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 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:
Apical impulse. During ventricular systole, the heart performs a rotational movement, turning from left to right. The apex of the heart rises and presses on the 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.
Decoding an ECG is the job of a knowledgeable doctor. This method of functional diagnostics evaluates:
- heart rate - the state of the generators of electrical impulses and the state of the heart system conducting these impulses
- condition of the heart muscle itself (myocardium), the presence or absence of inflammation, damage, thickening, oxygen starvation, electrolyte imbalance
However, modern patients often have access to their medical documents, in particular, to electrocardiography films on which medical reports are written. With their diversity, these records can reach even the most balanced but ignorant person. After all, the patient often does not know for certain how dangerous to life and health is what is written on the back of the ECG film by the hand of a functional diagnostician, and there are still several days before an appointment with a therapist or cardiologist.
To reduce the intensity of passions, we immediately warn readers that with not a single serious diagnosis (myocardial infarction, acute rhythm disturbances), a functional diagnostician will not let a patient leave the office, but, at a minimum, will send him for a consultation with a fellow specialist right there. About the rest of the “open secrets” in this article. In all unclear cases of pathological changes in the ECG, ECG monitoring, 24-hour monitoring (Holter), ECHO cardioscopy (ultrasound of the heart) and stress tests (treadmill, bicycle ergometry) are prescribed.
Numbers and Latin letters in ECG interpretation
PQ- (0.12-0.2 s) – atrioventricular conduction time. Most often it lengthens against the background of AV blockade. Shortened in CLC and WPW syndromes.
P – (0.1s) height 0.25-2.5 mm describes atrial contractions. May indicate their hypertrophy.
QRS – (0.06-0.1s) -ventricular complex
QT – (no more than 0.45 s) lengthens with oxygen starvation (myocardial ischemia, infarction) and the threat of rhythm disturbances.
RR - the distance between the apices of the ventricular complexes reflects the regularity of heart contractions and makes it possible to calculate heart rate.
The interpretation of the ECG in children is presented in Fig. 3
Heart Rate Description Options
Sinus rhythm
This is the most common inscription found on an ECG. And, if nothing else is added and the frequency (HR) is indicated from 60 to 90 beats per minute (for example, HR 68`) - this is the best option, indicating that the heart works like a clock. This is the rhythm set by the sinus node (the main pacemaker that generates electrical impulses that cause the heart to contract). At the same time, sinus rhythm implies well-being, both in the state of this node and the health of the conduction system of the heart. Denies the absence of other records pathological changes heart muscle and means that the ECG is normal. Except sinus rhythm, may be atrial, atrioventricular or ventricular, indicating that the rhythm is set by the cells in these parts of the heart and is considered pathological.
Sinus arrhythmia
This is a normal variant in young people and children. This is a rhythm in which impulses leave the sinus node, but the intervals between heart contractions are different. This may be due to physiological changes (respiratory arrhythmia, when heart contractions slow down during exhalation). Approximately 30% of sinus arrhythmias require observation by a cardiologist, as they are at risk of developing more serious rhythm disturbances. These are arrhythmias after rheumatic fever. Against the background of myocarditis or after it, against the background infectious diseases, heart defects and in persons with a family history of arrhythmias.
Sinus bradycardia
These are rhythmic contractions of the heart with a frequency of less than 50 per minute. In healthy people, bradycardia occurs, for example, during sleep. Bradycardia also often occurs in professional athletes. Pathological bradycardia may indicate sick sinus syndrome. In this case, bradycardia is more pronounced (heart rate from 45 to 35 beats per minute on average) and is observed at any time of the day. When bradycardia causes pauses in heart contractions of up to 3 seconds during the day and about 5 seconds at night, leads to disturbances in the supply of oxygen to tissues and is manifested, for example, by fainting, an operation is indicated to install a cardiac pacemaker, which replaces the sinus node, imposing a normal rhythm of contractions on the heart. 
Sinus tachycardia
Heart rate more than 90 per minute is divided into physiological and pathological. In healthy people, sinus tachycardia is accompanied by physical and emotional stress, drinking coffee, sometimes strong tea or alcohol (especially energy drinks). It is short-lived and after an episode of tachycardia, the heart rate returns to normal within a short period of time after stopping the load. At pathological tachycardia palpitations bother the patient at rest. Its causes include fever, infections, blood loss, dehydration, anemia,. The underlying disease is treated. Sinus tachycardia is stopped only in case of a heart attack or acute coronary syndrome.
