Atrial flutter. Atrial flutter on the ECG: causes, clinical manifestations Signs of atrial fibrillation on the ECG

The essence of arrhythmia is similar to atrial fibrillation (AF), but with atrial flutter (AF), instead of chaotic waves, one or more stable paths of circular motion of the impulse arise in the atria. As a result, the atria contract more coordinatedly than in AF, and therefore rhythmic F waves similar in shape are recorded on the ECG.

It should be noted that atrial flutter (AFL), under certain circumstances, can progress to AF and vice versa. Sometimes it is impossible to distinguish them. In such cases, it is legitimate to give the conclusion: “atrial fibrillation-flutter.” But before going to extremes, you still need to try to differentiate one arrhythmia from another.

So, the main signs of atrial flutter are:

1. Absence of P waves.

2. The presence of a sawtooth wave F instead of P waves, better visible in leads V1 and V2.

In this case, the frequency of atrial contraction ranges from 200 to 400 per minute, that is, the distance between the ridges (FF) = 150 to 300 ms or, practically speaking, from 7.5 mm to 15 mm (at a belt speed of 50 mm/s).

Anything more than 400 beats per minute is atrial fibrillation, and anything less than 200 is supraventricular tachycardia.

Of course, TP also has other features in several different forms, which we will now consider in the practical part.

ECG No. 1

Pay attention to leads V1 and V2; instead of an isoline, F waves, similar to saw teeth, are clearly visualized in them. They move rhythmically at an interval of FF = 8.5 small cells, that is, their frequency is about 350 rpm. Of course, under normal conditions * , The AV node is not able to conduct such a frequency to the ventricles, and therefore some of the waves are blocked. If there is one ventricular complex for every two waves, this flutter is called 2:1, if there are three waves, then 3:1, etc.

In this case, every fourth wave is carried out to the ventricles, that is, we are talking about a 4:1 flutter.

This is what a typical flutter looks like, and in this form its diagnosis is not difficult. But when the contraction frequency (AV conduction) increases, say 2:1, difficulties may arise. Look at ECG #2.

ECG No. 2

This is a typical 2:1 and 3:1 flutter, the F waves are hard to see, but if you look for them you can see them (note that I have highlighted the wave separately F in red. This is how the impulse passes through the atria, turn on your imagination and superimpose this segment on the main ECG and everything will become clear.

As you can see, the wave frequency is 375 per minute. Some alteration of the R waves is confused with irregularity, in which case it is probably not a big mistake to call it atrial fibrillation - atrial flutter (at least for a doctor who is not a cardiologist or a functional diagnostician). But it's still FP.

ECG No. 3

And here an unusual flutter is presented, the F waves are not at all similar to the usual saw, but their rhythm is clearly visible, the FF frequency is approximately 270 per minute, which clearly indicates AF (after all, with supraventricular tachycardia, the pulse frequency rarely exceeds even 200 per minute).
As you can see, the F waves merge in some places with the T (F+T) and R (R+T) waves, deforming them.

* In the presence of additional conduction pathways, 1:1 conduction may occur, which will entail a high frequency of ventricular contractions, which they are not able to “withstand,” and ventricular flutter or fibrillation develops with all the ensuing consequences.

Flickering (fibrillation) atrial fibrillation, or atrial fibrillation, is a heart rhythm disorder in which throughout the entire cardiac cycle there is frequent (from 350 to 700 per minute), erratic, chaotic excitation and contraction of individual groups of atrial muscle fibers, each of which is an ectopic focus of impulses. With atrial fibrillation, there is no atrial systole.

With atrial fibrillation, not all impulses can pass through the AV node to the ventricles, since many of them find it in a state of refractoriness. In this regard, the frequency of ventricular excitation during atrial fibrillation usually does not exceed 150-200 per minute, more often it is 90-140 per minute.

Atrial fibrillation in most cases is observed with organic changes in the atrial myocardium: coronary heart disease (cardiosclerosis), mitral stenosis, thyrotoxicosis, myocarditis, myocardial dystrophy, in the presence of additional conduction pathways.

