Heart rhythm disturbances are a very complex branch of cardiology. People who have no idea about the structure of the heart and its conduction system will find it difficult to understand the mechanisms of arrhythmia. No need! For this purpose, there is a whole section of cardiology that deals only with heart rhythm disturbances (arrhythmology), and the doctor who treats them is an arrhythmologist. Everyone must do their job.
Arrhythmias are very common in our lives, and every person should know what arrhythmia is, how and under what circumstances it occurs, how it manifests itself and why it is dangerous.
As simply as possible, without delving into the physiological mechanisms of arrhythmias, we will consider their most common types. What is arrhythmia
There is a special node in the heart - the sinus node. It sets the rhythm for the whole heart. The correct (normal) heart rhythm is called - sinus rhythm. The heart rate in normal (sinus) rhythm is 60-90 beats per minute. All rhythm disturbances(arrhythmias) are irregular (non-sinus) rhythms, with an increased (more than 90 beats per minute) or decreased (less than 60 beats per minute) heart rate. In other words, this is any deviation from the norm.
If the heart beats faster than 100 beats per minute, this is a disorder called tachycardia (increased heart rate). If the heart beats less frequently, for example, 55 beats per minute, this is bradycardia (rare heartbeats).
In young children, the heart rate is not 60-90 beats per minute, as in adults, but 140 or more, so for children 140 beats per minute is the norm.
Classification of arrhythmias. What are the types of arrhythmias?
1. Sinus tachycardia - increased heart rate to 120-200 beats per minute while maintaining normal rhythm(the heart beats faster, but the rhythm is correct).
Sinus tachycardia is a normal response of the heart to physical activity, stress, and drinking coffee. It is temporary and is not accompanied by unpleasant sensations. The restoration of normal heart rate occurs immediately after the cessation of the factors that caused it.
Doctors are only concerned about tachycardia that persists at rest, accompanied by a feeling of lack of air, shortness of breath, and a feeling of palpitations. The causes of such tachycardia may be diseases that manifest themselves in heart rhythm disturbances or are accompanied by them: hyperthyroidism (a disease thyroid gland), fever (increased body temperature), acute vascular insufficiency, anemia (anemia), some forms of vegetative-vascular dystonia, application medicines(caffeine, aminophylline).
Tachycardia displays work of cardio-vascular system in response to a decrease in the contractility of the heart, which is caused by heart diseases such as chronic heart failure, myocardial infarction (death of a section of the heart muscle), a severe attack of angina in patients with coronary heart disease, acute myocarditis (inflammation of the heart muscle), cardiomyopathies (changes in the shape of the heart muscle), and heart size).
2. Sinus bradycardia - slowing the heart rate to less than 60 beats per minute.
In healthy people, it indicates good fitness of the cardiovascular system and is often found in athletes (in response to stress, the heart does not start beating strongly because it is accustomed to the stress).
Causes of bradycardia not related to heart disease: hypothyroidism, increased intracranial pressure, overdose of cardiac glycosides (drugs for the treatment of heart failure), infectious diseases(flu, viral hepatitis, sepsis, etc.), hypothermia (lower body temperature); hypercalcemia (increased calcium in the blood), hyperkalemia (increased potassium in the blood).
Causes of bradycardia associated with heart disease: myocardial infarction, atherosclerosis (deposition atherosclerotic plaques on the wall of the vessel, which, when growing, narrow the lumen of the vessel and lead to circulatory disorders), post-infarction cardiosclerosis (a scar on the heart that interferes with its full functioning).
3. Paroxysmal ventricular tachycardia - a sudden onset and suddenly ending attack of increased heart rate from 150 to 180 beats per minute.
This type of arrhythmia occurs in people when the following diseases heart: myocardial infarction, post-infarction aneurysm (formation of a vascular “bag” of blood at the site of a heart attack after scarring), cardiomyopathies, heart defects (changes in the structure of the heart that interfere with its normal functioning).
Paroxysmal ventricular tachycardia occurs 2 times more often in women than in men and often causes a decrease in blood pressure and loss of consciousness.
4. Extrasystole - extraordinary contractions of the heart. It may be asymptomatic, but more often patients feel a jolt or a sinking heart.
Causes of extrasystole not related to heart disease: stress and, as a consequence, vascular reaction; emotional overstrain, overwork; abuse of coffee, smoking, alcohol, often during alcohol withdrawal due to chronic alcoholism (withdrawal syndrome); drug use.
Causes of extrasystole associated with heart disease: coronary heart disease, acute heart attack myocardium; mitral stenosis (narrowing mitral valve heart disease), rheumatic carditis (heart disease due to rheumatism), thyrotoxicosis (thyroid disease), intoxication with cardiac glycosides.
5. Ventricular fibrillation is a serious condition in which the heart contracts chaotically, incoherently, and has no rhythm. As a rule, ventricular fibrillation of the heart, a complication after extensive myocardial infarction, is the cause of death
Causes of rhythm disturbances (arrhythmias)
1. Cardiovascular diseases:
- coronary heart disease (myocardial infarction, angina pectoris, post-infarction cardiosclerosis) - ventricular arrhythmias and sudden cardiac arrest occur more often due to damage to the heart muscle and a decrease in the ability of the heart to contract:
- heart failure - there is an increase in the parts of the heart, loss of elasticity of the heart muscle, it ceases to contract adequately, blood stagnates inside the heart, or a turbulence in its flow occurs, resulting in arrhythmia;
- cardiomyopathy - when the walls of the heart are stretched, thinned or thickened, the contractile function of the heart decreases (it cannot cope with its work), which leads to the development of arrhythmia;
- acquired heart defects - disorders of the structure and structure of the heart (usually after rheumatism), which affect its functioning and contribute to the development of arrhythmia;
- congenital heart defects - congenital disorders of the structure and structure of the heart that affect its functioning and contribute to the development of arrhythmia;
- myocarditis - inflammatory disease cardiac muscle, which sharply reduces the function of the heart (prevents it from contracting) and can cause various arrhythmias; mitral valve prolapse - an obstruction in the mitral valve that prevents blood from flowing from the left atrium to the left ventricle (normally), blood from the ventricle is thrown back into the atrium (where it came from, but this should not happen), all these disorders can trigger the occurrence of arrhythmia .
2. Medicines. Overdose of cardiac glycosides, antiarrhythmic drugs, diuretics, beta blockers (drugs to regulate blood pressure and heart rate) leads to heart rhythm disturbances (arrhythmias).
