scholarly journals Patient-specific analysis of left ventricular blood flow

1998 ◽  
pp. 156-166 ◽  
Author(s):  
Timothy N. Jones ◽  
Dimitris N. Metaxas
Keyword(s):  
Blood Flow ◽  
Left Ventricular ◽  
Patient Specific ◽  
Specific Analysis

Estimation of left ventricular blood flow parameters: clinical application of patient-specific CFD simulations from 4D echocardiography

2017 ◽  
Author(s):  
David Larsson ◽  
Jeannette H. Spühler ◽  
Elif Günyeli ◽  
Tino Weinkauf ◽  
Johan Hoffman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Clinical Application ◽  
Left Ventricular ◽  
Patient Specific ◽  
Cfd Simulations ◽  
Flow Parameters

scholarly journals Image-Based Computational Hemodynamics Analysis of Systolic Obstruction in Hypertrophic Cardiomyopathy

2022 ◽  
Vol 12 ◽  
Author(s):  
Ivan Fumagalli ◽  
Piermario Vitullo ◽  
Christian Vergara ◽  
Marco Fedele ◽  
Antonio F. Corno ◽  
...  
Keyword(s):  
Blood Flow ◽  
Hypertrophic Cardiomyopathy ◽  
Pathological Condition ◽  
Ventricular Outflow Tract ◽  
Hypertrophic Obstructive Cardiomyopathy ◽  
Left Ventricular ◽  
Patient Specific ◽  
Cine Mri ◽  
Septal Myectomy ◽  
Blood Flow Dynamics

Hypertrophic Cardiomyopathy (HCM) is a pathological condition characterized by an abnormal thickening of the myocardium. When affecting the medio-basal portion of the septum, it is named Hypertrophic Obstructive Cardiomyopathy (HOCM) because it induces a flow obstruction in the left ventricular outflow tract. In any type of HCM, the myocardial function can become compromised, possibly resulting in cardiac death. In this study, we investigated with computational analysis the hemodynamics of patients with different types of HCM. The aim was quantifying the effects of this pathology on the intraventricular blood flow and pressure gradients, and providing information potentially useful to guide the indication and the modality of the surgical treatment (septal myectomy). We employed an image-based computational approach, integrating fluid dynamics simulations with geometric and functional data, reconstructed from standard cardiac cine-MRI acquisitions. We showed that with our approach we can better understand the patho-physiological behavior of intraventricular blood flow dynamics due to the abnormal morphological and functional aspect of the left ventricle. The main results of our investigation are: (a) a detailed patient-specific analysis of the blood velocity, pressure and stress distribution associated to HCM; (b) a computation-based classification of patients affected by HCM that can complement the current clinical guidelines for the diagnosis and treatment of HOCM.

scholarly journals An Intra-Cycle Optimal Control Framework for Ventricular Assist Devices Based on Atrioventricular Plane Displacement Modeling

2021 ◽  
Author(s):  
Clemens Zeile ◽  
Thomas Rauwolf ◽  
Alexander Schmeisser ◽  
Jeremi Kaj Mizerski ◽  
Rüdiger C. Braun-Dullaeus ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Flow ◽  
Aortic Valve ◽  
Left Ventricular ◽  
Patient Specific ◽  
Ventricular Assist ◽  
Pump Speed ◽  
Atrioventricular Plane Displacement ◽  
Valve Opening ◽  
Plane Displacement

AbstractA promising treatment for congestive heart failure is the implementation of a left ventricular assist device (LVAD) that works as a mechanical pump. Modern LVADs work with adjustable constant rotor speed and provide therefore continuous blood flow; however, recently undertaken efforts try to mimic pulsatile blood flow by oscillating the pump speed. This work proposes an algorithmic framework to construct and evaluate optimal pump speed policies with respect to generic objectives. We use a model that captures the atrioventricular plane displacement, which is a physiological indicator for heart failure. We employ mathematical optimization to adapt this model to patient specific data and to find optimal pump speed policies with respect to ventricular unloading and aortic valve opening. To this end, we reformulate the cardiovascular dynamics into a switched system and thereby reduce nonlinearities. We consider system switches that stem from varying the constant pump speed and that are state dependent such as valve opening or closing. As a proof of concept study, we personalize the model to a selected patient with respect to ventricular pressure. The model fitting results in a root-mean-square deviation of about 6 mmHg. The optimization that considers aortic valve opening and ventricular unloading results in speed modulation akin to counterpulsation. These in silico findings demonstrate the potential of personalized hemodynamical optimization for the LVAD therapy.

