scholarly journals Influences on myocardial perfusion in non-obstructive coronary disease: an observational quantitative perfusion mapping study

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
K Knott ◽  
A Seraphim ◽  
JB Augusto ◽  
C Camaioni ◽  
T Kotecha ◽  
...  
Keyword(s):  
Coronary Disease ◽  
Coronary Arteries ◽  
Clinical Training ◽  
Beta Blockers ◽  
Left Ventricular ◽  
Research Centre ◽  
Reference Ranges ◽  
Research Fellowship ◽  
Funding Sources ◽  
Rest Perfusion

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This study was supported by a Clinical Training Research Fellowship (K. Knott) from the British Heart Foundation and directly and indirectly from the Biomedical Research Centre at University College London Hospitals and Barts Heart Centre. Background Cardiovascular magnetic resonance (CMR) with automated inline perfusion mapping permits rapid fully automated non-invasive myocardial blood flow (MBF, ml/g/min). Understanding the microvascular component of MBF would help optimize epicardial coronary artery disease detection and potentially serve as an independent diagnostic / therapeutic target.  Purpose To explore MBF influences at stress and rest in patients with unobstructed epicardial coronary arteries. Methods 242 participants (mean age 56.9 years) from 5 European centers with unobstructed epicardial coronary arteries and no myocardial scar underwent adenosine vasodilator perfusion mapping at stress and rest. The factors influencing MBF were determined using univariate and multivariate linear regression analyses. Results Mean rest perfusion was 0.91+/-0.24ml/g/min. Rest perfusion was higher in females (0.97+/-0.22ml/g/min vs 0.83 +/- 0.24ml/g/min) and lower in patients on beta blockers. Mean stress MBF was 2.53+/-0.82ml/g/min. Factors independently associated with reduced stress MBF were increasing age, diabetes, increasing left ventricular mass (LVMi) and the use of beta blockers.  The predicted stress MBF can be obtained from the equation MBF = 2.66–0.015(age-60)–0.013(LVMi-57)-0.405(diabetes)–0.365(beta blocker). This means stress MBF falls 10% over 19 years and that diabetes drops the MBF by the equivalent of being 27 years older. These changes are large: for example, a 70-year-old diabetic would have 30% lower stress MBF than a 35 year-old non-diabetic.  Conclusions In the absence of obstructive epicardial coronary disease, stress MBF falls with age, diabetes, increased LV mass and beta-blockers. These data may help develop normal reference ranges, input to other modelling (eg CT FFR), and they advance perfusion mapping as a measure of microvascular function. Abstract Figure. Summary of the determinants of perfusion

Myocardial Infarction with Normal Coronary Arteries: The Pathologic and Clinical Perspectives

Angiology ◽  
2001 ◽  
Vol 52 (5) ◽  
pp. 299-304 ◽  
Author(s):  
Aung Tun ◽  
Ijaz A. Khan
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Coronary Arteries ◽  
Beta Blockers ◽  
Coronary Thrombosis ◽  
Coronary Spasm ◽  
Left Ventricular ◽  
Coronary Vasospasm ◽  
Term Survival ◽  
Normal Coronary Arteries

Myocardial infarction with normal coronary arteries is a syndrome resulting from numerous conditions but the exact cause in a majority of the patients remains unknown. Cigarette smokers and cocaine users are more prone to develop this condition. The possible mechanisms causing myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, intense sympathetic stimulation, non-atherosclerotic coronary diseases, coronary trauma, coronary vasospasm, coronary thrombosis, and endothelial dysfunction. It primarily affects younger individuals, and the clinical presentation is similar to that of myocardial infarction with coronary atherosclerosis. Thrombolytics, aspirin, nitrates, and beta blockers should be instituted as a standard therapy for acute myocardial infarction. Once normal coronary arteries are identified on subsequent angiography, the calcium channel blockers could be added since coronary vasospasm appears to play a major role in the pathophysiology of this condition. The beta blockers should be avoided in cocaine-induced myocardial infarction because the coronary spasm may worsen. In myocardial infarction with normal coronary arteries, complications such as malignant arrhythmia, heart failure, and hypotension are generally less common, and prognosis is usually good. Recurrent infarction, postinfarction angina, heart failure, and sudden cardiac death are rare. Stress electrocardiography and imaging studies are not useful prognostic tests and long- term survival mainly depends on the residual left ventricular function, which is usually good.

scholarly journals Left atrial reservoir strain is reduced in patients with myocardial infarction with non-obstructive coronary arteries

