Cardiac contractility is a key factor in determining pulse pressure and its peripheral amplification.

Area of Science:

• Cardiovascular Physiology
• Hemodynamics
• Biomedical Engineering

Background:

• Arterial stiffening and wave reflections are traditionally linked to elevated pulse pressure (PP) and isolated systolic hypertension.
• The role of cardiac contractility and ventricular ejection dynamics in these phenomena is increasingly recognized.

Purpose of the Study:

• To investigate the contributions of arterial compliance and ventricular contractility to aortic flow, central PP (cPP), peripheral PP (pPP), and PP amplification (PPa).
• To analyze these relationships in normotensive and hypertensive individuals and through computational modeling.

Main Methods:

• Pharmacological modulation of physiology in normotensive subjects.
• Examination of hypertensive subjects.
• In silico cardiovascular modeling with a focus on ventricular-aortic coupling.
• Quantification of wave reflections using emission and reflection coefficients.

Main Results:

• Central PP (cPP) correlated strongly with both contractility and compliance.
• Peripheral PP (pPP) and PP amplification (PPa) were predominantly associated with contractility.
• Inotropic stimulation (increased contractility) elevated peak aortic flow, cPP, pPP, and PPa.
• Vasodilation (increased compliance) reduced cPP but did not significantly alter pPP or PPa.

Conclusions:

• Ventricular contractility is a critical factor in increasing and amplifying PP.
• Changes in contractility alter aortic flow wave morphology, thereby influencing PP dynamics.