From this article you will learn: what is paroxysmal tachycardia, that it can provoke how it manifests itself. How dangerous and cured it is.
What happens in
With paroxysmal tachycardia, a short-term paroxysmal arrhythmia occurs from a few seconds to several minutes or hours in the form of a rhythmicacceleration of heartbeats in the range of 140-250 beats / min. The main feature of such an arrhythmia is that the exciting impulses come not from the natural pacemaker, but from the abnormal focus in the conduction system or myocardium of the heart.
Such changes in different ways can disrupt the condition of patients, which depends on the type of paroxysm and frequency of seizures. Paroxysmal tachycardia from the upper parts of the heart( atria) in the form of rare episodes can either not cause any symptoms at all, or manifests mild symptoms and malaise( in 85-90% of people).Ventricular forms cause severe circulatory disturbances and even threaten to stop the heart, and the death of the patient.
Complete recovery from the disease is possible - medications allow you to remove the attack and prevent its re-emergence, surgical techniques eliminate pathological foci, which are sources of accelerated impulses.
Doctors are cardiologists, cardiac surgeons and arrhythmologists.
What happens with the pathology of
Normally, the heart is shortened by regular pulses, emanating from 60-90 beats / min from the highest point of the heart - the sinus node( the main driver of rhythm).If their number is greater, this is called a sinus tachycardia.
In paroxysmal tachycardia, the heart also decreases more often than it should( 140-250 beats / min), but with significant features:
- The main source of impulse( the pacemaker) is not a sinus node, but a pathologically altered patch of cardiac tissue that must only impulses, and not create them.
- Correct rhythm - the heartbeats are repeated regularly, at regular intervals.
- Paroxysmal character - tachycardia arises and passes suddenly and simultaneously.
- Pathological significance - paroxysm can not be the norm, even if it does not cause any symptoms.
The table shows the general and distinguishing features of sinus( normal) tachycardia) from paroxysmal.
| Features | Sinus tachycardia | paroxysmal tachycardia |
|---|---|---|
| Heartbeat | Frequent | |
| Rhythm | correct, reducing rhythmic | |
| Source | Sinus | heart assembly further focus in the heart |
| flow | gradual beginning and end | episodic, abrupt onset and end of attack |
| value | Maybevariant of norm and evidence of pathology | Always pathological condition of |
All depends on the type of paroxysm
It is of fundamental importanceof paroxysmal tachycardia split into categories depending on the location of the hearth abnormal impulses and frequency of its occurrence. The main variants of the disease are given in the table.
| Localization of | Downstream |
|---|---|
Nadzheludochkovaya( from the upper parts of the heart - 80-90%):
| Acute seizures occur rarely( after several months or years) |
| Constantly recurrent( chronic) - seizures completely pass, but often recur( after a few days or weeks) | |
| Ventricular( from the lower ventricles - ventricles - 10-20%) | Continuously relapsing - a new attack occurs after the elimination of the previous |
The most favorable variant of paroxysmal tachycardia is an acute atrial form. She may not require treatment at all. The most dangerous continuously recurrent ventricular paroxysms - even in spite of modern methods of treatment, they can cause heart failure.
Mechanisms and causes of development of
The mechanism of occurrence of paroxysmal tachycardia is similar to extrasystole - an extraordinary contraction of the heart. Combines their presence of an additional focus of impulse in the heart, which is called ectopic. The difference between them is that the extrasystoles occur periodically chaotically against the background of the sinus rhythm, and in paroxysm, the ectopic focus generates pulses so often and regularly that it takes a short time to perform the function of the main pacemaker.
But in order for impulses from such foci to cause a paroxysmal tachycardia, there must be one more prerequisite, an individual feature of the heart structure - besides the main ways of carrying out impulses( which all people have), there must be additional ways. If people who have such additional pathways do not have ectopic foci, the impulses of the sinus node( the main pacemaker) stably seamlessly circulate along the main routes, without extending to additional ones. But with a combination of impulses from ectopic sites and additional paths, this is what happens in stages:
- A normal impulse, encountering a focus of pathological impulses, can not overcome it and pass through all parts of the heart.
- With each succeeding impulse, the voltage in the main paths above the obstacle increases.
- This leads to the activation of additional pathways that directly connect the atria and ventricles.
- Pulses begin to circulate in a closed circle according to the scheme: atrium - an additional bundle - ventricles - ectopic focus - atrial.
- Because excitation is propagating in the opposite direction, it further irritates the pathological site in the heart.
- The ectopic focus is activated and often generates strong pulses circulating through an abnormal closed circle.
Possible causes of
Factors causing the appearance of ectopic foci in the supraventricular zone and ventricles of the heart differ. Possible reasons for this feature are shown in the table.
| Causes of supraventricular paroxysm | Causes of ventricular paroxysm |
|---|---|
| Congenital and hereditary features - the presence of additional pathways in the heart | Chronic forms of coronary heart disease |
| Poisoning and overdose with cardiac glycosides preparations | Myocardial infarction |
| Neurogenic and psychogenic disorders( neurosis, neurasthenia) | Myocarditis of any characterand the origin of |
| Constant stress, tension, excess adrenaline rush | Cardiomyopathy |
| Alcohol and smoking abuse, narcotic substances | Myocardial dystrophy |
| Thyroid and adrenal gland diseases in the form of excessive hormone production | Congenital heart disease |
| Any serious illness leading to exhaustion, intoxication, disturbance of water-electrolyte balance | Cardiosclerosis of focal character( after a heart attack)and diffuse( general, common) |
Najelous paroxysms are mainly caused by general changes in the body, and not in the heart, Ludochkovye - various organic lesions of the heart.
