Ministry of Health of the Russian Federation |
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Nizhny Novgorod State |
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Medical Institute |
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A.V. Suvorov |
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NGMI Publishing House Nizhny Novgorod, 1993
Kiev - 1999.
UDC 616.12-008.3-073.96
Suvorov A.V. Clinical electrocardiography. - Nizhny Novgori
rod. Publishing house NMI, 1993. 124 p. Ill.
Suvorov A. V. Book is a good, complete aid application for doctors of cardiologists, therapists and students of senior courses of Medical institutions for all sections of electrocardiography. Details described the features of ECG records, normal ECG in standard and single-pole reluxers, all types of atrioventricular blockades, blockages of a feet of a beam of Gis, features of ECG in hypertrophy, conductivity disorders, arrhythmias, myocardial infarction, and thromboembolism, brain circulation disorders, etc.
Printed by the decision of the editorial and publishing council HMM
Scientific editor Professor S. S. Belousov
Reviewer Professor A. A. Obukhov
ISVN 5-7032-0029-6
© Suvorov A. V., 1993
Preface
Electrocardiography refers to the informative and most common methods of surveys of patients with heart disease. ECG makes it possible to diagnose diseases and syndromes requiring emergency cardiological care, and above all myocardial infarction, paroxysmal tachyarhythmias, conduction disorders with Morgali-Edems-Stokes syndrome and others. The need for their diagnosis occurs at any time of the day, but, unfortunately, interpretation ECG is significant difficulties for many doctors, and the reason for the weak study of the method at the institute, the lack of courses on the ECG diagnosis in the faculties of the improvement of doctors. It is very difficult to acquire literature on clinical electrocardiography. The author sought to fill this gap.
The electrocardiography benefit was built traditionally: first summarized the electrophysiological bases of electrocardiography, the section of a normal ECG in standard, single-pole and chest leads, the electrical position of the heart is presented in detail. In the section "ECG for Hypertrophy of myocardium" describes general features and criteria for hypertrophy of atrial and ventricles.
When describing the rhythm and conduction disorders, pathogenetic mechanisms for the development of syndromes, clinical manifestations and medical tactics are presented.
The sections on the ECG diagnosis of IBS are covered in detail, especially myocardial infarction, as well as infarction-like diseases that are of great importance to practice.
According to complex ECG, syndromam has developed an algorithm for diagnostic search that facilitates the diagnosis of pathology.
The book is intended for doctors who want independently or with the help of a teacher in a short time to explore the theory and practice of this important area of \u200b\u200bcardiology.
1. Electrocardiogram removal technique
The electrocardiogram is recorded with the help of electrocardiographs. They can be single-channel and multichannel. All electrocardiographs (Fig. 1) consist of an input device (1), the amplifier of the biopotential of the heart (2) and the recorder device (3).
The input device is a master switch with cables of different colors.
Amplifiers have a complex electronic circuit that allows to enhance the biopotentials of the heart a few hundred times. The power supply of the amplifier can be batteries or AC Network. For security reasons when working with an electrocardiograph and to prevent interference, the devices are grounded using a wire, one end of which is attached to a special terminal of an electrocardiograph, and the other to a special contour. In case of its absence, in emergency cases, it is possible to use for grounding (as an exception) tap pipes of central heating.
The registering device translates electrical oscillations into mechanical. The mechanical feathery record is carried out in ink or under copy paper. Recently, a warm record has received widespread.
The bottom line is that the feather is heated by electrical current melts the slick-melting layer of the ribbon, exposing the black base.
To record the ECG patient laid on the couch. To obtain good contact under the electrodes, gauze napkins moistened with saline. Electrodes are applied to the inner surfaces of the lower third of the upper and lower extremities, the red cable is connected to the right hand, black (patient grounding) - to the right leg, yellow color - to the left hand and green cable - to the left lower limb. The chest electrode in the form of a pear with a suction cup is connected to the white cable and is installed in certain positions on the chest.
ECG recording begins with a check male, which should be 10 mm.
IN abandoned 12 assignments are required - three standard, three single-pole and six breasts, III, AVF leaders are desirable to shoot in the inhalation phase. According to the testimony, additional leads are recorded.
IN each assignment should record at least 5 QRS complexes, with arrhythmias one of the assignment (II) is recorded on a long tape. The standard recording speed is 50 mm / s, during arrhythmias to reduce the paper consumption, a speed of 25 mm / s is used. The voltage of QRS complexes can be increased and reduced by 2 times depending on the task of the study.
Application for ECG research is written on a special form or in a journal, which indicates F.I.O., Paul, Hell, the age of the patient, diagnosis. Must be reported on the medicinal
rapy cardiac glycosides, β-blocks. diuretic, electrolytes, antiarrhythmic drugs of the County row, Rawolfia, etc.
2. Electrophysiological bases of electrocardiography
The heart is a hollow muscular organ separated by a longitudinal partition into two halves: left arterial and right venous. The transverse partition divides each half of the heart into two departments: atrium and ventricles. The heart performs certain functions: automatism, excitability, conductivity and contractility.
Automatom - the ability of a conductive heart system to develop pulses independently. In the greatest degree
automatic has a sinus node (center of automatic first order). At rest in it, 60-80 pulses are produced per minute. When pathology, a source of rhythm may be an atrioventricular node (second-order automatic center), it produces 40-60 pulses per minute.
The automatic function has a conductive ventricular system (idiovativericular rhythm). However, a minute is produced only 20-50 pulses (third-order automatic center).
Empathy - the ability of the heart to respond with a reduction in domestic and external stimuli. Normally, excitation and reduction of the heart occur under the influence of pulses from the sinus node.
The pulses may not only be null (from the sinus node), but also heterotopic (from other sections of the conductive heart system). If the heart muscle is in terms of excitation, it does not respond to other pulses (absolute or relative refractory phase). Therefore, the heart muscle cannot be in a state of a tetanic reduction. When myocardial is excited in it, an electromotive force arises in the form of vector quantities, which is written as an electrocardiogram.
