배경 및 목적:압반사 민감도의 측정은 고혈압등 심혈관 질환의 연구, 진단 및 예후판정에 중요하다. 본 연구는 심박 간격의 multifractal 분석만으로도 안정 시 그리고 기립 시 자발적 압반사 민감도를 추정할 수 있음을 보이기 위함이다.방 법:건강한 지원자 24명을 대상으로 안정상태와 기립경사상태에서 30분간 비침습적 수축기 혈압과 심박 간격을 측정하여 자발적 압반사 민감도를 계산하였고 multifractal Hurst 지수를 구하여 이 자발적 압반사 민감도와의 사이의 선형상관관계를 구한다.
결 과:
안정 시 SBRS와 H-5α, H-4α, H-3α, H-2α, H-1α, H1α, H2α, H3α, H4α, H5α 상관계수(p)는 -0.195(NS), -0.207(NS), -0.232(NS), -0.282(NS), -0.355 (NS), -0.621(0.003), -0.650(0.001), -0.677(0.001), -0.699(0.0006), -0.708(0.0005)였다. 기립경사 시 SBRS와 H-5β, H-4β, H-3β, H-2β, H-1β, H1β, H2β, H3β, H4β, H5β와의 상관관계는 각각 0.024(NS), 0.020(NS), 0.010(NS), -0.028(NS), -0.193(NS), -0.627(0.0034), -0.607(0.0045), -0.598(0.0053), -0.572(0.0084), -0.539(0.0141)였다.
결 론:
심박 간격의 초단기 및 단기 multifractal Hurst 지수의 일부 특히 H5α와 H1β는 각각 안정 시 및 기립경사 시 자발적 압반사 민감도를 추정하는데 사용될 수 있다.Background and Objectives:This study was designed to examine whether the multifractal Hurst exponents of heart rate can estimate activating and deactivating spontaneous baroreflex sensitivity (SBRS). Subjects and Methods:Age and sex matched 24 healthy volunteers were placed in the supine position and head-up tilt position for 30 minutes, and the systolic blood pressure and heart rate were measured in an noninvasive manner. When the RR interval (RRI) sequence and systolic pressure sequence simultaneously increased or decreased for more than three successive beats, the slope of the linear regression line of systolic blood pressure and RR interval sequence was defined as the value of spontaneous baroreflex sensitivity (SBRS). From the RR intervals, very short-term (α range, ≤12 heartbeats), short-term (β range, ≥12 heartbeats), and the multrifractal Hurst exponents were calculated to determine the linear correlation.coefficients for SBRS. Results:In the supine position, the linear correlation coefficients (p) of SBRS and H-5α, H-4α, H-3α, H-2α, H-1α, H1α, H2α, H3α, H4α, H5α were -0.195 (NS), -0.207 (NS), -0.232 (NS), -0.282 (NS), -0.355 (NS), -0.621 (0.003), -0.650 (0.001), -0.677 (0.001), -0.699 (0.0006) and -0.708 (0.0005), respectively. In the tilting position, the linear correlation coefficients of SBRS and H-5β, H-4β, H-3β, H-2β, H-1β, H1β, H2β, H3β, H4β, H5β were 0.024 (NS), 0.020 (NS), 0.010 (NS), -0.028 (NS), -0.193 (NS), -0.627 (0.0034), -0.607 (0.0045), -0.598 (0.0053), -0.572 (0.0084) and -0.539 (0.0141), respectively. Conclusion:Some of the very short-term and short-term generalized Hurst exponents, such as H5α and H1β, can be used for the estimation of spontaneous baroreflex sensitivity during patient placement in the supine and head-up tilt position, respectively. (Korean Circulation J 2007;37:443-448)