Tachycardia is an increase in the number of heart beats per minute (heart rate) in conditions of rest.
It is a fairly common ailment (symptom).
Heart rate is controlled by electrical signals transmitted through the heart tissue. In resting conditions, the heart rate is regular and, generally, it is between 60 and 100 beats per minute.
We talk about tachycardia when the heart rate is above 100 beats per minute. Temporarily increases during physical exercise, in conditions of stress, trauma or diseases that induce fever (sinus tachycardia), and then returns to normal.
Episodes of tachycardia are therefore common and are generally not a cause for alarm.
It becomes a disease, however, when the heart beats faster than normal in the upper (atria) or lower (ventricles) chambers, or both, at rest and in the absence of the conditions described above. It occurs when an abnormality in the heart produces very frequent electrical signals that cause an increase in heart rate (arrhythmia).
There are several types of tachycardia of a pathological nature (arrhythmia). The most common are:
- atrial fibrillation
- atrial flutter
- paroxysmal supraventricular tachycardia (TPSV)
- ventricular tachycardia
- ventricular fibrillation
When the heart beats too fast, it is unable to effectively pump blood throughout the body and, consequently, the organs and tissues of the body no longer receive the necessary amount of oxygen. This can cause the appearance of disorders (symptoms) such as:
- shortness of breath
- feeling of fainting
- palpitations, irregular heartbeat, or a feeling of discomfort in the chest
- chest pain
- fainting (syncope)
Tachycardia is caused by an alteration of the electrical impulses that control the normal pumping action of the heart. The factors that can directly or indirectly cause alterations in the electrical system of the heart are many and include, among others, cardiovascular and non-cardiovascular diseases, such as exercise, stress, unhealthy lifestyles, drugs, electrolyte imbalances, fever.
To ascertain (diagnose) the tachycardia and the cause that determines it, the doctor carries out the examination, evaluates the disorders (symptoms) and inquires about any previous illnesses. The cardiologist may also request a series of tests to measure heart rate, establish a link between increased heart rate and disorders (symptoms).
It may be necessary to undergo an electrocardiogram, echocardiogram and cardiac holter.
The treatment of tachycardia is aimed at addressing the causes that cause it, at slowing the heart rate during the attack, at preventing future episodes and at minimizing the risk of complications.
In fact, if left untreated, tachycardia can compromise the functioning of the heart and cause complications that vary according to the type of attack, its duration, the number of beats per minute and the presence of other heart disorders. Possible complications include:
- formation of blood clots (thrombi) which can cause a stroke or myocardial infarction
- inability of the heart to pump enough blood (heart failure)
- frequent episodes of fainting or loss of consciousness
- unexpected death, usually associated only with ventricular tachycardia or ventricular fibrillation
The most effective way to prevent tachycardia is to reduce the risk of developing cardiovascular disease. If you already suffer from these diseases, you need to monitor them over time and follow the treatment plan established with your doctor to reduce the risk of new episodes developing.
The electrical system of the heart
Knowing the functioning of the heart's electrical system helps to understand the causes and complications that can occur when the heartbeat rate and the heart's pumping function are significantly altered.
The heart has its own internal electrical system, through which impulses travel to make its muscle fibers contract. The electrical signal arises in a group of cells called sino-atrial node located in the right atrium, which determines the frequency of the normal heartbeat sinoatrial node the electrical signal propagates to the rest of the right atrium and the nearby left atrium, the atria contract and pump blood into the ventricles.
The electrical signal passes from the atria to the ventricles via the atrioventricular node, which is located on the border of the atria and ventricles. The atrioventricular node transmits the electrical signal to a bundle of specialized cells, called the bundle of His, which transmit the signal along a left branch to stimulate the left ventricle and along a right branch to stimulate the right ventricle.
When the electrical impulse travels along these branches, the ventricles contract and pump blood: the right ventricle sends oxygen-poor blood to the lungs where it is oxygenated and the left ventricle sends oxygen-rich blood to the whole body.
When something disrupts this complex impulse transmission system, the heart may be beating too fast (tachycardia), too slowly (bradycardia) or with an irregular rhythm (arrhythmia).
There are several types of tachycardia of a pathological nature; are classified according to the "origin and cause of the increased heart rate. The most common types are:
Atrial fibrillation is caused by disordered and irregular electrical impulses in the upper chambers of the heart (atria), which cause the atria to contract rapidly, irregularly, weakly and uncoordinatedly.
