Patient-Specific Numerical Analysis of Coronary Flow in Children With Intramural Anomalous Aortic Origin of Coronary Arteries

Author(s):  
Atefeh Razavi ◽  
Shagun Sachdeva ◽  
Peter C. Frommelt ◽  
John F. LaDisa
2021 ◽  
Author(s):  
Kelsey N Sommer ◽  
Mohammad Mahdi Shiraz Bhurwani ◽  
Vijay Iyer ◽  
Ciprian N Ionita

Abstract Background3D printing (3DP) used to replicate the geometry of normal and abnormal vascular pathologies has been demonstrated in many publications; however, reproduction of hemodynamic changes due to physical activities, such as rest versus moderate exercise, need to be investigated. We developed a new design for patient specific coronary phantoms, which allow adjustable physiological variables such as coronary distal resistance and coronary compliance in patients with coronary artery disease. The new design was tested in precise benchtop experiments and compared with a theoretical Windkessel electrical circuit equivalent, that models coronary flow and pressure using arterial resistance and compliance. MethodsFive phantoms from patients who underwent clinically indicated elective invasive coronary angiography were built from CCTA scans using multi-material 3D printing. Each phantom was used in a controlled flow system where patient specific flow conditions were simulated by a programmable cardiac pump. To simulate the arteriole and capillary beds flow resistance and the compliance for various physical activities, we designed a three-chamber outlet system which controls the outflow dynamics of each coronary tree. Benchtop pressure measurements were recorded using sensors embedded in each of the main coronary arteries. Using the Windkessel model, patient specific flow equivalent electrical circuit models were designed for each coronary tree branch, and flow in each artery was determined for known inflow conditions. Local flow resistances were calculated through Poiseuille’s Law derived from the radii and lengths of the coronary arteries using CT angiography based multi-planar reconstructions. The coronary stenosis flow rates from the benchtop and the electrical models were compared to the localized flow rates calculated from invasive pressure measurements recorded in the angio-suites. ResultsThe average Pearson correlations of the localized flow rates at the location of the stenosis between each of the models (Benchtop/Electrical, Benchtop/Angio, Electrical/Angio) are 0.970, 0.981, and 0.958 respectively. Conclusions3D printed coronary phantoms can be used to replicate the human arterial anatomy as well as blood flow conditions. It displays high levels of correlation when compared to hemodynamics calculated in electrically-equivalent coronary Windkessel models as well as invasive angio-suite pressure measurements.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
E Kalinina ◽  
A Zagatina ◽  
N Zhuravskaya ◽  
D Shmatov

Abstract Funding Acknowledgements Type of funding sources: None. Background There is a high prevalence of coronary artery disease (CAD) in the elderly population. However, symptoms of CAD are often non-specific. Dyspnoe, non-anginal pains are among the main symptoms in older patients. Exercise tests are of limited feasibility in these patients, due to neuro-muscular weakness, physical deconditioning, and orthopaedic limitations. Pharmacological tests often are contraindicated in a substantial percentage of elderly patients. Some recent studies indicate using local flow acceleration during routine echocardiography has prognostic potential for coronary artery assessments without stress testing. The aim of the study was to define the prognostic value of coronary artery ultrasound assessment in patients ≥75 years old. Methods This is a prospective cohort study. Patients ≥ 75 years old who underwent routine echocardiography with additional scans for coronary arteries over a period of 24 months were included in the study. The study group consisted of 80 patients aged 75-90 years (56 women; mean age 79 ± 4). Initial exams were performed for other reasons, primarily for arterial hypertension. Fifteen patients had known CAD. Death, non-fatal myocardial infarction (MI), and revascularization were defined as major adverse cardiac events (MACE). All patients were followed up with at a median of 32 months. Results There were 34 patients with high local velocities in the left coronary artery. Eight deaths, two non-fatal myocardial infarctions occurred, and 13 revascularizations were performed. With a ROC analysis, a coronary flow velocity >110 cm/s was the best predictor for risk of death (area under curve 0.84 [95% CI 0.74–0.92]; sensitivity 75%; specificity 88%). Only the maximal velocity in proximal left-sided coronary arteries was independently associated with death (HR 1.03, 95% CI 1.01; 1.05; p < 0.002), or death/MI (HR 1.03, 95% CI 1.01; 1.04; p < 0.0001). The cut-off value of 66 cm/s was a predictor of all MACE (area under curve 0.87 [95% CI 0.77–0.94]; sensitivity 80%; specificity 86%). Any causes of death or MI occurred more frequently in patients with velocities of >66 cm/s (27% vs. 2%; p < 0.002). The rates of MACE were 58.0% vs. 2%; p < 0.0000001, respectively. Conclusion The analysis of coronary flow in the left coronary artery during echocardiography can be used as a predictor of outcomes in elderly patients. Maximal velocities in proximal left-sided coronary arteries is independently associated with further death or myocardial infarction.


2022 ◽  
pp. 110919
Author(s):  
Simbarashe G. Chidyagwai ◽  
Madhurima Vardhan ◽  
Michael Kaplan ◽  
Reid Chamberlain ◽  
Piers Barker ◽  
...  

Angiology ◽  
2008 ◽  
Vol 60 (4) ◽  
pp. 431-440 ◽  
Author(s):  
Ahmet Soylu ◽  
Kurtulus Ozdemir ◽  
Mehmet Akif Duzenli ◽  
Mehmet Yazici ◽  
Mehmet Tokac

The aim of this study is to evaluate the effect of type 2 diabetes mellitus on epicardial coronary flow velocity assessed by the thrombolysis in myocardial infarction frame count. The thrombolysis in myocardial infarction frame count was measured in 272 coronary arteries from 101 patients with type 2 diabetes mellitus and in 271 coronary arteries from 104 age- and gender-matched patients without type 2 diabetes mellitus referred for coronary angiography. The thrombolysis in myocardial infarction frame count was measured only in normal arteries or in arteries without significant lesion. By both univariate and multivariate analysis, the thrombolysis in myocardial infarction frame count was not related with either type 2 diabetes mellitus or the duration and glycated hemoglobin levels in the patients with type 2 diabetes mellitus. The thrombolysis in myocardial infarction frame count was significantly associated with body surface area, heart rate, and proximal coronary artery diameter. Type 2 diabetes mellitus did not affect epicardial coronary flow velocity assessed by the thrombolysis in myocardial infarction frame count.


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