Tachycardia Symptoms and Treatment
tachycardia called excitation of the atria and / or ventricles at a frequency of more than 100 per minute.It takes only three consecutive excitations of one chamber of the heart (the waves, teeth or complexes on the ECG) to determine tachycardia.The clinical significance of tachycardia is determined primarily by an increase in heart rate, which is not always registered with supraventricular arrhythmias.How to use folk remedies in this illness, see here.
Terminology flow tachyarrhythmias hitherto insufficiently standardized.
call arose for the first time and repeated episodes of the first episode of arrhythmia was proposed in the latest international recommendations for atrial fibrillation - recurrent.In the case of spontaneous closure tachycardia episode is defined as paroxysmal, and if needed cardioversion - a persistent.
Some experts distinguish acute course - when a tachycardia in the acute period of the disease, such as viral myocarditis.For individual tachyarrhythmia characterized by continuousl
Localization: sinus, atrial, atrioventricular associated with PD, ventricular.
Current: sharp, paroxysmal, recurrent.
Movement: return, automatic trigger.
Symptoms: asymptomatic, symptomatic (cardiac failure, hypotension, angina, syncope).
include paroxysmal supraventricular tachycardia tachycardia dominated localization.Most VT occurs in myocardial infarction.
Defeats infarction: myocardial infarction, myocardial ischemia, cardio-myopathy, hypertensive heart, pulmonary heart, heart disease, myocarditis, trauma, surgery, tumor.
Medications: cardiac glycosides, sympathomimetics, anti-arrhythmic drugs, theophylline.
Metabolic disorders: hypokalemia, hypomagnesemia, renal failure, intoxication (alcohol, nicotine, caffeine).
Hypoxia: bronchopulmonary disease, heart failure, anemia.
Endocrine diseases: diabetes, hyperthyroidism.
Autonomic influences: vagotonia, sympathicotonia.
Other reasons: reflex (trauma), braditahikardii syndrome, the WPW syndrome.
Idiopathic (primary electrical heart disease).
Reentry (rientri, reciprocal, recurrent tachycardia).Under certain conditions in the myocardium appears excitation wave propagating in a closed loop.First, an electrical impulse (extrasystolic or sinus) meets land blockade of one of the directions, then this impulse bypassing the obstacle nonexcitability returns through initially blocked portion to form a continuous pulse movement in a closed loop and further excitation of the atria and ventricles.
Most tachyarrhythmias (80%) developed by this mechanism, called in English literature reentry (re-entry).Many
SVT due to congenital structural changes in the heart, predisposing to the development of reciprocating tachycardia.Additional AV pathway promotes orthodromic tachycardia, and longitudinal dissociation of the AV node appears AV nodal reciprocating tachycardia.Ventricular tachycardia is usually caused by reciprocal acquired lesions of the ventricles, eg, due to myocardial infarction.
reciprocating tachycardia begins and ends suddenly.Usually it is "fast" tachycardia with a heart rate of 140-200 per minute.Spontaneous beats and increased frequency of sinus rhythm provoke reciprocating tachycardia.
This is called tachycardia and docked with the programmable pacing.Vagal tests often help with supraventricular reciprocating tachycardia.Enough effective antiarrhythmic drugs, pacing and especially EIT.With EFI in cases of SVT, at least at VT, can be accurately mapped loop reentry and hold ablation sites loop.
Ectopic automaticity (ectopic, automatic focal tachycardia).Tachycardia is caused by increased electrical activity of cells of the conduction system and the myocardium.Automatic tachycardia up to 10% of tachycardias.
most often automatic tachycardia caused by metabolic disorders: hypokalemia, hypomagnesemia, or sympathicotonia sympathomimetics, changes in the acid-base balance, ischemia.Such arrhythmias are common in intensive care patients with acutely ill patients.
For automatic tachycardia is characterized by gradual onset and end.Usually it is "slow" tachycardia with a heart rate of 110-150 per minute, without hemodynamic disorders.
Automatic tachycardia is not induced and not docked or when the programmable pacing quickens.Extrasystoles not cause tachycardia and vagal tests are not able to stop the SVT.
The treatment is essential elimination of metabolic causes of arrhythmia.Ectopic automaticity is usually difficult to leche¬niyu antiarrhythmic drugs and the EIT.
To locate the arrhythmogenic focus in the myocardium by an electrical mapping of the heart can detect and effectively using ablation to eliminate the arrhythmia using catheter ablation.
