An Integrative Model of the Cardiovascular System Coupling Heart Cellular Mechanics with Arterial Network Hemodynamics

Abstract

The current study proposes a model of the cardiovascular system that couples heart cell mechanics with arterial hemodynamics to examine the physiological role of arterial blood pressure (BP) in left ventricular hypertrophy (LVH). We developed a comprehensive multiphysics and multiscale cardiovascular model of the cardiovascular system that simulates physiological events, from membrane excitation and the contraction of a cardiac cell to heart mechanics and arterial blood hemodynamics. Using this model, we delineated the relationship between arterial BP or pulse wave velocity and LVH. Computed results were compared with existing clinical and experimental observations. To investigate the relationship between arterial hemodynamics and LVH, we performed a parametric study based on arterial wall stiffness, which was obtained in the model. Peak cellular stress of the left ventricle and systolic blood pressure (SBP) in the brachial and central arteries also increased; however, further increases were limited for higher arterial stiffness values. Interestingly, when we doubled the value of arterial stiffness from the baseline value, the percentage increase of SBP in the central artery was about 6.7% whereas that of the brachial artery was about 3.4%. It is suggested that SBP in the central artery is more critical for predicting LVH as compared with other blood pressure measurements.

Modeling and Simulation Approaches for Cardiovascular Function and Their Role in Safety Assessment

“…Adrenergic and muscarinic receptors mediate this process, and drugs can be antagonists at these receptors which may cause changes in indexes of contractility or other effects, such as beta‐blockers (beta1 adrenoreceptor antagonists), which are used in the treatment of hypertension. To further link AP with hemodynamics, models have been produced describing the electromechanics of the whole heart, and these have combined cell excitation/contraction (EC) coupled with heart mechanics, system circulation, and autonomic control . While great progress has been made defining multiscale systems approaches ( Figure ), these have not yet been fully utilized for linking drug exposure with cardiovascular changes for the assessment of safety or efficacy.…”

Exploring the Utility of Pulse Wave Analysis in Patients with Uncontrolled Brachial Blood Pressures in the Routine Outpatient Setting

“…Safar et al [15] found that after adjustment for cofounders, only central pressure remained predictive in patients with renal failure. The Dicomano Study in Italy and a community based Taiwanese study also observed a stronger association between cardiovascular events and central, rather than brachial pressure [16,17] . Unfortunately with our study we did not have sufficient long term follow up to assess if elevated central blood pressure were indeed more predictive of adverse cardiovascular outcomes as compared to brachial blood pressure readings.…”

Physical and Mathematical Model of Heart and Cardiovascular System

“…In view of the above and the information of Constanzo [1] and other literature review, Circulatory system can be represented as in figure 1. Similarly as per the information of Kim et al [21] and other literature review, Circulatory system can be represented as in figure 2. The symbols used are as follows: The resistance of a circuit consisting of series of resistances is the sum of individual resistances, whereas in case of parallel resistances; the inverse of system resistance is the sum of inverse of individual resistances.…”

“…Resistances and Compliances of a few parts of the circulatory system are available in the paper published by Kim et al [21]. Volume of Blood stored in different parts of circulatory system and pressure at different points of circulatory systems are collected from Literature [1].…”

“…The peripheral circulation is divided into the upper body, renal, splanchnic, and lower extremity sections; the intrathoracic superior, inferior vena cava, and extra-thoracic vena cava are identified separately. The model thus consists of compartments, each of which is represented by resistance (R) and compliance or capacitance (C) [1,21]. Compliance or capacitance here is the volume of blood the vessel can hold per unit pressure.…”