Heart block - Causes, Symptoms and Treatment .MF .
To heart could provide the blood of every cell in the body, it must be reduced in the right rhythm and with a frequency of 55-60 to 80-90 beats per minute.The rhythm should be regular, with equal intervals between contractions, because the lack of oxygen carried by the blood, even for more than 30 seconds can have an impact on the work of the cell, and first of all, brain cells.The occurrence of oxygen deficiency (hypoxia) of the brain is particularly important for conditions such as heart block.
heart block are heart rhythm disturbances, or arrhythmias.Arrhythmias may be characterized as an increase in heart rate (tachycardia and tachyarrhythmia) and decrease (bradycardia, bradyarrhythmia).
Blockade heart - a group of diseases characterized by a slowing of the electrical signal to the heart, resulting from innate characteristics or, more commonly, diffuse replacement of normal heart muscle scar tissue (connective).In general, lead to the development blockade bradycardia with a frequency of less t
development blockades at this or that disease is due to the fact that often in the pathological process involved portions of the cardiac conduction system.This altered muscle cells, whose main task is to conduct an electrical signal to the heart around regularly held wave excitation.If these cells are exposed to inflammation, are drawn into the scar tissue, or may not transmit a pulse cells that resides on, there is a block on the pulse transmission path.
Depending on which portion of the cardiac conduction system is involved in the pathological process, the following types of blockade:
- sinuauricular (sinoatrial) - when locking the sinus node in the eye of the right atrium,
- intraatrial blockade - in violation of the route of the electric pulseon the walls of the atria,
- atrioventricular - block at the site, "switching" the excitement with the atria to the ventricles,
- intraventricular block, or block the right and left legs Gisa.Often full and complete;one-, two- and Three-beam.With the bundle branch block in the walls of the ventricular myocardium excitation is transmitted uniformly in their walls, causing the rhythmic contraction of the heart.
Depending on how the conductivity pulse broken, partially or completely, distinguish complete and incomplete blockade.
blockade of I - II degree is incomplete, and III - complete.In the first case, not all conductive fibers amazed, so part of the pulse is conducted to the lower portion of the myocardium.With complete blockade of pulses does not take place, so the reduction in downstream areas is carried out or due to ectopic (elsewhere) the centers of excitation, or not done at all.
prevalence of heart block is variable and depends on the age.So, I degree atrioventricular block in young patients occurs in 1% of cases, and the elderly - by 2.4%.The blockade II degree in young people found in 0.003% of the cases, and increases in the elderly.Congenital atrioventricular block III degree is extremely rare - one case per 20 000 live births.The blockade of right bundle branch block occurs in 2 - 5% of healthy individuals, and in the absence of severe cardiac disease may be a variant of the norm.
The causes of heart block
Blockade of I degree and junior branch block, not manifested clinically, may be a variant of the norm or common in athletes, patients with vascular dystonia, as well as in children, adolescents and young persons who have prolapsemitral valve, patent foramen ovale and other small anomalies of heart development.
block II and III degree, full intraventricular blocks, Three-beam blockage (and right, and the two branches of the left leg Gisa) almost always occur when organic lesions of heart tissue.For diseases that cause inflammation or scarring process in the myocardium are:
1. Myocarditis - an inflammation of the heart muscle caused by:
- viral infections - viruses Coxsackie, rubella, measles, Epstein - Barr virus (infectious mononucleosis), influenza, adenovirus,cytomegalovirus
- bacterial and parasitic infections - rheumatic fever, diphtheria, scarlet fever, toxoplasmosis, systemic chlamydia
- autoimmune diseases - rheumatoid arthritis (5 - 25% of patients have heart disease), systemic lupus erythematosus (5 - 15%), systemic sclerosis (20 - 40%)
2. Cardiomyopathy - a group of diseases with pathological changes in the normal anatomical structures of the heart (a significant thickening of the heart walls, or on the contrary, their thinning with the expansion of internal cavities of the heart, prevents them from properly contract and relax).May develop coronary heart disease, hypertension, imbalance of hormones in the body, the toxic effects of alcohol, drugs, metabolic disorders, myocarditis.
3. Cardiosclerosis - muscle tissue scarring involved in inflammation or necrosis zone area (death) following myocardial infarction.
