RU2300311C2 - Method of evaluation of electric properties of antriventicular joint - Google Patents

Abstract

FIELD: medicine; cardiology.

SUBSTANCE: method can be used for diagnosing and predicting heart arrhythmia. Auricular and then ventricular electric stimulation is performed through multiple contact diagnosis electrodes followed by measurement of intervals of A2-H2, H2-V2, R2-V2, A2-V2, V2-H2, H2-A2, and V2-A2 at any step. Then indexes of adiaphoria are calculated due to division of absolute meanings of corresponding intervals (in ms) by duration of that change (in ms). Electric condition of different departments of atriventricular joint is evaluated from index of adiaphoria.

EFFECT: improved precision.

9 dwg, 2 tbl, 2 att

Description

The invention relates to medicine, namely to cardiology, and can be used to diagnose and predict heart arrhythmias.

A known method for assessing the electrical properties of an atrioventricular compound (ABC), based on the registration of its conductivity and refractoriness [1, 2] in the process of electrophysiological research (EFI).

Three multi-contact diagnostic electrodes are passed through the main veins and placed in the cavity of the right atrium, right ventricle and the bundle of His.

To assess atrioventricular conduction, an accelerated pacemaker (EX) is performed through the atrial electrode until the appearance of the Wenckebach period by the electrogram of the right ventricle. The frequency of electrical stimulation corresponding to this moment reflects the maximum atrioventricular conduction. To assess atrioventricular conduction through the ventricular electrode, increased pacing is performed until the Wenckebach period appears on the electrocardiogram of the right atrium. The frequency of electrical stimulation corresponding to this moment reflects the maximum ventriculoatrial conduction.

Atrioventricular refractivity is determined during a programmed ECS of the right atrium or right ventricle. At the same time, the boundaries of the relative (PPR), effective (ERP) and functional refractory periods are distinguished.

Thus, the above methods characterize the static state of the myocardium and do not allow to determine the rate of change in the conduct of the myocardium, which is in a different refractory state.

The aim of this invention is to improve the accuracy of the assessment of the electrophysiological state of the atrioventricular compound.

This goal is achieved by the fact that with the help of diagnostic pacing, the refractivity indices are measured, the value of which is used to judge the change in conductivity in a different refractory state of the atrioventricular connection. The refractoriness index shows the degree of time retardation (VP) in different parts of the atrioventricular connection when scanning its relative refractoriness. To determine it, it is necessary to divide the time variation range by the duration of such a change. Thus, the scanning period is the difference between the PIU and the EPF, that is, the interval in which the deceleration occurs until the moment when the studied site of the atrioventricular connection ceases to be excited.

In this way,

where IR is the refractoriness index,

VPmax - maximum time (ms),

VPmin - minimum time (ms),

PPR - relative refractory period (ms),

ERP - effective refractory period (ms).

So, in accordance with the formula, the value of the refractivity index of 1.5 indicates that during the programmed ECS, when the delay of the extrastimulus is reduced by 1 ms, the time of conducting the atrioventricular connection in the studied area slows down by 1.5 ms.

The method is as follows.

Multi-contact diagnostic electrodes are installed in the cavity of the right ventricle, in the coronary sinus and in the bundle of His (with emergency EPI) or on the surface of the right atrium, right and left ventricle (with epicardial EPI) or in the projection of the left atrium (with transesophageal EPI);

potentials are recorded: through the ventricular endocardial electrode, the potentials of the right ventricle (V _pzh ), through the electrode at the His bundle, the histogram (potentials A, H and V), through the electrode in the coronary sinus, the potentials of the left atrium (A) and left ventricle (V _false ), through the epicardial atrial electrode - the potentials of the right atrium (A), through the epicardial ventricular electrodes - the potentials of the right and left ventricle (V _pf , V _false ), through the transesophageal electrode - the potentials of the left atrium (A) and the left ventricle (V _false ) ;

through the atrial, and then through the ventricular electrode, a programmed ECS is carried out with a base frequency of 10 pulses per minute exceeding the spontaneous frequency, and a sequential decrease in the delay of the extrastimulus by 10 ms;

during electrical stimulation, the surface electrocardiogram and electrograms (EG) from the remaining electrodes are continuously recorded on the monitor of the electrophysiological complex;

at each step, the following intervals are measured: A2-H2, H2-V2, R2-V2, A2-V2 with atrial pacing and V2-H2, H2-A2, V2-A2 with ventricular pacing, where

A2-H2 - the time interval between the potentials of the atrium and the bundle of His when applying atrial extrastimulus,

H2-V2 - the time interval between the potentials of the bundle of His and the ventricle when applying the atrial extrastimulus,

R2-V2 - the time interval between the beginning of the R-wave on the electrocardiogram and the potential of the ventricle when applying the atrial extrastimulus,