Left: sinus rhythm and the spread of excitation is normal. On right: atrial fibrillation, many independent excitation centers are visible in the atrium

ECG signs of atrial fibrillation:

Absence of P waves in all electrocardiographic leads;

The presence throughout the entire cardiac cycle of random f waves (f – fibrillatio), having different shapes and amplitudes. F waves are better recorded in leads V 1, V 2, II, III, aVF.

Irregularity of ventricular R–R complexes – irregular ventricular rhythm (R–R intervals of varying duration);

Presence of QRS complexes, having in most cases normal unaltered appearance without deformation or removal.

Depending on the size of the f wave, large and small wavy forms of atrial fibrillation are distinguished.

With a large-wavy form, the amplitude of the waves exceeds 0.5 mm, their frequency reaches 350–450 per minute. This form of atrial fibrillation often occurs in patients with severe atrial hypertrophy and in individuals with mitral stenosis.

With a finely wavy form of atrial fibrillation, the wave frequency reaches 600–700 per minute, and their amplitude is less than 0.5 mm. F waves are not visible on an ECG. This form of atrial fibrillation is observed in elderly people suffering from coronary heart disease, acute myocardial infarction, atherosclerotic cardiosclerosis, and thyrotoxicosis.

Depending on the frequency of ventricular contractions, bradysystolic, normosystolic and tachysystolic forms of atrial fibrillation are distinguished. With the bradysystolic form of atrial fibrillation, the frequency of ventricular contractions is less than 60 per minute, with the normosystolic form it is from 60 to 90 per minute, and with the tachysystolic form it is from 90 to 200 per minute.

17. Name the ECG signs of atrial flutter.

Atrial flutter is an increase in atrial contractions up to 200-400 per minute while maintaining the correct regular atrial rhythm.

Atrial flutter is observed with organic changes in the atrial myocardium during acute rheumatic fever, myocarditis, mitral heart defects, coronary heart disease, acute myocardial infarction and some other heart diseases.

Mechanisms of atrial flutter – increased automaticity of cells of the atrial conduction system; mechanism of re-entry of the excitation wave - re-entry. Unlike paroxysmal atrial tachycardia (the excitation wave circulates through the atria at a frequency of 140–250 per minute), with atrial flutter the frequency of rhythmic circulation of the excitation wave is 250–400 per minute.

ECG signs of atrial flutter: R-R intervals are the same (regular shape) or unequal (irregular shape), there is no P wave, there is a regular wavy line between the QRS complexes (F wave).

Waves F - arise as a result rhythmic excitation of the atria - This sawtooth waveform, which is characterized by a flat downward negative leg and a steeply rising upward leg; distance between atrial wave peaks F-F the same, correct regular atrial rhythm. F waves are better identified in leads V 1, V 2, II, III and aVF.

Ventricular complexes QRS with atrial flutter have normal unaltered form, since excitation through the ventricles is carried out in the usual way. The frequency of the ventricular QRS complexes is always less than the frequency of the atrial F waves, since the AV connection conducts no more than 220 impulses from the atria to the ventricles. In most cases, only every second or third atrial ectopic impulse is conducted to the ventricles, which indicates functional atrioventricular block 2:1, 3:1, 4:1 etc.

Atrial fibrillation refers to uneven contraction of the atrial muscle fibers due to the presence of chaotic electrical activity. This type of heart rhythm pathology is quite common in the practice of doctors of any specialty.

The etiology of atrial fibrillation may be:

primary(idiopathic), which occurs at a young age;
secondary(against the background of an existing pathology in the body).

The most common causes of atrial fibrillation are diseases of the cardiovascular system, which patients already have a history of. Such diseases include:

arterial hypertension (idiopathic or symptomatic);
coronary heart disease (post-infarction cardiosclerosis, early period of myocardial infarction);
congenital and acquired (as a result of infective endocarditis, acute rheumatic fever, etc.) heart defects.

