How complex phenotypes emerge from intricate gene expression patterns is a fundamental question in biology. Quantitative characterization of this relationship, however, is challenging due to the vast combinatorial possibilities and dynamic interplay between genotype and phenotype landscapes. Integrating high-content genotyping approaches such as single-cell RNA sequencing and advanced learning methods such as language models offers an opportunity for dissecting this complex relationship.
View Article and Find Full Text PDFBackground: Extracorporeal membrane oxygenation (ECMO) via femoral cannulation is a vital intervention capable of rapidly restoring perfusion for patients in shock. Despite increasing use to provide circulatory support, its hemodynamic effects are poorly understood and the impact of patient-specific anatomical variation on perfusion is unknown. This study investigates the complex failing heart-mechanical circulatory support circulation and analyzes the effect of patient-specific vascular anatomical variations on hemodynamics and end-organ perfusion.
View Article and Find Full Text PDFExtracorporeal membrane oxygenation (ECMO) is a vital mechanical circulatory support modality capable of restoring perfusion for the patient in circulatory failure. Despite increasing adoption of ECMO, there is incomplete understanding of its effects on systemic hemodynamics and how the vasculature responds to varying levels of continuous retrograde perfusion. To gain further insight into the complex ECMO:failing heart circulation, computational fluid dynamics simulations focused on perfusion distribution and hemodynamic flow patterns were conducted using a patient-derived aorta geometry.
View Article and Find Full Text PDFThe bicuspid aortic valve (BAV) is a common and heterogeneous congenital heart abnormality that is often complicated by aortic stenosis. Although initially developed for tricuspid aortic valves (TAV), transcatheter aortic valve replacement (TAVR) devices are increasingly applied to the treatment of BAV stenosis. It is known that patient-device relationship between TAVR and BAV are not equivalent to those observed in TAV but the nature of these differences are not well understood.
View Article and Find Full Text PDFExtracorporeal membrane oxygenation (ECMO) is increasingly deployed to provide percutaneous mechanical circulatory support despite incomplete understanding of its complex interactions with the failing heart and its effects on hemodynamics and perfusion. Using an idealized geometry of the aorta and its major branches and a peripherally inserted return cannula terminating in the iliac artery, computational fluid dynamic simulations were performed to (1) quantify perfusion as function of relative ECMO flow and (2) describe the watershed region produced by the collision of antegrade flow from the heart and retrograde ECMO flow. To simulate varying degrees of cardiac failure, ECMO flow as a fraction of systemic perfusion was evaluated at 100%, 90%, 75%, and 50% of total flow with the remainder supplied by the heart calculated from a patient-derived flow waveform.
View Article and Find Full Text PDFInteract Cardiovasc Thorac Surg
January 2020
Objectives: Clinical and subclinical leaflet thromboses are increasingly recognized complications following transcatheter aortic valve replacement. Identification of the risk factors is important to mitigate the occurrence of leaflet thrombosis in transcatheter aortic valves (TAVs) and ensure their long-term function. The goal of this study was to determine the effect of incomplete expansion of TAVs on the likelihood of leaflet thrombosis following transcatheter aortic valve replacement.
View Article and Find Full Text PDFBiomech Model Mechanobiol
October 2016
Ischemic stroke is a major cause of death and long-term disabilities worldwide. In this paper, we aim to represent a comprehensive simulation of the motion of emboli through cerebrovascular network within patient-specific computational model. The model consists of major arteries of the circle of Willis reconstructed from magnetic resonance angiography images, pulsatile flow and emboli with different sizes and material properties.
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