3. Electrolyte disturbances(violation of water-salt balance in the body): hypokalemia, hyperkalemia, hypomagnesemia (decreased magnesium in the blood), hypercalcemia (increased calcium in the blood).
4. Toxic effects on the heart: smoking, alcohol, bioactive supplements, herbal treatment, working with toxic substances (poisons).
Clinical manifestations (symptoms and signs) of arrhythmia
Arrhythmias may for a long time not manifest itself in any way, and the patient may not suspect that he has an arrhythmia until the doctor identifies the disease during normal medical examination or taking an electrocardiogram.
But often arrhythmias are not so “quiet” and make themselves known, significantly preventing a person from living his usual life. They can manifest themselves in the form of “turning over”, “transfusion” and “freezing” of the heart, but more often it is a feeling of interruptions in the heart, increased heartbeat, “fluttering” of the heart, extremely fast or, conversely, slow heartbeat, dizziness, shortness of breath, chest pain a cell of a pressing nature, a feeling of “failure” of the ground under your feet, nausea and (or) vomiting (especially when the normal rhythm changes to arrhythmia, and vice versa, when it is restored from arrhythmia to a normal heart rhythm), loss of consciousness.
Such diverse manifestations of arrhythmia do not always indicate the complexity of the rhythm disorder. People with minor rhythm disturbances may lose consciousness, but patients who have truly life-threatening rhythm disturbances do not show any complaints. Everything is very individual.
Risk factors for arrhythmia development
Age - with age, the heart muscle, our pump, weakens and can fail at any moment, and the diseases that we have “accumulated” over our lives will aggravate the situation.
Genetics - in people with congenital anomalies(defects) of the development of the heart and its conduction system, arrhythmias are much more common.
Heart diseases - myocardial infarction and the scar on the heart that forms after it, coronary heart disease with vascular damage and rheumatism with damage to the heart valves are fertile ground for the development of arrhythmia.
Arterial hypertension (systematic increase in blood pressure) - increases the risk of developing coronary disease heart and contributes to the development of left ventricular hypertrophy (increase in size), which also increases the risk of developing arrhythmia.
Obesity is a direct risk factor for the development of coronary heart disease with all the ensuing consequences.
Diabetes mellitus - an uncontrolled increase in blood glucose can easily trigger the development of arrhythmia; coronary heart disease and arterial hypertension, which contribute to the development of arrhythmia, are faithful companions of diabetes mellitus.
Reception medicines- uncontrolled use of diuretics and laxatives leads to disruption of the water-salt balance in the body and can cause arrhythmia.
Electrolyte disturbances - potassium, magnesium and sodium form the basis of the contractile mechanism of the heart, therefore, an imbalance in them (imbalance) can lead to arrhythmia.
Coffee, smoking and drugs are the cause of the development of extrasystole; amphetamine and cocaine provoke ventricular fibrillation and sudden cardiac arrest.
Alcohol abuse - risk of developing ventricular fibrillation; Chronic alcoholism leads to the development of cardiomyopathy (enlargement of the heart), followed by a decrease in the contractile function of the heart and the addition of arrhythmia. Complications of arrhythmia
A person with arrhythmia automatically falls into the risk group for the development of myocardial infarction and stroke, since the heart contracts incorrectly, the blood stagnates, blood clots (clots) form, which are carried throughout the body with the blood flow, and in the vessel where the blood clot gets stuck, it happens catastrophe. If a blood clot gets into the coronary (heart) vessels, there will be a heart attack, if it gets into the vessels of the brain, there will be a stroke. In third place, after the vessels of the heart and brain, are the vessels of the lower extremities.
Arrhythmia can cause the development of diseases such as myocardial infarction, cerebral stroke, thromboembolism pulmonary artery, thrombosis of intestinal vessels, thrombosis of vessels of the extremities with subsequent amputation, and also lead to sudden cardiac arrest. Diagnostics ECG arrhythmias(electrocardiogram) - recorded electrical activity heart, assess the rhythm, heart rate and condition of the heart parts.
Ultrasound or echocardiography (echocardiography) - obtains an image of the heart. This method allows you to see all sizes, shapes and abnormalities of the heart; determine how the valves and parts of the heart work; recognize scars after suffered a heart attack myocardium; assess the contractile function of the heart.
Daily Holter monitoring is the recording of an ECG during the day, which is possible thanks to a sensor attached to the patient. He wears it 24 hours, and an ECG is recorded during daily activities and during night sleep. After 24 hours, the rhythm, episodes of arrhythmia, at what time they occurred and what they are associated with are assessed.
EPI and mapping (electrophysiological study) is the most accurate and informative method for determining arrhythmia. Its essence is that the thinnest catheters are inserted into the cavity of the heart, recognizing the area of the heart from which incorrect impulses emanate. In this case, thermal radiofrequency exposure is used, which allows not only to identify, but also to eliminate the source of arrhythmia.
Treatment of heart rhythm disturbances (arrhythmias)
Under no circumstances should you treat arrhythmia yourself! The recommendations that can be found on the Internet regarding self-medication of arrhythmia are illiteracy, obvious negligence and disregard for the patient and his life. Arrhythmia is a disruption of the heart, the most important motor in the human body, and its inept treatment, namely self-medication, can lead to death.
Arrhythmia should be treated by a doctor after conducting a special examination and determining the type of arrhythmia: from which part of the heart and under the influence of what causes this condition arose.
The goal of treating arrhythmia is to restore the correct (sinus) rhythm of the heart, reduce the manifestations of arrhythmia, eliminate its consequences and prevent complications.
There are two types of treatment for arrhythmia: medication and surgery.
Drug treatment of arrhythmia
Provides for the prescription and use of antiarrhythmic drugs. Their range is quite large. In cardiological practice, there are four classes of antiarrhythmic drugs.
1. Antiarrhythmic drugs: verapamil, adenosine, digoxin - used to eliminate atrial arrhythmias; lidocaine, disopyramide, mixletine - for ventricular arrhythmias; amiodarone, propafenone, flecainide - for both atrial and ventricular arrhythmias.
Amiodarone (cordarone) is the most commonly used and well-proven drug for the treatment of almost all types of arrhythmias. It is prescribed for arrhythmias in patients with myocardial infarction and heart failure. At intravenous administration antiarrhythmic activity appears within the first 10 minutes after administration. Usually, for the first two weeks after the onset of arrhythmia, cordarone is used orally to saturate the heart, and then the dose is reduced to a maintenance dose and continued thereafter. Contraindications for use: bradycardia (slow pulse, 50 beats per minute or less), bronchial asthma, heart block (atrioventricular), thyroid disease and pregnancy.
