心室起搏诱发的心动过速对人体主动脉力学的影响。

Effects of ventricular pacing-induced tachycardia on aortic mechanics in man.

作者信息

Stefanadis C, Dernellis J, Vavuranakis M, Tsiamis E, Vlachopoulos C, Toutouzas K, Diamandopoulos L, Pitsavos C, Toutouzas P

机构信息

Hippokration Hospital, Department of Cardiology, University of Athens, Greece.

出版信息

Cardiovasc Res. 1998 Aug;39(2):506-14. doi: 10.1016/s0008-6363(98)00115-1.

DOI:10.1016/s0008-6363(98)00115-1

PMID:9798535

Abstract

OBJECTIVE

Effects of pacing-induced tachycardia on left ventricular function have been studied extensively. However, little attention has been focused on aortic elastic properties during heart rate increments. The aim was to determine the effects of right ventricular pacing on the aortic elastic properties.

METHODS

We studied 14 normal subjects (baseline blood pressure, 129/84 +/- 10/6 mmHg; aortic diameter, 23.5/21.3 +/- 2.4/1.9 mm) at rest, during rapid right ventricular pacing (at five stepwise heart rate increases of 20 bpm every 2 min) and after 5 min recovery. Shifts as well as changes in the slope and the stiffness constant of the pressure diameter (p-d) relation, derived from simultaneous tip-micromanometer aortic pressure recordings and high-fidelity ultrasonic intravascular aortic diameter recordings, were used as indices of aortic stiffness. Wave reflection was also studied.

RESULTS

Aortic pulse pressure and strain significantly decreased after pacing-induced tachycardia (p < 0.0001 and < 0.05, respectively). During pacing, the slope of the linear p-d relation as well as the stiffness constant were decreased, followed by increases at recovery (p < 0.0001). The augmentation index and the aortoventricular coupling ratio were significantly decreased (p < 0.0001).

CONCLUSIONS

Pacing-induced increases in pulse frequency may result in improved aortic distensibility and aortoventricular coupling.

摘要

目的

起搏诱发的心动过速对左心室功能的影响已得到广泛研究。然而，心率增加时主动脉弹性特性却很少受到关注。本研究旨在确定右心室起搏对主动脉弹性特性的影响。

方法

我们对14名正常受试者（静息血压为129/84±10/6 mmHg；主动脉直径为23.5/21.3±2.4/1.9 mm）进行研究，分别在静息状态、快速右心室起搏期间（每2分钟心率逐步增加5次，每次增加20次/分钟）以及5分钟恢复后进行观察。同步使用尖端微测压计记录主动脉压力和高保真超声血管内主动脉直径记录，得出压力-直径（p-d）关系的斜率、刚度常数的变化以及偏移，以此作为主动脉僵硬度的指标。同时也对波反射进行了研究。