Conductivity. Arriving in a sinus unit, the impulse is applied by orthogram on the myocardium of atria, then through an atrioventricular node, a beam of Gis, conductive system of ventricles. The intraventrician conductive system includes the right leg of the GISE beam, the main trunk of the left leg of the Gis beam and its two branches, the front and rear, and ends with Purkinier's voltage, which transmit the pulse to the cells of the contracting myocardium (Fig. 2).
The propagation rate of the excitation wave in the atrium is 1 m / s, in the conductive ventricular system 4 m / s, an atrioventricular node 0.15 m / s. The retrograde conductivity of the pulse is slowed down sharply, an atrioventricular delay makes it possible to reduce the atria before the ventricles. The wounded areas of the conductive system are: Atrioventricular node with AV delay, the right leg of a beam of Gis, the left front branch,
As a result of the pulse, the process of initiation (depolarization) of myocardium at the beginning of the interventricular partition, right and left ventricles begins. The excitation of the right ventricle can begin before (0.02 ") left. B Further depolarization captures myocardia of both ventricles, and the electromotive force (total vector) of the left ventricle is greater than the right
go. The depolarization process comes from the top to the heart of the heart, from endocardium to epicarde.
The process of recovery (repolarization) myocardium begins at epicardium and applies to endocardium. With repolarization, a significantly lower electromotive force (EMF) arises than during depolarization.
The process of depolarization and repolarization of myocardium is accompanied by bioelectric phenomena. It is known that the protein-phidic cage shell has the properties of a semi-permeable membrane. Through the membrane easily penetrate ions K + and phosphates, sulfates, proteins do not penetrate. Since these ions are charged negatively,
they attract positively charged ions to +. The concentration of ions to + inside the cell is 30 times higher than in extracellular fluid. Nevertheless, negative charges are dominated on the inner surface of the membrane. Na + ions are located mainly on the outer surface of the membrane, because the cell membrane is lowered for Na +. The concentration of Na + in extracellular fluid is 20 times higher than inside the cell. Cell potential at rest is equal
but 70-90 mV.
When depolarizing myocardium changes the permeability of cell membranes, sodium ions easily penetrate into the cell and change the charge of the inner surface of the membrane. Due to the fact that Na + goes into the cage, an electrical charge changes on the outer surface of the membrane. Depolarization changes the charge of the outer and inner surfaces of cell membranes. The potential difference arising during excitation is called the potential of action, it is about 120 mV. In the process of repolarization, ions K + go beyond the cells and restore rest potential. Upon completion of the repolarization of Na +, using sodium pumps, removed from the cell into the extracellular space, the ions K + are actively penetrated into the cell through a semi-permeable cell membrane (Fig. 3).
The repolarization process takes place slower than depolarization, causes a smaller EMF than the excitation process.
Repolarization begins in subepicarordial layers and ends in subendocardial.
The process of depolarization in the muscular fiber proceeds more complicated than in a separate cell. The excited area is charged negatively in relation to the area located at rest, dipole-charges are formed, equal in size and opposite in the direction. If the dipole is moving in a positive charge towards the electrode, a positive directional tooth is formed if
the trip is negatively directed.
Human heart includes many muscle fibers. Each excited fiber is a dipole. Dipoli move in different directions. The sum of the vectors of muscle fibers of the right and left ventricles is recorded as a scalar value.
– electrocardiograms.
IN each of the assignment, the ECG curve represents the sum of the vectors of the right and left ventricles and the atria (biocardiogram theory).
3. Normal ECG in standard leads
IN the beginning of the 20th century Enthoven was proposed standard leads. Einthoven Pedstatil the body of a person in the form of an equilateral triangle. The first standard lead is recorded by the difference in the potentials of the right and left hand, the second ratio of the potentials of the right hand and the left leg, the third is the difference in the potentials of the left hand and the left leg. According to the law of Kirchhoff, the second lead is the algebraic amount of the first and third lead. All elements of the electrocardiogram are observed to this rule. The first assignment reflects the potentials of the subepicardial surface of the left ventricle, the third - the potentials of the rear wall of the left ventricle and the subepicardial surface of the right ventricle.
Normal ECG in standard leads is represented by a number of teeth and intervals indicated by Latin letters (Fig. 4). If the amplitude of the teeth is more than 5 mm, it is indicated by the capital letter, if less than 5 mm, then a small letter.
Teeth P is this atrial complex consists of a hollow rising knee and a symmetrically located downward knee, which are connected to a rounded top. The duration (width) of the teeth does not exceed 0.08-0.1 seconds (1 mm - 0.02 "), the height P is 0.5-2.5 mm. The greatest amplitude r in
the second standard assignment. Normally PII\u003e PI\u003e PIII. PI\u003e 0, L "" testifies to the left atrium hypertrophy, at PIII\u003e 2.5 mm can talk about the hypertrophy of the right atrium. The duration of the teeth p is measured from the beginning of the upward to the end of the downward knee, amplitude
R - from the base of the prong to its top.
The PQ interval (R) is from the beginning of the P before the beginning of G or R. It corresponds to the time of passage of the pulse at the atria, through the atrioventriculus. The node, on the GIS bundle, the legs of the beam of Gis, Purkinier fibers.
The duration of the PQ interval normally fluctuates 0, 12 "" ÷ 0, 20 "" and depends on the frequency of the pulse. The lengthening of the PQ interval is observed in disruption of atrioventricular conductivity, the shortening of PQ is associated with a sympathetic reaction, the premature excitation syndrome of the ventricles, the atrial or nodal driver of the rhythm, etc.
The PQ segment - ranges from the end of the beginning Q (R). The ratio of P to the PQ segment is called the macruz index, its value is 1.1-1.6. An increase in the macroje index testifies to the left atrium hypertrophy.
