The normal resting heart rate is between 60 and 100 beats per minute; more than 100 is considered tachycardia.

Often athletes and the elderly have a lower than average frequency.

A high frequency indicates that the heart should make an extra effort to maintain normal blood flow . 
Among the consequences, there is a greater consumption of oxygen. 
If the cause is not resolved, a heart attack may occur over time.


Physiology of the heart beat (functioning)

The human heart is composed of four chambers (cavities):

  • Right and left atria: the two upper chambers.
  • Left and right ventricles: two lower cavities.

According to a Article ( reviewed by University of Illinois-Chicago School of Medicine ), the heart has a pacemaker (structure that regulates the beat) called natural sinus or sinoatrial node. 
It is located in the right atrium. 
The sinus node produces electrical impulses that trigger a heartbeat . 
The electrical impulses pass through the atria and cause the contraction of the atrial muscles. 
This muscle contraction pushes the blood into the ventricles .

The electrical impulses continue to the atrioventricular node or atrioventricular node, a group of cardiac cells. 
The atrioventricular node delays the electrical signals and then sends them to the ventricles. 
The delay in conduction of electrical signals allows the ventricles to fill with blood. 
When the muscles of the ventricle receive the electrical signals, they contract and pump the blood:

  • For the lungs,
  • For the rest of the body.

When there is a problem with the electrical impulses that cause a heart beat faster than normal, the individual has tachycardia.

A person’s heart rate is not constant, but varies according to:

  • Physical activity,
  • Some diseases,
  • Mental stress.

At night, while the person sleeps, the heart rate may decrease to about 50 beats per minute. 
In the morning, when the person gets up, he may have postural hypotension and reflex tachycardia; it is a normal situation characterized by:

Increased heart rate may be sudden in case of strong emotion or under stress.


Classification of tachycardia

The types of tachycardia are:

Ventricular Tachycardia
If tachycardia originates in the ventricles, it is called ventricular tachycardia. 
The electrical signals in the ventricles begin anomalously, this interferes with electrical signals from the sinoatrial node (the heart rate regulator). 
Accelerated heart rate does not allow filling of the ventricle prior to contraction. 
Thus, the heart does not pump enough blood into the tissues of the body. 
This type of tachycardia can be deadly.

2. Supraventricular or atrial tachycardia
Increased frequency originates in the upper part of the heart. 
This type is less severe and has a limited duration (a few minutes or a few hours). 
According to the American Heart Association , in the case of supraventricular tachycardia , electrical signals in the heart atria begin anomalously and this interferes with electrical signals from the sinoatrial node, the heart’s natural pacemaker. 
A series of premature heart beats in the atria accelerates heart rate.

Tachycardia is defined as paroxysmal supraventricular if it is:

  • Sudden,
  • Regular.

This can be caused by:

  • Wolff Parkinson’s syndrome White – a heart disease characterized by the presence of excess atrioventricular bundles connecting the atrium and ventricle (Source Mayo clinic).
  • Nodal reentrant tachycardia , in which excess (slower) electrical impulses are formed that interfere with normal heart rhythm.

3. Sinus Tachycardia
The sinoatrial node sends electrical signals faster than normal. 
The heart rate is fast, but the heart beats and pumps the blood correctly.


Causes of rapid heart beat

A high heart rate can be caused by illness or by temporary factors.

Temporary Causes
A high heart rate is not worrisome. 
The following factors stimulate the heart to beat at a faster rate for a short time.

  • Physical exercise,
  • Stress , anxiety, fear, nervousness,
  • Nightmares,
  • Cigarette , nicotine increases heart rate,
  • Anemia , the heart should pump more blood to make up for lack of oxygen,
  • Sports or when making physical effort,
  • Fever , the increase in frequency is about 10 beats for each degree of temperature beyond 37 degrees,
  • After heavy meals,
  • Certain medications, asthma medications , decongestants, levothyroxine for the thyroid, antidepressant drugs like fluoxetine, norepinephrine,
  • Lack of vitamins, especially C and B12 because it can cause anemia,
  • Electrolyte imbalance, for example, lack of potassium ,
  • After drinking alcohol or coffee,
  • Drugs (cocaine, amphetamines, etc.),
  • Consumption of chocolate, cocoa contains caffeine, so it is a stimulant substance,
  • Arrhythmia (can cause a rapid heartbeat for a few seconds),
  • Stimulating substances such as tea and coffee.