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Malaty ◽  
H H L Chen ◽  
G Gan
Keyword(s):  
Myocardial Infarction ◽  
Coronary Arteries ◽  
Left Atrial ◽  
Speckle Tracking ◽  
Global Longitudinal Strain ◽  
Strain Analysis ◽  
Left Ventricular ◽  
Funding Sources ◽  
Group Position ◽  
Lv Dysfunction

Abstract Background Myocardial infarction with non-obstructive coronary arteries (MINOCA) represents a management conundrum given the poorly understood pathogenic mechanisms. In recent years, novel echocardiographic measures such as deformation/strain analysis have enabled early identification of left atrial (LA) remodelling and dysfunction which take place prior to structural alterations. LA dysfunction is an important biomarker of cardiovascular disease and an independent predictor of atrial arrhythmias which may play a fundamental role in the pathogenesis of MINOCA. Purpose The goal of our study was to evaluate and characterise LA function by speckle tracking strain echocardiography in patients with MINOCA. Methods Patients admitted to our institution with acute myocardial infarction were assessed and those diagnosed with MINOCA who underwent transthoracic echocardiogram (TTE) within 48-hours of their coronary angiogram were included. Diagnosis of MINOCA was based on the 2017 ESC working group position paper on myocardial infarction with non-obstructive coronary arteries. Two-dimensional speckle tracking strain analysis of the LA and left ventricle (LV) was performed offline using vendor independent software (TomTec Arena). Clinical and echocardiographic measures were compared to healthy controls identified from our echocardiography database. We excluded patients with history of atrial fibrillation, heart failure and LV dysfunction (LVEF <50%). Results The cohort consisted of 82 patients; 41 patients with MINOCA were compared to 41 age and sex matched controls (61% male, mean age 51±12.8 years). At baseline, patients with MINOCA had a higher prevalence of modifiable vascular risk factors including smoking, hypertension and diabetes (p<0.001 for all). Of the echocardiographic parameters, no differences in left ventricular (LV) parameters including LV global longitudinal strain (p=0.463), indexed LV mass (p=0.084) and the E/e' (p=0.391) was appreciated. Though there was no difference in LA volumes or volumetric parameters of LA function (LAEF; p=0.328), patients with MINOCA had a lower LA reservoir strain (29.7±8.5% vs 33.2±6.5%; p=0.04; 95% CI 0.32–5.33). Conclusion Patients with MINOCA demonstrated lower LASr despite normal LV and LA volumes. This suggests that LA dysfunction may play a role in the pathogenesis of MINOCA. Further studies are required to evaluate the significance of our findings. FUNDunding Acknowledgement Type of funding sources: None.

Direct capture of the left bundle branch compared to left bundle branch area pacing deteriorates interventricular synchrony but improves left ventricular lateral wall depolarization duration

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
K Curila ◽  
P Jurak ◽  
P Waldauf ◽  
J Halamek ◽  
J Karch ◽  
...  
Keyword(s):  
Lateral Wall ◽  
Left Ventricular ◽  
Public Institution ◽  
Research Centre ◽  
Direct Capture ◽  
Funding Sources ◽  
Lead Placement ◽  
Septal Pacing ◽  
Ventricular Activation ◽  
Ventricular Depolarization

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): This paper was supported by the Charles University Research Centre program No. UNCE/MED/002 and 260530/SVV/2020 Background Direct and indirect pacing of the left bundle branch are novel pacing techniques preserving LV synchrony. Aim of the study was to compare differences in ventricular activation between them using an UHF-ECG. Methods The left septal lead placement was done in 68 patients with bradycardia. Four distinct ventricular captures were described; nonselective LBBp (nsLBBp), selective LBBp (sLBBp), paraLBBp and left bundle branch area capture (LBBap). The timings of local ventricular activations and local depolarization durations were displayed by the UHF-ECG. e-DYS was calculated as a difference between the first and last activation. Results There were 35 nsLBBp, 21 paraLBBp, 12 sLBBp and 96 LBBap obtained in 68 patients.  The nsLBBp compared to LBBap caused worse interventricular synchrony (e-DYS -23 ms (-28;-18) vs -12 ms (-17;-8), p < 0.001), but improved LV lateral wall depolarization duration. The sLBBp, nsLBBp and paraLBBp differed in e-DYS; -31 ms (-38;-24) vs -23 ms (-28;-17) vs -13 ms (-20;-7), p < 0.01 between each of them. Their left ventricular depolarization durations were the same, but they were longer when pacing resulted in the left axis deviation. If the direct capture of the LBB was not confirmed (LBBap), LV depolarization duration was deteriorated irrespective of the QSR morphology in the V1 or RWPT in the V5. Examples of UHF-ECG maps during LBBap, paraLBBp and nsLBBp are shown in Figure 1. Conclusions The direct capture of the left bundle branch deteriorates interventriclar synchrony but improves the depolarization duration of the left ventricular lateral wall compared to left ventricular myocardial septal pacing. Abstract Figure 1

