BOUVERET'S DISEASE (grech, paroxysmos irritation, excitement; tachycardia) — the pristupoobrazny increase of number of cordial reductions caused by pathological circulation of extrasystolic excitement or patholologically high activity of the center of geterotopny automatism in heart. Cordial reductions at P. of t. are strictly rhythmical, their frequency usually fluctuates from 120 to 220 in 1 min., at children can reach 260 in 1 min., the extent of an attack — from several seconds to several days, and sometimes and weeks, and the frequency of reductions does not change.
Wedge, picture P. of t. Buvre (L. Bouveret, 1899) and Goffmann (J. Hoffmann, 1900) was in details described in this connection this syndrome was called Buvre's disease earlier — Goffmanna.
In the location of the ectopic center of the automatism which is in the period of P. t. a pacemaker, allocate three of her forms: atrial, atrioventricular connection and ventricular. The first two forms name supraventricular P. t. Most of cardiologists P.'s emergence t. under the influence of an impulsation, coming from a sinus node (sinus P. of t.), does not admit though there are data on possible localization of the center of an impulsation in the fabrics directly adjacent to this node.
Border between group premature ventricular contraction and a short attack of P. of t. it is carried out conditionally. It is considered to be that if number of the ectopic reductions following one after another in a frequent rhythm more than three, then it is necessary to tell not about group premature ventricular contraction any more, and about a short paroxysm of tachycardia. Nek-ry cardiologists consider a paroxysm of tachycardia a series from bigger number of ectopic reductions.
In nek-ry cases short attacks of P. of t., consisting of 3 — 6 ectopic reductions, alternate with a sinoatrial rate, and it is sometimes almost constant, within several months and even years. It is accepted to call such cases the repeating form P. of t. Sometimes ectopic tachycardia gains constant character; in these cases it usually is interrupted by the short periods of a sinoatrial rate (so-called persistent tachycardia).
At supraventricular P. of t. its connection with a heart disease at 1/3 persons does not manage to be established. In other cases atrial P. of t. arises more often against the background of rheumatic heart diseases, is slightly more rare — against the background of a miokarditichesky cardiosclerosis, coronary heart disease, a thyrotoxicosis and an idiopathic hypertensia. Item of t. atrioventricular connection can develop at overdose of drugs of a digitalis, heart operations, at coronary heart disease, including at a myocardial infarction. Ventricular form P. of t. arises, as a rule, at severe damage of heart (he does not manage to be revealed only in 1/10 — 1/20 parts of cases) at patients with coronary heart disease, rheumatic defects, myocarditis, at overdose of cardiac glycosides, use of quinidine, a novokainamid, adrenaline and noradrenaline, heart operations, including at catheterization of its cameras and coronary angiography. At any form P. of t. emergence of an attack can be promoted by the emotional or physical pressure, deep breath with a hyperventilation, the act of swallowing, jump of position of a body, an overeating.
Trigger P. of t. the extrasystole is, as a rule, (see. Premature ventricular contraction ). Elektrofiziol, the mechanism which is the cornerstone of development of tachycardia can be various. Atrial form P. of t. it is more often caused by existence of the unidirectional blockade of a part of atrioventricular connection (longitudinal atrioventricular dissociation). In this case the impulse from auricles to ventricles (anterograde carrying out) is carried out by one part of a node, other its part is capable to carry out an impulse in the opposite direction (retrograde). At it lokalnokhm the block there is a mechanism of a repeated entrance of excitement to a myocardium (re-entry): excitement from auricles extends to ventricles and again is returned to auricles, circulating on a vicious circle (circulus movement). Quite often premises for implementation of a repeated entrance of excitement to a myocardium and emergence of circulation of an excitation wave in auricles form in the field of sinoaurikulyar-ny connection. The same re-entry mechanism is the cornerstone of a paroxysm of tachycardia at Wolff — Parkinson — Whyte a syndrome (see); in such cases the impulse can anterograd be carried out on atrioventricular connection, and retrogradno — on an additional bunch of Kent. At the same time ventricular complexes get normal width (the wave disappears And). If excitement gets from auricles to ventricles on Kent bunch, and P. of t is returned to auricles on atrioventricular connection. it is characterized by the wide deformed ventricular complexes.