5. Acute myocardial infarction - 15% of patients having conduction disorders.
6. Congenital and acquired heart defects.
7. intoxication cardiac glycosides, beta - blockers, the heart rate slows.
8. Hypertension frequently causes a disturbance of conduction in the atria of the heart.
symptoms of heart block
blockade degree I, incomplete single-beam branch block feet, intraatrial blockade, as a rule, does not manifest itself clinically and can be detected only by ECG at the planned survey.
Complete blockade manifested symptoms of arrhythmias and signs of the underlying disease.These clinical manifestations can occur suddenly, amid well-being, and there may be long-term, with the worsening of the period to which the patient has adapted and "learned" not to pay attention to them.However, if you noticed at some of these symptoms, you should consult a doctor for examination, because some symptoms can be a sign of impending dangerous conditions.
Symptoms of arrhythmias:
- weakness, fatigue, decreased ability to perform previous physical work,
- a sense of disruption of the heart - a sense of fading or heart failure, discomfort behind the breastbone,
- dizziness, flickering flies in front of the eyes, sudden totalweakness with a feeling of dizziness, tinnitus,
- attacks Morgagni - Edemsa - Stokes (MES seizures) - a sudden sharp pallor, cold clammy sweat, thready pulse rare, loss of consciousness, seizures may be due to brain hypoxia.As a rule, after much second or two - three minutes, consciousness is restored, but if that did not happen, and breathing and heartbeat absent, then developed asystole (stop) of the heart and clinical death,
- complete left block bundle branch block, which developed suddenly for the first timelife, can lead to acute left ventricular failure with pulmonary edema, which is characterized by dyspnea, cough, similar to the foam, the skin blue lips, face, fingers, a state of shock.
symptoms of the underlying disease - chest pain during exercise or at rest in patients with coronary heart disease, shortness of breath, cold hands and feet, cyanosis (bluish color) fingers, nose, ears, or just the face and extremities with heart defects, headaches occipitallocalization with nausea and vomiting, hypertension, high fever or prolonged temperature increase does not exceed 37.5º C in infections, skin and joint disease in systemic diseases and many others.
Diagnostics heart block
Preliminary diagnosis doctor may think more in refining the nature of the patient complaints.The following methods are used to further diagnose:
- standard ECG - basic informative method for proving the existence of the blockade.However, not always single electrocardiogram can "catch" the blockade signs, especially in the case of transient blockades heart.
Signs sinoatrial blockade - periodic loss complexes P - QRS due to the fact that not every impulse from the sinus node reaches the atria, and hence the ventricles.Increasing the RR interval is two and sometimes more than once.
Signs intraatrial blockade - splitting and expansion with a 0.11 wave P, and the related lengthening of PQ interval.Sometimes there is an additional negative prong P (when complete dissociation of the right and left atria and their abbreviations in a separate rhythm).
Signs atrioventricular block of I degree - permanent lengthening of PQ interval over 0.20, II of the degree type by type Mobitts 1 - with each subsequent reduction of PQ interval is more extended, until the fall one heart set of P-QRS, further whole cycle repeatsagain.The blockade II degree on the type Mobitts 2 - length of PQ interval in each contraction equally extended to more than 0.20, and ventricular QRS complexes fall randomly, with no clear periodicity and can be deformed.The blockade II extent 3 type - is not every second or two or more complexes of P-QRS row.Siege III degree - complete separation of rhythm the atria and ventricles - the frequency of contractions of the atria - 70 - 80 per minute, the ventricles - 40 - 50 per minute or less.Atrial P tine not associated with ventricular complexes QRS, may be laminated to be before or after them.
Signs intraventricular blockade: the incomplete blockade - QRS complex is not expanded, not deformed, there are changes in tooth R (enlarged and serrated) and S-wave in the left or right, respectively blockade leads type (right go left leg);under complete blockade - advanced deformed QRS complexes with a wider 0.12, a deep S wave in the respective leads (III, aVF, V 1,2 at the right blockade, I, aVL, V 5, 6 at the left block).
complete left bundle branch block blockade
- ECG monitoring during transient blockade informative, as it allows to analyze the heart rhythm and conductivity throughout the day, including at night.
- ECG with a load is applied to determine the exercise capacity, functional class allows you to set the coronary heart disease and chronic heart failure.