The QRS complex reflects the process of depolarization of ventricles is measured in the second standard assignment from the beginning q to the end S, the duration is normal amounts to 0.05-0.1 ". QRS elongation is associated with myocardial hypertrophy or intraventricular conduction disruption.
Teeth q - is associated with the excitation of the MCZheltococcus partition (optional, with a negative amplitude). The duration of Q in the first and second standard leads up to 0.03 "", in the third standard one-to-0.04 "". The amplitude q is not more than 2 mm or no more than 25% R. The broadening Q and an increase in it indicates the presence of focal changes in myocardium.
The prong R is due to the depolarization of the ventricles, has an upward knee, a vertex, downward knee. Time from Q (R) to perpendicular from the vertex R indicates the increase in the velocity of the ventricles depolarization and is called the internal deviation time for the left ventricle not more than 0.04 "", right - 0.035 "". Division R.
Electrocardiography is considered the simplest method of determining the quality of the heart, both in the norm and pathology. The essence of this method consists in catching up and fixing the electrical pulses of the hearts arising from its operation.
But in order to determine the degree of violation, it is necessary to decipher the ECG of the ECG, since the fixation of the specified pulses is performed using a specific graphic image over a certain time.
Indications for the implementation of the ECG:
- In preventive purposes;
- Directional determination of the frequency of cutting of the heart muscle and the rhythm of the body;
- Determination of acute and chronic heart failure;
- Identification of various conduction disorders inside the heart;
- In order to determine the physical condition of the heart;
- Diagnostics ;
- Obtaining information about pathologies arising outside the heart (for example, full or partial).
Principles of ECG decryption
On the electrocardiogram, three main indicators are schematically depicted:
- Teeth - bulges with a sharp angle, directed up or down and denote P, Q, R, S, T;
- Segments - are the distance between nearby teeth;
- The interval is the interval, including the prong, and the segment.
Thanks to the above indicators, the cardiologist determines the level of reduction and restoration of the heart muscle. In addition to the indicators, during the electrocardiogram, the electrical axis of the heart can be determined, which indicates the approximate location of the organ in the chest cavity. The latter depends on the constitution of human body and chronic pathology. The electrical axis of the heart can be: normal, vertical and horizontal.
Main indicators ECG decryption
When decoding, the norms will be as follows:
- The distance between the R and R and R should be smooth all over the cardiogram;
- The intervals between PQRST should be from 120 to 200 m / s, graphically is determined by 2-3 squares. This is an indicator of the passage of the impulse in all heart departments from the atria to the ventricles;
- The interval between Q and S testifies to the passage of the ventricular pulse (60-100 m / s);
- The duration of the contractile ability of the ventricles is determined using Q and T, normally 400-450 m / s;
With the slightest shift from the specified parameters, you can judge the beginning or development of the pathological process in the heart muscle. Especially expressed such parameters are changed in rheumatism.
It should also be noted that in some cases the ECG standards of decryption may change slightly due to the presence of some violations that are considered the norm, since their presence does not affect the development of heart failure (for example, respiratory arrhythmia). It is important to note that for ECG decryption in adults, the norm can be represented in different tables describing the passage rate between the elements of the cardiogram.
ECG decryption in adults rate in the table
ECG Decryption Norm Table
Such tables are an official document to determine possible pathological changes in the heart muscle.
Video: ECG decoding
Thank you
The site provides reference information solely to familiarize yourself. Diagnosis and treatment of diseases must be under the supervision of a specialist. All drugs have contraindications. Consultation of a specialist is obligatory!
Electrocardiogram represents a widespread method objective diagnostics A variety of human heart pathology, which is used today almost everywhere. The electrocardiogram (ECG) is removed in the clinic, in ambulance or in the hospital department. ECG is very important entries reflecting the condition of the heart. That is why the reflection of various variants of cardiac pathology on ECG describes a separate science - electrocardiography. Electrocardiography also deals with the problems of the correct ECG removal, deciphering issues, interpretation of controversial and obscure moments, etc.Definition and essence of the method
The electrocardiogram is a record of the work of the heart, which is represented as a lines curve on paper. The cardiogram line itself is not chaotic, it contains certain intervals, teeth and segments that correspond to certain stages of the heart.To understand the essence of the electrocardiogram, you need to know what specifically records the device called an electrocardiograph. The electrical activity of the heart is recorded on the ECG, which changes cyclically, in accordance with the onset of diastole and systole. The electrical activity of the human heart may seem fiction, but this unique biological phenomenon exists in reality. In reality, the heart has so-called conductive system cells that generate electrical pulses transmitted to the organ of the organ. It is these electrical pulses forcing myocardium to shrink and relax with certain rhythm and frequency.
The electrical pulse extends through the cells of the heart conductive system strictly consistently, causing the reduction and relaxation of the respective departments - ventricles and atrial. The electrocardiogram reflects precisely the total electric potential difference in the heart.
decoding?
The electrocardiogram can be removed in any polyclinic or a multi-profile hospital. You can contact a private medical center, where there is a specialist cardiologist or therapist. After recording a cardiogram, a tape with curves considers a doctor. It is he who analyzes the record, decrypts it and writes a final conclusion, which reflects all visible pathologies and functional deviations from the norm. The electrocardiogram is recorded using a special instrument - an electrocardiograph that can be multichannel or single-channel. The speed of the ECG record depends on the modification and modernity of the device. Modern devices can be connected to a computer, which in the presence of a special program will analyze the record and give a ready conclusion, immediately at the end of the procedure.
Any cardiograph has special electrodes that are superimposed in a strictly defined order. There are four clothespins of red, yellow, green and black, which are imposed on both hands and both legs. If you go in a circle, the clothespins are superimposed according to the rule "red-yellow-green-black", from the right hand. Remember this sequence is easy thanks to the student saying: "Each-Woman-Zlah-Dam." In addition to these electrodes there are still breasts, which are installed in intercostal spaces.