It can be temporary, but some episodes can last a long time and the fibrillation can stabilize if not treated properly at the first appearance. It represents the most common type of tachycardia. Its causes are not known, but it is a common disease with advancing age and is more common in people suffering from cardiovascular disease.
It can also be associated with over-functioning of the thyroid gland (hyperthyroidism) and lung disease.
Several other factors can contribute to the onset of atrial fibrillation, including: alcohol abuse, drug use and smoking.
Atrial flutter is similar to atrial fibrillation but the atria contract at a high rate in a rhythmic fashion. It is less common than atrial fibrillation, but it shares the same disorders (symptoms), causes, and possible complications. About one third of people with atrial flutter also suffer from atrial fibrillation. Episodes of atrial flutter may resolve on their own or require specific therapy.
Paroxysmal supraventricular tachycardia (TPSV) and Wolff-Parkinson-White syndrome
It is an "arrhythmia, characterized by a high frequency, which begins and ends suddenly. It can also occur in young people, following an important physical effort.
A particular form of it is the Wolff-Parkinson-White syndrome, in which the atrial electrical signals pass to the ventricles through an accessory path, without being 'filtered' by the atrio-ventricular node; for this reason the heart rate can be very high and dangerous.
It can last a few seconds or longer (sustained ventricular tachycardia). In this case it represents a medical emergency both because the heart is unable to pump blood efficiently into the arteries and because it can degenerate into ventricular fibrillation
It is a chaotic arrhythmia that originates in the ventricles and prevents them from contracting effectively to pump blood into the circulation. It can cause death in a few minutes, unless you intervene with a defibrillator, a device equipped with two plates which, placed on the patient's chest, deliver an electric shock that can resolve the arrhythmia.
Ventricular fibrillation can occur following a heart attack. Most people with ventricular fibrillation have cardiovascular disease (heart disease).
The heart beats too fast and is unable to effectively pump blood around the body. Insufficient blood supply can deprive organs and tissues of the necessary amount of oxygen and can cause some disorders (symptoms) related to tachycardia such as:
- shortness of breath
- feeling of fainting
- accelerated heart rate
- palpitations, very fast, irregular heartbeat, or a feeling of discomfort in the chest
- chest pain
- fainting (syncope)
In some people, tachycardia does not cause ailments (symptoms) and is only discovered during a doctor's visit or an EKG.
When to see your doctor
Certain diseases and conditions can cause rapid heart rate.When an adult or a child develops symptoms of tachycardia, a doctor should be consulted for a quick and accurate diagnosis and appropriate treatment.
In case of fainting, difficulty breathing or chest pain lasting more than a few minutes, you must call the single emergency number 112 (or 118, depending on the region in which you are located) by phone to request the dispatch. ambulance. It is also advisable to contact 112 when assisting another person experiencing these disorders (symptoms).
Tachycardia is caused by an alteration of the electrical impulses that control the pumping action of the heart. Several causes can cause a disturbance in the transmission of electrical impulses in the heart. These include:
- damage to the muscle tissue of the heart caused by cardiovascular disease
- anomaly of the heart's electrical impulse transmission system present from birth (congenital heart disease, including long QT syndrome)
- congenital heart disease or abnormality
- strenuous exercise
- sudden stress, such as fear
- hypertension crisis or arterial hypotension
- smoking habit
- feverish change
- alcohol abuse
- abuse of caffeinated drinks
- side effects of drugs
- drug abuse, like cocaine
- electrolyte imbalance, due to the excess / absence of mineral substances necessary for the correct generation of electrical impulses
- hyperactivity of the thyroid gland (hyperthyroidism)
In some cases, the cause of the tachycardia cannot be identified.
Any condition that causes damage to the heart or places excessive strain on it can increase the risk of tachycardia.
Adopting a healthy lifestyle and following the advice and treatment prescribed by your doctor can decrease the risk associated with the following factors:
- cardiovascular diseases
- sleep apnea
- thyroid overactive (hyperthyroidism)
- smoking habit
- excessive alcohol consumption
- excessive caffeine intake
- drug use
- psychological stress or anxiety
Other risk factors
Other factors that can increase the risk of developing tachycardia are:
- advanced age, the wear and tear of the heart linked to aging increases the likelihood of developing forms of tachycardia (arrhythmias)
- familiarity, people who have family members with some forms of tachycardia or other heart rhythm disorders have an increased risk of it
To ascertain (diagnose) tachycardia and determine the causes, the doctor (or cardiologist) performs a thorough medical examination, examines the present disorders (next medical history), assesses the state of health over time (past medical history), and any presence also in family members (family history).