As a result of myocardial remodeling (compensation of the hypertrophic type), excitation waves can circulate for a long time along individual muscle fibers.

Atrial fibrillation often occurs in patients with:

diseases of the thyroid gland (especially those accompanied by increased production of thyroid hormones, which subsequently leads to tachycardia);
COPD (pressure in the pulmonary circulation gradually increases and chronic cor pulmonale is formed).

The risk of this type of arrhythmia increases in older patients due to the fact that degenerative changes in cardiac tissue are observed in old age.

The fundamental element in the pathogenesis of atrial fibrillation is the occurrence of multiple re-entry waves.

The Re-entry mechanism is the “return” of an electrical impulse to single muscle fibers. As a result of the continuous circulation of low-amplitude electrical waves, small bundles of atrial muscle tissue contract.

It should be noted that the recirculating wave of excitation is not strong enough to bring the entire myocardium into a state of contraction. When the number of re-entry waves reaches a certain critical level, atrial fibrillation occurs.

The time period of chaotic contractions of individual fibers depends on several factors:

LA (left atrium) values.
The magnitude of the circulating excitation wave.

If the re-entry wavelength is shallow and the left atrium is hypertrophied, it means that the exciting impulse makes more circles (since the myocardial mass is increased). As a consequence, spontaneous return to sinus rhythm is almost impossible. In the case of normal heart sizes and the same return wavelength, a smaller number of muscle fibers are involved in the excitation process. In this case, the attack of arrhythmia may disappear on its own.

With atrial fibrillation, the diastolic filling of the ventricles is reduced. This leads to a decrease in cardiac ejection fraction, which subsequently reduces the oxygen concentration in the peripheral blood. To compensate for the hypoxic state, the ventricular myocardium gradually remodels according to the hypertrophic type. This increases the mass of the myocardium and the force of ventricular contraction.

It is worth noting that compensation occurs up to a certain point until its full potential is exhausted. Subsequently, subcompensation and decompensation develop, which is manifested by ventricular dilatation and a decrease in cardiac ejection fraction. Heart failure occurs and progresses.

Symptoms of atrial fibrillation

The atrial fibrillation clinic includes:

A sharp increase in heart rate. The patient perceives it as a sudden sensation of heartbeat. The palpitations may go away on their own within a couple of minutes or seconds. However, often this symptom does not disappear within several days or weeks, which requires qualified medical care.
Interruptions in the heart (patients describe this sign of atrial fibrillation as a feeling of “fading” of the heart).
The appearance of weakness, shortness of breath, chest pain.
In case of heart failure, there is “cardiac” edema. They usually appear in the evening on the legs; after pressing on them with a finger, a dimple remains. As decompensation increases, edema does not disappear.

Diagnosis of atrial fibrillation

To diagnose atrial fibrillation, the doctor:

conducts a survey, as a result of which it finds out how long ago the palpitations, interruptions in heart function began to bother you, and whether arrhythmia was previously treated;
conducts an objective examination (auscultation of the heart, counts the heart rate, determines the presence of pulse deficiency);
prescribes a study - recording the electrical activity of the heart (ECG). Based on the ECG criteria for atrial fibrillation, a conclusion is made about the presence of this heart rhythm disorder.

Atrial fibrillation on ECG

ECG signs of atrial fibrillation include:

Absence of the P wave before the ventricular complex (QRS);
The appearance of waves f;
Different intervals between R-R intervals (that is, the atria and ventricles of the heart contract independently of each other).

Differential diagnosis

Differential diagnosis of atrial fibrillation is carried out primarily with other arrhythmias, such as:

sinus tachycardia;
supraventricular form of paroxysmal tachycardia;
atrial flutter;
ventricular paroxysmal tachycardia.

The patient's complaints with the above forms of arrhythmias will be almost the same. Objective examination will show an increase in heart rate in all cases.