2. Beta-blockers are a group of drugs that have an antiarrhythmic and pronounced hypotensive (lowering blood pressure) effect. Beta blockers reduce heart rate and prevent the development of heart failure. Contraindications to the use of beta blockers are chronic diseases respiratory organs and bronchial asthma, since taking them can cause an attack of suffocation.
3. Cardiac glycosides - increase myocardial contractility, improve blood circulation and reduce the load on the heart (digoxin, digitoxin, strophanthin, korglykon).
4. Metabolic drugs - help improve metabolism, nourish the heart muscle and protect the myocardium from ischemic effects.
Surgical treatment of arrhythmia Radiofrequency ablation is a procedure that allows, using small punctures, to completely cure arrhythmia. A special catheter is used in the heart to cauterize the area (source) of the arrhythmia and restore the correct heart rhythm.
Installation of an electrical pacemaker (ECS), a device that eliminates cardiac arrhythmia. Main function ECS is the imposition of a certain (desired) heart rate on the patient’s heart to maintain the correct heart rhythm. For example, if a patient has bradycardia (slow pulse) with a heart rate of 40 beats per minute, then when setting the pacemaker, the correct rhythm is set with a frequency of 80 beats per minute.
ditch per minute. There are one-, two- and three-chamber pacemakers. Single-chamber pacemakers are activated on demand. When bradycardia appears against the background of normal rhythm and heart rate (heart rate is 40-50 beats per minute), the pacemaker is turned on with the desired heart rate. Dual-chamber pacemakers automatically control heart rate. Three-chamber pacemakers are used to treat arrhythmias, life-threatening patient (ventricular arrhythmias), and are reliable prevention of sudden death.
There is a so-called cardioverter - defibrillator. It instantly turns on and stimulates the heart, in other words, it resuscitates the heart when life-threatening arrhythmias develop.
Atrial fibrillation or atrial fibrillation
Atrial fibrillation (AF) is a heart rhythm disorder accompanied by an increase in heart rate to 350-700 beats per minute. At the same time, the heart rhythm is absolutely erratic and there is no way to accurately calculate the pulse. AF most often develops after 60 years and accounts for 40% of all hospitalizations for arrhythmias.
Causes of MA: heart disease (myocardial infarction, arterial hypertension, heart failure, cardiosclerosis, myocarditis, rheumatic diseases hearts); diseases of other organs (thyrotoxicosis; drug intoxication; overdose of cardiac glycosides; acute poisoning alcohol and chronic alcoholism; uncontrolled use of diuretics; hypokalemia - decrease in potassium content in the blood; complication of severe poisoning and overdose of diuretics; stress and neuropsychic strain).
MA forms by nature clinical course: paroxysmal - a first-time attack that lasts up to five days, usually less than a day; persistent - a condition when attacks are periodically repeated, the attack lasts more than seven days, but with effective treatment removed immediately after occurrence, after 3-5 hours; chronic (permanent) - erratic contractions of the heart over a long period of time.
- Based on the speed of heart contractions, the following variants of MA are distinguished: normosystolic - abnormal heart rhythm at a normal pace (60-90 beats per minute);
- tachysystolic - abnormal heart rhythm at a fast pace (90 or more beats per minute), patients tolerate this form of arrhythmia the worst;
- Bradysystolic - abnormal heart rhythm at a slow pace (60 or less beats per minute).
1. Fibrillation (atrial fibrillation). Normally, impulses from the atria enter the ventricles of the heart, and they contract, during which blood is pushed out of the heart. Fibrillation (atrial fibrillation) is a contraction not of the entire atrium, but only of its sections, and the remaining impulses do not reach the ventricles, but only jerk them and force them to contract in wrong mode. As a result, there is no complete transmission of the impulse from the atrium to the ventricles and proper contraction of the heart is impossible.
2. Atrial flutter - rapid contractions of the atria in the correct rhythm, but very fast (200-400 beats per minute). In this case, contraction of both the atria and ventricles suffers. The atria do not have time to relax because they work at a very fast pace. They become overfilled with blood and do not have time to give it to the ventricles. Because of this “greedy” relationship of the atria to the blood, the ventricles of the heart suffer, which cannot receive enough blood to push it out of the heart and give it to all the organs and tissues of the body.
Symptoms and complaints of patients with atrial fibrillation
Some patients may not feel the arrhythmia and still feel fine. Others feel a rapid heartbeat, “interruptions” in the heart, shortness of breath, which worsens with minimal physical activity. Chest pain may not always be present. Some patients feel pulsation in the neck veins. All this is accompanied by weakness, sweating, a feeling of fear and frequent urination. With a very high heart rate (200-300 or more beats per minute), dizziness and fainting are observed. All these symptoms disappear almost immediately after normal rhythm is restored. When the rhythm changes (from the correct rhythm to an arrhythmia and from an arrhythmia to the correct rhythm), nausea and vomiting may occur. Patients suffering from a permanent (chronic) form of MA stop noticing it. Complaints appear only with increased blood pressure, stress and physical activity, because the heart rate changes and arrhythmia reminds itself.
Complications of atrial fibrillation
Thromboembolism and stroke. In the presence of intracardiac thrombi, LA acts as a powerful provocateur of the development of thromboembolism in various organs. In AF, blood clots travel from the heart into the blood vessels of the brain and cause a stroke. Every seventh stroke develops in patients with MA.
Heart failure. MA in people suffering from mitral stenosis (narrowing of the mitral valve of the heart) and hypertrophic cardiomyopathy (thickening of the walls of the heart), against the background of heart failure, can lead to the development of cardiac asthma (an attack of suffocation) and pulmonary edema.
Dilated cardiomyopathy. MA against the background of heart failure provokes it and quickly leads to the development of dilated cardiomyopathy (enlargement of the cavities of the heart).
Arrhythmogenic shock. MA in the setting of heart failure can cause the development of arrhythmogenic shock (a sharp decrease in blood pressure, loss of consciousness and cardiac arrest).
Heart failure. AF (atrial fibrillation) can progress to ventricular fibrillation and cause cardiac arrest.