As a result, the electrocardiogram consists of twelve curves, six of which are recorded from breast electrodes, and are called breast leads. The remaining six devices are recorded from electrodes attached to hand and legs, and three of them are called standard, and three more - reinforced. Breast leads are marked with V1, V2, V3, V4, V5, V6, standard simply Roman numerals - I, II, III, and reinforced foot - letters AVL, AVR, AVF. Different challenges of the cardiogram are necessary to create the most complete picture of the heart activity, since some pathologies are visible on breasts, others on standard, and the third - in reinforced.
A man falls on the couch, the doctor fastens the electrodes and includes the device. While the ECG is written, a person must be absolutely calm. It is impossible to admit any stimuli, which are able to distort the true picture of the heart of the heart.
How to make an electrocardiogram with the subsequent
Decoding - video
Principle of decoding ECG
Since the electrocardiogram reflects the processes of contraction and relaxation of myocardium, then you can trace how these processes occur, and identify existing pathological processes. Electrocardiogram elements are closely related, and reflect the duration of the phases of the cardiac cycle - systole and diastole, that is, the reduction and subsequent relaxation. Decoding the electrocardiogram is based on the study of the teeth, from the position of each other relative to each other, duration, and other parameters. The following elements of the electrocardiogram are studying for analysis:1. Teeth.
2. Intervals.
3. Segments.
Teeth call all sharp and smooth convexities and concave on the ECG line. Each teeth is denoted by the letter of the Latin alphabet. Teeth P reflects the reduction of the atrium, the QRS complex is a reduction in the ventricles of the heart, Teeth T - relaxation of the ventricles. Sometimes after the tongue T on the electrocardiogram there is another prong U, but it has no clinical and diagnostic role.
The ECG segment is considered a segment concluded between adjacent teeth. To diagnose the pathology of the heart, the segments p - Q and S - T are played. The interval on the electrocardiogram is a complex comprising a tooth and interval. For diagnostics, the intervals P - Q and Q - T.
Often in the conclusion of the doctor you can see small Latin letters, which also denote the teeth, intervals and segments. Small letters are used if the tooth has a length of less than 5 mm. In addition, in the QRS complex, the appearance of several R - teeth, which are considered to indicate R ', R, etc. Sometimes the prong r is simply missing. Then the whole complex is indicated by only two letters - QS. All this has an important diagnostic value.
ECG Decoding Plan - General Results Reading Scheme
When deciphering the electrocardiogram, you must install the following parameters reflecting the work of the heart: - position of the electrical axis of the heart;
- determination of the correctness of the heart rate and conductivity of the electrical pulse (detect blockades, arrhythmias);
- determining the regularity of the reduction of the heart muscle;
- determination of heart rate;
- detection of the source of an electrical pulse (determined by the rhythm of sinus, or not);
- analysis of duration, depth and width of the atrial teeth P and interval P - Q;
- analysis of duration, depth, width of a complex of teeth of the ventricles of the heart QRST;
- analysis of the parameters of the RS segment and tongs;
- analysis of the parameters of the interval Q - T.
In conclusion on the electrocardiogram, the doctor must reflect the following parameters:
- sinus rhythm, or not;
- regularity of rhythm;
- heart rate (heart rate);
- position of the electrical axis of the heart.
An example of deciphering an electrocardiogram
At the very beginning of the tape of the electrocardiogram, there must be a calibration signal that looks like a large letter "P" with a height of 10 mm. If this calibration signal is not, the electrocardiogram is non-informative. If the height of the calibration signal is below 5 mm in standard and enhanced leads, and below 8 mm - in the chest, then there is a low voltage of the electrocardiogram, which is a sign of a series of pathologies of the heart. For the subsequent decryption and counting of some parameters, it is necessary to know which period of time is placed in one cell millimeter paper. At the speed of the tape in 25 mm / s one cell, 1 mm long cell is 0.04 seconds, and at a speed of 50 mm / s - 0.02 seconds.Checking the regularity of heart cuts
It is estimated at the R - R intervals. If the teeth throughout the record are located at the same distance from each other, then the rhythm is regular. Otherwise, it is called correct. Estimate the distance between the teeth R - R is very simple: an electrocardiogram record is made on millimeter paper, which is easy to measure any intervals in millimeters.Calculation of heart rate (heart rate)
It is carried out by a simple arithmetic method: count the number of large squares on millimeter paper, which are placed between two teeth R. Then the heart rate is calculated by the formula, which is determined by the speed of the ribbon in the cardiograph: 1. The ribbon speed is 50 mm / s - then the heart rate is 600 divided by the number of squares.
2. The ribbon speed is 25 mm / s - then the heart rate is 300 divided by the number of squares.
For example, if there are 4.8 large squares between the two teeth R, then the heart rate, with a tape speed of 50 mm / s, will be equal to 600 / 4.8 \u003d 125 shots per minute.
If the rhythm of heart abbreviations are incorrect, then determine the maximum and minimal heart rate, taking as a basis also the maximum and minimum distances between the teeth R.
Detection of the source of rhythm
The doctor studies the rhythm of heart abbreviations and finds out which node of nerve cells causes cyclic processes of contractions and relax muscles of the heart. This is very important to determine the blockade.Decoding ECG - Rhythms
Normally, the rhythm driver is a sinus nerve knot. And the very normal rhythm is called sinus - all other options are pathological. With different pathologies, any other node of the nerve cells of the conductive heart system can be played as a rhythm driver. In this case, cyclic electrical impulses are twisted and the rhythm of heart abbreviations is broken - arrhythmia takes place.With sinus rhythm On the electrocardiogram in the II decay, the PC is in front of each QRS complex, and it is always positive. In one assignment, all teeth r should have the same shape, length and width.
With atrial rhythm Teeth P in the II-OU and III leads - negative, but is available before each QRS complex.
Atrioventricular rhythms Characterized by the lack of teeth P on the cardiograms, or the appearance of this teeth after the QRS complex, and not before it, as normal. With this type of rhythm, the heart rate is low, and ranges from 40 to 60 shots per minute.