Additional Research

An electrocardiogram is a reliable method for differential diagnosis of atrial fibrillation from other types of arrhythmias. However, characteristic rhythm changes may not be recorded on the ECG. This may be because the patient has an intermittent form of atrial fibrillation (eg, atrial fibrillation attacks every other day) and the ECG was recorded during the interictal period. In this case, Holter monitoring will help make a differential diagnosis.

Holter monitoring is an instrumental research method based on long-term recording of an electrocardiogram. In this case, the patient leads his normal lifestyle. At the time of the attack, fibrillation is recorded on the ECG or other types of arrhythmias. A doctor, after analyzing the electrical activity of the heart over a long period, can make a diagnosis of a particular heart rhythm pathology.

It is also advisable to conduct additional research to establish the cause of atrial fibrillation. For example, echocardiography of the heart, which will show the presence of morphological and functional changes in the heart and its valve apparatus. Using a general blood test, a specialist will determine hypoxia, which is responsible for the increased levels of red blood cells and hemoglobin.

Each heartbeat is a series of two contractions, replacing each other with lightning speed. The first contraction occurs in the upper sections - the atria, the second - in the lower sections - the ventricles.

The sequence and rhythm of contractions is controlled by electrical impulses. Under normal conditions, they are generated in the natural pacemaker - the sinus node in the right atrium.

The impulse, passing through the upper parts of the heart, causes them to contract, and for a very short time it stops at the atrioventricular (AV) node, which is located in the upper part of the muscle wall between the two ventricles. This delay gives blood time to move from the atria to the ventricles.

The impulse then moves downward, creating a second ventricular contraction that pushes blood into the systemic circulation.

Source of excitatory impulses in normal conditions and during flutter

To understand what atrial flutter looks like on an ECG, you need to understand that it occurs when an abnormal contractile impulse generator develops within the muscle of the right atrium, causing it to contract too quickly, around 250-300 beats per minute.

These fast contractions slow down when they reach the AV node, but are still too fast (usually about 150 beats per minute, or every other atrial beat passing through the AV node to the ventricles).

This type of rhythm is called tachycardia. Because the flutter starts from the atrium, it is called supraventricular (above the ventricles) tachycardia.

The main danger of atrial flutter is that the heart pumps little blood if it beats too quickly. Vital organs such as the heart muscle and brain receive insufficient oxygen and nutrients, causing them to malfunction.

If atrial flutter is an intermittent phenomenon, it is called paroxysmal and usually lasts several hours or days. Less commonly, this condition is more or less permanent and is known as persistent atrial flutter.

Traditionally, for heart diseases in men, this pathology occurs 2 times more often than in women, and increases up to 5 times in the older age group. Most often combined with structural pathology in the heart muscle.

The main reasons for rhythm changes:

various forms of coronary heart disease,
consequences of cardiac surgery,
chronic lung diseases,
thyrotoxicosis,
pericarditis,
rheumatic disease,
arterial hypertension,
sinus node dysfunction,
cardiosclerosis.

Kinds

Atrial flutter on an ECG can have a typical or atypical variant.

Typical flutter provoked by the passage of an exciting impulse through the right atrium around the tricuspid valve. It can occur with activation of the septum dividing the atrium (the direction of the impulse is clockwise) and with the opposite activation of the structures of the atrial septum - counterclockwise.

Atypical runs along the left atrium around the perimeter of the mitral valve and around the pulmonary veins. This type of arrhythmia is much less common and, as a rule, is a consequence of heart surgery or radiofrequency treatment of a tumor.

Based on the ability to maintain a certain rhythm, flutters can be divided into rhythmic and irregular.

Atrial flutter in a ratio of 4:1, every fourth wave is conducted to the lower parts of the heart. There are no P peaks; instead, sawtooth flutter waves F are recorded. R-R intervals are the same, rhythm is preserved

Regularity is expressed in the onset of contraction of the lower sections, for example, after every fourth contraction of the upper sections. Ventricular contractions are rhythmic, due to the fact that the atrioventricular node is able to block excessive atrial contractions, approximately in a ratio of 2:1, 3:1. In this case, the F-R interval remains the same throughout the entire cardiogram.

