RU2169586C2 - Method for two-chamber electrostimulation of heart - Google Patents

Abstract

FIELD: medicine, cardiosurgery, cardiology. SUBSTANCE: an electric pulse is applied to the ventricles of the heart in a preset time interval with the aid of a two-chamber electrocardiostimulator and electrodes. Detection of precardiac potentials is carried out by the transesophageal method by means of the two-chamber electrocardiostimulator. The electric pulse is transmitted to the surface of the patient's body to the region of the additional ventricle flip-flop electrocardiostimulator. This pulse serves as a starting signal to generation of an electric pulse and application to the myocardium of the ventricles of the heart by the electronic circuit of the ventricle flip-flop electrocardiostimulator. EFFECT: simplified procedure, can be carried out in a hospital room, provision is made for simultaneous central homodynamics. 3 tbl, 1 dwg

Description

 The invention relates to medicine, namely to cardiac surgery and cardiology, and can be used to diagnose and correct disorders of central hemodynamics during electrical stimulation of the heart.

 Two-chamber electrical stimulation of the heart is an effective way to correct central hemodynamic disorders in patients with brady and tachycardia. Two-chamber electrical stimulation of the heart is effective in patients after heart surgery, patients with complicated myocardial infarction, pacemaker syndrome, and in the treatment of cardiomyopathies. There are various methods of bicameral pacemaker conducted by endocardial and myocardial methods / Bredikis Yu.Yu., Stirbis P.P., Drogaytsev A.D. Programmable cardiac electrical stimulation (clinical aspects). - M .: Medicine. 1989 .-- S. 67-69 /.

 The disadvantages of these methods are invasiveness, the inability to quickly start electrical stimulation of the heart in patients with life-threatening bradycardia, limited possibilities for use in emergency situations, during surgery, and also against the background of a previously implanted permanent pacemaker.

 The prototype of the proposed method is a two-chamber electrostimulation of the heart, carried out using a two-chamber pacemaker and atrial and ventricular electrodes installed in the heart cavities, through which the detection of native electrical potentials of the heart directly from the wall of the heart cavity and subsequent application after a predetermined time interval corresponding to the time of atrioventricular conduction of the heart, an electrical impulse to the ventricles of the heart with an amplitude of the impulse, and 75% greater than the excitation threshold value infarction / Bredikis YY, Stirbis PP, Drogaytsev AD Programmable cardiac electrical stimulation (clinical aspects). - M .: Medicine. 1989. - S. 71-72 /.

 The disadvantages of the method are invasiveness, the need for x-ray control of the location of the contact head of the electrode and puncture of the central veins (in the case of the endocardial intervention technique) or pericardiotomy (in the case of the myocardial technique), time consuming, requiring bed rest for patients, the need to use two (atrial and ventricular) electrodes , difficulty in achieving the stability of the intracavitary position of the atrial endocardial electrode, the risk of developing hemo- and nevmotoraksa.

The invention is aimed at solving the following problems:
- improving the efficiency and simplification of the method of two-chamber electrical stimulation of the heart;
- selection of the optimal model and mode of an implantable pacemaker, justification of the operation methodology and device parameters before the operation.

 These problems are solved by detecting native atrial activity and the subsequent application of an electrical impulse to the ventricles of the heart after a predetermined time interval corresponding to the time of the atrioventricular cardiac conduction using a two-chamber pacemaker and electrodes.

 New in the method is that the detection of atrial electric potentials of sinus origin is carried out transesophageally using an external two-chamber pacemaker, then an electrical impulse is transmitted to the patient’s body surface in the area of the body and electrode of an additional single chamber ventricular pacemaker. The applied electrical impulse is a trigger signal for the electronic circuit of the ventricular trigger pacemaker, which in turn transmits an electrical impulse to the heart through an implanted electrode with an energy value exceeding the excitation threshold of the ventricular myocardium.