A2-V2 - the time interval between the potentials of the atrium and ventricle when applying the atrial extrastimulus,

V2-H2 - the time interval between the potentials of the ventricle and His bundle when applying the ventricular extrastimulus,

H2-A2 - the time interval between the potentials of the bundle of His and atrium when applying the ventricular extrastimulus,

V2-A2 - the time interval between the potentials of the ventricle and atrium when applying the ventricular extrastimulus;

measure the effective and relative refractory periods of the atrioventricular junction, atrioventricular node, bundle of His, left and right legs of the bundle of His. For the relative refractory period of the atrioventricular node during anterograde conduction (ARI AVUa), the maximum value of A1-A2 in the histogram during atrial ECS is taken, in which there is an extension of the A2-H2 interval (Fig. 1A). For the effective refractory period of the atrioventricular node during anterograde conduction (ERP AVUa), the maximum value of A1-A2 in the histogram during atrial ECS is taken, in which there is no H2 potential behind the test spike (Fig. 1B). For the relative refractory period of the His bundle during anterograde conduction (ARP PHA), the maximum value of A1-A2 in the histogram during atrial ECS is taken, at which the lengthening of the H2-V2 interval occurs (Fig.2A). For the effective refractory period of the His bundle during anterograde conduction (EHF), take the maximum value of A1-A2 in the histogram during the atrial ECS, in which there is no potential V2 behind the test spike after potential H2 (Fig.2B). For the relative refractory period of the atrioventricular junction during anterograde conduction (ARS ABC), the maximum value A1-A2 is taken in the process of atrial ECS, in which lengthening of the interval A2-V2 occurs (Fig. 3A). For the effective refractory period of the atrioventricular junction during anterograde conduction (ERS AVS), the maximum value A1-A2 is taken during the atrial ECS, in which the test spike after potential A2 does not have potential V2 (Fig.3B). For the relative refractory period of the right bundle branch block (ARP PNPG), the maximum value A1-A2 is taken during the atrial ECS, in which a QRS complex appears as an incomplete blockade of the right bundle branch block (Fig. 4A). For the effective refractory period of the right leg of the bundle of His (ERP PNG) take the maximum value of A1-A2 in the process of atrial ECS, in which there is a QRS complex as a complete blockade of the right leg of the bundle of His (Fig.4B). For the relative refractory period of the left leg of the bundle of His (LNGH ERP), the maximum value A1-A2 is taken during the atrial ECS, in which a QRS complex appears as an incomplete blockade of the left leg of the bundle of His (Fig. 5A). For the effective refractory period of the left leg of the bundle of His (LNGH ERP), the maximum value A1-A2 in the atrial process is taken, in which a QRS complex appears as a complete blockade of the left leg of the bundle of His (Fig. 5B). For the relative refractory period of the atrioventricular node during retrograde conduction (ARI AVR), the maximum value of V1-V2 is taken from the histogram during ventricular ECS, in which there is an extension of the H2-A2 interval (Fig. 6A). For the effective refractory period of the atrioventricular node during retrograde conduction (ERP AVUR), the maximum value of V1-V2 is taken according to the histogram during the ventricular EX, in which A2 potential is absent behind the test spike H2 (Fig.6B). For the relative refractory period of the His bundle during retrograde conduction (PGRP), the maximum value of V1-V2 is taken from the histogram during ventricular ECS, in which there is an extension of the V2-H2 interval (Fig. 7A). For the effective refractory period of the His bundle during retrograde conduction (ERP PGR), the maximum value V1-V2 is taken from the histogram during the ventricular EX, in which there is no H2 potential behind the test spike after potential V2 (Fig. 7B). For the relative refractory period of the atrioventricular connection during retrograde conduction (ARP AVSp), the maximum value of V1-V2 in the process of ventricular ECS is taken, at which lengthening of the interval V2-A2 occurs (Fig. 8A). For the effective refractory period of the atrioventricular connection during retrograde conduction (ERP AVSp), the maximum value of V1-V2 during ventricular ECS is taken, in which there is no potential A2 behind the test spike after potential V2 (Fig. 8B);

calculate the indices of refractoriness (IR) of the working myocardium according to the formulas

IRAVUa - atrioventricular node refractoriness index during anterograde conduction,

A2H2max - the maximum value of the interval A2-H2 (ms),

A2H2min - the minimum value of the interval A2-H2 (ms),

ORPAVUa - the relative refractory period of the atrioventricular node during anterograde conduction (ms),

ERPAVUa - effective refractory period of the atrioventricular node during anterograde conduction (ms),

IRAVUR - index of refractoriness of the atrioventricular node in retrograde conduction,