Diagnosis of atrial fibrillation is similar to that described above (ECG, echocardiography or ultrasound of the heart, Holter daily monitoring, EPI and mapping, and also includes a conversation with the patient (they find out the probable causes of the arrhythmia, how long the person has been suffering from atrial fibrillation, how often and under what conditions the arrhythmia manifests itself), his examination (listen to erratic heartbeats and determine the pulse rate) and transesophageal electrophysiological study is a method of studying the heart, which makes it possible to determine the source and mechanism of development of AF).
Treatment of atrial fibrillation
Only a doctor should prescribe medicine, select doses and restore rhythm!
The goals of drug treatment for AF are: restoration of the correct (sinus) rhythm of the heart, prevention of relapses (repeats) of an attack of AF, control of the heart rate and maintenance of the correct heart rhythm, prevention of thromboembolism. In case of AF, it is first necessary to treat the diseases that led to the development of arrhythmia.
Drug treatment of AF (atrial fibrillation) is similar to that described above and includes: antiarrhythmic drugs, beta blockers, anticoagulant therapy, metabolic drugs,
Surgical treatment of AF (atrial fibrillation):
- Radiofrequency ablation. With frequently recurring attacks or chronic form MAs “cauterize” (using a special electrode) the area of the heart responsible for conducting the impulse, and thereby cause complete blockade in heart. After this, a pacemaker is installed, which sets the heart to the correct rhythm.
- Radiofrequency isolation of pulmonary veins. This is a method of radical elimination of MA (effectiveness is about 60%). The focus of “wrong” excitation, located at the mouth of the pulmonary veins, is isolated from the atria.
New techniques are being developed every year surgical treatment arrhythmias, improve antiarrhythmic drugs, reduce the number side effects; Research continues to develop a universal antiarrhythmic drug. But all this does not give us the right not to be treated on time and correctly.
The longer an arrhythmia lasts, the more likely it is that it will remain for life. Do you need such travel companions? Get rid of them before it's too late...
Attention! All information in the article is provided for informational purposes only and cannot be taken as a guide to self-medication.
Treatment of diseases of the cardiovascular system requires consultation with a cardiologist, a thorough examination, prescription of appropriate treatment and subsequent monitoring of the therapy.
A heart rhythm that originates from the sinus node and not from other areas is called sinus. It is determined both in healthy people and in some patients suffering from heart disease.
Cardiac impulses appear in the sinus node, then disperse through the atria and ventricles, which causes the muscular organ to contract.
Sinus rhythm of the heart on an ECG - what does it mean and how to determine it? There are cells in the heart that create impulse due to a certain number of beats per minute. They are located in the sinus and atrioventricular nodes, as well as in the Purkinje fibers, which make up the tissue of the cardiac ventricles.
Sinus rhythm on the electrocardiogram means that this the impulse is generated precisely by the sinus node(norm – 50). If the numbers are different, then the pulse is generated by another node, which produces a different value for the number of beats.
Normally, a healthy sinus rhythm of the heart is regular with varying heart rates depending on age.
In newborns, the rhythm frequency can be 60 - 150 per minute. With growing up, the rhythm frequency slows down and by 6-7 years it approaches adult levels. In healthy adults, the rate is 60–80 per 60 seconds.
Normal indicators in the cardiogram
What to pay attention to when performing electrocardiography:
- The P wave on the electrocardiogram necessarily precedes the QRS complex.
- The PQ distance corresponds to 0.12 seconds - 0.2 seconds.
- The shape of the P wave is constant in each lead.
- In an adult, the rhythm frequency corresponds to 60 – 80.
- The P–P distance is similar to the R–R distance.
- The P wave in a normal state should be positive in the second standard lead, negative in lead aVR. In all other leads (these are I, III, aVL, aVF), its shape may vary depending on its direction electrical axis. Typically, P waves are positive in both lead I and aVF.
- In leads V1 and V2, the P wave will be 2-phase, sometimes it can be predominantly positive or predominantly negative. In leads V3 to V6, the wave is predominantly positive, although there may be exceptions depending on its electrical axis.
- Normally, each P wave must be followed by a QRS complex and a T wave. The PQ interval in adults has a value of 0.12 seconds - 0.2 seconds.
Sinus rhythm together with the vertical position of the electrical axis of the heart(EOS) shows that these parameters are within normal limits. The vertical axis shows the projection of the position of the organ in the chest. Also, the position of the organ can be in semi-vertical, horizontal, semi-horizontal planes.
Rotations of the organ from the transverse axis can be determined, which only indicate the structural features of a particular organ.
When the ECG registers sinus rhythm, it means that the patient does not yet have problems with the heart. Very It is important not to worry or be nervous when undergoing the examination to avoid receiving false data.
You should not do the examination immediately after physical activity. or after the patient has climbed to the third to fifth floor on foot. You should also warn the patient that you should not smoke half an hour before the examination, so as not to get unreliable results.
Violations and criteria for their determination
If the description contains the phrase: sinus rhythm disturbances, then it is registered blockade or arrhythmia. An arrhythmia is any disruption in the rhythm sequence and its frequency.
Blockades can be caused if the transmission of excitation from nerve centers to the heart muscle. For example, rhythm acceleration shows that during a standard sequence of contractions, the heart rhythms are accelerated.
If a phrase about an unstable rhythm appears in the conclusion, this means that this is a manifestation of a small or presence of sinus bradycardia. Bradycardia has a detrimental effect on a person’s condition, since the organs do not receive the amount of oxygen required for normal activity.
Unpleasant symptoms of this disease may include dizziness, pressure changes, discomfort and even chest pain and shortness of breath.
If an accelerated sinus rhythm is recorded, then most likely this is a manifestation tachycardia. This diagnosis is made when the number of heart beats exceeds 110 beats.
Interpretation of results and diagnosis
To make a diagnosis of arrhythmia, you should compare the obtained indicators with the norm indicators. Heart rate for 1 minute should not be more than 90. To determine this indicator, you need to divide 60 (seconds) by duration R-R interval (also in seconds) or multiply the number of QRS complexes in 3 seconds (a section of tape equal to 15 cm in length) by 20.
In this way, the following deviations can be diagnosed:
- – Heart rate/min is less than 60, sometimes fixed P-P increase interval up to 0.21 seconds.
- Tachycardia– Heart rate increases to 90, although other signs of rhythm remain normal. Often there can be an oblique depression of the PQ segment, and an upward depression of the ST segment. It may look like an anchor. If the heart rate rises above 150 beats per minute, stage 2 blockades occur.
- Arrhythmia is an irregular and unstable sinus rhythm of the heart when R-R intervals differ by more than 0.15 seconds, which is due to changes in the number of beats per inhalation and exhalation. Often found in children.