Ventricular form P. of t., as well as atrial, it is more often caused by the re-entry mechanism, but both forms can be caused also by existence of the ectopic center of the automatism generating impulses with a frequency surpassing the frequency of a sinoatrial rate. In similar cases atrial tachycardia has persistent character more often.
Lack of symptoms of an organic heart disease approximately at 1/3 patients of atrial and atrioventricular P. of t. gave the grounds to assume a possibility of noncardiac) genesis of attacks under influence nek-ry nervous or neurohumoral influences (neurosises, Hypothalamic frustration, viscerovisceral reflexes). In favor of this assumption the possibility of experimental reproduction of the specified forms P. of t testifies. at electric irritation of hypothalamic area, administration of air in cerebral cavities. However elektrofiziol. researches showed that in a myocardium of patients from atrial and atrioventricular P. of t. almost always it is possible to reveal premises for emergence of circulation of an excitation wave: additional ways of carrying out excitement, longitudinal dissociation in atrioventricular connection. Apparently, funkts, condition of c. N of page or patol, viscerovisceral reflexes are not the reason, but the trigger P. of t in similar cases.
P.'s Symptoms of t. depend on duration of an attack, the location of the ectopic center and that disease, against the background of to-rogo the paroxysm developed.
Item of t. begins, as a rule, suddenly, sometimes it is preceded by unpleasant feelings of «interruptions», the «dying down» of heart connected with emergence of premature ventricular contraction.
If the attack proceeds some seconds or minutes, there is only an unpleasant heart consciousness or uncertain feeling of discomfort. At long attacks patients not only feel heartbeat, but also feel the general concern, fear, sometimes there is dizziness. With very high frequency of cordial reductions development of a syncopal state is possible (see. Syncope ). Supraventricular forms P. of t. in half of cases are followed by other displays of vegetative dysfunction: the trembling of a body, perspiration which is speeded up by an urination with allocation of a significant amount of urine of low specific weight, strengthening of a vermicular movement of intestines.
At a research of heart frequent rhythmical tones are listened. Because the diastole is shortened more than the systole, their duration can be made even; at the same time pauses between the first, second and following first tone become identical (a so-called pendulum rhythm, or an embryocardia).
Heart rate at supraventricular P. of t. (140 — 220 in 1 min.) is usually higher, than at ventricular (130 — 170 in 1 min.). However this distinction has relative value; in rare instances at ventricular tachycardia heart rate reaches 220 — 250 in 1 min. and even surpasses these sizes. Because of big frequency calculation of number of cordial reductions is very complicated. Patients with a ventricular form P. have a t. intensity of the first tone, as a rule, changes as a result of disturbance of ratios between auricular systoles (normal caused by activity of a sinus node) and an ectopic rhythm of ventricles. Sometimes during P. of t. there is a cantering rhythm (see. Gallop rhythm ). Pulse of usually small filling. The ABP, especially pulse and systolic, decreases. The long paroxysm, especially at patients with the expressed damage of a myocardium or heart diseases, can cause development of aritmogenny cardiogenic shock (see) or acute left ventricular heart failure (see) with fluid lungs (see). At the same time the size of cordial emission considerably decreases that leads to decrease and a coronary blood-groove, a cut it can be shown by stenocardia, especially at atherosclerosis of coronal arteries of heart, focal dystrophy or even a myocardial infarction. Clinically expressed symptoms of a hypoxia of a brain are observed seldom, but its small manifestations often are registered on EEG.
The paroxysm of tachycardia breaks also suddenly, as well as appears (or it is spontaneous, or as a result to lay down. actions). Occasionally paroxysms of tachycardia are replaced by attacks of an asystolia or very rare rhythm («a syndrome of a takhi-brada», or a sick sinus syndrome), to-ry can be followed by attacks of Morganyi — Adams — Stokes that usually indicates dysfunction of a sinus node. Before recovery of a sinoatrial rate there is a so-called preautomatic pause; its duration depends from funkts, conditions of a sinus node. This pause at patients with a sick sinus syndrome can reach several seconds that sometimes is followed by a syncopal state. After recovery of a sinoatrial rate, as well as before P. of t., separate extrasystoles, coming from the same ectopic center sometimes are registered, activity to-rogo created P. of t. Gradation to a normal sinoatrial rate is observed only at P. by t., the cut is the cornerstone the mechanism of sinus re-entry.
the Diagnosis is made on the basis of the feelings of the sick, characteristic beginning of an attack given to auscultation of heart. For specification of a form P. of t. registration of an ECG is of great importance during P. t.