H2V2max - the maximum value of the H2-V2 interval (ms),

H2V2min - the minimum value of the interval H2-V2 (ms),

ORPAVUR - the relative refractory period of the atrioventricular node in retrograde conduction (ms),

ERPAVUR - effective refractory period of the atrioventricular node in retrograde conduction (ms),

IRPGa - the index of refractoriness of the bundle of His during anterograde conduction,

H2V2max - the maximum value of the H2-V2 interval (ms),

H2V2min - the minimum value of the interval H2-V2 (ms),

ORPPGa - the relative refractory period of the His bundle during anterograde conduction (ms),

ERPPGa - effective refractory period of the His bundle with anterograde conduction (ms),

IRPGr - the index of refractoriness of the bundle of His in retrograde conduction,

V2H2max - the maximum value of the V2-H2 interval (ms),

V2H2min - the minimum value of the interval V2-H2 (ms),

ORPGr - the relative refractory period of the His bundle during retrograde conduction (ms),

ERPPGr - effective refractory period of the His bundle with retrograde conduction (ms),

IRAVS - index of refractoriness of the atrioventricular connection during anterograde conduction,

A2V2max - the maximum value of the interval A2-V2 (ms),

A2V2min - the minimum value of the interval A2-V2 (ms),

ORPAVSa - the relative refractory period of the atrioventricular connection during anterograde conduction (ms),

ERPAVSa - effective refractory period of the atrioventricular junction during anterograde conduction (ms),

IRAVSr - index of refractoriness of the atrioventricular connection during retrograde conduction,

V2A2max - the maximum value of the V2-A2 interval (ms),

V2A2min - the minimum value of the interval V2-A2 (ms),

ORPAVSr - the relative refractory period of the atrioventricular connection during retrograde conduction (ms),

ERPAVSr - effective refractory period of the atrioventricular connection with retrograde conduction (ms),

IRPNPG - index of refractoriness of the right leg of the bundle of His,

R2V2 ПЖmax - the maximum value of the interval R2-V2ПЖ (ms),

R2V2 ПЖmin - the minimum value of the interval R2-V2ПЖ (ms),

ORPNPG - the relative refractory period of the right leg of the bundle of His (ms),

ERPNPG - effective refractory period of the right leg of the bundle of His (ms),

IRLNPG - index of refractoriness of the left leg of the bundle of His,

R2V2LF max - the maximum value of the interval R2-V2LF (ms),

R2V2ЛЖmin - the minimum value of the interval R2-V2ЛЖ (ms),

ORPLNPG - the relative refractory period of the left leg of the bundle of His (ms),

ERPLNPG - effective refractory period of the left leg of the bundle of His (ms);

by the value of the refractivity index they judge the functional state of the corresponding department of the atrioventricular connection. The higher the IR value (which is manifested by a large slope of the conductance curve), the worse the conductivity in this area worsens when scanning the ABC refractory period.

The application of the method is illustrated by the following examples.

Example 1. Patient L-s, 2 g. 1 month. He was operated on in a clinic in 2001 for congenital heart disease. Peritoneal ventricular septal defect plasty and closing of an open oval window were performed. After thoracotomy and opening of the pericardial cavity, diagnostic electrodes are installed on the epicardial surface of the right atrium, right and left ventricle. The main indicators are measured (tab. 1, figa).

Table 1
Electrophysiological characteristic of ABC in patient L., 2 years. 1 month Options Value ORP ABC, ms 250 ERP AVSa, ms 160 ORP AVSr, ms 280 ERP AVSr, ms 170 ORP PNPG, ms 240 ERP PNPG, ms 170 A2V2max, ms 275 A2V2min, ms 145 V2A2max, ms 255 V2A2min, ms 140 R2V2 ПЖmax, ms 84 R2V2 ПЖmin, ms 10

Refractoriness indices were calculated using the formulas indicated above:

In the postoperative period, the child did not show any conduction disturbances along the atrioventricular node or legs of the bundle of His.

Example 2. Patient B-va, 2 g. 4 months. Operated in a clinic in 2000 regarding a defect in the ventricular septum and closure of the open ductus arteriosus. The initial values of electrophysiological indicators are presented in table. 2 and FIG. 9B.

table 2
Electrophysiological characteristic of ABC in patient B., 2 g, 4 months Options Value ORP ABC, ms 220 ERP AVSa, ms 180 ORP AVSr, ms 260 ERP AVSr, ms 180 ORP PNPG, ms 240 ERP PNPG, ms 200 A2V2max, ms 310 A2V2min, ms 150 V2A2max, ms 300 V2A2min, ms 145 R2V2 ПЖmax, ms 115 R2V2 ПЖmin, ms 12

Refractivity indices were calculated using the formulas above:

In the postoperative period, the child developed a complete atrioventricular block, which lasted for 4 days and ended with the restoration of the sinus rhythm, however, until discharge, the complete block of the right bundle branch block remained.