- Rigid rhythm– excessive regularity of contractions. R-R differs by less than 0.05 sec. This may occur due to a defect in the sinus node or a violation of its neurovegetative regulation.
Reasons for deviations
The most common causes of rhythm disturbances are:
- excessive alcohol abuse;
- smoking;
- long-term use of glycosides and antiarrhythmic drugs;
- bulging of the mitral valve;
- pathologies of thyroid function, including thyrotoxicosis;
- heart failure;
- infectious lesions of the valves and other parts of the heart - his disease is quite specific);
- overload: emotional, psychological and physical.
Additional Research
If the doctor, when examining the results, sees that the length of the area between the P waves, as well as their height, are unequal, it means sinus rhythm is weak.
To determine the cause, the patient may be advised to undergo additional diagnostics: pathology of the node itself or problems of the nodal autonomic system can be identified.
Additional examination is prescribed when the rhythm is lower than 50 and stronger than 90.
For uninterrupted operation heart to the body vitamin D needed, which is contained in parsley, chicken eggs, salmon, milk.
If you plan your diet correctly and adhere to a daily routine, you can achieve long and uninterrupted functioning of the heart muscle and not worry about it until you are very old.
Finally, we invite you to watch a video with questions and answers about heart rhythm disturbances:
Human heart in normal conditions beats evenly and regularly. The heart rate per minute ranges from 60 to 80 beats. This rhythm is set by the sinus node, which is also called the pacemaker. It contains pacemaker cells, from which excitation is transmitted further to other parts of the heart, namely to the atrioventricular node, and to the His bundle directly in the tissue of the ventricles.
This anatomical and functional division is important from the point of view of the type of a particular disorder, because a block in the conduction of impulses or acceleration of impulses can occur in any of these areas.
Heart rhythm disturbances are called and are conditions when the heart rate becomes less than normal (less than 60 per minute) or more than normal (more than 80 per minute). Also, arrhythmia is a condition when the rhythm is irregular (irregular, or non-sinus), that is, it comes from any part of the conduction system, but not from the sinus node.
Different types of rhythm disturbances occur in different percentages:
- Thus, according to statistics, the lion's share of rhythm disturbances with the presence of underlying cardiac pathology are atrial and ventricular, which occur in 85% of cases in patients with coronary artery disease.
- In second place in frequency are paroxysmal and permanent form atrial fibrillation, which occurs in 5% of cases in people over 60 years of age and in 10% of cases in people over 80 years of age.
Nevertheless, Disturbances in the functioning of the sinus node are even more common, in particular, and those that arose without heart pathology. Probably every inhabitant of the planet has experienced stress caused by stress or emotions. Therefore, these types of physiological abnormalities statistical significance Dont Have.
Classification
All rhythm and conduction disorders are classified as follows:
- Heart rhythm disturbances.
- Conduction disorders in the heart.
In the first case, as a rule, there is an acceleration of the heart rate and/or irregular contraction of the heart muscle. In the second, the presence of blockades is noted varying degrees with or without slowing down the rhythm.
Generally The first group includes disorders of the formation and conduction of impulses:
The second group of conduction disorders includes blocks () on the path of impulses, manifested by intraatrial block, 1, 2 and 3 degrees and bundle branch block.
Causes of heart rhythm disturbances
Rhythm disturbances can be caused not only by serious heart pathology, but also physiological characteristics body. For example, sinus tachycardia can develop during fast walking or running, as well as after playing sports or after strong emotions. Respiratory bradyarrhythmia is a variant of the norm and consists of an increase in contractions when inhaling and a decrease in heart rate when exhaling.
However, such rhythm disturbances, which are accompanied by atrial fibrillation (atrial fibrillation and flutter), extrasystole and paroxysmal types tachycardias, in the vast majority of cases, develop against the background of diseases of the heart or other organs.
Diseases that cause rhythm disturbances
Pathology of the cardiovascular system occurring against the background of:
- , including acute and transferred ones,
- , especially with frequent crises and long-term,
- (structural changes normal myocardial anatomy) due to the above diseases.
Non-cardiac diseases:
- Stomach and intestines, such as stomach ulcers, chronic cholecystitis and etc,
- Acute poisoning,
- Active pathology of the thyroid gland, in particular hyperthyroidism (increased secretion of thyroid hormones into the blood),
- Dehydration and disturbances in blood electrolyte composition,
- Fever, severe hypothermia,
- Alcohol poisoning
- Pheochromocytoma is a tumor of the adrenal glands.
In addition, there are risk factors that contribute to the occurrence of rhythm disturbances:
- Obesity,
- Bad habits,
- Age over 45 years,
- Concomitant endocrine pathology.
Do cardiac arrhythmias manifest themselves in the same way?
All rhythm and conduction disorders clinically manifest themselves differently in different patients. Some patients do not feel any symptoms and learn about the pathology only after scheduled ECG. This proportion of patients is insignificant, since in most cases patients note obvious symptoms.
Thus, rhythm disturbances accompanied by rapid heartbeat (from 100 to 200 per minute), especially paroxysmal forms, are characterized by a sharp sudden onset and interruptions in the heart, lack of air, pain in the sternum.
Some conduction disorders, such as fascicular blockades, do not appear in any way and are recognized only on an ECG. Sinoatrial and atrioventricular blockades of the first degree occur with a slight decrease in heart rate (50-55 per minute), which is why clinically they can manifest only slight weakness and increased fatigue.
Blockades of the 2nd and 3rd degrees are manifested by severe bradycardia (less than 30-40 per minute) and are characterized by short-term attacks of loss of consciousness, called MES attacks.
In addition, any of the listed conditions may be accompanied by a general severe condition with cold sweat, intense pain in the left half of the chest, decreased blood pressure, general weakness and loss of consciousness. These symptoms are caused by impaired cardiac hemodynamics and require close attention from an emergency physician or clinic.
How to diagnose pathology?
Establishing a diagnosis of rhythm disturbance is not difficult if the patient presents typical complaints. Before initial examination Doctor, the patient can independently count his pulse and evaluate certain symptoms.
However The type of rhythm disturbances can be determined only by a doctor after, since each species has its own signs on the electrocardiogram.
For example, extrasystoles are manifested by altered ventricular complexes, paroxysm of tachycardia - by short intervals between complexes, atrial fibrillation - by an irregular rhythm and heart rate of more than 100 per minute, sinoatrial block - by lengthening of the P wave, reflecting the conduction of the impulse through the atria, atrioventricular block - by lengthening the interval between the atria and ventricular complexes, etc.
