RU2480152C1 - Method of estimating reduction of coronary reserve in patients with painless myocardial isch - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to cardiology. Tetrapolar chest rheography is performed to patient in order to calculate coefficient of vasomyocardial ratios of central hemodinamics - CVMRCH. Echocardiography is carried out and index of weight of left ventricle myocardium (IWLVM, g/m²) is calculated. Day ECG monitoring is performed with obtaining data of total integral of ST segment displacement (mcV*min), coefficient of vasomyocardial ratios of central hemodynamics (CVMRCH, %), ischemia duration in standard protocol of 24-hour Holter ECG monitoring (minutes per day). Integral index of myocardial-hemodynamic ratios is calculated by formula. If value of integral index of myocardial-hemodynamic ratios decreases, aggravation of adaptation-compensatory possibilities of organism in patients with IHD with painless myocardial ischemia, progressing of coronary failure and aggravation of coronary reserve are predicted.

EFFECT: method makes it possible to carry out early diagnostics of severe forms of "hidden" IHD for prediction of aggravation of failure of blood supply of myocardium aimed at taking measures, preventing disease aggravation and control of therapy adequacy, as well as to carry out complex estimation of processes of myocardium remodeling and hemodynamics restructuring.

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Description

The invention relates to medicine, namely to cardiology.

Coronary heart disease (CHD) is a heart muscle disease caused by an imbalance between coronary blood flow and the metabolic needs of the heart muscle. CHD has been a leading cause of death in economically developed countries for many years. Large-scale epidemiological studies have shown that a significant portion of episodes of myocardial ischemia can occur without symptoms of angina pectoris or its equivalents, up to the development of painless myocardial infarction. According to the Framingham study, up to 25% of myocardial infarction is first diagnosed only with a retrospective analysis of an ECG series, and in half the cases, these myocardial infarctions are completely asymptomatic. The damaging effect of ischemia on the myocardium is determined not by the presence of pain, but by the severity and duration of the violation of its perfusion, and the negative prognostic value determines the number of episodes of myocardial ischemia, their severity and duration, regardless of whether they are painful or painless. BBIM (painless myocardial ischemia) is a predictor of the adverse course of coronary heart disease, the risk of sudden death is 3 times higher than the risk of death in patients with angina pectoris with the same coronary artery disease.

As a prototype, the author proposes to use the integral index of myocardial hemodynamic ratios (IIHMS), which is calculated as the ratio of the left ventricular myocardial mass index (LVMI) to the coefficient of vasomyocardial ratios of central hemodynamics (CVMSG).

IIIMGS = IMMI / KVMSTsG

Mass index of left ventricular myocardium (LVMI g / m ²⁾ and the coefficient ratios vazomiokardialnyh central hemodynamics (KVMSTSG%) are determined by the formulas:

LVMI = LVML / S of the _body , where

LML - the mass of the left ventricular myocardium (g),

S _bodies - _body surface area (m ² );

KVMSTsG = (UO + UI + SI) * 100% / UPS

UO - shock volume (ml),

UI - shock index (ml / m ² ),

SI - heart index (l / min / m ² ),

OSS - the specific peripheral vascular resistance (din * s * cm ^-5 / m ² ).

An increase in the integral index of myocardial hemodynamic ratios indicates an increase in hemodynamic load and a deterioration in endurance of blood circulation; a decrease indicates the adequacy of the therapy and the preservation of the contractile function of the myocardium. The determination of IIHM is carried out 2 times: before treatment and after 3 months of drug therapy to assess the adequacy of treatment.

The disadvantages of this method are:

1) with various variants of BBIM (only BBIM or a combination of BBIM and painful episodes of myocardial ischemia), significant fluctuations in this indicator are noted;

2) structural-morphological and hemodynamic parameters in BBIM do not reflect the various mechanisms of the formation of painless myocardial ischemia, including the effect of extracardiac factors on the severity and duration of the violation of myocardial perfusion.