An approach for comparative quantification of myocardial blood flow (0-15-H2O-PET), perfusion (Tc-99m-tetrofosmin-SPECT), and metabolism (F 18-FDG-PET)

2001 ◽  
Vol 40 (05) ◽  
pp. 164-171 ◽  
Author(s):  
B. Nowak ◽  
H.-J. Kaiser ◽  
S. Block ◽  
K.-C. Koch ◽  
J. vom Dahl ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Fdg Pet ◽  
Model Fitting ◽  
Compartment Model ◽  
Left Ventricular ◽  
Short Axis ◽  
New Approach ◽  
Single Compartment Model ◽  
Tissue Fraction

Summary Aim: In the present study a new approach has been developed for comparative quantification of absolute myocardial blood flow (MBF), myocardial perfusion, and myocardial metabolism in short-axis slices. Methods: 42 patients with severe CAD, referred for myocardial viability diagnostics, were studied consecutively with 0-15-H2O PET (H2O-PET) (twice), Tc-99m-Tetrofosmin 5PECT (TT-SPECT) and F-18-FDG PET (FDG-PET). All dato sets were reconstructed using attenuation correction and reoriented into short axis slices. Each heart was divided into three representative slices (base, rnidventricular, apex) and 18 ROIs were defined on the FDG PET images and transferred to the corresponding H2O-PET and TT-SPECT slices. TT-SPECT and FDG-PET data were normalized to the ROI showing maximum perfusion. MBF was calculated for all left-ventricular ROIs using a single-compartment-model fitting the dynamic H2O-PET studies. Microsphere equivalent MBF (MBF_micr) was calculated by multiplying MBF and tissue-fraction, a parameter which was obtained by fitting the dynamic H2O-PET studies. To reduce influence of viability only well perfused areas (>70% TT-SPECT) were used for comparative quantification. Results: First and second mean global MBF values were 0.85 ml × min-1 × g-1 and 0.84 ml × min-1 × g1, respectively, with a repeatability coefficient of 0.30 ml ÷ min-1 × gl. After sectorization mean MBF_micr was between 0.58 ml × min1 ÷ ml"1 and 0.68 ml × min-1 × ml"1 in well perfused areas. Corresponding TT-SPECT values ranged from 83 % to 91 %, and FDG-PET values from 91 % to 103%. All procedures yielded higher values for the lateral than the septal regions. Conclusion: Comparative quantification of MBF, MBF_micr, TT-SPECT perfusion and FDG-PET metabolism can be done with the introduced method in short axis slices. The obtained values agree well with experimentally validated values of MBF and MBF_micr.

Modified Septal Myectomy Using a Curved Knife for Left Ventricular Septal Hypertrophy

2014 ◽  
Vol 17 (5) ◽  
pp. 269
Author(s):  
Shinya Takahashi ◽  
Taiichi Takasaki ◽  
Futoshi Tadehara ◽  
Takahiro Taguchi ◽  
Keijiro Katayama ◽  
...  
Keyword(s):  
Blood Flow ◽  
Chest Pain ◽  
Aortic Valve ◽  
Cross Section ◽  
Left Ventricular ◽  
Chest Discomfort ◽  
Septal Myectomy ◽  
Asymmetric Septal Hypertrophy ◽  
Septal Hypertrophy ◽  
Septal Myocardium

An 86-year-old woman presented with chest pain and discomfort. Echocardiography revealed severe aortic valve stenosis and asymmetric septal hypertrophy. Aortic valve replacement and myectomy were performed using a curved knife. The blade was U-shaped in cross-section, and was curved upward along the long axis. Hypertrophic septal myocardium was removed along the long axis of the left ventricle (LV), and a groove for blood flow was constructed. The patient was discharged uneventfully without recurrence of her chest discomfort. Our result suggested that a curved knife is a reasonable option for transaortic septal myectomy in patients with obstructive LV hypertrophy.

Cardiac Resynchronisation Therapy – Evolving Strategies to Enhance Response

2010 ◽  
Vol 6 (1) ◽  
pp. 83
Author(s):  
Jagmeet P Singh ◽  
Keyword(s):  
Heart Failure ◽  
Systolic Heart Failure ◽  
Cardiac Resynchronisation Therapy ◽  
Left Ventricular ◽  
Patient Specific ◽  
Cardiac Resynchronisation ◽  
Clinical Benefits ◽  
Pacing Lead ◽  
Resynchronisation Therapy ◽  
Physiological Impact

Cardiac resynchronisation therapy (CRT) has gained widespread acceptance as a safe and effective therapeutic strategy for congestive heart failure (CHF) refractory to optimal medical therapy. The use of implantable devices has substantially altered the natural history of systolic heart failure. These devices exert their physiological impact through ventricular remodelling, associated with a reduction in left ventricular (LV) volumes and an improvement in ejection fraction (EF). Several prospective randomised studies have shown that this in turn translates into long-term clinical benefits such as improved quality of life, increased functional capacity and reduction in hospitalisation for heart failure and overall mortality. Despite these obvious benefits, there remain more than a few unresolved concerns, the most important being that up to one-third of patients treated with CRT do not derive any detectable benefit. There are several determinants of successful delivery and response to CRT, including selecting the appropriate patient, patient-specific optimal LV pacing lead placement and appropriate post-implant device care and follow-up. This article highlights the importance of collectively working on all of these aspects of CRT to enhance and maximise response.

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