Smulyan Harold, Siddiqui Danish S, Carlson Raymond J, London Gerard M, Safar Michel E
Department of Medicine, Upstate Medical University, State University of New York at Syracuse, 750 E Adams St, Syracuse, NY 13210, USA.
Hypertension. 2003 Aug;42(2):150-5. doi: 10.1161/01.HYP.0000084051.34269.A9. Epub 2003 Jul 14.
Brachial artery cuff blood pressures are but approximations of central aortic pressures. The actual pressures against which the left ventricle must pump would be useful clinical information if obtained noninvasively. Our aim was to determine the clinical utility of aortic pulses and pressures calculated from noninvasively obtained radial-artery pulses. Radial-arterial pulses were recorded by applanation and calibrated with arm/cuff oscillometric pressures. Aortic pulses and pressures were calculated from the radial pulses by Fourier analysis and transfer functions. These calculated aortic pulses were compared with directly recorded aortic pulses by a transducer-tip catheter in a series of 50 patients undergoing cardiac catheterization. The correlation coefficient (r) of the measured versus the calculated aortic systolic blood pressure was +0.89, but the scatter was large (standard deviation of the differences=+/-11.3 mm Hg). The pulse pressure correlations were less good (r=+0.79) and also had a large scatter (+/-13.6 mm Hg). The average calculated pulse pressure was 11.5 mm Hg lower than the measured value because the cuff diastolic blood pressures, used to calibrate the radial pulses, were systematically higher than those in the aorta (8.9 mm Hg). Multivariable analysis incorporating height, age, heart rate, and ejection fraction as additional, independent variables eliminated mean differences between the new "predicted" and measured pressures, significantly improved correlation coefficients, and reduced the scatter. However, the improvements were small. The inaccuracy of the oscillometric cuff method for measuring arm blood pressure appears to be the limiting factor in the prediction of clinically useful, noninvasive aortic pressures.
肱动脉袖带血压只是中心主动脉压的近似值。如果能无创获取左心室泵血时实际所对抗的压力，将是很有用的临床信息。我们的目的是确定从无创获取的桡动脉脉搏计算得出的主动脉脉搏和压力的临床实用性。通过压平法记录桡动脉脉搏，并用臂/袖带示波法压力进行校准。通过傅里叶分析和传递函数从桡动脉脉搏计算得出主动脉脉搏和压力。在50例接受心导管检查的患者中，将这些计算得出的主动脉脉搏与通过换能器尖端导管直接记录的主动脉脉搏进行比较。测量的与计算的主动脉收缩压的相关系数（r）为+0.89，但离散度较大（差值的标准差=±11.3 mmHg）。脉压相关性较差（r = +0.79），离散度也较大（±13.6 mmHg）。计算出的平均脉压比测量值低11.5 mmHg，因为用于校准桡动脉脉搏的袖带舒张压系统性地高于主动脉舒张压（8.9 mmHg）。纳入身高、年龄、心率和射血分数作为额外独立变量的多变量分析消除了新的“预测”压力与测量压力之间的平均差异，显著提高了相关系数，并减少了离散度。然而，改善幅度较小。示波袖带法测量上臂血压的不准确性似乎是预测临床上有用的无创主动脉压力的限制因素。