He can prescribe a series of tests to measure heart rate, establish a link between the increased heart rate and the disturbances (symptoms) and try to identify the underlying cause of the tachycardia.
Tests indicated for the diagnosis of tachycardia:
- electrocardiogram (ECG)
The ECG is the examination that records the rhythm and electrical activity of the heart. Normally, it is done in a hospital or outpatient clinic, takes only a few minutes and is not painful; during its unwinding of the small metal suckers, called electrodes, connected with cables to the device for the ECG, are positioned on the arms, legs and chest. Each time the heart beats, it produces electrical signals and the ECG device records them on the card. From the ECG trace, the doctor can identify the type of tachycardia.
Since it can be difficult to detect the episode of tachycardia, the doctor may also ask you to wear a portable ECG device during the normal course of daily activities, to better understand the episode of tachycardia and get more information on heart rate: cardiac holter, which can be placed in a pocket, attached to the belt or to a special shoulder strap placed around the shoulder. The device records the electrical activity of the heart for a period of 24 hours, thus providing the possibility to evaluate the heart rhythm for an extended period. Generally, it is required to keep a diary with the time and activities carried out and to describe any disturbances (symptoms ) that occur during the 24-hour recording of cardiac activity in order to be able to correlate them with rhythm anomalies
- electrophysiological study
The electrophysiological study is an examination that studies the electrical system of the heart and is, therefore, useful for identifying the mechanism and the location of the problem that causes tachycardia.
It can be performed trans-esophageal or endo-cavity. In the first case, a probe (thin flexible tube) is inserted into the esophagus which is positioned at the height of the heart and, on the one hand, emits electrical impulses that can induce arrhythmia, on the other, records the electrical activity of the atria and ventricles. In the second case, probes (catheters) are inserted into the vessels of the groin, arm or neck, they are guided up to the heart and positioned at various points to record, and possibly stimulate, the electrical activity of the heart
An echocardiogram is an ultrasound scan that produces a "moving image of the heart. Through the echocardiogram it is possible to identify areas of poor blood circulation, abnormal heart valves and alterations in the functioning of the heart muscle
- Exercise ECG
The doctor checks the heart rate, while the patient walks on a treadmill (treadmill) or pedal on an exercise bike, to check the variation during physical activity or when a drug is given to cause tachycardia
- tilt test
Also called passive orthostatic stimulation testhelps your doctor better understand how tachycardia contributes to fainting. Under careful monitoring, the person undergoing it takes a drug that causes an episode of tachycardia, then lies down on a tilting table, to which it is fixed with wrapping chest and abdomen bands, placed first in a horizontal position and then rotated in a vertical position. , as if lying on his feet. Doctors observe how the heart and nervous system respond to changes in position
- further examinations
The cardiologist can also prescribe other tests to ascertain (diagnose) the underlying causes of tachycardia and evaluate the condition of the heart: chest X-ray, magnetic resonance imaging (MRI), computed tomography (CT), coronary angiography
The treatment (therapy) of tachycardia is aimed at the causes that cause it, at slowing the heartbeat during the attack, at preventing future episodes and at minimizing complications.
Interruption of accelerated heart rate
A fast heartbeat can correct itself, in some cases it is possible to slow down the heart rate by implementing some specific maneuvers indicated by the general practitioner or specialist.
However, if it is not a temporary episode due to a specific cause, it may be necessary to take specific medications. Among the maneuvers to slow the heart rate:
- vagal stimulation or vagal maneuvers. The cardiologist can prescribe the so-called vagal maneuvers to be performed during tachycardia episodes.They stimulate the vagus nerve, which participates in the regulation of the heartbeat, and require:
- to cough
- exert pressure on the abdomen, in correspondence of the stomach
- apply an ice pack on the face
- medications. If the tachycardia does not respond to vagal maneuvers, the cardiologist may prescribe an antiarrhythmic drug. In some cases, intravenous administration may be required to restore normal heart rhythm. However, this treatment must be performed in the hospital
- cardioversion. With this procedure, the heart is stimulated by electrical impulses transmitted by a special instrument, the automatic external defibrillator (AED), through electrodes. Pacing the AED restores a normal heart rhythm. The defibrillator is generally used in an emergency or when medications have not been effective
Prevent tachycardia episodes
There are several ways to help prevent tachycardia episodes:
- anti-arrhythmic drugs. They can prevent tachycardia from appearing if used regularly. Other types of medicines, such as calcium channel blockers and beta blockers, may be prescribed alternatively or in combination with anti-arrhythmic drugs
- catheter ablation. Procedure used when tachycardia is caused by the appearance of an alternate electrical pathway of cardiac pacing. It is aimed at selectively destroying the affected part of the heart and interrupting abnormal electrical circuits. It is taken into consideration in cases where drugs are not effective or are not tolerated by the patient.