Extarsystole
These are rhythm disturbances in which foci outside the sinus rhythm give extraordinary cardiac contractions, after which there is a pause of twice the length, called compensatory. In general, the patient perceives heartbeats as uneven, rapid or slow, and sometimes chaotic. The most worrying thing is the dips in heart rate. May occur in the form of tremors, tingling, feelings of fear and emptiness in the stomach.
Not all extrasystoles are dangerous to health. Most of them do not lead to significant circulatory disorders and do not threaten either life or health. They can be functional (against the background of panic attacks, cardioneurosis, hormonal imbalances), organic (with ischemic heart disease, heart defects, myocardial dystrophy or cardiopathy, myocarditis). Intoxication and heart surgery can also lead to them. Depending on the place of occurrence, extrasystoles are divided into atrial, ventricular and anthrioventricular (arising in the node at the border between the atria and ventricles).
- Single extrasystoles most often rare (less than 5 per hour). They are usually functional and do not interfere with normal blood flow.
- Paired extrasystoles two each accompany a certain number of normal contractions. Such rhythm disturbances often indicate pathology and require further examination (Holter monitoring).
- Allorhythms - more complex types extrasystoles. If every second contraction is an extrasystole, this is bigymenia, if every third contraction is trigymenia, every fourth is quadrigymenia.
It is customary to divide ventricular extrasystoles into five classes (according to Lown). They are assessed at daily ECG monitoring, since the results of a regular ECG may not show anything in a few minutes.
- Class 1 - single rare extrasystoles with a frequency of up to 60 per hour, emanating from one focus (monotopic)
- 2 – frequent monotopic more than 5 per minute
- 3 – frequent polymorphic ( different shapes) polytopic (from different foci)
- 4a – paired, 4b – group (trigymenia), episodes of paroxysmal tachycardia
- 5 – early extrasystoles
The higher the class, the more serious the violations, although today even grades 3 and 4 do not always require drug treatment. In general, if there are less than 200 ventricular extrasystoles per day, they should be classified as functional and not worry about them. For more frequent cases, ECHO CS is indicated, and sometimes cardiac MRI is indicated. It is not the extrasystole that is treated, but the disease that leads to it.
Paroxysmal tachycardia
In general, a paroxysm is an attack. A paroxysmal increase in rhythm can last from several minutes to several days. In this case, the intervals between heart contractions will be the same, and the rhythm will increase over 100 per minute (on average from 120 to 250). There are supraventricular and ventricular forms of tachycardia. This pathology is based on abnormal circulation of electrical impulses in the conduction system of the heart. This pathology can be treated. Home remedies to relieve an attack:
- holding your breath
- increased forced cough
- immersing face in cold water
WPW syndrome
Wolff-Parkinson-White syndrome is a type of paroxysmal supraventricular tachycardia. Named after the authors who described it. The appearance of tachycardia is based on the presence of an additional nerve bundle between the atria and ventricles, through which a faster impulse passes than from the main pacemaker.
As a result, an extraordinary contraction of the heart muscle occurs. The syndrome requires conservative or surgical treatment(with ineffectiveness or intolerance of antiarrhythmic tablets, with episodes of atrial fibrillation, with concomitant heart defects).
CLC – syndrome (Clerk-Levi-Christesco)
is similar in mechanism to WPW and is characterized by earlier excitation of the ventricles than normal due to an additional bundle along which the nerve impulse travels. The congenital syndrome is manifested by attacks of rapid heartbeat.
Atrial fibrillation
It can be in the form of an attack or permanent shape. It manifests itself in the form of atrial flutter or fibrillation.
Atrial fibrillation
Atrial fibrillation
When flickering, the heart contracts completely irregularly (the intervals between contractions of very different durations). This is explained by the fact that the rhythm is not set by the sinus node, but by other cells of the atria.
The resulting frequency is from 350 to 700 beats per minute. There is simply no full contraction of the atria; contracting muscle fibers do not effectively fill the ventricles with blood.
As a result, the heart’s output of blood deteriorates and organs and tissues suffer from oxygen starvation. Another name for atrial fibrillation is atrial fibrillation. Not all atrial contractions reach the ventricles of the heart, so the heart rate (and pulse) will be either below normal (bradysystole with a frequency of less than 60), or normal (normosystole from 60 to 90), or above normal (tachysystole more than 90 beats per minute ).