Thus, the registration of the overestimated values of IRAVS and IRPNPG made it possible to predict the occurrence of atrioventricular blockade and blockade of the right bundle branch block after surgery.

The method described above allows to qualitatively and quantitatively evaluate the electrical state of all departments of the atrioventricular connection in patients with any cardiac pathology, regardless of the age and size of the heart.

Information sources

1. Josephson M.E. Clinical cardiac electrophysiology, Techniques and interpretations Philadelphia, Lea & Febiger, 2002, p. 456.

2. Akhtar Metal A comparative analysis anterograde and retrograde conduction patierns in man. Circulation, No. 52, 1975, p.p.766-778.

Claims (1)

A method for evaluating the electrical properties of an atrioventricular connection, including determining the conductivity and refractoriness of various departments of the atrioventricular connection, characterized in that the multi-contact electrodes are installed on the epicardial surface of the right atrium, right and left ventricles or in the coronary sinus, right ventricle, to the His bundle from the endocardium or transocarp an electrode to the left heart through the atria, and then through the ventricular electrodes conduct a programmed electric car iostimulation and at each step of electrical stimulation from the remaining electrodes, the intervals A2-H2, H2-V2, R2-V2, A2-V2 are measured for atrial electrical stimulation and V2-H2, H2-A2, V2-A2 for ventricular electrical stimulation, after which the refractivity indices are calculated different departments of the atrioventricular connection according to the formulas

where IRAVUa is the index of refractoriness of the atrioventricular node during anterograde conduction, A2H2max - the maximum value of the interval A2-H2 (ms), A2H2min - the minimum value of the interval A2-H2 (ms), ORPAVUa - the relative refractory period of the atrioventricular node during anterograde conduction (ms), ERPAVUa - effective refractory period of the atrioventricular node during anterograde conduction (ms), IRAVUR - index of refractoriness of the atrioventricular node in retrograde conduction, H2V2max - the maximum value of the H2-V2 interval (ms), H2V2min - the minimum value of the interval H2-V2 (ms), ORPAVUR - the relative refractory period of the atrioventricular node in retrograde conduction (ms), ERPAVUR - the effective refractory period of the atrioventricular node in retrograde conduction (ms), IRPGa - the index of refractoriness of the bundle of His during anterograde conduction, H2V2max - the maximum value of the H2-V2 interval (ms), H2V2min - the minimum value of the interval H2-V2 (ms), ORPPGa - the relative refractory period of the His bundle during anterograde conduction (ms), ERPPGa - effective refractory period of the His bundle with anterograde conduction (ms), IRPGr - the index of refractoriness of the bundle of His in retrograde conduction, V2H2max - the maximum value of the V2-H2 interval (ms), V2H2min - the minimum value of the interval V2-H2 (ms), ORPGr - the relative refractory period of the His bundle during retrograde conduction (ms), ERPPGr - effective refractory period of the His bundle with retrograde conduction (ms), IRAVS - index of refractoriness of the atrioventricular connection during anterograde conduction, A2V2max - the maximum value of the interval A2-V2 (ms), A2V2min - the minimum value of the interval A2-V2 (ms), ORPAVSa - the relative refractory period of the atrioventricular connection during anterograde conduction (ms), ERPAVSa - effective refractory period of the atrioventricular junction during anterograde conduction (ms), IRAVSr - index of refractoriness of the atrioventricular connection during retrograde conduction, V2A2max - the maximum value of the V2-A2 interval (ms), V2A2min - the minimum value of the interval V2-A2 (ms), ORPAVSr - the relative refractory period of the atrioventricular connection during retrograde conduction (ms), ERPAVSr - effective refractory period of the atrioventricular connection with retrograde conduction (ms), IRPNPG - index of refractoriness of the right leg of the bundle of His, R2V2ПЖmax - the maximum value of the interval R2-V2ПЖ (ms), R2V2 ПЖmin - the minimum value of the interval R2-V2ПЖ (ms), ORPNPG - the relative refractory period of the right leg of the bundle of His (ms), ERPNPG - effective refractory period of the right leg of the bundle of His (ms), IRLNPG - index of refractoriness of the left leg of the bundle of His, R2V2LF max - the maximum value of the interval R2-V2LF (ms), R2V2ЛЖmin - the minimum value of the interval R2-V2ЛЖ (ms), ORPLNPG - the relative refractory period of the left leg of the bundle of His (ms), ERPLNPG - effective refractory period of the left leg of the bundle of His (ms), and by the value of the refractivity index they judge the functional state of the corresponding department of the atrioventricular connection.

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