Tachycardia - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Diseases Of The Heart And Blood Vessels

Causes tachycardia tachycardia

Symptoms Diagnosis Treatment
tachycardia
Lifestyle, complications and prognosis

correct heart rhythm reductions provided for conducting electrical signals conduction system to the muscle cells, providing a direct reduction of the atria and ventricles.By conducting system include sinus node in the right atrium, the atrioventricular node between the atria and ventricles, bundle of His in the thickness of the partition between the left and right ventricle and the Purkinje fibers in the muscle wall of the ventricles.Normal sinus rhythm set in the node, spreading evenly down and carried out at 60 - 80 beats per minute.Heart rate is supported not only the ability of the heart to the automatism (self-pulse generation), but also by means of neuro - humoral regulation, ie a balancing effect on the heart muscle of the autonomic nervous system (sympathetic and parasympathetic) and chemicals (neurotransmitters), allocated to the nerve contact sitesterminals with conduction syste

m cells or muscle cells.Also on the heart muscle contraction affect adrenal hormones (epinephrine, norepinephrine) and thyroid (T3, T4).

If the effect of the sympathetic nervous system, causing increased heart rate, is prevalent, and if the heart muscle are increased amounts of hormones in the body, toxic agents, or it struck pathological processes (inflammation, scarring), then there is the acceleration of the heart rate, which bearstitle tachycardia.The mechanism of development is associated with a direct impact on the incidence rate of these substances, or the formation of re-entry excitation wave when at blocking the downstream fiber impulse returns and stimulates already cut fiber, ie the undamaged fibers have to a greater number of pulses than necessary.So there is an ectopic focus of excitation.

Tachycardia - a symptom that can accompany many cardiac and noncardiac disease, and is characterized by an increase in heart rate greater than 90 beats per minute while maintaining the correct regular rhythm when the atria and ventricles, though often, but at the same frequency.

following types of tachycardia:

1. The physiological and pathological.
2. sinus and ectopic.

Sinus comes from the sinus node, ectopic - of ectopic excitation center (not located in the sinus node).

Ectopic divided into:

- atrial tachycardia - focus of excitation in the walls of the atria,
- node (atrioventricular) - the function of the initial pulse generation takes over the atrioventricular node, becoming a pacemaker instead of the sinus node, and the excitement extends not only down asOK, but up to the atrium,
- ventricular - focus of excitation in the walls of the ventricles.

Supraventricular by - other supraventricular (atrial and nodal) and ventricular tachycardia can be paroxysmal and neparoksizmalnymi (accelerated).The differences between these two forms are manifested clinically and on the ECG and will be described below.

Causes tachycardia

Sinus tachycardia can be a variant of the norm in healthy subjects and to appear during exercise, stress, use of coffee and nicotine.This is considered to be a physiological tachycardia.Pathological sinus tachycardia is considered if its occurrence led the following diseases:

1. Organic pathology of heart:
- myocarditis
- kardimiopatii, myocardiodystrophy
-
ischemic heart disease - myocardial infarction in the acute stage of myocardial infarction
- heart defects
-bacterial endocarditis
- rheumatic heart disease
- pericarditis
- chronic heart failure
2. Endocrine disorders
- pheochromocytoma (a tumor of the adrenal medulla)
- hyperthyroidism (excessive production of thyroid hormones)
3. Neurogenic disorders
- neuroses
- neurasthenia
-cardiopsychoneurosis
4. intoxication
-
chronic use of alcohol - fever
- septicemia (blood poisoning)
- tuberculosis
- an overdose of drugs - cardiac glycosides, antiarrhythmic drugs, capable of providing proaritmogennoe action (capable of causing arrhythmias - propafenone, quinidine, etmozin), beta - agonists in asthma (salbutomol, Flomax, fenoterol)
5. Other reasons - reduction of pressure as a result of shock, collapse, acute pain

supraventricular tachycardia (atrial and nodal form) is most often caused by endocrine, neurogenic diseases described above, as well as the intoxication of the organism, hypertension, heart diseases, children may develop the syndrome of Wolff - Parkinson - White (ERW - syndrome).

