RU2387364C2 - Method of evaluating efficiency of left auricle posterior wall isolation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to cardiosurgery and arhythmology. Registration of local electrocardiogram of isolated posterior wall of left auricle is performed. After carrying out arhythmologic operation which includes isolation of posterior wall of left auricle, electrode is passed through nasal or oral cavity into esophagus, positioned at the level of left auricle, electrocardiogram is registered from electrode, simultaneously with it superficial electrocardiogram is registered and in case if local activation on transesophagal electrocardiogram does not correspond to global auricle activation on superficial electrocardiogram, conclusion about efficient isolation of posterior wall of left auricle is made.

EFFECT: method is low -invasive, sinple in application, can be used in any hospital and policlinic and allows to dynamically evaluate effect of arhythmologic operation connected with auricle fibrillation during unlimited observation time.

2 ex, 5 dwg

Description

The invention relates to medicine, namely to cardiac surgery and arrhythmology, and can be used for intraoperative assessment of the effect of arrhythmological operations aimed at eliminating atrial fibrillation (AF).

Atrial fibrillation is the most relevant arrhythmology problem at present. This heart rhythm disturbance is most common in the human population, is characterized by refractory to ongoing drug therapy and, in its progressive course, can lead to the development of heart failure, thromboembolic complications and strokes, and increase the risk of sudden death.

Currently, several arrhythmological operations are used to treat this complex pathology. A mandatory component of a number of operations is the isolation of the posterior wall of the left atrium (ZSLP). These operations include:

1) cardiac surgery procedure "LABYRINTH" (or MAZE-III) according to the method J. Soh;

2) various modifications of the cardiac surgical procedure "LABYRINT";

3) “LABYRINTH” using physical factors (radio frequency energy, microwave exposure, photocoagulation, laser ablation, etc.);

4) catheter procedure “LABYRINTH”;

5) thoracoscopic procedure “LABYRINTH”;

6) radiofrequency catheter isolation of the mouth of the pulmonary veins with isolation and fragmentation of the posterior wall of the left atrium.

Isolation of the posterior wall of the left atrium carries an important pathogenetic value, since:

1) isolates several important anatomical substrates of AF located in the back wall (“rotors”, Marshall ligament, etc.);

2) turns off a large volume of the atrial surface from the excitation, which, according to the "law of critical mass", has a powerful antiarrhythmic effect;

3) orders the sinus activation of the left atrium.

A known method for evaluating the effectiveness of isolation of the posterior wall of the left atrium based on the registration of a local electrogram [1].

Moreover, during an arrhythmological operation, a patient with AF after performing the main stage, including isolation of the posterior wall of the left atrium, an electrode is installed in this area from the side of the endocardium or epicardium, through which bipolar electrogram is recorded. The lack of electrical activity in ZSLP or the detection of its own rhythm (isolated automatism, atrial fibrillation), which is different from the activation of the rest of the atrium (by surface ECG), indicates the effective isolation of the posterior wall of the left atrium.

The main disadvantage of this method is that the assessment of isolation of ZSLP is carried out intraoperatively. It is impossible to apply this method to obtain information about the condition of the posterior wall after surgery.

The aim of this invention is to expand the capabilities and increase the information content of evaluating the effectiveness of isolation of ZSLP after arrhythmological surgery for atrial fibrillation.

This goal is achieved by the fact that the reliability of isolation of ZSLP is evaluated in the postoperative period by recording transesophageal electrogram.

The method is as follows:

after performing an arrhythmological operation, including isolation of ZSLP (in the early or distant postoperative period), the electrode is passed through the nasal or oral cavity into the esophagus,

the electrode is positioned at the level of the left atrium based on traditional anatomical and electrophysiological criteria (figure 1),

an electrogram is recorded from the electrode; at the same time a surface electrocardiogram is recorded,

in case of mismatch of local activation (transesophageal electrogram) of global atrial activation (surface electrocardiogram), a conclusion is made about the continued effective isolation of the posterior wall of the left atrium.

Several options for mismatching the transesophageal electrogram to the surface electrocardiogram are possible. For example:

1) lack of electrical activity, or own independent automatism, or fibrillation on the transesophageal electrogram against the background of a sinus or atrial rhythm on the surface electrocardiogram;

2) lack of electrical activity or own independent automatism in the transesophageal electrogram against fibrillation or atrial flutter on the surface electrocardiogram.

Physiological substantiation of the proposed method

The essence of the proposed method is to check the electrical impermeability of the linear damage created by the surgeon, which should not conduct any electrical excitation. If the isolated posterior wall of the left atrium is surrounded by a continuous electrical barrier, then the sinus (or other) atrial excitation is not able to cross the insulating lines and excite ZSLP. Therefore, there is no activity in this area, or it generates its own activity, not associated with the excitation of the rest of the atrium. This, in turn, causes dissociation between local activation of the posterior wall and atrial activation on the surface electrocardiogram. The transesophageal electrogram reflects the local activity of ZSLP, since this area is anatomically adjacent to the anterior wall of the esophagus.

