Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: Modeling incremented pulmonary vascular resistance and heart rate

Vallecilla, Carolina; Khiabani, Reza H.; Sandoval, Néstor; Fogel, Mark A.; Briceño, Juan Carlos; Yoganathan, Ajit P.

doi:10.1016/j.jbiomech.2014.03.021

Cited by 7 publications

(7 citation statements)

References 43 publications

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“…In a typical Fontan patient with low normal PA pressures, cardiac output at rest is already reduced to 65%–70% of normal. In Fontan patients with mean PA pressures of 20–25 mm Hg, a further preload-dependent reduction in cardiac output is anticipated, even in the presence of normal ventricular function 7 16. In our Fontan group at low altitude, the effective PBF at rest was 71% of the PBF in controls, as expected.…”

Section: Discussionsupporting

confidence: 80%

Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients

Staempfli

Schmid

Schenker

et al. 2016

Heart

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Section: Discussionsupporting

confidence: 80%

Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients

Staempfli

Schmid

Schenker

et al. 2016

Heart

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“…The general approach is based on previous LPMs (Penati et al 1997; Penati et al 2000; Peskin et al, 1986; Pekkan et al, 2005; Sundareswaran et al, 2008; Vallecilla et al 2014) where vascular structures are modeled as transient compliant chambers and valves as switches. Baseline systemic resistance, baseline PVR, hemoglobin content, baseline SaO 2 , and BSA were used as input variables for each patient (Table 1).…”

Section: Methodsmentioning

confidence: 99%

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio

Vallecilla

Khiabani

Trusty

et al. 2015

Journal of Biomechanics

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In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data.

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“…As altitude increases, lower atmospheric pressures lead to reduced atmospheric oxygen partial pressures and arterial blood oxygen levels, causing hypoxic damage (Askew, 2002; Vallecilla et al, 2014). Under normal circumstances, people are able to resist mild oxidative stress and restore redox balance via the body's naturally equipped antioxidant system.…”

Section: Ros Generation In Various Types Of Exercisementioning

confidence: 99%

Redox Mechanism of Reactive Oxygen Species in Exercise

et al. 2016

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It is well known that regular exercise can benefit health by enhancing antioxidant defenses in the body. However, unaccustomed and/or exhaustive exercise can generate excessive reactive oxygen species (ROS), leading to oxidative stress-related tissue damages and impaired muscle contractility. ROS are produced in both aerobic and anaerobic exercise. Mitochondria, NADPH oxidases and xanthine oxidases have all been identified as potential contributors to ROS production, yet the exact redox mechanisms underlying exercise-induced oxidative stress remain elusive. Interestingly, moderate exposure to ROS is necessary to induce body's adaptive responses such as the activation of antioxidant defense mechanisms. Dietary antioxidant manipulation can also reduce ROS levels and muscle fatigue, as well as enhance exercise recovery. To elucidate the complex role of ROS in exercise, this review updates on new findings of ROS origins within skeletal muscles associated with various types of exercises such as endurance, sprint and mountain climbing. In addition, we will examine the corresponding antioxidant defense systems as well as dietary manipulation against damages caused by ROS.

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Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: Modeling incremented pulmonary vascular resistance and heart rate

Cited by 7 publications

References 43 publications

Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients

Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio

Redox Mechanism of Reactive Oxygen Species in Exercise

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