An attack of atrial fibrillation is difficult to miss.
- It usually starts with a strong beat of the heart.
- It develops as a series of absolutely irregular heartbeats with a high or normal frequency.
- The condition is accompanied by weakness, sweating, dizziness.
- The fear of death is very pronounced.
- There may be shortness of breath, general agitation.
- Sometimes observed.
- The attack ends with normalization of the rhythm and the urge to urinate, during which a large amount of urine is released.
To stop an attack, they use reflex methods, drugs in the form of tablets or injections, or resort to cardioversion (stimulating the heart with an electric defibrillator). If an attack of atrial fibrillation is not eliminated within two days, the risks of thrombotic complications (thrombembolism) increase pulmonary artery, stroke).
With a constant form of heartbeat flicker (when the rhythm is not restored either against the background of drugs or against the background of electrical stimulation of the heart), they become a more familiar companion to patients and are felt only during tachysystole (rapid, irregular heartbeats). The main task when detecting signs of tachysystole of a permanent form of atrial fibrillation on the ECG is to slow down the rhythm to normosystole without trying to make it rhythmic.
Examples of recordings on ECG films:
- atrial fibrillation, tachysystolic variant, heart rate 160 b'.
- Atrial fibrillation, normosystolic variant, heart rate 64 b'.
Atrial fibrillation can be developed in the program coronary disease heart, against the background of thyrotoxicosis, organic heart defects, with diabetes mellitus, sick sinus syndrome, intoxication (most often with alcohol).
Atrial flutter
These are frequent (more than 200 per minute) regular contractions of the atria and equally regular, but less frequent contractions of the ventricles. In general, flutter is more common in acute form and is better tolerated than flicker, since circulatory disorders are less pronounced. Fluttering develops when:
- organic heart diseases (cardiomyopathies, heart failure)
- after heart surgery
- against the background of obstructive pulmonary diseases
- in healthy people it almost never occurs
Clinically, flutter is manifested by rapid rhythmic heartbeat and pulse, swelling of the neck veins, shortness of breath, sweating and weakness.
Conduction disorders
Normally, having formed in the sinus node, electrical excitation travels through the conduction system, experiencing a physiological delay of a split second in the atrioventricular node. On its way, the impulse stimulates the atria and ventricles, which pump blood, to contract. If in any part of the conduction system the impulse is delayed longer than the prescribed time, then excitation to the underlying sections will come later, and, therefore, the normal pumping work of the heart muscle will be disrupted. Conduction disturbances are called blockades. They can appear like functional disorders, but more often are the results of medicinal or alcohol intoxication And organic diseases hearts. Depending on the level at which they arise, several types are distinguished.
Sinoatrial blockade
When the exit of an impulse from the sinus node is difficult. In essence, this leads to sick sinus syndrome, slowing of contractions to severe bradycardia, impaired blood supply to the periphery, shortness of breath, weakness, dizziness and loss of consciousness. The second degree of this blockade is called Samoilov-Wenckebach syndrome.
Atrioventricular block (AV block)
This is a delay of excitation in the atrioventricular node longer than the prescribed 0.09 seconds. There are three degrees of this type of blockade. The higher the degree, the less often the ventricles contract, the more severe the circulatory disorders.
- In the first, the delay allows each atrial contraction to maintain an adequate number of ventricular contractions.
- The second degree leaves some of the atrial contractions without ventricular contractions. It is described, depending on the prolongation of the PQ interval and the loss of ventricular complexes, as Mobitz 1, 2 or 3.
- The third degree is also called complete transverse blockade. The atria and ventricles begin to contract without interconnection.
In this case, the ventricles do not stop because they obey the pacemakers from the underlying parts of the heart. If the first degree of blockade may not manifest itself in any way and can be detected only with an ECG, then the second is already characterized by sensations of periodic cardiac arrest, weakness, and fatigue. With complete blockades, the manifestations are added brain symptoms(dizziness, spots in the eyes). Morgagni-Adams-Stokes attacks may develop (when the ventricles escape from all pacemakers) with loss of consciousness and even convulsions.
Impaired conduction within the ventricles
In the ventricles to muscle cells the electrical signal propagates through such elements of the conduction system as the trunk of the His bundle, its legs (left and right) and branches of the legs. Blockades can occur at any of these levels, which is also reflected in the ECG. In this case, instead of being simultaneously covered by excitation, one of the ventricles is delayed, since the signal to it bypasses the blocked area.