Major causes of non-temporary rapid heart beat
Several diseases can cause an increase in heart rate (or arterial pulse). 
The different diseases that cause heart rate increase are:

Heart Diseases Heart
diseases that cause a rapid heart beat can be:

  • Obstruction of coronary arteries ,
  • Pericardite (WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on February 16, 2016),
  • Congenital heart disease (such as Wolff Parkinson White syndrome),
  • Aortic regurgitation, etc.

The hardening of defective or damaged arteries or valves of the heart causes difficulty in pumping blood and the consequence is an increase in heart rate.

disorders Hyperactivity of the thyroid gland (or hyperthyroidism ) is one of those responsible for tachycardia. 
The thyroid controls the body’s metabolism; therefore, if it is hyperactive it causes an increase in heart rate.

If hyperthyroidism is causing the rapid heartbeat, the patient also has the following symptoms:

1. Sweating , 
2. Tremor, 
3. Anxiety, 
4. Insomnia, etc.

Heart Atrial Abnormalities
An irregular rhythm ( atrial fibrillation ) or an injury to the upper chamber of the heart causes tachycardia.

Heart failure
The heart failure is a disease characterized by the inability of the heart to pump the blood needed to meet the demands of the body. 
Other symptoms are:

The emphysema or chronic obstructive pulmonary disease (COPD) causes the tachycardia.

pneumonia is inflammation of lung tissue. 
This disease affects the efficiency of the lungs and the heart has to work harder to pump an adequate amount of oxygen to the different parts of the body. The result is a rapid heartbeat.

Cardiac infarction
High heart rate is very common after myocardial infarction.

During pregnancy, a pregnant woman’s heart should also pump blood to the fetus. 
This increased demand causes additional work for the heart to pump at a faster rate to meet the increased demand. 
Since the beginning of pregnancy, the recorded heart rate is higher at 10-20 beats per minute, but the rhythm returns to normal when the baby is born.


Fetal heart rate

Normal fetal heart rate chart

Period Number of beats per minute
5 weeks starts at 80 and ends at 103 bpm
6 weeks starts at 103 and ends at 126 bpm
7 weeks starts at 126 and ends at 149 bpm
8 weeks starts at 149 and ends at 172 bpm
9 weeks 155-195 bpm (175 bpm average)
12 weeks 120 180 bpm (average 150 bpm)
After 12 weeks 120-160 bpm (140 bpm average)

The data written in the table describe the fetal heart rate in the first and second trimesters. 
During the third quarter is relatively stable. 
The fetal heart rate decreases slightly during the last (third) trimester before delivery, but is still twice as high as an adult’s heart rate. 
In normal pregnancy, a child’s heart rate is about 140 beats per minute at birth, while the frequency of a premature fetus is about 155 beats.


Normal heart rate of a child

The resting heart rate indicates the number of times the heart beats in a minute when a person is completely relaxed. 
Experts say that the best time to measure resting heart rate is about 5-10 minutes after waking up in the morning.

Heart rate for children
To calculate the heart rhythm, simply place the index and middle finger under the child’s jaw near the windpipe to locate the spot where the heart feels. 
It is necessary to measure the heart rate for one minute.

Newborn 100-160
12 years 80-130
25 years 80-120
5 – 12 years 70-110
More than 12 years 60-100


As you can see from the table, the pulse tends to decrease with time.

Usually, the frequency is higher than normal if the child has a fever . 
The body responds to fever by increasing heart rate, breathing rate, and blood circulation.


High heart rate at rest

The pulse rate lets you know how many times your heart beats in a minute. Severe fluctuations in heart rate indicate a problem in the heart and / or lungs.