In any case, only a cardiologist or therapist can correctly interpret changes in the ECG. Therefore, when the first symptoms of rhythm disturbance appear, the patient should seek medical help as soon as possible.
In addition to an ECG, which can be performed upon the arrival of an ambulance team at the patient’s home, additional examination methods may be needed. They are prescribed in the clinic, if the patient was not hospitalized, or in the cardiology (arrhythmology) department of the hospital, if the patient had indications for hospitalization. In most cases, patients are hospitalized because even a mild heart rhythm disorder can be a precursor to a more serious, life-threatening rhythm disorder. The exception is sinus tachycardia, since it is often stopped with the help of tablet drugs even at the age of prehospital stage, and generally does not pose a threat to life.
From additional methods diagnostics usually indicate the following:
- during the day (according to Holter),
- Samples from physical activity(walking on stairs, walking on a treadmill - treadmill test, cycling - ),
- Transesophageal ECG to clarify the location of the rhythm disturbance,
- in the case when a rhythm disturbance cannot be registered using a standard cardiogram, and it is necessary to stimulate the heart contractions and provoke a rhythm disturbance in order to find out its exact type.
In some cases, an MRI of the heart may be required, for example, if the patient is suspected of having a heart tumor, myocarditis, or a scar after a myocardial infarction that is not reflected in the cardiogram. A method such as is a mandatory research standard for patients with rhythm disturbances of any origin.
Treatment of rhythm disturbances
Treatment for rhythm and conduction disorders varies depending on the type and the cause that caused it.
So, for example, in the case of coronary heart disease, the patient receives nitroglycerin (thromboAss, aspirin cardio) and means to normalize higher level cholesterol in the blood (atorvastatin, rosuvastatin). For hypertension, the prescription of antihypertensive drugs (enalapril, losartan, etc.) is justified. In the presence of chronic heart failure, diuretics (Lasix, Diacarb, Diuver, Veroshpiron) and cardiac glycosides (digoxin) are prescribed. If the patient has a heart defect, he may be indicated surgical correction vice.
Regardless of the reason, urgent Care in the presence of rhythm disturbances in the form of atrial fibrillation or paroxysmal tachycardia, consists of administering rhythm-restoring (antiarrhythmics) and rhythm-slowing drugs to the patient. The first group includes drugs such as panangin, asparkam, novocainamide, cordarone, strophanthin for intravenous administration.
For ventricular tachycardia, lidocaine is administered intravenously, and for extrasystole, betalocaine is administered in the form of a solution.
Sinus tachycardia can be stopped by taking anaprilin under the tongue or egilok (Concor, Coronal, etc.) orally in tablet form.
Bradycardia and blockades require completely different treatment. In particular, prednisolone, aminophylline, atropine are administered intravenously to the patient, and in case of low blood pressure, mesaton and dopamine along with adrenaline. These drugs “accelerate” the heart rate and make the heart beat faster and stronger.
Are there possible complications of heart rhythm disturbances?
Heart rhythm disturbances are dangerous not only because blood circulation throughout the body is disrupted due to improper functioning of the heart and decreased cardiac output, but also the development of sometimes dangerous complications.
Most often, patients develop against the background of one or another rhythm disturbance:
- Collapse. It manifests itself as a sharp drop in blood pressure (below 100 mmHg), general severe weakness and pallor, pre-syncope or fainting. It can develop both as a result of a direct rhythm disturbance (for example, during an attack of MES), and as a result of the administration of antiarrhythmic drugs, for example, procainamide during atrial fibrillation. In the latter case, this condition is interpreted as drug-induced hypotension.
- Arrhythmogenic shock- arises as a result sharp decline blood flow in internal organs, in the brain and in arterioles skin. It is characterized by the general severe condition of the patient, lack of consciousness, pallor or cyanosis of the skin, pressure below 60 mmHg, and a rare heartbeat. Without timely assistance, the patient may die.
- occurs due to increased thrombus formation in the heart cavity, since when paroxysmal tachycardias the blood in the heart “beats”, like in a mixer. The resulting blood clots can settle on the inner surface of the heart (mural thrombi) or spread throughout blood vessels into the brain, blocking their lumen and leading to severe ischemia of the brain substance. It manifests itself as sudden speech disturbances, unsteadiness of gait, complete or partial paralysis of the limbs.
- occurs for the same reason as a stroke, only as a result of blockage of the pulmonary artery by blood clots. Clinically manifested by severe shortness of breath and suffocation, as well as bluish discoloration of the skin of the face, neck and chest skin above the level of the nipples. At complete obstruction pulmonary vessel, the patient experiences sudden death.
- Acute myocardial infarction due to the fact that during an attack of tachyarrhythmia the heart beats at a very high frequency, and the coronary arteries are simply not able to provide the necessary blood flow to the heart muscle itself. Oxygen deficiency occurs in the cardiac tissues, and an area of necrosis, or death of myocardial cells, forms. Manifests sharp pain behind the sternum or in the chest on the left.
- Ventricular fibrillation, and clinical death . More often they develop with paroxysm of ventricular tachycardia, which turns into ventricular fibrillation. In this case, it is completely lost contractility myocardium, and the vessels do not receive an adequate amount of blood. A few minutes after fibrillation, the heart stops and clinical death develops, which, without timely assistance, turns into biological death.
In a small number of cases, the patient immediately develops a rhythm disturbance, any of the complications and death. This condition is included in the concept of sudden cardiac death.
Forecast
The prognosis for rhythm disturbances in the absence of complications and in the absence of organic heart pathology is favorable. Otherwise, the prognosis is determined by the degree and severity of the underlying pathology and the type of complications.
Heart rhythm and factors influencing it. The heart rhythm, i.e. the number of contractions per minute, depends mainly on functional state vagus and sympathetic nerves. When the sympathetic nerves are stimulated, the heart rate increases. This phenomenon is called tachycardia. When excited vagus nerves heart rate decreases - bradycardia. The rhythm of the heart can change under the influence of humoral influences, in particular the temperature of the blood flowing to the heart. Local irritation by heat of the area of the right atrium (localization of the leading node) leads to an increase in heart rate; when cooling this area of the heart, the opposite effect is observed. Local irritation by heat or cold of other parts of the heart does not affect the heart rate. However, it can change the speed of excitations through the conduction system of the heart and affect the strength of heart contractions.