Ventricular rhythm It is characterized by an increase in the width of the QRS complex, which becomes large and rather frightening. Protesses P and QRS complex are completely connected with each other. That is, there is no strict proper normal sequence - the prong r, and after the QRS complex followed. The ventricular rhythm is characterized by a decrease in heart rate - less than 40 shots per minute.
Identification of the pathology of the conductivity of the electrical impulse according to the structures of the heart
For this purpose, the duration of the teeth P is measured, the interval P - Q and the QRS complex. The duration of these parameters is calculated by a millimeter tape on which a cardiogram is recorded. At first, it is considered how many millimeters takes each tooth or interval, after which the value is multiplied by 0.02 at a recording rate of 50 mm / s, or 0.04 at a 25 mm / s recording rate.The normal duration of the PC is up to 0.1 seconds, the interval P - Q is 0.12-0.2 seconds, the QRS complex is 0.06-0.1 second.
Electric axis heart
Designated as an angle alpha. It can have a normal position, horizontal or vertical. Moreover, in a thin person, the axis of the heart is more vertical relative to the average values, and the full - more horizontal. The normal position of the electrical axis of the heart is 30-69 o, vertical - 70-90 o, horizontal - 0-29 o. The angle of alpha equal to 91 to ± 180 o reflects the sharp deviation of the electrical axis of the heart to the right. The angle of alpha, equal to 0 to -90 o, reflects the sharp deviation of the electrical axis of the heart to the left. The electrical axis of the heart can be deviated at different pathological conditions. For example, hypertensive disease leads to a deviation to the right, the conduction disorder (blockades) can shift it to the right or left.
Atrial prigning r
The atrial prong r should be:- positive in I, II, AVF and breasts (2, 3, 4, 5, 6);
- negative in AVR;
- two-phase (part of the teeth lies in the positive area, and the part is in negative) in III, AVL, V1.
Pathological forms of teeth P may indicate the following pathologies:
1.
High and sharp teeth in II, III, AVF leads appear with the hypertrophy of the right atrium ("pulmonary heart");
2.
Teeth P with two vertices with a large width in I, AVL, V5 and V6 leads speaks of the left atrial hypertrophy (for example, a vice of a mitral valve).
Interval P - Q
The interval P - Q has a normal duration from 0.12 to 0.2 seconds. An increase in the duration of the interval P - Q is a reflection of an atrioventricular blockade. On the electrocardiogram, three degrees of atrioventricular blockade can be distinguished (AV):- I degree: Simple lengthening of the interval P - Q with the preservation of all other complexes and teeth.
- II degree: The elongation of the P - Q interval with a partial loss of some QRS complexes.
- III degree: Lack of communication between the P and QRS complexes. In this case, atrium works in their rhythm, and the ventricles in their own.
Ventricular qrst complex
The ventricular QRST complex consists of itself from the QRS complex and the S - T segment. The normal duration of the QRST complex does not exceed 0.1 seconds, and its increase is detected at the blockades of the legs of the GISS bundle. QRS-complex It consists of three teeth, respectively, Q, R and S. q shoulder visually on the cardiogram in all leads, except 1, 2 and 3 pectoons. The normal tooth Q has an amplitude of up to 25% of such a teeth R. The duration of the tooth Q is 0.03 seconds. Tusk R is recorded absolutely in all leads. Teeth S is also visible in all leads, but its amplitude decreases from the 1st thoracic to the 4th, and in the 5th and 6th, it may not be absent. The maximum amplitude of this teeth is 20 mm.
Segment S - T is Very important from a diagnostic point of view. It is about this tooth that can be revealed to the myocardial ischemia, that is, the lack of oxygen in the heart muscle. Usually, this segment takes place in an isolated, in 1, 2 and 3 breasts, it can rise up a maximum of 2 mm. And in 4, 5 and 6 breast leads, the S - T segment can shift below the insulation to the maximum half a million. It is the deviation of the segment from the insulance that reflects the presence of myocardial ischemia.
Teeth T.
Teeth T is a reflection of the process in the end of the relaxation in the heart muscle of the hearts of the heart. Usually with a large amplitude of the R teeth R, the Tusk T also will be positive. The negative teeth of T is registered only in the AVR assignment.Interval Q - T
The Q - T interval reflects the process in the end of the reduction in the myocardium of the ventricles of the heart.ECG Decoding - Norm Indicators
The decoding of the electrocardiogram is usually written by a doctor in conclusion. A typical example of a normal heart cardiogram is as follows:1. PQ - 0.12 s.
2. QRS - 0.06 p.
3. Qt - 0.31 p.
4. RR - 0.62 - 0.66 - 0.6.
5. CSS is 70 - 75 shots per minute.
6. Rhythm sinusovy.
7. The electric axis of the heart is normal.
Normally, rhythm should be only sinusov, an adult heart rate - 60 - 90 shots per minute. The P tooth in the norm is no more than 0.1 s, the interval P - Q is 0.12-0.2 seconds, the QRS complex is 0.06-0.1 second, Q - T to 0.4 s.
If the cardiogram is a pathological, then it indicates specific syndromes and deviations from the norm (for example, a partial blockade of the left leg of the GISS beam, myocardial ischemia, etc.). The doctor may also reflect specific disorders and changes in the normal parameters of the teeth, intervals and segments (for example, the shortening of the teeth of the P or the interval Q - T, etc.).
