute and are remarkably fit.

On the other hand, in cases where the heart cannot adequately supply the organs with oxygen, we speak of symptomatic bradycardia. The following forms are the most common:

• Sinoatrial node dysfunction. This usually causes a heartbeat of less than 50 per minute. The most common cause is scar tissue that disrupts or replaces the sinoatrial node;
• Atrioventricular block. This defect in the transmission of the electrical impulse (slowing down, occasional interruptions or complete interruption) between the atria and the ventricles causes a slowdown in the heartbeat.

Causes

The causes ofarrhythmia cardiac are multiple and include the following:

• Normal aging;
• Stress;
• Abuse of tobacco, alcohol, coffee or any other stimulant; cocaine use;
• Dehydration;
• Arteriosclerosis and atherosclerosis;
• Taking certain medications;
• Broncho-pneumopathies (problems with the respiratory system);
• Pulmonary embolism;
• Coronary insufficiency leading to a lack of oxygenation of the heart tissue.

Possible complications

Certain types of arrhythmia increase the risk of complications such as:

• a cerebrovascular accident (stroke);
• heart failure;
• a loss of consciousness (rarely, only certain types of arrhythmia).

When to consult a doctor?

Contact them emergency services right away if you experience symptoms such as heart palpitations, chest pain or a lack of breath, unexpectedly and unexplained.