METHOD FOR QUANTITATIVE ESTIMATION OF DAILY HEART RATE VARIABILITY Russian patent published in 2017 - IPC A61B5/402 

FIELD: medicine.

SUBSTANCE: heart rate variability (HRV) analysis is performed over the long periods of time for healthy subjects and patients with various forms of cardiopathology. It involves 24-hour ECG monitoring. Rhythmogram is plotted for the entire period of observation. The following is allocated on the rhythmogram: all double breaks - four consecutive intervals RR-RR[i], RR[i+1], RR[i+2], RR[i+3], where the adjacent RR intervals differ by at least 24 ms and for which the group of inequalities RR[i]<RR[i+1]>RR[i+2]<RR[i+3] or the group of inequalities RR[i]>RR[i+1]<RR[i+2]>RR[i+3] is made. Rhythmogram is divided into short sections of 33 RR intervals, for each the average value of RRM and rhythmogram short sections variations (SSV) are determined. All short rhythmogram sections are divided into sections containing double rhythmogram breaks and areas not containing any double breaks. Change Gap for RRM values measured in seconds, is divided into 8 ranges arranged in the ascending order with numbers i, where i = 1, 2, 8: (1) <0.573, (2) 0.573-0.648, (3) 0.649-0.724, (4) 0.725-0.800, (5) 0.801-0.873, (6) 0.874-0.948, (7) 0.949-1.024, (8)>1.024. Each short rhythmogram section belongs to the group with the number equal to the band number, covering its RRM value. For each group obtained by this method and having number i, number n1(i) of short rhythmogram sections covered by the i-th group and not containing double breaks, mean SSVM1(i) value, SSV values of sections belonging to the i-th group and not containing double breaks, number n2(i) of short rhythmogram sections covered by the i-th group and containing double breaks, mean SSVM2(i) value,SSV values of sections belonging to the i-th group and containing double breaks. The weighted average rhythmogram variations WARV1 and WARV2 are calculated by the formula: WARV1 = Σ (nl(i)*q(i)*SSVM1(i))/(n1(l)+n1(2)+…+ n1(8)), WARV2 = Σ (n2(i)*q(i)*SSVM2(i))/(n2(1)+n2(2)+…+n2(8)). In the formulas: i = 1,…,8 are the numbers of ranges, and the weighting factors q(i) are given by q(1) = 3.04, q(2) = 2.75, q(3) = 2.33, q(4) = 1.88, q(5) = 1.56, q(6) = 1.34, q(7) = 1.15 and q(8) = 1. Double breaks effect factor is calculated DBEF = WARV2/WARV1. If WARV1<550 ms, or DBEF>3, or DBEF>2 at WARV1<700 ms, HRV is considered abnormal.

EFFECT: method allows to quantify the daily heart rate variability to determine objectively whether the heart rate variability is normal.

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