Thin and soft probes (catheters) are guided through a vein to the heart, to record its electrical activity. Once the part of the heart tissue that is the site of the anomaly has been traced, it is destroyed by conveying a source of energy, such as high-frequency radio waves that generate heat, through the scaler catheter.The procedure can take two to three hours and is usually done under general anesthesia
- heart stimulator (pacemaker). Some types of tachycardia can be treated by implanting a pacemaker.
The pacemaker consists of a battery-operated pulse generator and one or more tubes, called leads, that are capable of delivering electrical impulses to the heart. It is implanted under the collarbone and leads are guided to the heart through the veins. The pacemaker controls the heartbeat and generates the electrical impulses necessary to change the rate appropriately.
Most pacemakers are also able to record some information on cardiac activity that the cardiologist can use to check the functioning of the heart. For this reason it is necessary to schedule regular checks of the functionality of the heart, also to ensure the proper functioning of the pacemaker
- implantable cardioverter. If you are at risk of having a life-threatening episode of tachycardia, your doctor may recommend an implantable cardioverter defibrillator (CDI).
The device, the size of a small mobile phone, is surgically implanted in the chest. CDI constantly monitors heart rate, detects any increase in heart rate and, if necessary, delivers precisely calibrated electrical impulses that restore normal heart rhythm
- surgery. Open heart surgery may be necessary, in some cases, to destroy the alternate electrical pathway that causes the tachycardia.
In another type of intervention, called maze procedure, the surgeon makes small incisions in the heart tissue to create scar tissue. Because scar tissue does not conduct electricity, its formation blocks the stray electrical impulses that cause some types of tachycardia.
Surgery is usually only used when other treatment options don't work or when surgery is needed to treat another heart disorder.
Prevention of blood clots
Some people with tachycardia have an increased risk of developing a blood clot (blood thrombus) which can cause a stroke or myocardial infarction. In these cases, the specialist doctor may prescribe a blood thinning drug (anticoagulant) and thus help reduce the risk of blood clots forming.
Treating a disease that can cause tachycardia
If another medical problem such as cardiovascular disease or excessive thyroid function (hyperthyroidism) causes or facilitates the onset of tachycardia, its treatment can prevent, or minimize, tachycardia episodes.
Complications of tachycardia vary in severity based on various factors such as the type, frequency, and duration of the tachycardia, as well as the presence of other heart disorders. Possible complications include:
- formation of blood clots (blood clots) which can cause a stroke or heart attack (myocardial infarction)
- inability of the heart to pump enough blood to be supplied to organs and tissues (heart failure)
- frequent episodes of fainting or loss of consciousness
- unexpected death, usually associated with ventricular fibrillation
The most effective way to prevent tachycardia is to reduce the risk of developing cardiovascular disease. If you already suffer from it, you need to monitor them and follow the treatment plan prescribed by your doctor (lifestyles and therapies).
If symptoms (symptoms) change, worsen or develop new ones, you should inform your doctor immediately.
Prevent cardiovascular disease
The most effective prevention against the onset of cardiovascular diseases consists in "adopting healthy lifestyles:
- follow a varied diet and balanced
- not smoking
- keep blood pressure within normal levels (120/80 mm Hg, taking into account that normal blood pressure ranges vary with age)
- carry out moderate and regular physical activity
A varied and balanced diet, made up of modest portions, with low consumption of saturated fats and cholesterol, low in salt and sugar, rich in vegetables and fruit, whole grains, legumes and fish decreases the risk of developing cardiovascular diseases. Fruits and vegetables are rich in vitamins, minerals and fiber, and they help keep the body healthy. The ideal is to eat at least five 80g portions of fruit and vegetables every day.