In addition to the place of origin, there are complete or incomplete blockade, as well as constant and non-permanent. The causes of intraventricular blocks are similar to other conduction disorders (ischemic heart disease, myocarditis and endocarditis, cardiomyopathies, heart defects, arterial hypertension, fibrosis, heart tumors). Also affected are the use of antiarthmic drugs, an increase in potassium in the blood plasma, acidosis, and oxygen starvation.
- The most common is blockade of the anterosuperior branch of the left bundle branch (ALBBB).
- In second place is right leg block (RBBB). This blockade is usually not accompanied by heart disease.
- Left bundle branch block more typical for myocardial lesions. Wherein complete blockade(PBPBB) is worse than incomplete (NBLBB). It sometimes has to be distinguished from WPW syndrome.
- Block of the posteroinferior branch of the left bundle branch may occur in persons with a narrow and elongated or deformed chest. Among pathological conditions, it is more typical for overload of the right ventricle (with pulmonary embolism or heart defects).
The clinical picture of blockades at the levels of the His bundle is not expressed. The picture of the underlying cardiac pathology comes first.
- Bailey's syndrome - two-bundle block (right leg and posterior branch left bundle branch).
Myocardial hypertrophy
With chronic overload (pressure, volume), the heart muscle in certain areas begins to thicken, and the chambers of the heart begin to stretch. On the ECG, such changes are usually described as hypertrophy.
- (LVH) – typical for arterial hypertension, cardiomyopathy, a number of heart defects. But even normally, athletes, obese patients and people engaged in heavy physical labor may experience signs of LVH.
- Right ventricular hypertrophy- an undoubted sign of increased pressure in the pulmonary blood flow system. Chronic cor pulmonale, obstructive pulmonary diseases, cardiac defects (pulmonary stenosis, tetralogy of Fallot, ventricular septal defect) lead to RVH.
- Left atrial hypertrophy (LAH)) – with mitral and aortic stenosis or insufficiency hypertension, cardiomyopathy, after.
- Right atrial hypertrophy (RAH)– with cor pulmonale, tricuspid valve defects, deformities chest, pulmonary pathologies and pulmonary embolism.
- Indirect signs of ventricular hypertrophy is a deviation of the electrical axis of the heart (EOC) to the right or left. The left type of EOS is its deviation to the left, that is, LVH, the right type is RVH.
- Systolic overload- This is also evidence of hypertrophy of the heart. Less commonly, this is evidence of ischemia (in the presence of angina pain).
Changes in myocardial contractility and nutrition
Early ventricular repolarization syndrome
Most often, this is a variant of the norm, especially for athletes and people with congenital high body weight. Sometimes associated with myocardial hypertrophy. Refers to the peculiarities of the passage of electrolytes (potassium) through the membranes of cardiocytes and the characteristics of the proteins from which the membranes are built. It is considered a risk factor for sudden cardiac arrest, but does not provide clinical results and most often remains without consequences.
Moderate or severe diffuse changes in the myocardium
This is evidence of a malnutrition of the myocardium as a result of dystrophy, inflammation () or. Also, reversible diffuse changes accompany disturbances in water and electrolyte balance (with vomiting or diarrhea), taking medications (diuretics), and heavy physical activity.
Nonspecific ST changes
This is a sign of deterioration in myocardial nutrition without severe oxygen starvation, for example, in case of disturbances in the balance of electrolytes or against the background of dyshormonal conditions.
Acute ischemia, ischemic changes, T wave changes, ST depression, low T
This describes reversible changes associated with oxygen starvation myocardium (ischemia). This can be either stable angina or unstable, acute coronary syndrome. In addition to the presence of the changes themselves, their location is also described (for example, subendocardial ischemia). Distinctive feature such changes are their reversibility. In any case, such changes require comparison of this ECG with old films, and if a heart attack is suspected, troponin rapid tests for myocardial damage or coronary angiography. Depending on the type of coronary heart disease, anti-ischemic treatment is selected.
Advanced heart attack
It is usually described:
- by stages: acute (up to 3 days), acute (up to 3 weeks), subacute (up to 3 months), cicatricial (all life after a heart attack)
- by volume: transmural (large focal), subendocardial (small focal)
- by location of heart attacks: there are anterior and anterior septal, basal, lateral, inferior (posterior diaphragmatic), circular apical, posterobasal and right ventricular.