Ventricular tachycardia , especially paroxysmal, is prognostically less favorable form, because it can lead to ventricular fibrillation and cardiac arrest.As a rule, it caused severe organic heart disease listed above.

symptoms of tachycardia

Sinus tachycardia is characterized by an increase in heart rate greater than 90 beats per minute, reaching 150, rarely 180 per minute.In most cases well tolerated by the patient without causing discomfort in the heart.This is especially true of people with a lack of heart disease.In the case of an organic lesion of the cardiac tissue may appear tachycardia episodes palpitations, fatigue, particularly during physical exertion, there are symptoms of the underlying disease (shortness of breath, pain in the heart, dizziness, etc.). If the pulse is constantly speeded up more than one hundred per minute, even at rest, and even more is accompanied by severe discomfort (sensation of hard blows to the chest, feeling stops beating heart, chest pain, loss of consciousness), should consult a doctor to rule out organic diseasesheart, served the cause of sinus tachycardia.

supraventricular tachycardia (atrial and atrioventricular) can be paroxysmal and neparoksizmalnymi.Paroxysm is suddenly developed suddenly ended the attack of tachycardia, lasting from a few seconds to several days and is characterized by an increase in heart rate up to 140 - 250 beats per minute.As a rule, the patient can clearly indicate the beginning and end of the attack, proyavlyayuschegosyasya severe palpitations, pain and discomfort in the heart, shortness of breath, dizziness, anxiety or panic attacks, lower blood pressure.The patient may lose consciousness.

Ventricular tachycardia can be paroxysmal and neparoksizmalnoy.When a sudden paroxysm of developing heart palpitations with a frequency of 140 - 220 beats per minute, accompanied by pressing pains in the neck and chest, sweating, weakness, shortness of breath, pressure reduction.You may experience fainting, neurological symptoms (intermittent limb paresis, visual impairment, speech).If ventricular tachycardia developed with acute myocardial infarction, it may cause cardiogenic shock, pulmonary edema.The frequency of attacks varies from a few short runs (three - four ventricular complex on ECG) per minute to one attack in a lifetime.If seizures recur very often, and the patient is not receiving proper treatment, it may lead to ventricular fibrillation and death.Therefore, in a paroxysm, has arisen for the first time, or frequently recurring paroxysms, should consult a doctor to determine the cause and purpose of treatment, especially if previous therapy ineffective .

Neparoksizmalnye form of supraventricular and ventricular tachycardia (accelerated ectopic beats) are characterized by high, but lower than in paroxysms, heart rate, reaching a maximum of 120 - 130 beats per minute.This tachycardia is much easier tolerated by the patient, and the beginning and end of the increased frequency of rhythm is not always possible to notice.At the forefront complaints related to underlying cardiac disease.Developed with severe organic changes in the heart muscle.For the duration of this type of tachycardia may be from several minutes to several days or even months.

Diagnostics tachycardia

presence of tachycardia can be assumed on the basis of complaints of the patient and the disease, but to determine what his type of tachycardia, it is necessary to carry out ECG and possibly a full examination if the doctor deems it necessary.

1. ECG:
So, the following diagnostic methods can be assigned.During the one-time ECG alone may be registered such features as:
- in sinus tachycardia (often discovered by chance, without complaints of frequent palpitations) - increase in heart rate in the range of 90 - 150 (180) strokes per minute, sinus rhythm, right,P-wave is positive.
- with supraventricular tachycardia - HR 140 - 250 per minute, ventricular QRS complex is normal P-wave during atrial tachycardia may be negative, biphasic (+/-) or deformed, is located in front of the QRS complex, with atrioventricular tachycardia - a negative, it is afterQRS complex (normally when pacemaker is the sinus node, should be placed in front of him)
- with ventricular tachycardia - HR 140 - 220 per minute, QRS complex deformed, expanded more than 0.12 seconds, there is atrioventricular dissociation - ventricles at their own pace,and the atrium in his.Chance posttahikardialny syndrome - a negative T wave and ST-segment depression for some time after the attack of tachycardia (signs of myocardial ischemia due to sharply increased myocardial oxygen demand)
- when neparoksizmalnyh forms of supraventricular and ventricular tachycardia - the signs are the same, not withsuch a high frequency that is within 120 - 130 per minute.