Deciphering ECG in children and pregnant women
In principle, in children and pregnant women, the normal indicators of the electrocardiogram of the heart are the same as in healthy adults. However, there are certain physiological features. For example, the frequency of heart abbreviations in children is higher than in an adult. Normal Church of the child up to 3 years of age is 100-110 beats per minute, 3-5 years - 90 - 100 shots per minute. Then gradually the heart rate is reduced, and in adolescence, it is compared with that in an adult - 60 - 90 blows per minute.Pregnant women may have a slight deviation of the electrical axis of the heart in the late period of gestation due to the compression of the growing uterus. In addition, sinus tachycardia is often developing, that is, an increase in heart rate of heart rate to 110-120 - 120 beats per minute, which is a functional state, and passes independently. An increase in heart rate is associated with a large amount of circulating blood and increased load. Due to the increase in the load on the heart in pregnant women, the overload of various separations of the organ can be detected. These phenomena are not pathology - they are associated with pregnancy, and will be held independently after delivery.
Decryption of electrocardiogram with heart attack
Myocardial infarction is a sharp cessation of oxygen intake to heart muscle cells, as a result of which the leaf of the tissue area is developing in a state of hypoxia. The reason for the infringement of oxygen flow can be different - most often this blockage of the blood vessel, or its gap. The infarction captures only a part of the muscle tissue of the heart, and the lesion volume depends on the size of the blood vessel, which turned out to be clogged or torn. The myocardial infarction electrocardiogram has certain signs for which it can be diagnosed. In the process of developing myocardial infarction, four stages are distinguished, which have different manifestations of the ECG:
- acute;
- acute;
- tray;
- scar.
Sometimes it is possible to catch the myocardium ischemia phase preceding the acute, which is characterized by high teeth T.
Acute Stage The heart attack flows 2 to 3 weeks. During this period, the ECG registers a wide and high-ampludinal prong of Q, and the negative teeth of T.
Subacious stage Takes up to 3 months. A very large negative teeth t is recorded on the ECG with a huge amplitude, which is gradually normalized. Sometimes the rise of the S - T segment is revealed, which was to be aligned to this period. This is an alarming symptom, because it may indicate the formation of the aneurysm of the heart.
Scar Stage The heart attack is the ultimate, since a connective tissue is formed on a damaged place, unable to reduce. This scar is registered on the ECG in the form of the Q of Q, which will remain for life. Often, the Tusk is so smoothed, has a low amplitude, or at all is negative.
Decoding the most common ECG
In conclusion, doctors write the result of the ECG decryption, which is often incomprehensible, since it consists of terms, syndromes and just a statement of pathophysiological processes. Consider the most common ECG conclusions that are incomprehensible to a person without medical education. Ectopic rhythm It means not sinus - what can be both pathology and norm. The norm ectopic rhythm is when there is a congenital improper formation of a conductive heart system, but a person does not impose no complaints and does not suffer from other heart pathologies. In other cases, ectopic rhythm indicates the presence of a blockade.
Changes in repolarization processes The ECG reflects the violation of the process of relaxation of the heart muscle after the reduction.
Sinus rhythm - This is a normal heart rhythm of a healthy person.
Sinus or sinusoidal tachycardia It means that the person has the right and regular rhythm, but the increased frequency of heart abbreviations is more than 90 blows per minute. Young people up to 30 years old is an option for the norm.
Sinus bradycardia - This is a low number of heart abbreviations - less than 60 shots per minute amid normal, regular rhythm.
Nonspecific changes ST-T Means that there are minor deviations from the norm, but their reason can be completely unnecessary with the pathology of the heart. It is necessary to undergo a full examination. Such nonspecific changes ST-T can develop with potassium ions imbalance, sodium, chlorine, magnesium, or various endocrine disorders, often during women's period.
Two-phase prong r. In combination with other signs of a heart attack indicates damage to the anterior wall of myocardium. If other signs of heart attack were not identified, the two-phase prong r is not a sign of pathology.
Qt extension It may indicate hypoxia (lack of oxygen), rickets, or the overexcusion of the nervous system in a child, which is a consequence of the generic injury.
Myocardial hypertrophy This means that the muscular wall of the heart is thickened, and works with a huge load. This can lead to the formation:
- heart failure;
- arrhythmia.
Moderate diffuse changes in myocardium Means that the nutrition of the tissues is broken, dystrophy of the heart muscle developed. This is a corrected state: you need to consult a doctor and pass an adequate treatment course, including nutritional normalization.
Deviation of the electrical axis of the heart (EOS) Left or right possible with left or right ventricle hypertrophy, respectively. The left EOS can deviate in obese people, and the right - in thin, but in this case it is the option of the norm.
Left type ECG - Deviation of EOS left.
NBPNPG - Abbreviation, denoting "incomplete blockade of the right leg of a beam of Gis." This state may occur in newborn children, and is an option for the norm. In rare cases, NBPNPG may cause arrhythmia, but mainly does not lead to the development of negative consequences. The blockade of the leg feet of Giss is quite often found in humans, but if there are no complaints about the heart - then it is completely not dangerous.
BPVLNPG - Abbreviation, meaning "blockade of the front branch of the left feet of the beam of Gisa." Reflects the violation of the electrical pulse in the heart, and leads to the development of arrhythmias.
Small height of teeth R in v1-v3 It may be a sign of a heart attack of the interventricular partition. To accurately determine if it is, it is necessary to make another ECG study.
CLC syndrome (Klein-Levi-Cretesco syndrome) is a congenital feature of the conductive heart system. It may cause arrhythmia development. This syndrome does not require treatment, but you must regularly be examined by a doctor - cardiologist.
Low voltage ECG It is often registered with pericade (a large volume of connective tissue in the heart, indiscriminate muscle). In addition, this feature may be a reflection of depletion or myxedema.
Metabolic changes They reflect the failure of the nutrition of the heart muscle. It is necessary to be examined by a cardiologist and under the course of treatment.
Slow conduction It means that the nerve impulse passes through the tissues of the heart slower than normal. In itself, this condition does not require special treatment - this may be a congenital feature of the conductive heart system. Recommended regular monitoring of a cardiologist.
Blockade 2 and 3 degrees Reflects a serious violation of the conductivity of the heart, which is manifested by arrhythmia. In this case, treatment is necessary.
Rotate the heart with right ventricle forward It may be an indirect sign of the development of hypertrophy. In this case, it is necessary to find out its cause, and under the course of treatment, or correct the diet and lifestyle.