Electrocardiographic diagnosis. At an atrial form P. of t. the form of a ventricular complex on an ECG, as a rule, does not change — remains same what this patient had it to an attack. The tooth of P can remain positive, but in a form in a varying degree differs from a tooth of P in the period of a sinoatrial rate as the course of an excitation wave on auricles changes. If the ectopic rhythm proceeds from lower parts of the auricles adjoining the field of atrioventricular connection, the tooth of P can be negative. Because excitement gets into ventricles from auricles, the usual sequence of teeth of an ECG remains, i.e. the tooth of P precedes the QRS complex. Detection of teeth of P with the QRS complexes which are regularly following them through identical time terms allows to distinguish this form of P. of t. from other its forms, but it is not always easy to reveal a tooth of P since it can accumulate on a tooth T previous cycles; in need of its identification it is possible to resort to registration of additional assignments (esophageal, intra atrial) or records of an elektrogramma of a ventriculonector.
At P. of t., coming from atrioventricular connection, on an ECG the negative tooth P is registered, for the rest it does not differ from an ECG at atrial P. in t. Depending on an arrangement of the ectopic center and features of retrograde carrying out the tooth of P can be located just before the QRS complex, merge with it or follow later (fig. 1). Assessment of a tooth of P at this form meets big difficulties; where she does not work well at all, it is impossible to distinguish this form from atrial on the basis of the usual ECG. If at P. of t. ventricular complexes have a normal form and width on an ECG, and the tooth of P is absent, usually establish atrioventricular P. to t.
At a ventricular form P. of t. the QRS T complex is sharply deformed: duration of the QRS complex, as a rule, surpasses 0,12 sec.; initial and final parts of a ventricular complex become discordant. The separate ventricular complex gets the form characteristic of a ventricular extrasystole. In a form of the QRS complex it is possible to establish in what of ventricles the ectopic center (fig. 2) is located. It is better to be guided in a form of a complex in the first chest assignment (V1). At right ventricular localization of the ectopic center the main tooth of the QRS complex is sent in this assignment down (fig. 2, a), an at left ventricular — up (fig. 2,6). To establish ventricular P.'s source of t. it is possible not always. A tooth of P at a ventricular form P. of t. usually positive, but in these cases it is not connected with the QRS T complex, and follows in, more rare, than a rhythm of ventricles, the speed determined by activity of a sinus node. Retrograde carrying out excitement from ventricles in auricles is occasionally observed; in these cases the deformed QRS complex is followed by negative
R. K tooth in the majority of assignments to rare forms of ventricular P. of t. the so-called bidirectional form belongs, at a cut the multidirectional QRS complexes alternate (e.g., all even complexes have the QRS form, and all odd — the QS form that, apparently, is connected with distribution of an excitation wave on different vnutrizhelu-dochkovy ways owing to the refrakternost developing in them serially after each reduction), and also so-called torsade de point (rotation of the ballerina on a sock), or bidirectional spindle-shaped tachycardia — the form of ventricular tachycardia which is characterized by gradual repeated turn of an electrical axis of heart on 180 °. The reasons of the last form are not clear.
When the ECG manages to be registered at the beginning and at the end of an attack, it is possible to reveal that the first complex beginning P. with t., it is brought closer to the last sinus complex and in essence is an extrasystole, and at recovery of a sinoatrial rate before its first complex there is a preautomatic pause, similar to a compensatory pause at premature ventricular contraction.
In rare instances at supraventricular forms P. of t. there can be a disturbance of intra ventricular or atrioventricular conductivity. Disturbance of intra ventricular conductivity (aberrant carrying out) arises in those cases of tachycardia when in some department of the carrying-out system of ventricles there are disturbances which are coming to light only at tachycardia. In such sites the relative refractory period is increased, and they are not capable to carry out impulses if intervals between them it is less, than duration of this period. As a result at P. of t. on an ECG there can be a picture of a bloyada of a leg of a ventriculonector. To carry out the differential diagnosis between supraventricular P. in t. with aberrant carrying out and ventricular P. of t. very difficult. Existence of the last form is demonstrated by detection of the teeth P following in the rhythm, slower than a rhythm of ventricles; they can be revealed, applying so-called atrial or esophageal assignments. However the vnutrnpolo-stny elektrogramma of heart (fig. 3 and 4) allows to receive the most exact diagnosis.
