Arrhythmias are a violation of cardiac conduction, as well as the frequency and regularity of its contractions, resulting in a disruption in the normal functioning of the heart and subjectively unpleasant symptoms.
Arrhythmias are understood to mean any changes in the work of the heart, which, as a result, violate its proper contraction, both in speed and in synchronicity of the work of its departments. Normally, the heart beats in a certain rhythm, having in its cycle a successive contraction and relaxation of the atria and ventricles. This is ensured by the harmonious conductive mechanism of the heart, which is formed by:
- automatism (the ability to generate impulses regardless of our will),
- excitability (the ability of his muscles to respond actively to impulse),
- contractility (the ability of muscles to contract under the action of impulses),
- conduction of the heart (the ability to freely conduct a signal to all parts of the heart).
If there is a violation in any of these mechanisms, arrhythmia may develop. Sinus rhythm is normal, all deviations from it are essentially arrhythmias. Arrhythmias can be both independent cardiac pathologies, and occur in the form of complications of other heart problems – heart attacks, ischemia, myocarditis. Arrhythmias are to blame for 15% of heart deaths.
According to the main mechanism of development of arrhythmia can be divided into:
- caused by organic lesions of the heart (usually blockades),
- caused by functional disorders of the heart (disorders of the frequency of contractions, extrasystoles ).
Arrhythmias due to organic causes (when the heart muscle is damaged) can occur when:
- coronary heart disease,
- heart attacks
- developmental disabilities
- injuries and wounds of the heart, including operative,
- heart failure,
Functional arrhythmias result from:
- neurogenic influences, which include activation of the autonomic nervous system, the effects of stress, emotions, mental or physical work, psychostimulants (nicotine, alcohol, coffee, tea), neuroses, nutritional components (spicy, salty, spicy).
- metabolic disorders of electrolytes that are important for the heart (potassium, magnesium, sodium, calcium).
- iatrogenic interventions (caused by treatment), which include diuretics, beta-blockers, cardiac glycosides, adrenomimetiki .
- hormonal influences, such as adrenaline and noradrenaline, an excess of thyroid hormones, ACTH (adrenocorticotropic hormone), cortisol .
- painful conditions such as fever, intoxication, hypoxia, anemia.
- idiopathic disorders (with unknown cause).
With organic arrhythmias, the formation of defects in the heart muscle occurs, because of which it can not normally conduct impulses along the damaged branches of nerves. If the pacemaker is affected – the sinus node, the impulses start to be generated incorrectly.
In functional arrhythmias, there is a violation of the flow of impulses to the heart due to external influences or the inability of the heart is formed to correctly process all the signals coming to it.
Today there are many options for the classification of arrhythmias.
- atrial, localization of lesions in the region of one or both atria,
- ventricular arrhythmias, localization of ventricular lesions,
- sinus problems in the area of the sinus node,
- atrioventricular, localization at the junction of valves.
Classification by frequency of contractions and their regularity:
- irregular rhythm.
The most complete classification, which is based on electrophysiological indicators:
Arrhythmias due to impaired pulse formation
- nomotopic (impulse is formed in the sinus node), they include weakness of the sinus node, arrhythmia, tachi – or bradycardia.
- ectopic ( heterotopic – a pulse is formed outside the sinus node). They are passive and active.
Arrhythmias due to problems with intracardiac conduction pulses. These include:
- sinoatrial blockade
- atrioventricular block,
- intra atrial blockade
- intraventricular blockade,
- syndrome of premature excitability of the ventricles.
Arrhythmias of the combined type.
Symptoms of arrhythmias depend on heart rate and their regularity. It is important whether arrhythmias affect the vital organs on the blood circulation. There may be clinically not manifested arrhythmias, which are detected only on the ECG.
- heart failure,
- heart palpitations with seizures, in violation of well-being,
- feeling of a sinking heart
- chest pains
- feeling choking
- development of shock.
Arrhythmias can be episodic or permanent, aggravated by the influence of negative factors. Complications of arrhythmias are especially dangerous. The most dangerous are:
- fibrillation or flutter of the ventricles,
- circulatory arrest,
- shortness of breath with lung edema,
- bouts of Morgagni- Stox ( syncopal loss of consciousness due to a sharp disturbance in the blood circulation of the brain),
Initially, the patient is asked about complaints and examined, listen to the heart and examine the pulse. The specialist necessarily pays attention to what medications the patient is currently taking. To determine the cause of arrhythmia, you must first assign:
- biochemical analysis of blood: potassium , glucose , thyroid hormones , etc. (both elevated and reduced rates are possible);
- blood test for clotting , including INR – a mandatory study to select the correct dosage of drugs that prevent thickening of the blood.
But to clarify the type of arrhythmia and the severity of the lesion is necessary:
- ECG holding a 12-lead, and daily holter -monitorirovaniya ECG – to identify the very fact of arrhythmia,
- Ultrasound of the heart (echocardiography) at rest and with a dosed physical and drug load (stress tests) – to assess the structural changes in the heart, which can cause conduction disturbances and identify functional impairment and organ function at rest and during exercise,
- transesophageal echocardiography reveals in the heart of the structures kotroye poorly visible during ultrasound through the chest wall, for example, blood clots (thrombi) in the left atrial appendage, which are most often the cause of major complications of atrial fibrillation – ischemic stroke,
- transesophageal electrical stimulation of the heart is used to determine the nature and mechanisms of the formation of certain conduction disorders.
Cardiologists are involved in the treatment of arrhythmias. Therapy of the underlying disease and the simultaneous correction of the heart rhythm.
Depending on the severity and neglect of the disease, different tactics are used: conservative (use of medicinal substances) or surgical.
The following drugs are used in the treatment of arrhythmias:
- cell membrane stabilizers ( procainamide , trimecain , propafenone ),
- adrenergic blockers (atenolol, nadolol ), however, recently, preference is given to such drugs as concor , aegiloc , carvedilol , sotalol ;
- potassium channel blockers (amiodarone),
- calcium channel blockers ( verapamil ).
But it is not so much arrhythmias that are dangerous, but their complications, such as thrombosis and thromboembolism. Therefore, drugs are added to therapy to prevent their appearance:
- antagonists of vitamin K ( warfarin );
- antiplatelet substances (acetylsalicylic acid);
- New oral anticoagulants ( xarelto , pradax ) are the most advanced today, since they simplify their use in many respects, since there is no need to monitor blood clotting rates every month.
It is very important to understand that when using traditional medicine, it is necessary to report their use to your doctor, since there is a high probability of overdose of certain substances that may aggravate the situation.
From other methods prescribe:
- electrical cardioversi (a way to restore the heart rhythm using a special mode defibrillator);
- transesophageal atrial electrical stimulation;
- implantation of pacemakers
- radiofrequency ablation (method of extinguishing pathological impulses).
The prognosis of arrhythmias depends on their type and severity of violations.
A major role is played by concomitant diseases. Thus, each person is individual and everyone needs their own approach and treatment, which the cardiologist must determine.