Heart rate healthy person depends on age.
What are the indicators of cardiac activity?
Indicators of cardiac activity. Indicators of cardiac performance are systolic and cardiac output.
Systolic, or stroke, volume of the heart is the volume of blood that comes from the ventricle in one systole. The size of the systolic volume depends on the size of the heart, the condition of the myocardium and the body. In a healthy adult at relative rest, the systolic volume of each ventricle is approximately 70-80 ml. Thus, when the ventricles contract in arterial system 120-160 ml of blood arrives.
Cardiac minute volume is the amount of blood that the heart pumps into the pulmonary trunk and aorta in 1 minute. The minute volume of the heart is the product of the systolic volume and the heart rate per minute. On average, the minute volume is 3-5 liters. Systolic and cardiac output characterizes the activity of the entire circulatory system.
Assessment of the functional state of the body, taking into account the level of their physical activity
It is known that there is a stage in the formation of regulatory mechanisms of the cardiovascular system, which is manifested in the nature of its response to the same impact in different periods of postnatal development (Frolkis V.V., 1975). In this regard, the dynamics of the features of indicators of autonomic regulation of HR in individuals of primary and secondary school age in formed groups with different levels of motor activity. Features of changes in SR regulation during at different levels motor activity is predominantly determined not by the age of the student, but by the tone of the ANS. This was consistent with the idea that the initial autonomic tone is one of the important characteristics, determining the type of response (Kaznacheev V.P., 1980). Because of this, the features of changes in SR parameters in groups among schoolchildren of different ages, were associated mainly with the fact that in the older school age among persons with regulation unusual for them, persons with sympathicotonia predominate, and at primary school age – with vagotonia.
Since changes in the regulation of SR have common dynamics for individuals with the same ANS tone, regardless of their age, then, therefore, if we take into account the initial ANS tone when analyzing the body’s response to motor activity, no need for selection age groups. Therefore, to analyze changes in the physical activity of the body in schoolchildren in each of the groups with different motor activity, three subgroups of individuals with different initial ANS tone were identified - eutonics, sympathotonics and vagotonics.
In group 1 (with a lower load), it turned out that people with eutonia had no significant changes in FS. Moreover, in 39% of people with eutonia it was characterized by satisfactory adaptation, in 33% - by strained adaptation mechanisms, and in 28% - by unsatisfactory adaptation.
It can be assumed that the muscle load in this group did not have an effect on individuals with eutonia due to its insignificance. However, it should be noted that according to the literature (Iskakova Z.B., 1991; Antropova M.V. et al., 1997), by the end school year Schoolchildren develop tension in their regulatory systems, and since the completion of our research occurred in the middle of the second half of the school year, we can talk about leveling out this tension due to physical activity. This indicated a stabilizing effect of motor activity on the characteristics of autonomic regulation.
In the majority of people with sympathicotonia (73%), the body's physical function significantly improved and began to be characterized by satisfactory adaptation. The same was observed in 50% of individuals with vagotonia. However, 30% of people with vagotonia retained FS, which was characterized by tension in adaptation mechanisms, and in 20%, unsatisfactory adaptation.
The analysis showed that in group 1 (with less load) the proportion of people with different FS changed significantly compared to the beginning of the study. The proportion of people with satisfactory adaptation has increased significantly, and the number of people with strained adaptation mechanisms and unsatisfactory adaptation has significantly decreased. The observed dynamics of physical activity in the group with low muscle load was apparently associated not with the training effect, but with the development of favorable nonspecific adaptive reactions in the body. This is consistent with the studies of a number of authors (Garkavi L. Kh., Kvakina E. B., Ukolova M. A., 1990; Ulyanov V. I., 1995; Fleshner M., 1999).
As a result of the characteristics of the body's physical function in group 2 (with a higher load), it turned out that significant changes in physical function occurred only in individuals with eutonia. The number of eutonics with satisfactory adaptation increased from 30% to 70%. Persons characterized by unsatisfactory adaptation have completely disappeared.
Among persons with sympathicotonia and vagotonia, no significant changes in FS occurred. At the same time, the majority of individuals (74%) with sympathicotonia retained FS, characterized by tension in adaptation mechanisms. The sample of persons with vagotonia consisted of three parts, similar in size: persons with satisfactory adaptation - 31%, with strained adaptation mechanisms - 29%, with unsatisfactory adaptation - 40%.
The lack of improvement in physical activity in individuals with vagotonia and sympathicotonia in group 2 (with a higher load) indicated that they require more careful planning of motor activity depending on the body's physical activity.
Thus, this indicates that the formation adaptive reactions significantly depended on the individual characteristics of autonomic regulation and the volume of muscle load. Thus, in the group with lower loads, the formation of adaptive reactions depended to a lesser extent on the nature of differentiation of the type of autonomic regulation. At the same time, in the group with a higher load, satisfactory adaptation was formed only in individuals with sufficiently plastic autonomic regulation, and in individuals with a strictly defined type of regulation, adaptive changes were observed to a much lesser extent.
The results obtained develop an understanding of the formation of mechanisms of autonomic regulation of heart rate in ontogenesis and can be used to assess the adequacy of various types of exposure to the individual adaptive capabilities of the body.
Heart rhythm disturbances
Heart rhythm disturbances are a very complex branch of cardiology. The human heart works throughout life. It contracts and relaxes 50 to 150 times per minute. During the systole phase, the heart contracts, ensuring blood flow and delivery of oxygen and nutrients throughout the body. During the diastole phase it rests. Therefore, it is very important that the heart contracts at regular intervals. If the systole period is shortened, the heart does not have time to fully provide the body with blood movement and oxygen. If the diastole period is shortened, the heart does not have time to rest. Heart rhythm disturbance is a disturbance in the frequency, rhythm and sequence of contractions of the heart muscle. Cardiac muscle - the myocardium consists of muscle fibers. There are two types of these fibers: working myocardium or contractile, conducting myocardium that provides contraction, creating an impulse to contract the working myocardium and ensuring the conduction of this impulse. Contractions of the heart muscle are provided by electrical impulses arising in the sinoauricular or sinus node, which is located in the right atrium. Electrical impulses then travel along the conductive fibers of the atria to the atrioventricular node, located in the lower part of the right atrium. The bundle of His originates from the atrioventricular node. It runs in the interventricular septum and is divided into two branches - the right and left bundle branches. The branches of the His bundle, in turn, are divided into small fibers - Purkinje fibers, through which the electrical impulse reaches the muscle fibers. Muscle fibers contract under the influence of an electrical impulse in systole and relax in its absence in diastole. The frequency of the normal (sinus) contraction rhythm is from about 50 contractions during sleep, at rest, to 150-160 during physical and psycho-emotional stress, and when exposed to high temperatures.
