Frederick's syndrome

Frederick's syndrome is a symptom complex consisting of clinical features of pathology and electrocardiographic manifestations that occur with complete atrioventricular block with accelerated contraction of individual muscle fibers of the heart, disrupting the heart rhythm (the pulse is rhythmic, but very rare) and pumping function.

In Frederick's syndrome, the most common disorder is a disruption of the stable functioning of the atria, which begin to contract erratically. A rarer case is when atrial flutter appears on the cardiogram instead of atrial fibrillation, and cardiac examinations reveal a failure of stable intracardiac blood flow. All this leads to the cessation of the movement of electrical impulses from the atria to the ventricles, which entails a complete atrioventricular block.

In the Frederick phenomenon, various functional parts of the heart are affected and the movement of control electrical impulses is disrupted. At first, the human body uses internal reserves. Then pathological processes can already be seen on the cardiogram, and the patient begins to notice various features in his health. Such an unstable situation can be disrupted, the reserves are exhausted, and the patient needs urgent treatment with dubious chances of success.

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Causes Frederick's syndrome

The following may be the sources of severe cardiac pathology:

• Chronic cardiac ischemia (angina pectoris) in a state of stress and rest.
• Cardiosclerotic manifestations that occur after a heart attack.
• Myocarditis (damage to the heart muscle, inflammatory genesis).
• Severe congenital or acquired changes in the structure of the heart.
• Cardiomyopathy (changes in the heart muscle of unclear etiology).
• Myocardial infarction (ischemic heart disease (IHD), leading to necrosis of a section of the myocardium as a result of insufficient blood supply).

All of the above diseases cause vascular sclerosis, which results in proliferation of connective tissue in the heart muscle. Inflammation and dystrophic processes of the myocardium have a great influence on such growth. When connective tissue is formed, it replaces typical cells (cardiomyocytes) that conduct electrical impulses. All this leads to a change in functional conductivity and the manifestation of AV block.

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Risk factors

Factors that may contribute to the development of Frederick's syndrome include:

• taking certain medications (M-anticholinergics, beta-adrenergic agonists and some sodium blockers);
• excessive physical exertion, when stimulated by pharmaceutical drugs;
• diseases of the heart and blood vessels of any genesis;
• hereditary factor (familial hyperlipidemia);
• neurocirculatory dystonia;
• electrolyte imbalance.

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Symptoms Frederick's syndrome

Using the ECG, it is possible to say for sure that the patient has the Frederick phenomenon. The clinical manifestations that accompany it in everyday life, requiring close attention, are the following:

• Rare but regular pulse.
• The contraction rate is from 30 to 60 times per minute.
• Fatigue.
• Drowsiness.
• Dizziness.
• Fainting states.
• Cyanosis of the face.
• Cramps.

All the symptoms listed above are characteristic of a state of insufficient oxygen supply to the brain. These symptoms may also indicate other diseases of both the cardiovascular and nervous systems.

Only the use of an electrocardiogram with a high degree of probability allows us to confirm or refute that the patient has the Frederick phenomenon. Clinical manifestations accompanying it in everyday life, to which the patient should pay attention to a rare but regular pulse with a heart rate of at least 30 and no more than 60 times per minute. A drop in pulse rate is noted due to the fact that the pumping work of the heart is reduced.

If a person does not pay attention to the listed symptoms, they may worsen, a short-term (5-7 sec.) cardiac arrest may occur, and loss of consciousness may occur due to increased ventricular contraction.

The first signs of Frederick's syndrome

Frederick's phenomenon can be suspected if the patient complains of:

• Unstable heart function.
• The heart rate slows down.
• Weakness is noted.
• Shortness of breath combined with interruptions and slowing of the rhythm.
• The appearance of peripheral edema of the ankle joints at the end of the day.
• The electrocardiogram shows atrial fibrillation.

The Frederick phenomenon does not have any clearly defined symptoms; they are more similar to various cardiac diseases.

Diagnostics Frederick's syndrome

The clinical picture of the disease with Frederick's phenomenon loses the features characteristic of atrial fibrillation. Changes associated with complete transverse blockade begin to come to the fore:

• No complaints of palpitations or irregularities in the functioning of the heart muscle.
• There are attacks of dizziness.
• Loss of consciousness.
• Heart sounds are rhythmic.
• The pulse is regular and rare.

It is difficult to diagnose this syndrome clinically. This condition can be suspected in a patient only if there is a permanent form of atrial fibrillation, as well as loss of consciousness, a slow pulse. If atrial fibrillation is combined with atrioventricular block, the patient's condition worsens significantly, especially with a rare ventricular contraction rate (20-30 beats per minute). The patient may have attacks of loss of consciousness. They are associated with insufficient oxygen supply to the brain, during a period of prolonged cessation of cardiac activity with the disappearance of bioelectrical activity. Death may occur during this period.

Heart failure appears or increases. In Frederick's syndrome, the patient's condition largely depends on the established ventricular contraction rate. In some cases, when the ventricular contraction rate is established within 50-60 beats per minute, the patient may experience a satisfactory condition. The disturbing subjective manifestations of atrial fibrillation disappear:

• Heartbeat
• Heart failure
• Pulse - regular rhythmic
• When articoventricular block develops, it seems to the patient, and often to the doctor, that atrial fibrillation has disappeared and the sinus rhythm has been restored. Blood circulation remains at a good level for quite a long time.