The author offers his own method for predicting the progression of coronary insufficiency in patients with painless myocardial ischemia by determining the hemodynamic load on the myocardium. At the same time, the author's proposed integral indicator of myocardial hemodynamic ratios (IPMGS) is calculated as the ratio of the left ventricular myocardial mass index and the total ST segment displacement integral (μV * min) to the coefficient of vasomyocardial ratios of central hemodynamics and the total duration of myocardial ischemia during ECG Holter monitoring ( 24 hours), in minutes. A decrease in the value of this indicator indicates an increase in hemodynamic load and a deterioration in endurance of blood circulation; increase - indicates the adequacy of the therapy and the preservation of the contractile function of the myocardium. To confirm the results of the study, applicants examined 134 people with IHD. Verification of the diagnosis was carried out during the XM ECG. 98 patients had painless myocardial ischemia in combination with functional class II-III angina (group 1), and 36 had only painless myocardial ischemia (group 2). All patients underwent tetrapolar thoracic rheography (TPRG) and echocardiography (ECHO-KG), 24-hour Holter ECG monitoring (XM ECG). At the same time, shock volume, stroke index, cardiac index, specific peripheral vascular resistance were determined by TPRG, and the coefficient of vasomyocardial ratios of central hemodynamics was calculated; by ECHO-KG - the left ventricular myocardial mass index by dividing the myocardial mass by the body surface area calculated by the Du Bois formula. Moreover, according to the generally accepted criteria for myocardial ischemia, the number of episodes of myocardial ischemia, the total integral of the ST segment displacement (μV * min), and the total duration of ischemia (in minutes) were determined. IPMHS, obtained as the quotient of the left ventricular myocardial mass index and total ST segment displacement integral by the coefficient of vasomyocardial ratios of central hemodynamics and the duration of ischemia, was 478.32 ± 0.01 (group 1), respectively, and in patients of the 2nd IIHS group was 382.29 ± 0.01 (p <0.001). Verification of the diagnosis was carried out using Holter monitoring in accordance with generally accepted criteria for ischemia. All patients received treatment according to the scheme generally accepted for coronary heart disease, its effectiveness was confirmed after 3 months to reduce IPMHS. In the group of patients with painless ischemia in combination with angina pectoris, a decrease in IPMGS occurred in 44 patients (p <0.001), in 22 it increased (p> 0.05), which indicates various mechanisms of the formation of painless myocardial ischemia, including the effect of extracardiac factors, and determines different management tactics for these patients. Holter monitoring confirmed a decrease in the number of episodes, the total integral of the ST segment shift, the amplitude of maximum depression while maintaining a threshold heart rate at the level of tachycardia. In 23 patients with BBIM, IPMHS did not change after treatment, while in 7 patients it decreased slightly (p <0.05). Control Holter monitoring of the dynamics of the above indicators in patients with angina pectoris did not reveal. Thus, the calculated IPMHS indicator allows us to identify patients with reduced coronary reserve and the formation of persistent hypokinetic hemodynamic parameters in the early stages of the disease on an outpatient basis, which further determines the management tactics of the patient, including cardiac surgery.

The advantages of the proposed method are:

- the possibility of early diagnosis of severe forms of "hidden" coronary heart disease to predict the deterioration of myocardial insufficiency in order to take measures to prevent exacerbation of the disease and control the adequacy of therapy;

- a comprehensive assessment of the processes of myocardial remodeling and restructuring of hemodynamics;

- a simple, economical method that does not require the use of additional costs, allowing more widely use the diagnostic capabilities of the equipment;

- the use of the results by cardiologists on an outpatient basis;

- with dynamic observation allows monitoring the effectiveness of therapy.

Clinical examples.

Case history No. 19467. Patient K., 48 years old, a candidate for master of sports in boxing, asked about recurring unmotivated weakness in the morning, worsening exercise tolerance. During TPRG, a hyperkinetic variant of blood circulation is recorded (UI - 63.8 ml / m ² , SI - 3.7 ml * s / m ² , UO - 125.8 ml, UPSS - 656.3 dyn * s cm- ⁵ / m ² , KVMSTsG - 29.5%), indicating the preservation of high kinetic parameters of the heart; ECHO-KG - atherosclerotic changes in the aorta, impaired diastolic function of the left ventricle, hypokinesia of the posterior wall of the left ventricle (LVMI - 106.4 g / m ² ), indicating the presence of myocardial remodeling according to a mixed type. IPMHS was 476.9. During Holter monitoring, 8 episodes of painless myocardial ischemia were recorded from 6 to 11 a.m. and from 13 to 15 hours, a total duration of 37 minutes per day with an average threshold heart rate of 98 beats / min with a maximum amplitude of depression of the ST segment of 1.7 mm , the total displacement integral is 4892 μV * min. Treatment was prescribed, the effectiveness of which after 3 months was assessed by repeated TPRG, ECHO-KG, and IPMHS calculation. The information content of IPMGS was confirmed using Holter monitoring. It was established that there was an increase in IPMHS to 700.1 (increased MHCMS up to 35.6% due to a decrease in OCCI, and almost no change in LVMI, amounting to 106.1 g / m ² ). Holter monitoring confirmed the effectiveness of the prescribed therapy (2 episodes of painless myocardial ischemia were recorded, lasting 12 minutes a day, from 7 to 9 a.m., with an average threshold heart rate of 95 beats / min with a maximum amplitude of ST segment depression of 1.3 mm and a total displacement integral 2819 μV * min).