The endocrine system, through the hormones contained in the blood, and the autonomic system have a regulatory effect on the activity of the sinus node. nervous system- its sympathetic and parasympathetic divisions. An electrical impulse in the sinus node occurs due to the difference in the concentrations of electrolytes inside and outside the cell and their movement across the cell membrane. The main participants in this process are potassium, calcium, chlorine and, to a lesser extent, sodium. The causes of heart rhythm disturbances are not fully understood. It is believed that the main two reasons are changes in nervous and endocrine regulation or functional disorders, and anomalies in the development of the heart, its anatomical structure - organic disorders. Often there are combinations of these underlying causes. An increase in heart rate of more than 100 per minute is called sinus tachycardia. In this case, the full contractions of the heart muscle and the cardiac complexes on the electrocardiogram do not change, an increased rhythm is simply recorded. This can be a healthy person’s reaction to stress or physical activity, but it can also be a symptom of heart failure, various poisonings, and thyroid diseases. A decrease in heart rate less than 60 per minute is called sinus bradycardia. Cardiac complexes on the ECG also do not change. This condition can occur in well-trained physically people (athletes). Bradycardia is also accompanied by diseases of the thyroid gland, brain tumors, mushroom poisoning, hypothermia, etc. Disturbances in cardiac conduction and rhythm are very common complications of cardiovascular diseases. The most common heart rhythm disturbances are:
Extrasystole (extraordinary contraction)
Atrial fibrillation (completely irregular rhythm)
Paroxysmal tachycardia (sharp increase in heart rate from 150 to 200 beats per minute).
The classification of rhythm disturbances is very complex. Arrhythmias and blockades can occur anywhere in the conduction system of the heart. Their type depends on the place of occurrence of arrhythmias or blockades.
Extrasystoles or atrial fibrillation are felt by the patient as palpitations, the heart beats faster than usual or there are interruptions in the heart.
If the patient feels fading, cardiac arrest, and at the same time he experiences dizziness and loss of consciousness, most likely the patient has a heart rhythm block or bradycardia (decreased heart rate). If any cardiac arrhythmia is detected in the patient, it is necessary to carry out full examination to clarify the cause of arrhythmia. The main method for diagnosing heart rhythm disorders is an electrocardiogram. An ECG helps determine the type of arrhythmia. But some arrhythmias occur sporadically. Therefore, Holter monitoring is used to diagnose them. This study provides an electrocardiogram recording over several hours or days. At the same time, the patient leads a normal lifestyle and keeps a diary, where he notes the actions he performs hourly (sleep, rest, physical activity). When decrypting ECG data electrocardiograms are compared with diary data. The frequency, duration, time of occurrence of arrhythmias and their connection with physical activity are determined, while signs of insufficiency of the blood supply to the heart are analyzed. Echocardiography allows you to identify diseases that contribute to the development of arrhythmias - valve prolapse, congenital and acquired heart defects, cardiomyopathies, etc. More are used modern methods research:
Endocardial (from the inner cavity of the heart)
Transesophageal electrophysiological research methods
Heart rhythm and factors influencing it. The heart rhythm, i.e. the number of contractions per minute, depends mainly on the functional state of the vagus and sympathetic nerves. When the sympathetic nerves are stimulated, the heart rate increases. This phenomenon is called tachycardia. When the vagus nerves are stimulated, the heart rate decreases - bradycardia.
The state of the cerebral cortex also affects the heart rhythm: with increased inhibition, the heart rhythm slows down, with increased excitatory process it is stimulated.
The rhythm of the heart can change under the influence of humoral influences, in particular the temperature of the blood flowing to the heart. Experiments have shown that local irritation of the region of the right atrium with heat (localization of the leading node) leads to an increase in heart rate; when cooling this region of the heart, the opposite effect is observed. Local irritation by heat or cold of other parts of the heart does not affect the heart rate. However, it can change the speed of excitations through the conduction system of the heart and affect the strength of heart contractions.
The heart rate in a healthy person depends on age. These data are presented in the table.
What are the indicators of cardiac activity?
Indicators of cardiac activity. Indicators of cardiac performance are systolic and cardiac output.
Systolic, or stroke, volume of the heart- this is the amount of blood that the heart releases into the corresponding vessels with each contraction. The size of the systolic volume depends on the size of the heart, the condition of the myocardium and the body. In a healthy adult at relative rest, the systolic volume of each ventricle is approximately 70-80 ml. Thus, when the ventricles contract, 120-160 ml of blood enters the arterial system.
Minute volume of the heart- this is the amount of blood that the heart ejects into the pulmonary trunk and aorta in 1 minute. The minute volume of the heart is the product of the systolic volume and the heart rate per minute. On average, the minute volume is 3-5 liters.
Systolic and cardiac output characterizes the activity of the entire circulatory system.
4. External manifestations of heart activity.
How can you determine the work of the heart without special equipment?
There is data by which the doctor judges the work of the heart by external manifestations its activities, which include the apical impulse, heart sounds. More details about this data:
Apex impulse. During ventricular systole, the heart performs a rotational movement, turning from left to right. The apex of the heart rises and presses on chest in the area of the fifth intercostal space. During systole, the heart becomes very dense, so pressure of the apex of the heart on the intercostal space can be seen (bulging, protrusion), especially in thin subjects. The apical impulse can be felt (palpated) and thereby determined its boundaries and strength.
Heart sounds- These are sound phenomena that occur in the beating heart. There are two tones: I-systolic and II-diastolic.
Systolic tone. The atrioventricular valves are mainly involved in the origin of this tone. During ventricular systole, the atrioventricular valves close, and vibrations of their valves and the tendon threads attached to them cause the first sound. In addition, sound phenomena that occur during contraction of the ventricular muscles take part in the origin of the first tone. According to its sound characteristics, the first tone is drawn-out and low.
Diastolic tone occurs at the beginning of ventricular diastole during the protodiastolic phase, when the semilunar valves close. The vibration of the valve flaps is the source of sound phenomena. According to the sound characteristics, tone II is short and high.
Also, the work of the heart can be judged by the electrical phenomena that occur in it. They are called cardiac biopotentials and are obtained using an electrocardiograph. They are called electrocardiograms.