In any case, a heart attack is a reason for immediate hospitalization.
All the variety of syndromes and specific changes on the ECG, the difference in indicators for adults and children, the abundance of reasons leading to the same type ECG changes, do not allow a non-specialist to interpret even the finished conclusion of a functional diagnostician. It is much wiser, having the ECG result in hand, to visit a cardiologist in a timely manner and receive competent recommendations for further diagnosis or treatment of your problem, significantly reducing the risks of emergency cardiac conditions.
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 excited, the 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.
The heart rate in a 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 their level motor 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). Due to this, the features of changes in SR parameters in groups among schoolchildren of different ages, were mainly associated with the fact that at senior school age, among persons with regulation unusual for them, persons with sympathicotonia predominate, and at primary school age, those with vagotonia predominate.
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, there is no need to isolate 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 in persons with eutonia there were 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 persons 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.
Regulatory influence on the activity of the sinus node is exerted by endocrine system, through the hormones contained in the blood and the autonomic 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 abnormalities in the development of the heart and 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, diseases thyroid gland. A decrease in heart rate below 60 beats 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 (not completely correct 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 where arrhythmias or blockades occur.
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). At ECG decoding Electrocardiogram data 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
Cardiac activity disorder are represented mainly by disturbances in the tempo, rhythm or strength of heart contractions. In some cases, they do not affect well-being and ability to work (they are detected by chance), in others they are accompanied by various painful sensations, for example: dizziness, palpitations, pain in the heart area, shortness of breath. Happy Birthday. do not always indicate heart disease. Often they are caused by imperfections or violations nervous regulation cardiac activity in diseases various organs, endocrine glands. Some abnormalities in the activity of the heart can sometimes be observed in practically healthy people. The heart rhythm is normally formed by electrical impulses, which with a frequency of 60-80 per 1 min originate in the so-called sinus node, located in the wall of the right atrium. The rhythm of heart contractions subordinated to these impulses is called sinus. Each of the sinus nodes spreads along the conduction paths, first to both atria, causing them (at the same time being pumped into the ventricles of the heart), then to the ventricles, with the contraction of which blood is pumped into vascular system. This appropriate sequence of contraction of the heart chambers is ensured precisely by sinus rhythm. If the source of the rhythm becomes not the sinus, but another part of the heart (it is called the ectopic source of rhythm, and the rhythm itself is ectopic), then this sequence of contraction of the chambers of the heart is disrupted the more, the further away from the sinus node the ectopic source of rhythm is located (when it is in the ventricles of the heart , they contract earlier than the atria). Ectopic impulses occur with pathological activity of their source and in cases where the sinus node is depressed or its impulses do not excite the ventricles of the heart due to a violation of their conduction (blockade) in the conduction pathways. All these disorders are well recognized using electrocardiography, and many of them can be determined in oneself and in other people by palpating the pulse on the radial artery (in the area of the wrist joint) or on carotid arteries min. (on the anterolateral surfaces of the neck to the right and left of the epiglottis). In healthy people at rest, it is defined as moderately strong arterial filling impulses occurring at approximately equal intervals (regular rhythm) with a frequency of 60-80 beats per 1 The main deviations in the pace and rhythm of the heart include a very slow pace (), an excessively fast pace () and irregularity (arrhythmia) of heart contractions, which can be combined with a slow pace (bradyarrhythmia) or tachycardia (tachyarrhythmia). All these deviations may concern sinus rhythm (sinus bradycardia and tachycardia, sinus arrhythmia ) or generated by ectopic impulses. Of ectopic origin are, for example, such forms of cardiac arrhythmia as premature (extraordinary) contractions of the heart - including group, forming paroxysmal ectopic tachycardia (), as well as complete irregularity of heart contractions in the so-called atrial fibrillation. Rare