Quantification of the contribution of cardiac and arterial remodeling to hypertension

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Hypertension Research

Background:

• Hypertension is a complex condition influenced by both cardiac and arterial factors.
• Understanding the interplay between heart function and arterial properties is crucial for managing hypertension.
• Left ventricular adaptation patterns in hypertension are diverse and impact cardiovascular dynamics.

Purpose of the Study:

• To quantify the distinct and combined roles of the heart and arterial system in driving systolic blood pressure in hypertension.
• To investigate how different left ventricular adaptation patterns modify the contributions of cardiac and arterial systems to hypertension.
• To differentiate the effects of vascular stiffening versus increased peripheral resistance on blood pressure regulation.

Main Methods:

• Utilized a computational heart-arterial model to simulate cardiovascular parameters.
• Assessed model parameters in both normotensive controls and hypertensive patients stratified by left ventricular adaptation (normal, concentric remodeling, concentric hypertrophy, eccentric hypertrophy).
• Performed simulations to isolate and quantify the contributions of arterial stiffening, peripheral resistance, and cardiac pump function.

Main Results:

• Vascular stiffening alone increases pulse pressure but not systolic blood pressure.
• Arterial stiffening contributes to systolic hypertension in concentric remodeling and concentric hypertrophy only when combined with increased peripheral resistance.
• Cardiac contribution to systolic hypertension varies significantly with left ventricular adaptation: 55% in normal, 21% in concentric remodeling, 65% in concentric hypertrophy, and 108% in eccentric hypertrophy.

Conclusions:

• Both arterial changes (stiffening and resistance) and cardiac remodeling/hypertrophy are significant contributors to hypertension.
• The relative importance of cardiac versus arterial factors in hypertension is dependent on the specific pattern of left ventricular adaptation.
• Eccentric hypertrophy in hypertension can lead to a cardiac contribution exceeding 100% of the observed increase in systolic blood pressure, indicating a critical role for cardiac dysfunction.