Women generally have a higher heart rate than men. 
Several disorders can affect normal heart rate: 
1. Age, 
2. Anxiety (also causes headaches ), 
3. Stress, 
4. Gender (male or female), 
5. Medications, 
6. Training, 
7. Smoking.

Resting heart rate data helps to assess health status. 
High heart rate means the heart has to work harder. 
This situation indicates a low efficiency of the heart, causing a smaller flow of blood to the rest of the body. 
The consequence is an increased demand for oxygen to the heart. 
Regular exercise helps improve heart efficiency, so it can pump more blood during each beat. 
The result is a decrease in resting heart rate.


Causes of high heart rate at rest

Normal heart rate is calculated at rest.

  • A younger woman has a higher frequency than an older woman.
  • An overweight woman has a higher heart rate than a woman of the same age and race with a lower weight.

Usually, the resting heart rate for athletes is about 35/45 beats per minute.

High resting heart rate is called tachycardia.

Among the main causes of high resting heart rate are:

  • Fever , the heart rate increases by about 10 beats for each degree of temperature;
  • Infection ;
  • It may be a symptom of pregnancy because of hormonal changes;
  • Hormonal imbalance, excessive production of hormones such as epinephrine ( adrenaline );
  • Young women may have low blood pressure and fast heart rate because of cigarette and caffeine use;
  • Heart valves malfunction;
  • Myocarditis (inflammation of the heart muscles);
  • Pericarditis (inflammation of the pericardium);
  • Insufficient supply of oxygen to the heart muscles;
  • Diseases that cause dense blood;
  • Disorders of the atria or ventricles of the heart (such as pericarditis or Wolff Parkinson White syndrome);
  • Abnormal electrical activity in the atria that causes fibrillation;
  • Blood circulation problems ;
  • Tachycardia can also occur after eating because digestion increases the demand for oxygenated blood and thus the heart has to pump more;
  • Thyroid disorders, such as hyperthyroidism;
  • Pulmonary diseases such as emphysema, pulmonary embolism , pneumonia, etc .;
  • Certain medications such as cortisone ( cortisone- based medicine) and non-steroidal anti-inflammatory drugs .


Fast heartbeat at night

Fast heartbeat at night can be caused by shortness of breath and can trigger awakening during sleep ( sleep apnea ).

The causes of a higher heart rate at night when the person lies down are often: fear, anxiety or stress. 
The individual goes to bed, but before sleeping he experiences various symptoms caused by anxiety, including:

1. Headaches, 
2. Tingling in the fingers , 
3. Shortness of breath , 
4. Constipation 
5. Chest pain , 
6. Muscle aches , 
7. Diarrhea , 
8. Nausea 
9. Vomiting , 
10. Sweating , 
11. Dry mouth , 
12. Dizziness .


Symptoms of tachycardia

Some diseases that cause accelerated heartbeats can also cause:

  • Vertigo
  • Shortness of breath
  • Palpitations
  • Chest pain
  • Feeling of fainting


Risks and complications of rapid heart beat

Tachycardia causes excessive exertion in the heart muscle which therefore needs more oxygen and nutrients compared to a normal heart. 
If there are other diseases of the circulatory system (such as atherosclerosis), cells may have insufficient oxygen and the risk of heart disease increases, for example:

  1. Heart attack,
  2. Coronary artery disease.


What to do for the fast heartbeat?

Treatment depends on the cause. 
Usually doctors prescribe antiarrhythmics (cardiac arrhythmia is the term used to describe abnormal heart rhythms), anticoagulants, or other medications that help decrease heart rate. 
This helps restore the functionality of the heart.


Natural Remedies for Tachycardia

In addition to medications, some changes in lifestyle and diet can lower heart rate. 
Avoid taking:

  • Many medications,
  • Caffeine,
  • Alcohol,
  • Supplements

In addition it  is advisable to stop smoking.

The physical activity is essential to strengthen the heart. 
This allows you to reduce your heart rate per minute because your heart can pump more blood with each beat.

It is advisable to talk with your doctor to understand the recommended physical activity based on:

  • At age,
  • In health conditions.

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