cuts hearts min. Bradycardia includes a heart rate less than 60 beats per 1 min. This border is conditional. You should not be alarmed if the pulse rate, upon random examination, is within 45-60 per 1 . This rate of heart contractions is often found in completely healthy people, especially often in people engaged in physical labor and athletes, sometimes combined with a decrease blood pressure . In these cases, bradycardia is due to the slowing effect on the impulse of the sinus node in connection with the reconfiguration of the heart to a more economical mode of metabolism and energy in the body. Has a similar origin sinus bradycardia for injuries and diseases of the brain, decreased function of the thyroid gland and adrenal glands. This form of cardiac dysfunction does not require special treatment and disappears during the process of recovery from the disease that caused it. A different attitude should be taken to a pronounced decrease in pulse detected during an attack of chest pain, fainting, or in connection with the patient’s complaints of sudden lightheadedness, severe general weakness, in the form of rare strong heartbeats. In such cases, bradycardia is often ectopic and is most often associated with a blockade of the conduction of excitation impulses from the atria to the ventricles of the heart. The complaints described above (except for the complaint about the chest, which is closer to the cause than to the consequence of bradycardia) usually appear at a heart rate of 40 per 1 min or with significant bradyarrhythmia (with separate pauses between contractions of more than 2 With), and if it is less than 30 in 1 min, then deep and prolonged fainting is possible, sometimes with the appearance of convulsive seizures. In such cases, bradycardia requires emergency treatment, and those around them must organize assistance for the patient with a series of actions, the sequence of which is determined by the severity of the condition and the nature of the patient’s complaints. First of all, the patient should be placed in horizontal position on your back with your legs raised, placing 2 pillows under your feet, and only a roll of a towel or a small pillow under your head (if you have lost it, then it is better to lay it on a hard surface, for example, covered with a blanket). If a patient complains of chest pain, it is necessary to give him 1 tablet or 2 1% solution (on a piece or on a bottle stopper) of nitroglycerin as quickly as possible. After this, waiting for the action of nitroglycerin (2-4 min) or immediately (if there is someone to do this) you need to call ambulance and determine the actions that are possible before her arrival. If the patient has already had similar conditions, then the recommendations received in this case from the doctor earlier are followed. Most often they involve the use of isadrin, 1 tablet of which (0.005 G) should be placed under the patient’s tongue until completely absorbed. At the same time, the pulse quickens, and the patient’s condition improves somewhat after 5-10 min. If an attack of bradycardia occurs for the first time and isadrin was not purchased in advance, the patient should be given orally belladonna extract, crushed into 2 tablets of 0.015 each. G. If the effect is positive, the pulse will begin to increase after 30-40 min. If among your neighbors or those around you there is a person suffering from bronchial asthma, it is advisable to borrow from him a dosed aerosol of isadrin (euspiran) or alupent (asthmopent, ipradol) and irrigate with three doses (i.e., using three finger presses on the head of the inhaler at intervals of 5- 7 With) any of these remedies under the patient's tongue, expecting action after 3-6 min. Most often, ectopic bradycardia occurs in a patient with chronic disease hearts. His first aid kit may contain medications that should absolutely not be given in case of bradycardia; if the patient took them, then from the moment bradycardia occurs they should be immediately discontinued. These medications include (digoxin, celanide, isolanide, lantoside, digitoxin, acedoxin, cordigitate, digitalis leaf powder, lily of the valley), the so-called anaprilin (obzidan, inderal), trazicor (oxprenolol), visken (pindolol), cordanum (talinolol) ), Korgard (nadolol) and many, including amiodarone (cordarone), verapamil (isoptin, finoptin), novocainamide, ethmosin, etatsizin, disopyramide (rhythmylen, rhythmodan), quinidine. Frequent contractions Rare cuts. Athletes who control their heart rate know well that with significant physical activity, its frequency can increase to 140-150 per 1 min. This is a normal phenomenon, indicating that the sinus rhythm regulation system brings it into line with the metabolic rate in the body. Sinus tachycardia during fever has the same nature (for every 1° increase in body temperature, the rate of heart contraction increases by 6-8 beats per 1 min), emotional excitement, after drinking alcohol, with increased thyroid function. With heart defects and cardiac weakness, sinus tachycardia is often compensatory (adaptive). As a sign of imperfect regulation of cardiac activity, sinus tachycardia is possible with physical inactivity, neurocirculatory dystonia, neuroses, various diseases accompanied by