Tachycardia

Tachycardia refers to an acceleration of the heart rate greater than 90 beats / min. A “normal” heart rate is estimated to be between 60 and 90 beats per minute. It can be slightly slower in athletes.

The apposite of tachycardia is Bradycardia is a Slow Heart Rate

Causes

What can cause tachycardia? Tachycardia is a natural phenomenon during muscular effort. Accelerating the heart allows faster muscle oxygenation. Sometimes conditions can lead to tachycardia such as fever, anemia, hyperthyroidism, hemorrhage, dehydration, stress, anxiety attack, spasmophilia attack, tetany attack, asthma attack, pulmonary embolism, acute lung edema or even excessive consumption of alcohol, cannabis, coffee or other stimulants… Specific heart attacks are also the cause of tachycardias.

There are several types of tachycardia:

Sinus tachycardia

it is not due to a heart problem but to an adaptation of the heart to a particular circumstance. It is called sinus because the general rhythm of the heartbeat is determined by a specific place in this organ called the sinus node (an area normally source of regular and adapted electrical impulses causing heart contractions). This sinus acceleration of the heart can be normal, such as when it is related to physical exertion, lack of oxygen at altitude, stress, pregnancy (the heart naturally accelerates at this point in life) or taking an arousal like coffee.
In the case of physical exercise, for example, the heart speeds up in order to supply more oxygen to the working muscles. So this is an adaptation. In the case of altitude, since oxygen is scarcer, the heart speeds up to provide enough oxygen to the body despite its scarcity in ambient air.

But this sinus acceleration of the heart may be linked to an abnormal situation in which the heart adapts by accelerating its rhythm. This happens for example in case of fever, dehydration, taking a toxic substance (alcohol, cannabis, certain drugs or medications), anemia or even hyperthyroidism.

In the case of dehydration for example, the volume of fluid in the vessels being reduced, the heart accelerates to compensate. In the case of anemia, the lack of red blood cells leading to a lack of oxygenation, the heart speeds up its rate in an attempt to provide enough oxygen to all the organs in the body. With sinus tachycardia, quite often the person does not realize that their heart is beating fast. This tachycardia can be discovered by the doctor.

Sinus tachycardia can also be linked to a tired heart. If the heart fails to contract effectively enough, the sinus node will tell it to contract more often to allow enough oxygen to flow throughout the body.

Tachycardia linked to a heart problem

It is fortunately rarer than sinus tachycardia. Because the heart is abnormal, it speeds up while the body does not need a faster beating heart.

Tachycardia linked to Bouveret’s disease

It is relatively common (more than one in 450 people) and most often relatively benign. This is an abnormality in the heart’s electrical system. This abnormality occasionally causes sudden attacks of tachycardia for a period of time before ceasing just as abruptly. The heart can then beat more than 200 per minute. This is embarrassing and often causes discomfort forcing you to lie down for a while. Despite this anomaly, the hearts of these people are not sick, and this problem does not decrease life expectancy.
Another type of tachycardia is Wolf-Parkinson White syndrome, which is also an abnormality in the electrical system of the heart. It is called paroxysmal supraventricular tachycardia.

Ventricular tachycardias

These are accelerated contractions of the ventricles of the heart related to heart disease (various diseases). The ventricles are pumps used to send oxygen-rich blood throughout the body (left ventricle) or oxygen-poor blood to the lungs (right ventricle). The problem is, when the ventricles start to beat too quickly, the ventricular cavity doesn’t have time to fill with blood. The ventricle no longer plays an efficient pump role. There is then a risk of stopping the efficiency of the heart and therefore a fatal risk.

Symptoms

The main symptoms are an increased heart rate (the feeling that “the heart is racing”), a feeling of “bumping” in the chest with palpitations, and / or a feeling of being unwell, which may occur. lead to unconsciousness in severe cases.

• Sinus tachycardia
This is the most common tachycardia: the atria beat too fast while the ventricles follow the opposite rhythm.

• Tachycardia and arrhythmia
We speak of tachyarrhythmia when the heartbeat is fast and irregular. These are mainly cardiac arrhythmia caused by atrial fibrillation or atrial flutter. Atrial tachycardia corresponds to the uncontrolled activation of an ectopic cardiac focus.