In fig. 4 the example of differential diagnosis between ventricular tachycardia and atrial tachycardia in combination with blockade of the right leg of a ventriculonector on the basis of data of an endocardiac electrophysiologic research is presented. The electrocardiographic curves received at outside registration at ventricular tachycardia (fig. 4, a) and atrial tachycardia (fig. 4,6) in the corresponding assignments are quite similar among themselves. The tooth of P in assignment of V1 can be interpreted and as a symptom of supraventricular tachycardia, and as a result of the retrograde carrying out from ventricles in auricles sometimes observed at ventricular tachycardia. However on an elektrogramma from the field of atrioventricular connection (giso-gram) registered at ventricular tachycardia it is possible to identify only ventricular oscillations of F whereas at atrial (see fig. 4,6) they are preceded by an atrial tooth And yes the potential of a ventriculonector of H. Lack of two of these components demonstrates that the impulse of excitement is not carried out neither from auricles to ventricles, nor in an opposite direction. At the same time on the elektrogramma which is written down in a cavity of the right auricle teeth And, not connected in time with oscillations of V on an elektrogramma from the field of atrioventricular connection (full atrioventricular dissociation) are visible. On the contrary, at atrial tachycardia with blockade of the right leg of a ventriculonector on an elektrogramma from the field of atrioventricular connection all elements which are available normal and located in the usual sequence are visible. It gives the grounds to come to a conclusion that in this case excitement extends from auricles in ventricles in the regular way, i.e. tachycardia has an atrial origin.
At atrial P. of t. blockade at the level of atrioventricular connection can develop. It can be partial or full. At development of a total block of reduction of auricles ventricles in, much more rare follow in very frequent rhythm, and. This arrhythmia should be differentiated with an atrial flutter, based on absence at P. of t. broadenings of an atrial complex and existence of isoelectric segments of PP.
Rare electrocardiographic option of atrial tachycardia is its so-called multifocal form. Heart rate at the same time is not really high (100 — 120 in 1 min.), but the tooth of P changes the form, at the same time three of its various configurations indicating existence of several sources of an impulse or its distribution on various intra atrial ways are at least noted (migration of a pacemaker in a sinus node). Such form of tachycardia often is a harbinger of atrial fibrillation.
After the termination of an attack of P. of t. the so-called posttakhi-kardnalny syndrome can develop: inversion of teeth T and depression of segments S T. These changes reflect existence of superficial dystrophy of a myocardium and disappear in 1 — 3 week. In such cases are shown dynamic clinic - electrocardiographic observation and additional laboratory researches not to pass a myocardial infarction, to-ry, though it is very rare, can develop in P.'s time of t. or (much more often) to be its cause.
At supraventricular forms, especially at an atrial form P. of t., attacks often (almost in 80% of cases) manage to be stopped irritation of a vagus nerve by massage of a carotid sine (on 20 — 30 sec. alternately on both sides), the pressing by fingers on eyeballs of the patient during 15 — 20 sec. (Ashner's test) strengthened by a natuzhivaniye at the closed glottis (test of Valsal-vy), calling of an emetic reflex. It is important to calm at the same time the patient, and also to give it sedatives. Elderly persons in view of danger have damages of the carotid arteries affected with atherosclerosis to refrain from massage of a carotid sine better.
If reflex influences are unsuccessful, it is necessary to use pharmaceuticals.