 The method is shown in the drawing, where 1 is a single chamber ventricular trigger pacemaker; 2 - esophageal electrode; 3 - the esophagus; 4 - sinus node of the heart; 5 - external two-chamber pacemaker; 6 - unipolar cutaneous electrode; 7 - implanted ventricular electrode.

 The method is as follows. In a patient with an atrial rhythm of sinus origin and an implanted single-chamber ventricular biocontrolled pacemaker (1), a cardiac electrostimulation program is installed using a regulating device (programmer): the mode is trigger (VVT), the sensitivity is unipolar with an absolute value of 0.5-1 mV, the pulse amplitude is by an amount exceeding the threshold of excitation of the ventricular myocardium.

 Note: the developed method of two-chamber electrostimulation of the heart is contraindicated in patients with a ventricular pacemaker programmed for inhibition (VVI) mode due to the risk of disconnecting the electronic circuit of the implanted device with cutaneous electric stimuli. This can lead to severe clinical symptoms in patients dependent on a pacemaker.

 A sterile prepared esophageal bi- or multipolar (type PEDSP-2 or PEDM - 4,6,9; all production of SLE MET, Kamenetz-Podolsky, Ukraine) electrode (2) is introduced into the patient's esophagus (3) through the nasal passage. The optimal localization of the electrode in the esophagus is determined by the maximum amplitude of the recorded bipolar atrial electrogram activated by the sinus node of the heart (4). In this position, the esophageal electrode (2) is fixed to the wing of the nose of the patient with adhesive tape. The selected poles of the esophagus electrode (oriented according to the maximum amplitude of the electrogram) are connected to the terminals of the atrium of the external two-chamber pacemaker (5), for example, an implantable pacemaker EKS-444 manufactured by ZAO Elestim (Russia) or model 3070 manufactured by Peissetter St. Jude Medical (USA).

Install the program of a two-chamber pacemaker (5):
1. Mode - two-chamber universal sequential (DDD) or atrial-dependent (VDD);
2. The base frequency of pacing - should be 5-10 imp / min below the frequency of the sinus rhythm (usually the base frequency is set to 50 imp / min);
3. The maximum frequency of pacing - depends on the age of the patient, the presence of angina pectoris, myocardial infarction (more often set to a value in the range of 90-140 imp / min);
4. Atrioventricular interval - in the interval from 62 to 250 ms.

 The amplitude of the electrical impulse of the ventricular channel of the external two-chamber pacemaker is set individually for each patient, taking into account the programmed sensitivity of the implanted trigger pacemaker. More often set to a value in the range of 0.5 - 2.5 V.

 The proximal segments of unipolar electrodes (6) are connected to the terminals of the ventricular channel of the two-chamber pacemaker, for example, an EPVP type produced by SLE MET. The distal segments of the same electrodes are attached dermally with an adhesive tape so that one is placed 1 cm from the subcutaneous bed of the implanted ventricular trigger pacemaker, and the other in the region of the apical impulse of the heart (corresponds to the projection of the intracardiac contact head of the implanted ventricular electrode).

 After turning on the autonomous power source, the external two-chamber pacemaker (5) recognizes the electrical activity of the atria activated by the sinus node of the heart, then, after a predetermined time period corresponding to the atrioventricular conduction of the heart, transmits an electrical stimulus to the bed area of the implanted ventricular trigger pacemaker (1). An electrical stimulus applied to the skin is a trigger for an electronic circuit of an implanted ventricular trigger pacemaker. The latter through an implanted electrode (7) applies an electric impulse to the myocardium with a value sufficient to excite the ventricles of the heart.

 Thus, an external two-chamber pacemaker (with esophageal and cutaneous electrodes) and an implanted ventricular trigger pacemaker form a chain of biocontrolled atrial-dependent cardiac pacing.