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Tests

When a pathology such as Frederick's syndrome is detected, the following tests may be prescribed for a more complete examination of the patient:

• Clinical blood test is a laboratory diagnostic method that includes counting various types of cells in the blood, their size, shape, etc.; hemoglobin level; leukocyte formula; hemacrit.
• A biochemical blood test is a laboratory study that allows you to determine: how internal organs (kidneys, liver, etc.) work; learn information about metabolic processes (lipid, protein, carbohydrate); determine the body's need for microelements.
• Lipidogram is a blood test for cholesterol, low-density lipoproteins, high-density lipoproteins, triglycerides and the reasons for changes in the indicators of this study.
• Reberg test or endogenous creatinine clearance. Helps the doctor evaluate the excretory function of the kidneys, in addition, the ability of the renal tubules to excrete or absorb various substances.
• Clinical urine analysis is a laboratory test that allows for an assessment of the physicochemical characteristics of urine and microscopy of sediment.
• Urine analysis according to Nechiporenko is a laboratory diagnostic method that can be used to determine the presence of leukocytes, erythrocytes and cylinders in urine, and to assess the condition and functioning of the kidneys and urinary tract.

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Instrumental diagnostics

To establish an adequate diagnosis, the following types of studies may be prescribed:

• An electrocardiogram (ECG) can detect tachycardia or bradycardia, and various heart blocks.
• Holter monitoring (HM) is a functional study of the CVS (cardiovascular system).
• Transesophageal electrophysiological examination is used to diagnose transient blocks using conventional ECG and HM methods.
• Chest X-ray helps determine the size of the cardiac shadow and the presence of venous congestion.
• Ultrasound examination (ultrasound) of the heart helps to identify pathological changes in the myocardium
• Treadmill test or bicycle ergometry – identifies coronary heart disease and evaluates the increase in heart rate contractions under the influence of physical activity.

ECG signs of Frederick's syndrome

When the Frederick phenomenon becomes persistent, the ECG records:

• the conduction system in the ventricles is deformed and dilated;
• the P wave disappears;
• An increase in the frequency of ff waves is noticeable, which reflect pre-atrial fibrillation, or large FF waves are recorded, indicating atrial flutter;
• Ventricular rhythm of non-sinus nature - ectopic (nodal or idioventricular);
• The RR interval is constant (the rhythm is regular);
• The number of ventricular contractions is no more than 40 - 60 per minute.

Frederick's syndrome accounts for 10-27% of cases of complete atrioventricular block.

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Differential diagnosis

Frederick's syndrome must be distinguished from bradystolic atrial fibrillation. In bradystolic atrial fibrillation, chaotic contractions of the ventricles are observed, while in Frederick's syndrome, the R-R distance is the same. Physical activity contributes to an increase in heart rate in arrhythmia, while in SF, the rhythm is normal. It should be borne in mind that the main distinguishing factor of the bradystolic form of atrial fibrillation is incomplete transverse heart block.

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Treatment Frederick's syndrome

If AV block is detected, serious and long-term treatment will be required. The goals of such therapy are:

• Preventive measures to prevent sudden death due to abnormal heart function.
• Alleviation of clinical manifestations.
• Prevention of exacerbations (heart failure).

Treatment includes drug and non-drug therapy. Non-drug treatment is based on compliance with dietary instructions by those patients who have a history of diagnoses of coronary heart disease, arterial hypertension and decompensation of cardiac activity. If possible, drugs that aggravate heart block are discontinued. Such drugs include antiarrhythmic drugs, calcium antagonists, etc.

Drug therapy is used to eliminate the causes that caused the complete block. Also, its main focus is the treatment of the underlying disease. It is necessary to limit or exclude drugs that worsen AV conduction.

Taking anticholinergics, such as atropine, is prohibited due to the occurrence of pathologies of the central nervous system in the patient (“atropine delirium”).

Surgical treatment

Third-degree block combined with ventricular fibrillation requires surgical treatment, the main goal of which is the implantation of a permanent pacemaker.

During the surgical intervention, single-chamber ventricular stimulation (VVI or VVIR) may be used. For this procedure, electrodes are placed in the ventricle of the heart, one stimulating the heart muscle, and the other causing it to contract. The number of contractions is preset (usually 70 shocks per minute).

The VVIR mode means the following - two electrodes (stimulating and receiving) are located in the right ventricle and during spontaneous activity of the ventricle its stimulation will be blocked. This is the most optimal stimulation method.

Prevention

Heart block is a very serious disease. If the prognosis worsens and additional diseases are present, regular visits to a cardiologist are necessary. If any problems are detected during the examination, it is necessary to immediately begin treating them and not neglect the doctor's recommendations.

To support the heart muscle, you need to take medications containing magnesium and potassium. The doctor will help you choose the required amount of these elements.

In Frederick's syndrome, maximum effort must be made to keep the heart working, but these efforts lead to a prolongation of life.

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Forecast

The duration of disability and prognosis depend on the severity of the underlying disease.

If fainting occurs due to a sharp decrease in heart rate and cerebral ischemia as a result of a sudden disturbance in heart rhythm (Morgagni-Adams-Strokes attack) and an ECS (electrocardiographic stimulation) is not implanted, the patient's life expectancy is about two and a half years.

Improvement in the quality of life of patients occurs through constant stimulation.

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