Symptoms of
Symptoms that can cause paroxysmal tachycardia vary widely - from total absence( in 10% of cases) to critical circulatory disorders with immediate threat of death. Manifestations depend on:
- The types of paroxysm - the atrial flow easier, ventricular heavier.
- Its forms and durations - acute unstable( less than 30 sec.) Do not disrupt blood circulation, chronic and persistent cause alteration and dystrophy( weakness) of the myocardium.
- General condition and age - in young physically healthy people the symptoms are minimal, in older people more pronounced;
- Causal factors and diseases - the symptoms of the underlying pathology layer on the manifestations of paroxysm.
Click on photo to enlarge The table describes the most common common and specific symptoms of ventricular and supraventricular paroxysmal tachycardia at the time of the attack.
| Nadzheludochkovy type | Ventricular type |
|---|---|
| The onset of an attack in 35-55% is felt as a sharp push in the heart region | |
| In 25-45% there is an aura - a sense of approaching an attack, anxiety, fear | |
| Feeling of accelerated heartbeat, tremors in the chest, interruptions in the heart(50%) | |
| Pulse weak and so frequent that it is difficult to calculate | |
| Light or moderate general weakness | Severe weakness, impotence |
| Feeling of lack of air | Shortness of breath, frequent breathing |
| Dizziness | Short-termloss of consciousness |
| Pale skin | Pale blue, cold, sweaty skin |
| Abundant urination or defecation after an attack | Reduction of blood pressure, up to complete absence |
In the interictal period of 90-95%, symptoms of paroxysmal tachycardia are absent.
In 70-75%, the immediate provoker of an attack is: a stressful situation or a strong psychoemotional shock;
The emerging symptoms of paroxysmal tachycardia either completely go away within a few seconds or hours( after the cessation of supraventricular impulses), or overgrow into fibrillation and even provoke cardiac arrest and clinical death.
If a person with a ventricular paroxysmal tachycardia does not provide emergency care, he may die.
Diagnostic methods
To confirm the diagnosis, the following are used:
- ECG during an attack, at rest, and stress tests;
- daily ECG monitoring( Holter);
- ECHO-cardiography;
- transesophageal examination of cardiac electrical activity;
- additional methods - coronary angiography, computed tomography of the heart.
First aid and treatment methods
Because paroxysmal tachycardia is always a pathological condition, its treatment is compulsory. The scope of care is determined by the nature and severity of paroxysmal symptoms.
Tactics should be as follows:
- emergency treatment during an attack;
- prevention of recurrence;
- is a radical treatment aimed at eliminating the cause of paroxysm or an ectopic focus in the heart.
Elementary emergency care during an attack
First aid measures for paroxysmal tachycardia:
- Take the patient.
- Assess consciousness, breathing, palpitation, blood pressure. If they are persistently absent - start an indirect cardiac massage and artificial respiration.
- Create conditions for good fresh air access: free the chest, neck, respiratory tract from compressive and objects that make breathing difficult.
- Call an ambulance on the phone 103.
- Do the following - vagal tests:
- ask the patient to hold his breath after a deep breath, strain or cough;
- gently push on the closed eyeballs;
- push the area of the solar plexus on the abdomen;
- massage the area of the carotid arteries around the neck.
Drug treatment during an attack of
If paroxysmal tachycardia is unstable, does not cause severe symptoms, has gone away on its own or has been eliminated by simple methods, drug treatment is required.
In all other cases:
- Intravenous drug administration:
- Treatment with supraventricular form - Digoxin, ATP, Verapamil, Amiodarone.
- With ventricular paroxysm - Lidocaine, Novokainamide, Amiodarone.
- With low blood pressure - treatment with Mesaton.
- Additionally, you can take a tablet of Propranolol or Metoprolol( if the patient's condition allows and the pressure is not lowered).
- Electropulse treatment, cardioversion and defibrillation - the impact on the heart of electrical impulses. It is shown with expressed or protracted ventricular paroxysms, complicated by fibrillation or threatening to stop the heart.
Radical anti-relapse and surgical treatment
Patients with rare acute paroxysms of tachycardia do not require medication and any special treatment. It is enough to observe a sparing lifestyle in relation to psycho-emotional and physical exertion, to eliminate bad habits and to combat possible causative diseases.
If these measures are not enough and seizures disturb patients, systematic treatment with antiarrhythmic drugs is indicated: bisoprolol, metoprolol, Kordaron.
Surgical treatment should be resorted to if the disease causes severe circulatory disorders or with frequent protracted attacks. Two methods are used:
- Radiofrequency ablation is the elimination of an altered site in the heart with the help of radiofrequency waves directly connected to it through a catheter. The method is effective and safe.
- Stages of a pacemaker - an artificial source of electrical impulses that will become a new rhythm driver.
Radiofrequency ablation 
Consequences and Forecasts
Nadzheludochkovaya paroxysmal tachycardia in 75-85% proceeds favorably, responds well to treatment by adjusting the way of life and taking medication. But if it is not treated, it will progress and intensify, especially among young people.
Ventricular forms are more dangerous, especially if they occur against a myocardial infarction - in 40-50% of cases end in the death of patients during the year. The use of surgical methods by 75-85% improves the prognosis even for patients with the most severe forms of paroxysmal tachycardia.