Price electrocardiogram with decoding
The cost of an electrocardiogram with decoding fluctuates significantly, depending on the particular medical institution. Thus, in state hospitals and clinics, the minimum price for the ECG removal procedure and the decryption by its doctor is from 300 rubles. In this case, you will get films with recorded curves and the conclusion of a doctor on them, which he will do, or with the help of a computer program.If you want to get a thorough and detailed conclusion on an electrocardiogram, an explanation by the doctor of all parameters and changes - it is better to contact a private clinic that provides such services. Here the doctor will not only be able to write a conclusion, decrypting the cardiogram, but also calmly talk to you, not athleting to clarify all the points of interest. However, the cost of such a cardiogram with decoding in a private medical center ranges from 800 rubles to 3,600 rubles. It should not be assumed that in a conventional clinic or hospital there are bad experts - just a doctor in a state institution, as a rule, is a very large amount of work, so it simply has once to talk with each patient very detailed.
One of the leading causes of death among people around the world are cardiovascular diseases. Over the past decades, this figure has significantly decreased due to the emergence of more modern methods of examination, treatment, and, of course, new drugs.
Electrocardiography (ECG) - the method of registration of electrical activity of the heart, one of the first ways of research, which for a long time remained almost the only in this area of \u200b\u200bmedicine. Around the century ago in 1924, Willem Einthoven received the Nobel Prize in medicine, he designed the device, with the help of which the ECG was recorded, gave the name to her tooths and identified the electrocardiographic signs of certain heart disease.
Many research methods with the advent of more modern developments lose their relevance, but it does not apply to electrocardiography. Even with the advent of visualizing methods (, CT, etc.), the ECG for decades continues to remain the most common, very informative, and in some way and the only one affordable heart research method. Moreover, over the age of its existence, the device itself nor the method of using it has not changed significantly.
Indications and contraindications
A person can be appointed ECG for the purpose of prophylactic examination, as well as in suspected any heart disease.Electrocardiography is a unique examination method that helps to make a diagnosis or becomes a starting point for drawing up a plan for further patient survey. In any case, diagnosis and treatment of any heart disease begins with ECG.
ECG is an absolutely safe and painless way of examination for people of all ages, there are no contraindications for conventional electrocardiography. The study takes only a few minutes and does not require any special training.
But the testimony for electrocardiography is so much that it is simply impossible to list them. The main ones are as follows:
- general examination during the clinicalization or medical commission;
- assessment of the condition of the heart in various diseases (, atherosclerosis, lung disease, etc.);
- differential diagnosis with stubborn pains and (often have no cardiac cause);
- suspicion of, as well as the control of the course of this disease;
- diagnosis of heart rate disorders (daily monitoring of the ECG on the holder);
- violation of electrolyte metabolism (hyper-or hypokalemia, etc.);
- an overdose of drugs (for example, cardiac glycosides or antiarrhythmic drugs);
- diagnosis of extracardial diseases (pulmonary thromboembolism), etc.
The main advantage of the ECG is that the study can be performed outside the hospital, many ambulance machines are equipped with electrocardiographs. This makes it possible to a doctor at home in a patient to identify myocardial infarction at its very beginning, when damage to the heart muscle is just beginning and partially reversible. After all, treatment in such cases begins even during the transportation of the patient to the hospital.
Even in cases where the urgent is not equipped with this device and the doctor soon does not have the ability to perform a study at the pre-hospital stage, the first diagnostic method in the receiving rest will be an ECG.
ECG decoding in adults
In most cases, cardiologists, therapists, ambulance doctors are working with electrocardiograms, but a specialist in this field is a functional diagnosis. ECG decoding is a difficult task that is not under the person who does not have appropriate qualifications.
Usually, the ECG of a healthy person can distinguish five teeth recorded in a certain sequence: p, q, r, s and t, sometimes the teeth u are sometimes recorded (its nature is not yet known for today). Each of them reflects the electrical activity of myocardium of different parts of the heart.
When registering ECG, several complexes corresponding to heart cuts are usually recorded. In a healthy person, all the teeth in these complexes are located at the same distance. The difference in the intervals between the complexes indicates.
In this case, in order to accurately establish the form of arrhythmia, the Holter monitoring of the ECG may be needed. Using a special small portable device, the cardiogram is recorded continuously for 1-7 days, after which the recording is processed using a computer program.
- The first teeth of P reflects the process of depolarization (excitement coverage) atrial. According to its width, amplitude and form, the doctor may suspect hypertrophy of these heart chambers, violation of the pulse on them, assume the presence of the patient of the body and other pathologies in the patient.
- The QRS complex reflects the process of coverage with the excitation of the ventricles of the heart. The deformation of the form of the complex, a sharp decrease or an increase in its amplitude, the disappearance of one of the teeth can talk about the set of diseases: myocardial infarction (with the help of the ECG, it is possible to establish its localization and prescription), scars, conductivity impairment (blockages of the feet of the Gis beam), etc.
- The last tooth is determined by the repolarization of the ventricles (conventionally speaking, relaxation), the deformation of this element can talk about electrolyte disorders, ischemic changes and other pathologies of the heart.
ECG sections that bind various teeth, got the name "segments". Normally, they lie on the insulation, or their deviation is not significant. Between the teeth there are intervals (for example, PQ or Qt), which reflect the time of the electric pulse through the heart departments, in a healthy person they have a certain duration. The elongation or shortening of these intervals is also a significant diagnostic sign. To see and evaluate all changes to the ECG, only a qualified doctor can.
Each millimeter is important in decoding ECG, sometimes even half a millionther are crucial in the choice of therapeutic tactics. Very often, an experienced doctor can make an accurate diagnosis on an electrocardiogram without the use of additional research methods, and in some cases its informativeness exceeds other types of research. In essence, this screening method of examination in cardiology, allowing to identify or at least suspect heart disease in the early stages. That is why the electrocardiogram will remain one of the most sought-after diagnostic methods in medicine for many years.