Activity Trigger (trigger, focal tachycardia).After the excitation wave trace electrical processes do¬statochnoy intensity can lead to tachycardia.Trigger tachycardia inherent features automatic and reciprocal tachyarrhythmias: a gradual beginning and end of the call and relief when pacing (significantly worse than the reciprocal).
Note that regular ECG insufficiently informative for the diagnosis of tachycardia mechanism and holding EFI required.
spoken tachycardia mechanism largely determines the choice of method for treating arrhythmias and antiarrhythmic drug.In 1990 it was developed a classification of antiarrhythmic drugs ( "Sicilian Gambit"), based on the effect of drugs on the electrophysiological mechanisms and vulnerable parameters arrhythmias.However, the complexity of the classification and the inability in many cases to accurately determine the electro-physiological properties of arrhythmia prevent the widespread use of this classification.
was recently asked to classify atrial tachycardia in the focal (focal), including arrhythmias with increased ectopic automaticity, trigger activity and mikrorientri (very small circles recurrent excitation), and with the participation of makrorientri.
Patients with tachyarrhythmias often complain of palpitations.This symptom occurs according to epidemiological studies in 16% of the population.
However, the subjective feeling of the heartbeat is not always caused by arrhythmias.For example, in ECG monitoring only 17-61% heart rate is accompanied by disturbances of heart rhythm.
most common cause of palpitations, not related to arrhythmia, consider mental disorders.For example, in a study B. E. Weber et al.(1996) among the 190 patients with palpitations in 31% of cases the symptom was caused by psychiatric cause.The most common among mental dysfunction occurs in the presence of heart panic disorder.
arrhythmias, especially ventricular arrythmia, may be the cause of chronic cough that persists antiarrhythmic therapy.
ECG Holter ECG and Event-
transtelephonic ECG monitoring
Tactics cupping tachycardia depends on the presence of hemodynamic disturbances and prognosis.In the case of severe complications tachycardia (shock, acute heart failure, acute cerebrovascular accident, myocardial ischemia) show EIT because antiarrhythmic drugs less effective, do not always act quickly and may even worsen the situation, such as reducing blood pressure.
When sinus node dysfunction or AV block grade 2-3 the risk of developing severe bradycardia, asystole until inhibit tachyarrhythmia therapy.
Saving causes tachyarrhythmias (hyperthyroidism, severe heart disease), failure of the relief of the previous attacks or inability to long-term preservation of sinus rhythm do not very promising restoration of sinus rhythm.
Asymptomatic tachycardia often do not require treatment.At the same time in coronary atherosclerosis and increased risk of VF shown restore sinus rhythm.
for non-severe symptoms (fatigue, palpitations, shortness of breath under load) are commonly used antiarrhythmic drugs.
antiarrhythmic drugs used for the relief of tachyarrhythmias
Class 1A: giluritmal, disopyramide, procainamide, quinidine sulfate.
Class 1B: lidocaine, mexiletine, phenytoin.
Class 1C: VFS, moratsizin, propafenone, flecainide, etatsizin.
Class 2: Beta-blockers: propranolol, esmolol.
Class 3: amiodarone, bretylium tosylate, dofetilide, Ibutilide, nibentan, sotalol.
Class 4: Calcium antagonists: verapamil, diltiazem.
other drugs ATP, potassium, magnesium.
Note that the effect of amiodarone, unlike other drugs develops sufficiently slowly, such as when AF average after 5.5 hours (from 2 h to 48 h).This hampers the use of drug-threatening conditions requiring immediate effect.
nibentan drug, showed a fairly high efficiency in the treatment of atrial fibrillation and flutter can be complicated by the long QT syndrome with dangerous ventricular tachycardia.
In the absence of life-threatening situation, a temporary contraindication for cardioversion believe glycoside intoxication, hypokalemia and uncompensated heart failure.If there is no clinical or electrocardiographic signs of an overdose of cardiac glycosides, digoxin cancel before the EIT is not necessary.Otherwise it is better to delay cardioversion, usually more than 24 hours, due to the risk of refractory ventricular tachyarrhythmias.
In the case of low heart rate at SVT, not related to drugs, imeet¬sya damage to the conduction system.Therefore, due to the risk of severe bradycardia pacing may need replacement.
When the patient is conscious and not possible to effect the general anesthesia, to reduce the discomfort of the electric discharge intravenous diazepam (& gt; 10 mg) and morphine.
to recommend short-acting anesthetic drugs to after cardioversion patient quickly recovered and did not need to leave the patient in a hospital overnight.