An important risk factor for the onset of cardiovascular disease is cholesterol, of which there are two types:
- with low density lipoprotein (LDL), consisting mainly of fat and a small amount of protein; this type of cholesterol is deposited in the wall of the arteries and can obstruct them, therefore it is often referred to as "atherogenic cholesterol" or "bad cholesterol"
- with high density lipoprotein (HDL), consisting mainly of proteins plus a small amount of fat; this type of cholesterol is not deposited in the arteries and is therefore often referred to as "good cholesterol"
The increase in LDL cholesterol is favored by the intake of foods containing saturated fats and cholesterol, such as:
- sausages, fatty meats, lard and bacon
- butter and cream
- egg yolk (yolk)
- sweets and cookies
- foods that contain coconut or palm oil (rich in saturated fat)
On the other hand, including polyunsaturated fats in the diet decreases the levels of LDL cholesterol in the blood and increases those of HDL cholesterol, helping to reduce atherosclerotic plaques in the arteries.Foods rich in polyunsaturated fats include:
- blue fish
- nuts and seeds
- sunflower and rapeseed oil
Extra virgin olive oil is rich in monounsaturated fats; even monounsaturated fats have the peculiarity of lowering LDL cholesterol levels and increasing HDL cholesterol levels.
However, remember that fats are very caloric, therefore it is recommended to use them in moderate quantities.
Smoking is a major risk factor for cardiovascular disease, causing arteriosclerosis and arterial hypertension. Smoking significantly increases the risk of having a stroke, as it narrows the arteries and makes blood clots more likely. Quitting smoking reduces the likelihood of it happening.
In Italy there is a Green Telephone against Smoking (TVF): 800 554 088, an anonymous and free national service that carries out consultancy activities on issues related to the phenomenon of smoking (for more information: Istituto Superiore di Sanità. Toll-free telephone against smoking) .
High blood pressure (arterial hypertension)
Consistently high blood pressure (high blood pressure) can place excessive strain on the heart, increasing the risk of heart attack.
Arterial hypertension can be reduced by moderating the consumption of alcoholic beverages, reducing weight and keeping it normal, carrying out regular and daily physical activity and following a varied and balanced diet, with modest portions, low in salt, saturated fat, cholesterol and sugars.
Salt increases blood pressure and it is therefore recommended to use little, both for cooking and for seasoning, less than 5g (about a teaspoon) per day, also considering the salt contained in packaged foods.
Alcohol does not contain any vitamins or other nutrients, it only gives calories.Drinking wine or other alcohol on a regular basis increases blood pressure and weight. Men should not drink more than 14 alcohol units per week, women no more than 7 alcohol units per week (in men it is recommended not to drink more than two glasses of wine in the whole day, in women, only one glass). If you drink 14 alcohol units a week it would be better if they were spread over three or more days and accompany the meal.
Excess alcohol consumption can lead to increased blood pressure (hypertension) and an irregular heartbeat (atrial fibrillation): both of these factors can increase the risk of having a stroke.
Being overweight forces the heart to work harder to circulate blood in the body, and this can cause blood pressure to rise.
If you are overweight or obese, losing even a few pounds can make a big difference in your blood pressure and overall health.
Staying active and practicing physical activity regularly lowers blood pressure, keeping the heart and blood vessels in good condition. Regular physical activity also helps to lose weight and to control emotional tension.
Medium-intensity aerobic activities such as walking, swimming, and cycling are recommended. More demanding activities, such as soccer and tennis, may not be suitable; it is advisable to consult your doctor to make choices suitable for your state of health.
If you are recovering from a stroke, you should discuss with your doctor what physical activity plan you can do. In fact, it may not be possible to do it in the first weeks or months after the stroke, but it should be feasible to start exercising once rehabilitation is well under way.
Control your stress
Avoid unnecessary stress and learn techniques for dealing with and managing everyday stress.
Get regular medical checks and report any signs or symptoms to your doctor.
It is the attending physician who knows how to evaluate and indicate the frequency of checks.
Monitor and treat existing cardiovascular diseases
If you already suffer from cardiovascular disease, it is necessary to strictly follow the doctor's instructions on adopting a healthy lifestyle and to follow the prescribed treatment plan.
If your symptoms change, get worse, or new ones appear, you should inform your doctor immediately.
You need to carefully follow your doctor's directions by following a healthy lifestyle and prescribed treatment plan. This also helps to calmly cope with and manage tachycardia episodes adequately.
It is important to ask your doctor to explain:
- what your normal heart rate is and how to detect it (take the pulse)
- when and how to use vagal maneuvers, if they are adequate
- when to call your doctor
- when to ask for emergency treatmenta by calling an ambulance or going to the emergency room
Support from family and friends can help reduce stress and better manage tachycardia.
Ministry of Health. Cardiac arrhythmias
Mayo Clinic. Tachycardia (English)
EpiCentro (ISS). Steps indicators: consumption of alcoholic beverages