Chern Chang-Ming, Hsu Hung-Yi, Hu Han-Hwa, Chen Yen-Yu, Hsu Li-Chi, Chao A-Ching
Section of Cerebrovascular Disease, Neurological Institute, Taipei Veterans General Hospital & National Yang-Ming University School of Medicine, Taipei, Taiwan.
J Cardiovasc Pharmacol. 2006 Feb;47(2):169-74. doi: 10.1097/01.fjc.0000199225.17928.f5.
Baroreflex sensitivity (BRS) and heart rate variability (HRV) are potential therapeutic targets. The present study was conducted to assess changes in BRS and HRV after monotherapy with losartan versus that of atenolol in uncomplicated essential hypertension. Thirty subjects with uncomplicated essential hypertension were randomized to receive atenolol 50 mg to 100 mg (n = 15) or losartan 50 mg to 100 mg (N = 15) daily for 6 months. Instantaneous systolic blood pressure (SBP) and heart rate were assessed using servo-controlled infrared finger plethysmography before treatment and at the end of 3 months and 6 months after treatment. The fluctuation in SBP and interpulse interval (IPI) was divided into three specific frequency ranges by fast Fourier transform as high frequency (HF; 0.15 Hz-0.4 Hz), low frequency (LF; 0.04 Hz-0.15 Hz), and very low frequency (VLF; 0.004 Hz-0.04 Hz). The BRS was expressed as (1) SBP-IPI transfer function with its magnitude in the HF and LF ranges and (2) BRS index alpha. The HRV was expressed as total power and power in the LF and HF ranges of interpulse interval. Blood pressure was reduced to a similar extent in both groups. Compared with the baseline, BRS did not improve in both groups at month 3. However, BRS was significantly improved in the losartan group (P < 0.05) but not in the atenolol group at month 6. In addition, BRS was significantly higher in the losartan group than the atenolol group at month 3 and month 6 (P < 0.05). Moreover, heart rate variability was significantly reduced in the atenolol group at month 6 (P < 0.05), but not in the losartan group. The HRV in the losartan group was significantly higher than that in the atenolol group at month 6 (P < 0.05). These findings suggest superior effects of losartan on BRS and HRV than atenolol in uncomplicated essential hypertension, which may be beyond blood pressure reduction/resetting.
压力反射敏感性（BRS）和心率变异性（HRV）是潜在的治疗靶点。本研究旨在评估在单纯性原发性高血压患者中，氯沙坦与阿替洛尔单药治疗后BRS和HRV的变化。30例单纯性原发性高血压患者被随机分为两组，分别每日服用50毫克至100毫克阿替洛尔（n = 15）或50毫克至100毫克氯沙坦（N = 15），为期6个月。在治疗前、治疗3个月末和6个月末，使用伺服控制的红外手指体积描记法评估瞬时收缩压（SBP）和心率。通过快速傅里叶变换将SBP和脉搏间期（IPI）的波动分为三个特定频率范围，即高频（HF；0.15赫兹 - 0.4赫兹）、低频（LF；0.04赫兹 - 0.15赫兹）和极低频（VLF；0.004赫兹 - 0.04赫兹）。BRS表示为：（1）SBP - IPI传递函数及其在HF和LF范围内的幅度；（2）BRS指数α。HRV表示为脉搏间期的总功率以及LF和HF范围内的功率。两组血压降低程度相似。与基线相比，两组在第3个月时BRS均未改善。然而，在第6个月时，氯沙坦组BRS显著改善（P < 0.05），而阿替洛尔组未改善。此外，在第3个月和第6个月时，氯沙坦组的BRS显著高于阿替洛尔组（P < 0.05）。而且，在第6个月时，阿替洛尔组的心率变异性显著降低（P < 0.05），而氯沙坦组未降低。在第6个月时，氯沙坦组的HRV显著高于阿替洛尔组（P < 0.05）。这些发现表明，在单纯性原发性高血压中，氯沙坦对BRS和HRV的影响优于阿替洛尔，这可能不仅仅是血压降低/重置的作用。