 The frequency of the ventricular pulses of the implanted trigger pacemaker will correspond to the frequency of spontaneous atrial depolarization from the sinus node of the heart, but will not exceed the specified value of the maximum frequency of the external two-chamber pacemaker. The size of the interval between the atrial P wave and the ventricular artifact of the implanted trigger pacemaker on the ECG will correspond to the specified value of the atrioventricular interval of the external two-chamber pacemaker.

 The assessment of central hemodynamics during two-chamber electrical stimulation of the heart is carried out by echocardiography, pressure measurement in the cavities of the heart and large vessels. A study of the tolerance of patients to everyday stress is carried out through instrumental tests of physical activity (bicycle ergometry and treadmill) and questionnaires of physical activity.

Case Studies
Example 1. Patient O., 36 years old. Diagnosis: Hypertrophic obstructive cardiomyopathy. Atrioventricular block III art. Implanted single-chamber biocontrolled ventricular pacemaker DESH 29203. Depletion of a power source. Functional Class II by the New York Association of Cardiology (NYHA).

 Given the presence of depletion of the pacemaker and the patient’s low exercise tolerance, a two-chamber cardiac pacing was performed according to the developed method to select the optimal mode and parameters of continuous cardiac pacemaker during future replacement of the pacemaker. As an external two-chamber device, an EKS-444 pacemaker manufactured by Elestim CJSC (Russia) was used. The amplitude of the cutaneous impulse of the ventricular canal of the two-chamber pacemaker was 2.5 V.

 Some indicators of central hemodynamics of patient O. with various modes of cardiac electrical stimulation (single chamber ventricular, two-chamber) and atrioventricular interval values (only with two-chamber electrical stimulation) are given in Table. 1.

 The greatest decrease in the systolic gradient in the exit tract of the left ventricle was detected with two-chamber electrical stimulation of the heart with an atrioventricular interval of 62 ms. When testing patient O. on a bicycle ergometer and a treadmill under conditions of isolated ventricular electrical stimulation of the heart, chronotropic insufficiency of the atrioventricular node was revealed with a decrease in exercise tolerance.

 It was noted that the increase in the frequency of the sinus node under load reached an age-related value (according to the Shepard table). A similar physical test in a patient performed under conditions of two-chamber electrical stimulation of the heart revealed an increase in physical performance of the operated patient by an average of 46%, which was due to an increase in the frequency of impulses of the ventricular trigger pacemaker due to tracking the atrial activity of the heart by an external two-chamber pacemaker via the transesophageal pathway and transmission of cutaneous electric pulses.

 Taking into account the results obtained during two-chamber electrical stimulation of the heart, the patient was replaced by a single-chamber ventricular pacemaker DESH 29203 with a two-chamber device ERGOS TS0Z. A two-chamber cardiac electrostimulation program with a shortened atrioventricular interval (50 ms) was established. Examined after 2, 4, 6 months. The condition of the operated person has improved. Tolerance to physical activity is high. He works according to his previous specialty (driver). The value of the NYHA functional class decreased to 1. A persistent decrease in the systolic pressure gradient in the exit tract of the left ventricle remains.

 Example 2. Patient I., 49 years old. Diagnosis: Coronary heart disease. Acute myocardial infarction of the posterior diaphragmatic localization, complicated by true cardiogenic shock and complete atrioventricular block. Subacute stage. Implanted single chamber biocontrolled ventricular pacemaker Premier 8081. NYHA Functional Class III.

 For the correction of central hemodynamics in the subacute stage of myocardial infarction, the patient underwent two-chamber electrical stimulation of the heart according to the developed method.

 As an external two-chamber pacemaker, model 3070 manufactured by the company Peissetter-St. Jude Medical (USA) was used. The amplitude of the cutaneous impulse of the ventricular canal of the two-chamber pacemaker was 0.5 V.

 Some indicators of central hemodynamics of patient I. in dynamics for various modes of electrical stimulation of the heart are given in table. 2.