Figures are given ECG with different types of tachycardia:

Normal ECG

Sinus tachycardia

supraventricular tachycardia

Ventricular tachycardia

2. ECG monitoringHolter is necessary for the study of patients complained of disruptions in the heart, as well as for people with organic heart disease.It allows you to register the occurrence of episodes of tachycardia during the day.
3. heart ultrasound is used to confirm or rule out heart disease, which was the cause of tachycardia.It has prognostic value in determining the function of the left ventricle - ejection fraction, stroke volume (see below.)
4. EFI - electrophysiological study of the heart (endocardial and transesophageal - intracardiac) may be appointed to clarify the location of the ectopic focus (topical diagnosis) or,if other methods of diagnosis were uninformative
5. samples of the load (treadmill test, bicycle ergometry) for sinus and supraventricular tachycardia are used to identify the connection to the load and evaluation of tolerance to it.If ventricular tachycardia should be used with caution and only in case the patient indicates that it provokes load tachycardia episode.Cabinet shall be equipped with a set for reanimation as ventricular tachycardia can cause ventricular fibrillation and asystole (cardiac arrest).
6. MRI or cardiac MSCT is used to refine the location, extent and nature of the pathological focus in heart tissue, if any

Also instrumental appointed laboratory tests:
- common blood and urine
- biochemical analysis of blood (hepatic activitykidneys, blood glucose, lipid profile etc.)
- hormonal investigation of suspected pathology of the thyroid gland, adrenal glands, for diabetes
- immunological studies, rheumatologic tests in autoimmune diseases, rheumatic nature of heart disease

Individual survey plan will be appointed by the attendingdoctor on internal reception, self-diagnosis in the presence of complaints of palpitations can not do.

Treatment

tachycardia Sinus tachycardia , occurring in patients without organic heart disease and do not cause significant discomfort, does not require treatment.In the case of tachycardia neurogenic nature require a neurologist's consultation with sedative drugs (motherwort, valerian, St. John's wort, sage, psychotropic drugs).If the patient has an underlying condition that caused tachycardia (cardiac or endocrine disease, alcoholism, sepsis, etc.), treatment is required in the first instance of this pathology.Tachycardia therapy actually reduced to the purpose of beta - blockers (prindolol, carvedilol etc.) or calcium channel blockers (verapamil, diltiazem).
doctor can teach the patient to independently use vagal samples in the event of symptoms of tachycardia - Valsalva maneuver (straining with a deep breath), Aschner (pressure on the closed eyeballs in the supine position), encasing the face with ice cubes or sponging with cold water, try inhaling with a closed glottis, evoking the vomiting or cough reflex.As a rule, these measures within 30 seconds allows to stop unpleasant symptoms due to a reflex slowing heart rate.
With the ineffectiveness of the therapy, the presence of clinical manifestations and concomitant severe disease may be imposed on the testimony of cardiac surgery treatment - radiofrequency ablation of pulmonary veins or the mouth of the implantation of the pacemaker (pacemaker).

attack supraventricular tachycardia independently as possible to try to stop using vagal samples.If this type of tachycardia is already installed before the patient, the symptoms do not significantly pronounced hemodynamic and not, rather visiting doctor in the clinic with treatment if necessary correction.
If the attack palpitations developed for the first time in his life, that is, the patient does not know what his type of tachycardia, and even more so if there is significant pain in the heart, suffocation, hemodynamic instability (a sharp decrease in blood pressure, loss of consciousness)you should immediately call an ambulance.In this case, hospitalization in a hospital with medical - diagnostic purposes.
tachycardia therapy of this type is to assign beta - adrenergic blockers, calcium channel antagonists and antiarrhythmic drugs in tablet form or intravenously (in a hospital).From novokainamid used antiarrhythmics (intravenously), sotalol, etatsizin, VFS, aymalin et al. Amiodarone is rarely used.
In the absence of the effect of the therapy such as surgical treatments can be used, as in sinus tachycardia.

Ventricular tachycardia is more dangerous for the patient's life, so cupping necessarily spent in the hospital. Held intravenous infusion of not less than one day, if you managed to stop the attack antiarrhythmics drugs - lidocaine, procainamide, amiodarone.If the attack is not stopped, and if there are signs of shock (pressure below 80 mm Hg, thready pulse, pallor and skin cyanosis, lack of urine through a catheter) in the department of intensive care patients underwent cardioversion, that is, through the heart of a patient with a defibrillator an electric current of a certain strengthto "restart" the heart and ask him the right rhythm.
After successful recovery rate and discharge from the hospital the patient should be indefinitely taking beta - blockers, and antiarrhythmics.

therapists Sazykina OJ