Menzies Research Institute Tasmania, University of Tasmania, Private Bag 23, Hobart 7000, Australia.
Hypertension. 2013 Jul;62(1):175-82. doi: 10.1161/HYPERTENSIONAHA.111.00584. Epub 2013 May 28.
Exercise hypertension independently predicts cardiovascular mortality, although little is known about exercise central hemodynamics. This study aimed to determine the contribution of arterial wave travel and aortic reservoir characteristics to central blood pressure (BP) during exercise. We hypothesized that exercise central BP would be principally related to forward wave travel and aortic reservoir function. After routine diagnostic coronary angiography, invasive pressure and flow velocity were recorded in the ascending aorta via sensor-tipped intra-arterial wires in 10 participants (age, 55±10 years; 70% men) free of coronary artery disease with normal left ventricular function. Measures were recorded at baseline and during supine cycle ergometry. Using wave intensity analysis, dominant wave types throughout the cardiac cycle were identified (forward and backward, compression, and decompression), and aortic reservoir and excess pressure were calculated. Central systolic BP increased significantly with exercise (Δ=19±12 mm Hg; P<0.001). This was associated with increases in systolic forward compression waves (Δ=12×10(6)±17×10(6) W·m(-2)·s(-1); P=0.045) and forward decompression waves in late systole (Δ=9×10(6)±6×10(6) W·m(-2)·s(-1); P<0.001). Despite significant augmentation in BP (Δ=9±6 mm Hg; P=0.002), reflected waves did not increase in magnitude (Δ=-1×10(6)±3×10(6) W·m(-2)·s(-1); P=0.2). Excess pressure rose significantly with exercise (Δ=16±9 mm Hg; P<0.001), and reservoir pressure integral fell (Δ=-5×10(5)±5×10(5) Pa·s; P=0.010). Change in reflection coefficient negatively correlated with change in central systolic BP (r=-0.68; P=0.03). We conclude that elevation of exercise central BP is principally because of increases in aortic forward traveling waves generated by left ventricular ejection. These findings have relevance to understanding central BP waveform morphology and pathophysiology of exercise hypertension.
运动性高血压可独立预测心血管死亡率，尽管对于运动中心血管动力学知之甚少。本研究旨在确定动脉波传播和主动脉储器特性对运动中心血压（BP）的贡献。我们假设运动中心 BP 主要与前向波传播和主动脉储器功能有关。在常规诊断性冠状动脉造影后，10 名无冠状动脉疾病且左心室功能正常的参与者（年龄 55±10 岁，70%为男性）经内置动脉线的传感器尖端在升主动脉中记录压力和流速。在基线和仰卧位踏车运动期间记录测量值。使用波强度分析确定整个心动周期中的主导波类型（前向和后向、压缩和减压），并计算主动脉储器和超压。中心收缩压随运动显著增加（Δ=19±12 mm Hg；P<0.001）。这与收缩期前向压缩波（Δ=12×10(6)±17×10(6) W·m(-2)·s(-1)；P=0.045）和晚期收缩期前向减压波（Δ=9×10(6)±6×10(6) W·m(-2)·s(-1)）的增加相关；P<0.001）。尽管 BP 显著增加（Δ=9±6 mm Hg；P=0.002），反射波的幅度并未增加（Δ=-1×10(6)±3×10(6) W·m(-2)·s(-1)；P=0.2）。运动时超压显著升高（Δ=16±9 mm Hg；P<0.001），储器压力积分下降（Δ=-5×10(5)±5×10(5) Pa·s；P=0.010）。反射系数的变化与中心收缩压的变化呈负相关（r=-0.68；P=0.03）。我们得出结论，运动中心 BP 的升高主要是由于左心室射血产生的主动脉前向传播波的增加。这些发现与理解中心 BP 波形形态和运动性高血压的病理生理学有关。