 Two-chamber electrical stimulation of the heart was performed for 4 days. With stabilization of central hemodynamics, the two-chamber ES was discontinued. Discharged in satisfactory condition on the 10th day after implantation of a pacemaker. Examined after 4 months. The condition of the patient is satisfactory. NYHA functional class dropped to 1.

 Example 3. Patient K., 64 years old. Diagnosis: Coronary heart disease. Postinfarction cardiosclerosis. Sick sinus syndrome, tachy-bradyform. Paroxysmal tachysystolic form of atrial fibrillation. Transient atrioventricular block II no. Implanted single-chamber biocontrolled ventricular pacemaker PICOS 01. Depletion of the power source. NYHA Functional Class III.

 Given the presence of depletion of the pacemaker and the patient’s low tolerance to daily stress, a two-chamber cardiac pacemaker was performed according to the developed method to select the optimal regime and parameters of continuous cardiac pacemaker during future replacement of the pacemaker.

 As an external two-chamber pacemaker, model 3070 manufactured by the company Peissetter-St. Jude Medical (USA) was used. The amplitude of the cutaneous impulse of the ventricular canal of the two-chamber pacemaker was 0.5 V.

 Some indicators of central hemodynamics of patient K. under various modes of cardiac electrical stimulation (single chamber ventricular, two-chamber) and atrioventricular interval values (only with two-chamber electrical stimulation) are given in Table. 3.

 As follows from the table. 3, optimization of central hemodynamic parameters was achieved with two-chamber electrostimulation of the heart with an atrioventricular interval of 200 ms.

 During a stress study of the patient on a bicycle ergometer and a treadmill with one- (VVI) and two-chamber (DDD) modes of electrical stimulation of the heart, it was noted that with bifocal electrical stimulation, load tolerance increased by an average of only 15%. This was due to an inadequate frequency response (lack of chronotropic function) of the sinus and atrioventricular nodes of the heart.

 During bicameral electrical stimulation (in contrast to the single-chamber ventricular regime), atrial fibrillation paroxysms did not recur.

 Based on the results obtained, the patient was replaced by a single-chamber ventricular non-frequency-adaptive pacemaker PIKOS 01 with a two-chamber orthochronotropic system SYNCHRONI II. A dual-chamber frequency-adaptive cardiac electrostimulation mode DDIR with the optimal value of the atrioventricular interval has been programmed.

 Examined after 6, 12 months. The condition is satisfactory. Paroxysms of atrial fibrillation did not recur. Tolerance to everyday stress is satisfactory. Performs housework and gardening. The value of the functional class according to NYHA decreased to 1.

 The method of two-chamber electrostimulation of the heart is non-invasive, does not require large expenditures of time, X-ray control of the location of the electrode and can be performed in a hospital ward, operating room, in ambulance and medical aviation, increases the efficiency of electrostimulation in clinical practice, corrects central hemodynamics after surgery, with myocardial infarction , pacemaker syndrome, helps to expand the patient's motor mode with a pacemaker. The method of two-chamber electrostimulation of the heart can be used to select the optimal implantation method of a pacemaker, the mode and parameters of cardiac electrostimulation with simultaneous non-invasive assessment of central hemodynamics without surgery, diagnosis of insufficiency of chronotropic heart function and pacemaker syndrome.

Claims (1)

 A method of two-chamber electrostimulation of the heart with the detection of native atrial activity and the subsequent application of an electrical impulse to the ventricles of the heart through a predetermined time interval corresponding to the time of the atrioventricular conduction of the heart using a two-chamber pacemaker and electrodes, characterized in that through an external two-chamber pacemaker using its atrial atrial electrical potentials transesophageal using the ventricle marketing channel, transmitting an electric pulse to the patient's body surface via two electrodes which have a distal dermally, one - in the region of the additional trigger ventricular pacemaker implanted, and other - in the probe head projection implanted ventricular electrode.

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