At supraventricular P. of t. are effective verapamil (Isoptinum) in a dose of 5 — 10 mg intravenously, novokainamid in a dose of 50 — 100 mg intravenously or intramusculary, propranolol in a dose of 3 — 5 mg intravenously. All these means can lower the ABP that it is possible to warn preliminary intramuscular introduction of 1 ml of 1% P ~ Ra of a phenylephine hydrochloride. Isoptinum should be entered into a vein slowly, having parted 2 — 4 ml of 0,25% of solution of drug in 20 ml of isotonic solution of sodium chloride. Nek-ry cardiologists recommend to enter into a vein 10 mg of undiluted solution of Isoptinum quickly, however thus falling of the ABP is more often observed. Novokainamid also enter slowly or fractionally intravenously (2,5 ml of 10% of bucketed solution of 2 — 3 min. to the general dose of 10 ml) or intramusculary in the same dose (10 ml of 10% of solution). Propranolol (3 — 5 ml of 1% of solution) before introduction to a vein is dissolved in 20 ml of isotonic solution of sodium chloride and entered within 5 — 10 min. under control of an ECG. The paroxysm of supraventricular tachycardia quite often manages to be stopped intravenous administration of cardiac glycosides or 3 — 6 receptions of quinidine on 0,2 g in 2 hours. When the paroxysm arose against the background of overdose of drugs of a digitalis, the good effect gives administration of potassium chloride, to-ry is better to appoint together with glucose and insulin (the so-called polarizing mix: 4 g of potassium chloride, 8 PIECES of insulin in 250 ml of 10% of solution of glucose). If the paroxysm developed against the background of Wolff's syndrome — Parkinsonauayta, then it is recommended to begin treatment with intravenous administration of 2 ml of 2,5% of solution of Ajmalinum in 10 — 20 ml of isotonic solution of sodium chloride or intravenous administration of lidocaine (120 — 150 mg).
At a ventricular form of a Bouveret's disease most often apply lidocaine, 1% solution to-rogo enter intravenously in a dose 10 — 15 ml struyno. If necessary administration of lidocaine can be repeated. It is effective, but causes side effects novokainamid more often.
If use of pharmaceuticals the attack of tachycardia does not manage to be stopped, especially when heart failure accrues, it is possible to apply other methods: at supraventricular P. of t. — so-called urezhayushchy stimulation (see. Cardiostimulation ), and at ventricular — countershock (see).
The forecast and Prevention
the Forecast depends on a form P. of t., from a basic disease, against the background of to-rogo it arose, and duration of an attack. The forecast at atrial P. is optimum of t. when the heart trouble is not defined. Ventricular P.'s cases of t have the heaviest forecast. at patients with coronary heart disease, especially a myocardial infarction. The forecast is adverse and at it is long the proceeding P. of t. If the attack does not manage to be stopped within ten days or it is possible, but only for the short period, then the lethal outcome is possible.
Prevention. Prevention of a recurrence of P. of t. it is made taking into account its form, origins and frequency of a recurrence. At rare paroxysms (one for several months or years) their medicinal prevention is inexpedient, but to the patient make recommendations about an occasion of a way of life, employment (if necessary); smoking and alcohol abuse are excluded. At P. of t., connected with a heart trouble, therapy and prevention of exacerbations of the main disease is carried out. At a frequent recurrence of P. of t. there is a need for use of sedative and antiarrhytmic means: propranolol on 20 — 40 mg 4 times a day, a kordarona — 7 days on 0,6 g a day, then 7 days on 0,4 g, are long after that on 0,2 g a day in one step (by with a sick weight less than 70 kg it is necessary to do 1 — 2 time a week a break in administration of drug); quinidine on 0,2 — 0,4 g 4 times a day (or hini-dyne-durules on 0,25 — 0,5 g 3 times a day) or drugs of an aminoquinolinic row — Chingaminum on 0,25 g or plaquenil and on 0,2 g, the first 10 days 3 times a day, and further 1 time, one night better. In some cases, especially at the patients receiving diuretics use of drugs of potassium (potassium chloride, Pananginum) is reasonable.
At some patients, including with a ventricular form P. of t., its prevention is reached by use Ajmalinum (see) and the drugs supporting him.
Bibliography: Sumarokov A. V. and Mikhaylov A. A. Arrhythmias of heart, page 35, M., 1976; H and z about in E. I. and Bogolyubov V. M. Disturbance of a heart rhythm, page 143, M., 1972; Chernogorov I. A. Disturbances of a heart rhythm, M., 1962; In e 1-1 e t S. Clinical disorders of the heart beat, Philadelphia, 1971.
A. V. Sumarokov, V. A. Bogoslovsky.