To which doctor to turn
Behind the ECG direction, you need to refer to the therapist or cardiologist. Analysis of the cardiogram and the conclusion according to it gives a doctor of functional diagnostics. In itself, the ECG concluding is not a diagnosis and should be considered by a clinician in combination with other patient data.
Basics of electrocardiography in the cognitive video:
Video course "ECG for everyone", lesson 1:
Video course "ECG under the power of each", lesson 2.
Electrocardiogram reflects only electrical processes In myocardium: depolarization (excitation) and repolarization (restoration) of myocardial cells.
Ratio eCG intervals from phases of the heart cycle (systole and diastole ventricles).
Normally, depolarization leads to a reduction in muscle cell, and repolarization - to relaxation. To simplify, then I will instead of "depolarization-repolarization" sometimes use the "reduction-relaxation", although this is not exactly exactly: there is a concept " electromechanical dissociation", In which depolarization and repolarization of myocardium do not lead to its visible reduction and relaxation. A little more about this phenomenon I wrote earlier .
Elements of normal ECG
Before moving to the decoding of the ECG, you need to figure out which items it consists.
Teeth and intervals on ECG. It is curious that abroad the P-Q interval is usually called P-R..
Any ECG consists of teeth, segments and intervals.
Teeth - These are bulging and concave on the electrocardiogram. The following teeth are distinguished on the ECG:
P. (reducing atrial),
Q., R., S. (All 3 teeth characterize the reduction of ventricles),
T. (relaxation of ventricles),
U. (non-permanent teeth, rarely registered).
Segments Segment on ecg called cut straight line (isolated) between two adjacent teeth. Segments P-Q and S-T have the greatest value. For example, the P-Q segment is formed due to the delay of the excitation in the preservation of the ventricular (AV-) node.
Intervals The interval consists of teeth (complex of teeth) and segment. Thus, the interval \u003d the tooth + segment. The most important are the intervals P - Q and Q-T.
Teeth, segments and intervals on ECG. Pay attention to large and small cells (about them below).
QRS complex teeth
Since the myocardium of the ventricles is massive than the myocardium atrial and has not only the walls, but also a massive interventricular partition, the extension of the excitation in it is characterized by the appearance of a complex complex QRS. on the ECG As correct to highlight the teeth in it?
First of all evaluate amplitude (sizes) of individual teeth QRS complex. If the amplitude exceeds 5 mm, the prong is denoted capital (big) letter Q, R or S; if the amplitude is less than 5 mm, then little): Q, R or S.
Tung R (R) called any positive (directed up) tooth, which is included in the QRS complex. If the teeth are somewhat, the subsequent teeth are denoted strokes: R, R ', R ", etc. Negative (directional down) KRS COMPAGE, which is tonna R., denotes as Q (Q), and after - like s (s). If there are no positive teeth in the QRS complex, the ventricular complex is indicated as QS..
Variants of the QRS complex.
In the norm of the proven Q. reflects the depolarization of the interventricular partition, the tooth R. - the main mass of myocardial ventricles, prong S. - Basal (i.e. near the atrium) departments of the interventricular partition. The prong r V1, V2 reflects the excitation of the interventricular septum, and R v4, V5, V6 is the excitation of the muscles of the left and right ventricles. Death of myocardial sites (for example, myocardial infarction ) Causes the expansion and deepening of the K tooth Q, so close attention is always paying attention to this teeth.
Analysis of ECG
General decryption Scheme ECG
Check the correctness of the ECG registration.
Analysis of cardiac rhythm and conduction:
evaluation of the regularity of heart abbreviations,
counting cardiac frequency (heart rate),
determination of the source of excitation
conductivity assessment.
Determination of the electrical axis of the heart.
Analysis of the atrial teeth P and interval P - Q.
Analysis of the ventricular complex QRST:
analysis of the QRS complex,
rS - T segment analysis,
teeth Analysis T,
analysis of the interval Q - T.
Electrocardiographic conclusion.
Normal electrocardiogram.
1) Checking the correctness of the ECG registration
At the beginning of each ECG ribbon should be calibration signal - so-called control Millivolt. To do this, at the beginning of the record, a standard voltage in 1 Milvololt is applied, which should be displayed on the tape deviation in 10 mm. Without a calibration signal, the ECG record is considered incorrect. Normally, at least in one of the standard or reinforced assignments from the limbs, the amplitude must exceed 5 mm, and in breasts - 8 mm. If the amplitude is lower, it is called reduced voltage ECGwhich happens with some pathological conditions.
Control Millivolt on ECG (at the beginning of the record).
2) Analysis of cardiac rhythm and conductivity:
evaluation of the regularity of cardiac abbreviations
Rhythm regularity is estimated at the R-R intervals. If the teeth are at an equal distance from each other, the rhythm is called regular, or correct. Allowed variation of the duration of individual intervals of R-R no more ± 10% From their average duration. If the rhythm is sinus, it is usually correct.
candle Candidage Frequency (Heart rate)
Large squares are printed on the ECG film, each of which includes 25 small quadraticles (5 vertically x 5 horizontally). For the rapid counting of heart rate, with the right rhythm, the number of large squares between the two adjacent teeth R - R.
With a tape speed 50 mm / s: heart rate \u003d 600 / (Number of large squares). At the speed of the tape 25 mm / s: heart rate \u003d 300 / (Number of large squares).
On the overlying ECG, the R-R interval is approximately 4.8 large cells, which at a speed of 25 mm / s gives 300 / 4.8 \u003d 62.5 Ud. / Min.
At 25 mm speed / s each little cell equal 0.04 C., and at a speed of 50 mm / s - 0.02 S.. This is used to determine the duration of the teeth and intervals.
With incorrect rhythm usually consider maximum and minimum heart rate According to the duration of the smallest and large range of R-R, respectively.
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