Case history No. 98467. Patient V., 54 years old, turned to a cardiologist about a recurrent intense headache with bouts of severe weakness. During TPRG, a hyperkinetic variant of blood circulation was recorded (UI - 59.8 ml / m ² , SI - 3.2 ml * s / m ² , UO - 118.4 ml, UPSS - 716.3 dyn * s cm ^-5 / m ² , KVMSTsG - 25.3%), indicating the preservation of high kinetic parameters of the heart; with ECHO-KG - atherosclerotic changes in the aorta, impaired diastolic function of the left ventricle, hypokinesia of the posterior and anterolateral wall of the left ventricle (LVMI - 107.2 g / m ² ), indicating the presence of myocardial remodeling according to a mixed type. IIIGS amounted to 4.2. During Holter monitoring, 5 episodes of painless myocardial ischemia were recorded between 5 a.m. and 10 a.m. and from 2 p.m. to 5 p.m. for a total duration of 42 minutes per day with an average threshold heart rate of 102 beats per minute with a maximum amplitude of depression of the ST segment of 1.9 mm , the total displacement integral is 5282 μV * min. IPMGS was 535. A treatment was prescribed, the effectiveness of which after 3 months was assessed by repeated TPRG, ECHO-KG, and IPMGS calculation. The informativeness of IMIGS was confirmed using Holter monitoring. It was established that there was an increase in IIMHI to 596.5 (increased MHCMS to 29.5% due to a decrease in OSS and did not change LVMI, amounting to 106.9 g / m ² ). Holter monitoring confirmed the effectiveness of the prescribed therapy (3 episodes of painless myocardial ischemia were recorded, lasting 19 minutes per day, from 7 to 10 am, with an average threshold heart rate of 98 beats / min with a maximum amplitude of depression of the ST segment of 1.5 mm and a total displacement integral 3119 μV * min).

Claims (1)

A method for assessing a reduction in coronary reserve in patients with painless myocardial ischemia, characterized in that tetrapolar thoracic rheography is performed, the coefficient of vasomyocardial central hemodynamics is determined - CVMCSG, echocardiography and the left ventricular myocardial mass index, daily Holter ECG monitoring and total integral ECG duration - total ST segment displacements and the integral indicator of myocardial hemodynamic relations is calculated by the formula:
IPMGS = LVMI * total integral of the displacement of the ST segment / CVMCSG * total duration of myocardial ischemia, where
IPMHS - an integral indicator of myocardial hemodynamic
ratios;
LVMI - left ventricular myocardial mass index (g / m ² );
total ST displacement integral - total ST segment displacement integral (μV · min / day) during 24-hour Holter ECG monitoring;
KVMSTsG - coefficient of vasomyocardial ratios of the central hemodynamics (%)
KVMSTsG = (UO + UI + SI) · 100% / UPS
UO - stroke volume (ml);
UI - shock index (ml / m ² );
SI - heart index (l / mii / m ² );
UPCC - specific peripheral resistance (dyn · s cm ^-5 / m ² );
the total duration of myocardial ischemia - the duration of painless ischemia (min / day) during a 24-hour Holter monitoring of ECG; and with a decrease in the integral indicator of myocardial hemodynamic ratios, the deterioration of the aditational compensatory capacity of the body is predicted in patients with coronary artery disease with painless myocardial ischemia, the progression of coronary insufficiency and the deterioration of the coronary reserve.