autonomic dysfunction. The reason for contacting a doctor, including urgently, is usually not tachycardia, but other signs of diseases in which it is observed. At the same time, you should consult a doctor (as planned) regardless of the severity of other manifestations of the disease in all cases when, on different days under conditions of complete rest, the pulse rate is above 80 per 1 min. Unlike ectopic tachycardia, which occurs in the form of an attack (see below), the heart rate during sinus tachycardia the expression depends on the level of physical activity, and it changes gradually (smoothly) and does not, as a rule, exceed 140 in 1 min. Attack of tachycardia, or paroxysmal tachycardia, refers to conditions that require emergency care, because It reduces the efficiency of the heart, especially if ectopic rhythm does not come from the atria (supraventricular tachycardia), but from the ventricle of the heart (ventricular tachycardia). The attack begins suddenly. Initially, the patient feels a sharply rapid heartbeat, dizziness, and weakness. Sometimes an attack is accompanied by other autonomic disorders: sweating, frequent and profuse urination, increased blood pressure, rumbling in the stomach, etc. The more pronounced these vegetative disorders, which usually frighten the patient, the more favorable the attack, because these disorders occur only with supraventricular tachycardia, most often associated with a disorder of the functions of the nervous system, and not with heart disease. With a prolonged attack, pain often appears, worsening in a lying position (the patient is forced to sit). The attack often goes away on its own (without treatment), and it ends as suddenly as it begins. In case of repeated attacks, medications recommended by the doctor are used to relieve them. If the attack occurs for the first time, you should call an ambulance. Before the doctor arrives, you must, first of all, calm the patient down, relieve the pain that often occurs at the beginning of the attack, and also try to interrupt the attack with some simple techniques. There should be no fuss, much less panic in the behavior of those around the patient; the patient is created with rest conditions in a position that is comfortable for him (lying or half-sitting), and is offered to take what is available at home - valocordin (40-50 drops), preparations of valerian, motherwort, etc., which in itself can stop the attack. Techniques that can help stop an attack include a quick change of body position from vertical to horizontal, straining for 30-50 With, inducing a gag reflex by finger irritation of the pharynx. There are other techniques, but only . He also uses special medications to relieve an attack and recommends medications that the patient should have with him and use independently in case of a recurrence of the attack. Irrhythmic heart contractions. Inequality of intervals between heartbeats and, accordingly, irregular pulse are sometimes observed in practically healthy people. For example, in healthy children and adolescents, often (less often in adults) the intervals between heartbeats differ significantly during inhalation and exhalation, i.e., respiratory sinus arrhythmia is observed. It is not felt in any way, does not interfere with the functioning of the heart, and in all cases is assessed as a variant of the norm. To irregular heartbeats that require special attention, and sometimes special treatment, include extrasystole and. Extrasystole is a contraction of the heart that is extraordinary in relation to the main rhythm. Depending on the location of the ectopic focus of excitation, supraventricular and ventricular extrasystoles are distinguished. Previously, it was believed that extrasystoles were always caused by some disease. In recent years, when recording an electrocardiogram around the clock, it has been established that rare supraventricular extrasystoles also occur in healthy people, but more often they are associated with a violation of the nervous regulation of cardiac activity. Ventricular extrasystoles, as a rule, indicate existing or past heart disease. These two types of extrasystole can be reliably distinguished using electrocardiography, but often a doctor can do this based on the characteristics of the manifestations of extrasystole. The patient can detect an extrasystole when examining the pulse as a premature appearance of a pulse beat, as well as in cases when there are interruptions in the work of the heart (premature contraction followed by an extended pause), “tumbling” of the heart, “bird fluttering” in the chest, etc. The more distinct such sensations are and the more pronounced the sometimes accompanying feelings of fear, anxiety, “fading” of the heart and others discomfort general, the more reason to assume supraventricular extrasystole. Ventricular extrasystoles are rarely felt by the patient, and their presence and quantity are discussed more characteristic changes pulse rhythm. If you suspect that you have supraventricular extrasystole, especially if it occurs rarely (several extrasystoles per day), you should consult a doctor as planned. If the extrasystoles are frequent (one or more per minute) or paired or group (three or more in a row) and appear for