- echocardiography, chest X-ray, MRI of the heart, coronary angiography used to search for the underlying disease, entailing a conduction abnormalities.
treatment of heart block
blockade Therapy begins with the treatment of the underlying disease.Blockade of I degree, not manifested clinically, do not require treatment.
case of overdose drugs, slowing down the rhythm, carried out a complete cancellation of these drugs.With heart block contraindicated beta - blockers (propranolol, bisoprolol, atenolol, propranolol, tenorik, obzidan, egilok etc.), cardiac glycosides (strofantin, Korglikon, digoxin), antiarrhythmics (aymalin, Cordarone, verapamil, diltiazem, quinidine).
When functional blockades associated with vascular dystonia, small abnormalities of the heart, playing sports, at the sinoatrial blkadah I - II degree, and intracardiac blockades prescribers, improve metabolism in the heart muscle - ATP Riboxinum, vitamins, anti-oxidants (ubiquinone mexidolaktovegin).
complete atrioventricular block treated appointment isoprenaline and ortsiprenalina course, then decide whether to implant an artificial pacemaker.
no specific drugs for the treatment of intraventricular blockade there.In severe cases (complete blockade of the right or left on the background of an acute myocardial infarction, two - Three-beam and the blockade, especially with attacks MES) used temporary or permanent pacing.
First aid blockade
heart as first aid for a patient with seizures MES Showing 1 - 2 tablets under the tongue izadrina (5 - 10 mg), subcutaneous administration of atropine, intravenous adrenaline, noradrenaline.In the absence of respiratory and cardiac - chest compressions and artificial respiration to the arrival of an ambulance.
ambulance in case of clinical death held cardioversion (rhythm recovery) using electrical discharge from a defibrillator and emergency hospitalization in the intensive care unit for further address the issue of the artificial implant cardioverter - defibrillator in the heart.
For the treatment of the underlying disease are used non-steroidal anti-inflammatory drugs, glucocorticoids (prednisone, hydrocortisone), penicillin antibiotics, diuretics (diuretics), antihypertensive drugs (enalapril, perindopril), aspirin to reduce thrombus formation in the bloodstream and in the heart walls, drugs, normalizingcholesterol (statins), and others.
Lifestyle cardiac blockade
Lifestyle reduced to voltage correction increases in dietary protein, vegetable fats and complex carbohydrates and limitation animal fats and simple carbohydrates, reducing significant physical exertionthe proper organization of the regime of the day with plenty of leisure time.
child with congenital or acquired heart block can not lead a normal for children his age, lifestyle, since he will not be allowed physical education classes, visiting sports teams and clubs, and any significant load.The young man with the blockade II degree or higher, most likely, will not be fit to serve in the army.The issue of child bearing women are strictly solved individually with the participation of doctors in a consultation cardiologist, cardiac surgeon, obstetrician - gynecologist and other specialists.
is mandatory timely access to a doctor with an increase of unpleasant symptoms and significant deterioration in health.A patient with a blockage should take responsibility for their disease and understand that a high degree of blockade may at any time be fatal.To this did not happen, to be attentive to their health, listen to the advice of doctors and to abide scrupulously by their diagnostic and therapeutic purposes.
Heart Complications include:
- the progression of the blockade, for example, AV - block of 1 degree often progresses to blockade II degree type 1, rarely - to complete AV - block.In this regard, it is important to dynamic monitoring with ECG - monitoring the patient.Initially available AV - block II degree type II often progresses to a total blockade.
- complete blockade complications - acute left ventricular failure with pulmonary edema, ventricular asystole, and sudden death.
- the progression of chronic heart failure.
- pulmonary embolism, myocardial infarction, ischemic stroke.
Prevention is the competent medical treatment of the underlying disease, the timely identification of indications for pacemaker implantation.
Weather forecast for the blockade of I degree in the absence of organic heart disease favorable.
For complete blockade prognosis depends on the nature of the underlying disease, the degree of cardiac function and stage of chronic heart failure.The frequency of attacks and the number of MEAs are not predictors of mortality, that is, do not affect the prognosis - some patients attacks may occur frequently, while others have a single bout of a lifetime can lead to death.
The prognosis for patients with acute myocardial infarction complicated by the development of a complete right or left bundle branch block, extremely unfavorable.
therapists Sazykina OJ