Cardiovascular disease‐induced thermal responses during passive heat stress: an integrated computational study

Abstract

The cardiovascular system plays a crucial role in human thermoregulation; cardiovascular diseases may lead to significantly degrading the thermoregulation ability for patients during exposure to heat stress. To evaluate the thermal responses of patients with common chronic cardiovascular diseases, we here propose an integrated computational model by coupling a two-node thermoregulation model with a closed-loop, multi-compartment, lumped-parameter cardiovascular model. This bioheat transfer model is validated, capable to predict cardiovascular functions and thermal responses under varying environmental conditions. Our results demonstrate that the cardiovascular disease-induced reduction in cardiac output and skin blood flow causes extra elevation in core temperature during hyperthermic challenges. In addition, a combination of aging, obesity, and cardiovascular diseases shows a pronounced increase in core temperature during heat exposure, which implies that such combined effect may increase the risk of heat-related morbidity and mortality. Copyright © 2016 John Wiley & Sons, Ltd.

A Coupled Flow-Thermoregulation Lumped Model to Investigate Cardiac Function

“…In fact, each signal implies the warmness or coldness, thus, the corresponding mechanism will be activated to regulate the body temperature. To mathematically describe, these signals are defined as follows [4]:…”

“…where, ℎ -W (m 2 K) ⁄ and ℎ , W (m 2 K) ⁄ are the convective and radiative heat transfer coefficients, respectively. In the present study, ℎ , is assumed to be constant, which is equal to 4.65 W (m 2 K) ⁄ [4] and ℎis expressed as follows [26]:…”

“…Examining body thermal response to different physiological and environmental conditions is another application of lumped technique to understand biological performance of human's body. The thermoregulation model proposed by Gagge et al [3] is one of the preliminary attempts, which was later on developed by several authors, such as one of the very recent improvement proposed by Zhang et al [4]. In this model, the body is divided into skin and core regions, hence, it is called two-node thermoregulation model.…”

Personalized Hemodynamic Modeling of the Human Cardiovascular System: A Reduced-Order Computing Model

“…At the distal ends of the 1D model, widely used three-element RCR 0D models, also known as Windkessel models [28] [29], were applied to model peripheral vessels (Fig. 1c).…”

Intersecting vulnerabilities in human biology: Synergistic interactions between climate change and increasing obesity rates

“…On average, the risk of heat stress is elevated among children and adults with obesity (Chung & Pin, 1996; Dougherty, Chow, & Kenney, 2010), such that individuals with clinically high BMIs tend to maintain higher core body temperatures during heat exposure (Habibi, Momeni, & Dehghan, 2016; Zhang, Noda, Himeno, & Liu, 2016). It has been hypothesized that individuals with higher body fat maintain warmer core temperatures because the thickness of fat causes an increase in thermal resistance between the core and periphery, thus restricting heat dissipation (Zhang et al, 2016). The insulative value of human body fat, however, is currently under debate (Brychta, Cypess, Reitman, & Chen, 2019; Fischer, Cannon, & Nedergaard, 2019).…”