Figure 1 shows the anatomical relationship of the esophagus (Fig.1, 1) and the posterior wall of the left atrium (rear view). The esophagus is adjacent to ZSLP and passes in the middle between the mouths of the pulmonary veins. The gray line schematically shows the line isolating the right and left pulmonary veins with two separate collectors, as well as the posterior wall of the left atrium. The electrode in the esophagus (figure 1, 2) is in the projection of an isolated area.

The effectiveness of the proposed method was evaluated in patients operated on for AF. The study involved 77 patients who performed catheter radiofrequency isolation of the mouths of the pulmonary veins in NIIPK in combination with isolation of the posterior wall of the left atrium in the period from 2004 to 2006. In all patients, during the operation, effective isolation of ZSLP was achieved according to the intraoperative criteria given earlier.

Later, transesophageal electrogram was recorded 1, 3, 6, 12, 24, and 36 months after surgery. In parallel, the arrhythmic status (the presence of atrial fibrillation) was assessed according to the electrocardiogram or daily monitoring. The mean follow-up was 18.2 ± 4.7 months (10 to 40 months).

There were no complications during the procedure. Figure 2 presents a diagram illustrating the frequency of the phenomenon of the lack of effective isolation of ZSLP (according to the method presented by us) and the frequency of recurrence of arrhythmia (atrial fibrillation) after catheter ablation. The correlation coefficient was +0.74 (p <0.01). Thus, a close relationship has been shown between the loss of isolation of ZSLP and the resumption of AF paroxysms. Therefore, this method can be considered as a method for predicting the effectiveness of these arrhythmological interventions.

We give two examples of the application of the method.

Patient N., 56 years old. Operated in January 2005 for frequent daily AF attacks. The patient underwent circular isolation of the mouths of the pulmonary veins, supplemented by isolation of the posterior wall of the left atrium. With intraoperative control, effective isolation of ZSLP was achieved. The postoperative period was uneventful.

After 1 month when registering a transesophageal electrogram, the criteria for isolation of ZSLP are preserved: against the background of a sinus rhythm, there is no local excitation of ZSLP on the electrogram, which indicates its effective isolation (Fig. 3; the arrow shows the place where the atrial potential was to be recorded; speed - 100 mm /from).

After 3 months, atrial fibrillation attacks resumed. When re-registering the transesophageal electrogram, isolation of the ZSLP is absent: against the background of the sinus rhythm, a high-amplitude local atrial potential is noted (Fig. 4; the arrow shows the atrial potential; speed - 100 mm / s; I, II, III, AVR, AVL, AVF - leads of the surface electrocardiograms, emergency - transesophageal electrogram). The patient was operated repeatedly. During the mapping process, a defect of the lower horizontal line through which the activation of the entire ZSLP was restored was verified. Several applications of radio frequency energy are applied to the defect region, which led to its elimination. In the postoperative period, AF was not recorded.

Thus, the use of our proposed method made it possible to detect the cause of the recurrence of arrhythmia after ablation and determine the subsequent surgical tactics.

Patient M., 66 years old. Operated in November 2004 for chronic AF for 5 years. The patient underwent circular isolation of the mouths of the pulmonary veins, supplemented by isolation of the posterior wall of the left atrium. In the process of ablation, the sinus rhythm was restored. With intraoperative control, effective isolation of ZSLP was achieved. The postoperative period was uneventful.

The patient is observed in the clinic for 3.5 years. When registering a transesophageal electrogram, the criteria for isolation of ZSLP are retained in dynamics: against the background of a sinus rhythm, an electrocardiogram with a frequency of 129 per minute is recorded to activate its own ZSLP with a frequency of 112 per minute (Fig. 5; the arrow shows the local potential of ZSLP; speed is 100 mm / s). Thus, maintaining isolation of ZSLP allowed the patient to maintain a sinus rhythm for 3.5 years after surgery.

Our proposed method allows us to evaluate the effect of arrhythmological surgery for AF in dynamics for an unlimited time of observation. The method is minimally invasive, easy to use and can be used in any hospital and clinic.

Claims (1)

A method of evaluating the effectiveness of the isolation of the posterior wall of the left atrium, including recording a local electrogram of the isolated posterior wall of the left atrium, characterized in that after performing an arrhythmological operation, including isolation of the posterior wall of the left atrium, the electrode is passed through the nasal or oral cavity into the esophagus, positioned at the level of the left atria, the electrogram is recorded from the electrode, simultaneously with it the surface electrocardiogram is recorded and in case of discrepancy locally activation transesophageal atrial electrogram global activation on the surface electrocardiogram conclude an effective insulation of the rear wall of the left atrium.

Images