the first time, you should immediately consult a doctor, and if they are combined with chest pain or sudden shortness of breath, you should call an ambulance help. For chest pain, before the doctor arrives, the patient should be put to bed and given one nitroglycerin tablet under the tongue. If extrasystole does not occur for the first time, then during periods of its increase, follow the doctor’s recommendations received from him earlier. It should be borne in mind that even frequent extrasystoles do not always require treatment with special antiarrhythmic drugs. With supraventricular extrasystole, the use of sedatives (valocordin, valerian, motherwort, tazepam) is often more effective. Only a doctor can determine the correct treatment program. Atrial fibrillation is a complete irregularity of heart contractions due to the chaotic occurrence of excitation impulses in different parts of the atria. These impulses vary in strength, some of them do not reach the ventricles of the heart at all, others come to them after such a short pause that the ventricles contract before they have time to fill with blood. As a result, the pulse beats not only occur at different intervals, but also have different sizes. Atrial fibrillation can be permanent (with some heart defects, after myocarditis or myocardial infarction) with a normal heart rate or in the form of bradyarrhythmia or tachyarrhythmia. In the latter case, the doctor recommends a treatment aimed at slowing down heart contractions. Persistent arrhythmia is often preceded by paroxysms that last from several minutes to several hours or days. They usually occur in the form of tachyarrhythmia. In this case, the patient suddenly feels an erratic heartbeat, often dizziness, sudden general weakness, shortness of breath, and in some cases these sensations are preceded by chest pain. First aid tactics are almost the same as for paroxysmal tachycardia (see above). The patient should avoid drinking coffee, tea, or smoking. If the patient was taking medications before the attack, then, except for the treatment of angina pectoris (nitroglycerin, nitrong, nitrosorbide, etc.), all medications are immediately discontinued. It is especially unacceptable to take medications such as caffeine, aminophylline, ephedrine, and heart medications before the doctor arrives. 1. Small medical encyclopedia. - M.: Medical encyclopedia. 1991-96 2. First health care. - M.: Great Russian Encyclopedia. 1994 3. Encyclopedic Dictionary medical terms. - M.: Soviet encyclopedia. - 1982-1984.
KIDNEYS- KIDNEYS. Contents: I. Anatomy of P.................... $65 II. Histology P. . ............... 668 III. Comparative Physiology 11......... 675 IV. Pat. Anatomy II................ 680 V. Functional diagnostics 11........ 6 89 VI. Clinic P… I (lat. pulsus blow, push) periodic fluctuations in the volume of blood vessels associated with contractions of the heart, caused by the dynamics of their blood filling and pressure in them during one cardiac cycle. The pulse is determined normally by palpation at all... ... Medical encyclopedia Pulse- Determination of the pulse on the radial artery. Determination of the pulse on the radial artery. Pulse is a jerky oscillation of the walls of blood vessels that occurs as a result of cardiac activity and depends on the release of blood from the heart into the vascular system. Distinguish... ... First aid - popular encyclopedia I Asthma (Greek asthma shortness of breath, suffocation) an attack of suffocation that develops either in connection with an acute narrowing of the lumen of the bronchi, acute bronchial obstruction syndrome (see Bronchial asthma), or as a manifestation of acute cardiac, ... ... Medical encyclopedia Grindelia - Grindelia robusta, powerful Grindelia- From the Aster family (Asteraceae). Perennial herbaceous plant 50-100 cm in height. The stems are straight, branched, with longitudinal grooves, ending in apical flower baskets. Leaves up to 5 cm long, broad-lobed, ovate to... ... Handbook of Homeopathy HEART- HEART. Contents: I. Comparative anatomy.......... 162 II. Anatomy and histology........... 167 III. Comparative Physiology......... 183 IV. Physiology................... 188 V. Pathophysiology................ 207 VI. Physiology, pat.... ... Great Medical Encyclopedia I Medicine Medicine is a system of scientific knowledge and practical activities, the goals of which are to strengthen and preserve health, prolong the life of people, prevent and treat human diseases. To accomplish these tasks, M. studies the structure and... ... Medical encyclopedia HEART DEFECTS- HEART DISEASES. Contents: I. Statistics...................430 II. Individual forms P.S. Bicuspid valve insufficiency. . . 431 Narrowing of the left ventricular orifice......................................436 Narrowing of the aortic orifice... Great Medical Encyclopedia TROPHIC EFFECT- TROPHIC ACTION. The concept of T. of the nervous system penetrated into physiology from the clinic. Practical doctors constantly encountered facts that indicated that the nutrition of organs and tissues is in some undeniable dependence... Great Medical Encyclopedia VVGBTATNVTs-AYA- HEt BHiH S I S YEAR 4 U VEGETATIVE NEGPNAN CIH TFMA III y*ch*. 4411^1. Jinn RI"I ryagtskhsh^chpt* dj ^LbH )