An example of an irregular rhythm caused by a change in the degree of AV block. Conducted every second or third exciting signal

Lack of rhythm occurs when the impulse from the atria penetrates the ventricles intermittently, the ratio of AV blockade constantly changes. Contractions in the lower chambers of the heart are irregular, and an F-R interval of varying duration can be seen on the ECG.

G. F. Lang proposed to designate irregular contractions as “atrial fibrillation.”

Subjective sensations

When this type of rhythm disturbance occurs, patients usually note:

feeling of heartbeat,
shortness of breath,
general weakness,
chest pain,
inability to exercise.

A decrease in blood output from the heart also causes more serious symptoms - a sharp decrease in pressure, dizziness, loss of consciousness and cardiac arrest due to extremely frequent contractions of the atria. The main threat is the possibility of transformation of atrial flutter into ventricular tachycardia and ventricular fibrillation.

Differential diagnosis

Atrial flutter should be distinguished from other types of tachycardia - sraventricular, atrial and intraatrial tachycardia, constantly recurrent with a source in the AV junction.

The correct diagnostic method is electrocardiography of the electrical activity of the heart in 12 leads.

The most important sign is that the source of the electrical impulse that triggers the contraction of the heart structures is not in the sinus node. It may be in the wall of the atria or ventricle. The impulses occur irregularly, with a high frequency, interrupting the sinus rhythm. But on the ECG this is manifested by the absence of the P wave.

The so-called “sawtooth” waves, designated “p,” are recorded on the cardiogram. They have a characteristic appearance with a gradual jagged rise and a sharp decline. When talking about a high frequency of flutters, they mean 250 contractions per minute, versus the usual 60–90 times.

The frequency of atypical excitation waves does not allow the normal impulse from the sinus node to “break through” to the heart muscle; this condition is called atrioventricular AV block.

However, electrical flutter waves reach the lower chambers of the heart along the normal paths of the ventricular conduction system. On the cardiogram, the QRS complex, which characterizes the electrical activity of the ventricles, looks typical, without pathological changes.

On an ECG, atrial flutter of a typical type counterclockwise has a negative F wave (fibrillation).

On an ECG, atrial flutter of a typical type counterclockwise has a negative F wave (fibrillation)

This is a graphical representation of simultaneous activation of the interatrial septum from bottom to top. Also, all positive complexes characterizing atrial electrical activity are greatly reduced.

Atrial flutter in a clockwise direction has a positive wave direction and is comparable in magnitude to the negative F wave.

High-frequency contractions that spread to the lower chambers of the heart are a direct threat to life. It is necessary to know exactly the signs of ventricular flutter on the ECG.

The characteristic appearance of a ventricular flutter cardiogram is a continuous wavy line

The absence of a pronounced QRS complex, ST segment and T peak forms monophasic curves, and there is no isoelectric line. The waves during ventricular flutter are uniform and similar in shape, their amplitude depends on the frequency of contractions. A high flutter frequency reduces their amplitude; the complexes are very wide.

On average, these indicators are in the range of 150–300 times per minute, when this figure approaches 400, then flicker occurs - ventricular fibrillation - a state of clinical death.

Regular monitoring of heart activity using an ECG will help identify this pathology and begin timely treatment under the guidance of a cardiologist.

Atrial flutter is a common heart rhythm disorder. It does not have pronounced clinical manifestations, but is well determined using electrocardiographic examination. Pathology occurs for various reasons in children and adults.

The article talks about a type of cardiac arrhythmia - atrial flutter. The symptoms of the pathology and signs on the electrocardiogram are described

Atrial flutter, or atrial fibrillation, is a type of arrhythmia in which regular contractions of areas of the atrial myocardium are observed with a frequency of 250-300 per minute. This is a rather unstable condition that quickly turns into a normal heart rhythm or into fibrillation. Therefore, flutter is rarely diagnosed.

