Hemodynamic Factors Regulating Blood Pressure During Sleep in Patients With Mild Essential Hypertension Tochikubo Osamu Kawano Yoshiyuki Miyajima Eiji Ishikawa Toshiyuki Ishii Masao 社団法人日本循環器学会 Japanese circulation journal 00471828 61 1 25 37 1996-12-20 Blood pressure (BP) values (systolic BP=Ps, diastolic BP=Pd, heart rate=HR) fluctuate widely throughout the day, and are at their lowest levels during sleep (sleep-Ps=P_<S0>, sleep-Pd=Pd_0, sleep-HR=HR_0). We analyzed the relationships among these values using the Windkessel model (logarithmic gradient of diastolic pressure decay A=E/R, E=elastic modulus, R=vascular resistance). Intra-arterial BP and ECG were recorded throughout 24 hours in 23 patients with mild essential hypertension (EH) by telemetry, and EEG was monitored during the night. The waveform of each BP pulse was analyzed by computer. The dye-dilution method was used to obtain the cardiac output while the subjects were awake, recumbent and during slow-wave sleep on the EEG. A high correlation coefficient (r) was observed between mean BP and √<E>×√<R> during sleep (r=0.88, p<0.001). Sleep-HR was determined from the waveform that most effectively permitted peripheral blood flow. Furthermore, the simple algebraic relationships Pd≒φ× Pd_0 and φ≒FI+a_1(BI)+b_1 (a_1, b_1=constant) were observed between Pd_0 and different 24h Pd values [FI=e^<A(RRo-RR)>; BI=baroreflex index=RR×Pd/(RR_0×Pd_0)-1, which was significantly correlated with the baroreflex sensitivity, r=0.79; RR_0 and RR are the RR intervals in Pd_0 and Pd waves]. The mean r between Pd_0×φ and the actual Pd over 24 h was 0.91±0.02 <SD>. We conclude that sleep-BP and sleep-HR depend mainly on √<E>×√<R>, m [m=log_e(Ps/Pd)] and E/R, whereas BP variability (φ) over a 24 h period is related to HR variation, the baroreflex index and E/R in mild EH patients. 1996-12-20 110002563390 AA00690731 ENG CJP CJPref NII-ELS 3 26 7 Hemodynamic Factors Regulating Blood Pressure During Sleep in Patients With Mild Essential Hypertension Tochikubo Osamu Kawano Yoshiyuki Miyajima Eiji Ishikawa Toshiyuki Ishii Masao Japanese Circulation Society Japanese circulation journal Blood pressure (BP) values (systolic BP=Ps, diastolic BP=Pd, heart rate=HR) fluctuate widely throughout the day, and are at their lowest levels during sleep (sleep-Ps=P_<S0>, sleep-Pd=Pd_0, sleep-HR=HR_0). We analyzed the relationships among these values using the Windkessel model (logarithmic gradient of diastolic pressure decay A=E/R, E=elastic modulus, R=vascular resistance). Intra-arterial BP and ECG were recorded throughout 24 hours in 23 patients with mild essential hypertension (EH) by telemetry, and EEG was monitored during the night. The waveform of each BP pulse was analyzed by computer. The dye-dilution method was used to obtain the cardiac output while the subjects were awake, recumbent and during slow-wave sleep on the EEG. A high correlation coefficient (r) was observed between mean BP and √<E>×√<R> during sleep (r=0.88, p<0.001). Sleep-HR was determined from the waveform that most effectively permitted peripheral blood flow. Furthermore, the simple algebraic relationships Pd≒φ× Pd_0 and φ≒FI+a_1(BI)+b_1 (a_1, b_1=constant) were observed between Pd_0 and different 24h Pd values [FI=e^<A(RRo-RR)>; BI=baroreflex index=RR×Pd/(RR_0×Pd_0)-1, which was significantly correlated with the baroreflex sensitivity, r=0.79; RR_0 and RR are the RR intervals in Pd_0 and Pd waves]. The mean r between Pd_0×φ and the actual Pd over 24 h was 0.91±0.02 <SD>. We conclude that sleep-BP and sleep-HR depend mainly on √<E>×√<R>, m [m=log_e(Ps/Pd)] and E/R, whereas BP variability (φ) over a 24 h period is related to HR variation, the baroreflex index and E/R in mild EH patients. Tochikubo Osamu the Second Department of Internal Medicine, Urafune Hospital of Yokohama City University Kawano Yoshiyuki the Second Department of Internal Medicine, Urafune Hospital of Yokohama City University Miyajima Eiji the Second Department of Internal Medicine, Urafune Hospital of Yokohama City University Ishikawa Toshiyuki the Second Department of Internal Medicine, Urafune Hospital of Yokohama City University Ishii Masao the Second Department of Internal Medicine, School of Medicine, Yokohama City University