Piccioli Francesco, Li Ye, Valiani Alessandro, Caleffi Valerio, Chowienczyk Phil, Alastruey Jordi
Department of Engineering, University of Ferrara, Ferrara, Italy.
King's College London British Heart Foundation Centre, Department of Clinical Pharmacology, St Thomas' Hospital, London, United Kingdom.
Front Cardiovasc Med. 2023 Jun 23;10:1197842. doi: 10.3389/fcvm.2023.1197842. eCollection 2023.
Arterial stiffening and peripheral wave reflections have been considered the major determinants of raised pulse pressure (PP) and isolated systolic hypertension, but the importance of cardiac contractility and ventricular ejection dynamics is also recognised.
We examined the contributions of arterial compliance and ventricular contractility to variations in aortic flow and increased central (cPP) and peripheral (pPP) pulse pressure, and PP amplification (PPa) in normotensive subjects during pharmacological modulation of physiology, in hypertensive subjects, and using a cardiovascular model accounting for ventricular-aortic coupling. Reflections at the aortic root and from downstream vessels were quantified using emission and reflection coefficients, respectively.
cPP was strongly associated with contractility and compliance, whereas pPP and PPa were strongly associated with contractility. Increased contractility by inotropic stimulation increased peak aortic flow (323.9 ± 52.8 vs. 389.1 ± 65.1 ml/s), and the rate of increase (3193.6 ± 793.0 vs. 4848.3 ± 450.4 ml/s) in aortic flow, leading to larger cPP (36.1 ± 8.8 vs. 59.0 ± 10.8 mmHg), pPP (56.9 ± 13.1 vs. 93.0 ± 17.0 mmHg) and PPa (20.8 ± 4.8 vs. 34.0 ± 7.3 mmHg). Increased compliance by vasodilation decreased cPP (62.2 ± 20.2 vs. 45.2 ± 17.8 mmHg) without altering , pPP or PPa. The emission coefficient changed with increasing cPP, but the reflection coefficient did not. These results agreed with data obtained by independently changing contractility/compliance over the range observed .
Ventricular contractility plays a key role in raising and amplifying PP, by altering aortic flow wave morphology.
动脉僵硬度和外周波反射被认为是脉压（PP）升高和单纯收缩期高血压的主要决定因素，但心脏收缩性和心室射血动力学的重要性也得到认可。
我们研究了在生理药理学调节过程中，正常血压受试者、高血压受试者以及使用考虑心室-主动脉耦合的心血管模型时，动脉顺应性和心室收缩性对主动脉血流变化、中心（cPP）和外周（pPP）脉压升高以及PP放大（PPa）的贡献。分别使用发射系数和反射系数对主动脉根部和下游血管的反射进行量化。
cPP与收缩性和顺应性密切相关，而pPP和PPa与收缩性密切相关。通过正性肌力刺激增加收缩性会增加主动脉血流峰值（323.9±52.8对389.1±65.1ml/s）以及主动脉血流增加速率（3193.6±793.0对4848.3±450.4ml/s），导致更大的cPP（36.1±8.8对59.0±10.8mmHg）、pPP（56.9±13.1对93.0±17.0mmHg）和PPa（20.8±4.8对34.0±7.3mmHg）。通过血管舒张增加顺应性会降低cPP（62.2±20.2对45.2±17.8mmHg），而不改变pPP或PPa。发射系数随cPP增加而变化，但反射系数不变。这些结果与在观察范围内独立改变收缩性/顺应性获得的数据一致。
心室收缩性通过改变主动脉血流波形形态，在升高和放大PP中起关键作用。