The causes of fluttering can be:

ischemic disease in the form of angina or heart attack;
inflammation of the membranes of the heart;
surgical interventions;
alcohol abuse;
exposure to electric current;
severe pneumonia;
heart defects;
pathology of the thyroid gland.

The mechanism by which flutter occurs is re-entry, or “re-entry.” The essence of this process is the presence of an ectopic focus of excitation, which creates a circular movement of the impulse along the atrial myocardium. As a result, some areas of the myocardium are in a state of constant excitation.

Symptoms include sudden weakness, dizziness, and a feeling of rapid heartbeat. Episodes of loss of consciousness may occur. Fluttering is a transient condition, so it is difficult to diagnose it based on external symptoms.

How to determine on an ECG

The main method for diagnosing atrial fibrillation is an ECG. A characteristic ECG sign of atrial flutter is the appearance of F waves in the second and third standard leads, which have a sawtooth shape (photo).

The number of teeth of this wave is about 300 per minute. In this case, the AV node blocks some of the impulses, so the ventricles contract at a frequency of about 150 per minute.

It should be remembered that atrial fibrillation is quite difficult to “catch” on an ECG, since it is a quickly transient condition. Holter monitoring should be performed to detect episodes of flutter.

This diagnostic method is a daily recording of an electrocardiogram. As a result, it is possible to determine the presence of episodes of atrial flutter, their frequency, as well as the situations that contribute to their occurrence.

Determining the causes

Using an ECG, you can determine not only the signs of atrial flutter, but also the causes that cause this condition.

Table. The main causes of atrial flutter on the ECG:

Sometimes the cause of fluttering is sick sinus syndrome. This is a condition in which the main pacemaker (SA node) does not fully perform its function.

In this case, an inferior atrial rhythm develops - on the ECG this means that the pacemaker becomes the atrium itself, or rather, the ectopic foci in it. This leads to unsynchronized contraction of areas of the myocardium.

An atrial rhythm on an ECG in a child can be diagnosed in the presence of certain congenital defects. In a teenager, the atrial rhythm on the ECG is often a consequence of vegetative-vascular dystonia.

Treatment

In most cases, detection of signs of atrial flutter on an ECG does not require special treatment. But in the chronic form, or with a high risk of rhythm failure, cardioversion is performed. This is a way to restore an abnormal heart rhythm using medications or electric current.

Table. Types of cardioversion:

Cardioversion may not be performed on every patient. Contraindications to this treatment method are:

sick sinus syndrome;
acute inflammation of the heart muscle;
bradysystole;
enlargement of the right atrium on the ECG;
the presence of valve defects.

If there are no contraindications, cardioversion helps restore heart rhythm in 97% of cases. If there are organic lesions of the heart, their treatment is required, since otherwise arrhythmia will occur constantly.

ECG changes with atrial flutter are not constant. They can be detected accidentally at the time of an attack, or if Holter monitoring is performed. Arrhythmia does not always require special treatment, and in children it usually goes away on its own with age. But if there is a risk of hemodynamic compromise, cardioversion is required.

Questions for the doctor

Good afternoon. I had a medical examination at work, including a cardiogram. In conclusion, I read that an atrial rhythm was detected on the ECG - what is it, is this condition dangerous?

Irina, 46 years old, Novosibirsk

Good afternoon, Irina. Atrial rhythm is a condition in which the sinus node cannot fully function. In this case, the rhythm is set by foci in the atrial myocardium. This condition can cause various types of arrhythmias, including atrial flutter and atrial fibrillation. Contact your doctor for further testing.

Hello. During the medical examination, I was given a cardiogram, and the ECG revealed a load on the right atrium. What diseases can this indicate?

Nikolay, 52 years old, Lipetsk

Good afternoon, Nikolay. Signs of right atrium overload on the ECG appear in the presence of congenital or acquired valve defects, especially the tricuspid one. You need to do an ultrasound of the heart to identify pathology.