One common error is the lack of anesthesia.In this case, patients are not only experiencing discomfort, but can remember this feeling.
strong electrical discharge can cause damage to the myocardium, causing changes in the ECG and increased cardiac biomarkers in the blood.
often occurs rise or depression of segment ST (35%), negative T wave (10%).Usually, these changes take place within 5 minutes, but in rare cases may persist for up to 30-60 min.Negative T waves can persist for several days.
in 7-10% of cases after cardioversion increased levels of cardiac biomarkers in the blood.Note that troponin activity, in contrast to the CK and myoglobin does not increase, it is important in the diagnosis of myocardial infarction
Asystole with slips rhythm caused by a massive release of acetylcholine and usually disappear within 5 seconds.When administered atropine-resistant bradycardia.
with unsynchronized cardioversion of the cardiac cycle may be complicated by ventricular fibrillation (0.4%), which can be easily eliminated by repeated discharge.
In 2-3% of cases may develop pulmonary edema after 1-3 hours after restoration of sinus rhythm, the origin of which is unclear.Kol¬laps unspecified nature develops in 3% and may continue for several hours.
the most popular among the possible methods of increasing the efficiency of cardioversion following:
high energy discharge at the outer (720 joules two defibrillators) and internal (200-300 J) cardioversion,
change of position of electrodes,
compression of the thorax,
introduction of anti-arrhythmic drug, and repeat the procedure,
electrical cardioversion on the background of anti-arrhythmic therapy.
causes and predisposing factors
possible, you need to identify and eliminate the cause tachyarrhythmias (hyperthyroidism, coronary atherosclerosis, hypokalemia), and eliminate the predisposing factors (hypoxia, sympathicotonia).Often there are situations when a combination of several factors leads to the appearance of tachyarrhythmia and need complex treatment.
In the case of severe symptomatic tachyarrhythmias usually initially docked tachycardia, and then there is the task of eliminating the causes of arrhythmia.It should also take into account the peculiarities of treatment of arrhythmia based on the existing reasons and the presence of comorbidity.
To prevent tachycardia recurrence following measures are applied:
Removing the cause of the arrhythmia: myocardial revascularization, valve defect correction, the treatment of hyperthyroidism.
antiarrhythmic drug treatment.
non-drug therapies (Catheter radiofrequency ablation, surgery, ICD, pacemaker protivotahikarditichesky).
Elimination of provoking factors.
Precipitating factors tachyarrhythmias
Mental factors: stress, anxiety, dipressiya.
Alcohol, smoking, coffee.
reflex effect: cholelithiasis, swallowing, hiatus hernia, constipation, eating, sharp turn, low back pain and other
Changes in blood pressure..
Eliktrolitnye disorders: hypokalemia, hypomagnesemia.
Medications:. Theophylline, diuretics, hormones and other glands schetovidnoy
noted the importance of identifying precipitating factors that facilitate the occurrence of tachycardia.The elimination or correction of these factors often helps to reduce the frequency of relapses, and the dose of anti-arrhythmic drugs.At the same time the connection between the factors that can trigger arrhythmias, and heart rhythm disturbances are not always proven.For example, in patients with recurrent ventricular tachycardia ICD therapy need not depend on potassium balance disorders.
often in the first few months-years after the onset of paroxysmal tachycardia, there is one or two precipitating factor, and in the later stages are usually numerous situations contribute to the emergence of arrhythmia.
medical or surgical prevention of tachycardia episodes there is an alternative - relief of recurrent attacks.Therefore, you must first resolve the issue of the need for preventive treatment.
Permanent antiarrhythmic drugs has its disadvantages, such as adverse drug effects (including arrhythmogenic).
decision on preventive treatment if adopted positive changes as a result of the treatment greatly outweigh the possible negative aspects.Prophylactic treatment is indicated in the following cases:
Attacks of tachycardia, accompanied by severe hemodynamic disturbances (syncope, angina, shock, acute cerebrovascular accident).
tachycardia can cause ventricular fibrillation (sustained VT with coronary artery disease).
Tachycardia with moderate hemodynamic disorders (dyspnea, fatigue), occurs frequently (for example, & gt; 1 time per week) and demands for relief of intravenous drugs.
Tachycardia often recur and cause subjective discomfort without significant hemodynamic disturbances.
criteria of treatment effectiveness
To evaluate the effectiveness of preventive treatment for symptomatic paroxysmal tachycardia can focus on the patient experience.In this case, the period of observation is required in excess of the maximum interval between bouts of tachycardia is not less than 3 times.
Results of treatment of frequent daily paroxysms of tachycardia may be assessed using a daily ECG monitoring by comparing the frequency of arrhythmia episodes before and after treatment.In this case, you must take into account the variability in the frequency of arrhythmias in different days.