• Bouveret or junctional tachycardia
Bouveret’s disease, or junctional tachycardia, is characterized by a rapid and sudden runaway of the heart: these palpitations have a sudden onset and end. Heartbeats can be around 200 / min and loss of consciousness is possible.

• Ventricular tachycardia
During a ventricular tachycardia, the ventricles beat very quickly: this tachycardia requires urgent management and transfer to intensive care. It is a vital emergency. It is secondary to a serious pathology.

• Wolff-Parkinson-White syndrome
Tachycardia due to Wolff-Parkinson-White syndrome is caused by a birth defect in the electrical conduction inside the heart. This anomaly is the result of an abnormal cardiac muscle fiber that connects the atria and ventricles.

Is it dangerous?

The danger of tachycardia is above all that of its cause. An increased heart rate due to stress, anxiety, fever or anemia is never very high. It gives the sensation of palpitations. Treatment for fever, anxiety, or anemia is enough to calm the heartbeat. More serious causes like pulmonary embolism, massive hemorrhages cause reactive tachycardias which can be dangerous. Cardiac arrhythmias can be complicated by vascular thromboses (or clots) and be the cause of vascular accidents. Finally, Bouveret’s disease is usually mild and Wolff-Parkinson-White syndrome requires specific treatment. Ventricular tachycardia is a real danger because death can quickly occur in the absence of urgent care.

Diagnostic

The diagnosis of tachycardia is made simply by taking the pulse. The number of heart beats in one minute is calculated by taking the pulse at the wrist or other place where the arteries are palpable. The cause of the tachycardia is then explored through the practice of an electrocardiogram or ECG, which will make it possible to measure the activity of the heart and especially its rhythm. After this first assessment, the examinations will be guided by the cardiologist.

Anti seizure or crisis treatments

Treatment for tachycardia depends on its cause. Reactive tachycardias should benefit from treatment of the cause. Arrhythmias must be “reduced” through the use of techniques or drugs aimed at regulating the heart rhythm. Anticoagulant treatment often accompanies this management to avoid thrombotic complications. Bouveret’s disease may benefit from treatment that avoids rapid heartbeat such as beta-blockers.

How to treat tachycardia?

Sinus tachycardia. It is usually treated well by treating the problem causing the increased heart rate. For example, treating hyperthyroidism cures associated tachycardia. Cure anemia too.
In some cases, the cardiologist may prescribe treatment that slows down the heart while waiting for the disease to be treated.

Ventricular tachycardia. Treatment of the attack is urgent because of the risk of sudden death. The doctor may use antiarrhythmic drugs, external electric shock (if cardio respiratory arrest or loss of consciousness). The endocavitary stimulation, electric shock but this time internal, is produced by a probe and placed in a hospital environment. This is only possible if the emergency is not extreme and does not put the person’s life in danger.

Preventive treatment of ventricular tachycardia attacks is also implemented with, for example, an anti-arrhythmic drug, a beta blocker, and sometimes ablation of the area that causes the ventricular tachycardia attacks (by surgery or radiofrequency to treat the dysfunctional area). Finally, the placement of an implantable defibrillator that triggers and produces an electric shock in the event of the onset of ventricular tachycardia, may be proposed.
And then, when possible, the basic treatment of the heart problem that causes ventricular tachycardias should of course be implemented.

Atrial tachycardia. In the event of a rhythm disturbance in the atria, anticoagulant therapy is instituted, so as to prevent the formation of clots in this place. They would be dangerous because they would be sent into the ventricles and then into the arteries that they could block.

Atrial tachycardia can be treated with medication, which is effective in about two-thirds of cases. In other cases, the specialist doctor may prescribe a treatment, electrical reduction, which consists of sending an electric current so as to restart contractions at a normal rate in the atria.

Photo credit: Wikimedia Commons, Web MD, Heart, NHS UK

Photo explanations: Ventricular tachycardia (V-tach or VT) is a type of regular, fast heart rate that arises from improper electrical activity in the ventricles of the heart. Although a few seconds may not result in problems, longer periods are dangerous.