scholarly journals COMPARATIVE ANALYSIS OF DEMOGRAPHIC, ANAMNESTIC, CLINICAL-LABORATORY AND INSTRUMENTAL DATA IN PATIENTS WITH MYOCARDIAL INFARCTION WITH AND WITHOUT OBSTRUCTIVE LESION OF CORONARY ARTERIES

2019 ◽  
Vol 33 (4) ◽  
pp. 69-75
Author(s):  
S. V. Kruchinova ◽  
E. D. Kosmacheva ◽  
V. A. Porkhanov
Keyword(s):  
Myocardial Infarction ◽  
Comparative Analysis ◽  
Coronary Disease ◽  
Coronary Arteries ◽  
Obstructive Coronary Artery Disease ◽  
Laboratory Data ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Coronary Syndrome ◽  
Obstructive Lesion

Objective: to give a comparative characterization of myocardial infarction with and without obstructive lesion of coronary arteries.Material and Methods. The study involved 4639 patients included in the first total register of acute coronary syndrome in the Krasnodar Territory for the first 12 months of register operation. A comparative analysis of patients with myocardial infarction with obstructive lesion and without obstructive lesion of coronary arteries was performed.Results. Between November 2016 and November 2017, 4453 patients with myocardial infarction with obstructive coronary disease, including 2261 men (50.8%) and 2192 women (49.2%) were enrolled in the register. The mean age of patients was 68.3±12.03 years (69.3±3.42 years in men; 63.4±7.35 years in women). The criteria for myocardial infarction without obstructive coronary artery disease were present in 186 people (4.1%), including 72 men (38.7%) and 114 women (72.3%). The average age of the patients was 54.2±4.53 years; age of men with myocardial infarction without obstructive coronary disease was 56.3±3.52 years; age of women was 52.1±3.12 years. The article presents a detailed comparative analysis of demographic, medical history, clinical-instrumental, and laboratory data of these patient groups. Conclusion. Compared with patients who had obstructive coronary changes, the cohort of patients with myocardial infarction without obstructive lesions of the coronary arteries was younger and included more female patients; among the risk factors in this group, smoking and arterial hypertension were significant; the rates of newly diagnosed diabetes mellitus and Q-positive myocardial infarction were higher. According to the analysis of echocardiographic data, significant decrease in global contractility of the left ventricular myocardium was less common; analysis of laboratory data showed that patients more often had low platelet count.

Mechanisms of angina in patients with biopsy-proven viral myocarditis: insights from intracoronary acetylcholine testing

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Seitz ◽  
V Martinez Pereyra ◽  
A Hubert ◽  
K Klingel ◽  
R Bekeredjian ◽  
...  
Keyword(s):  
Coronary Arteries ◽  
Coronary Spasm ◽  
Viral Myocarditis ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Funding Source ◽  
Pathophysiological Mechanism ◽  
Ecg Changes ◽  
Ventricular Ejection Fraction ◽  
Microvascular Spasm

Abstract Background Patients with myocarditis often present with angina pectoris despite unobstructed coronary arteries. The underlying pathophysiological mechanism of angina in these patients remains to be elucidated. Coronary artery spasm is a well-known cause of angina in patients with unobstructed coronary arteries. In this study, we sought to assess the frequency of coronary vasomotor disorders in patients with biopsy-proven viral myocarditis. Methods In total, 700 consecutive patients who underwent endomyocardial biopsy for suspected myocarditis between 2008 and 2018 were retrospectively screened. Of these patients, viral myocarditis was confirmed in 303 patients defined as histological/immunohistological evidence of myocardial inflammation and presence of viral genome confirmed by PCR. Of these patients, 34 patients had angina despite unobstructed coronary arteries and underwent intracoronary acetylcholine (ACh) provocation testing in search of coronary spasm. Epicardial spasm was defined as acetylcholine-induced reproduction of the patient's symptoms associated with ischemic ECG changes and >90% epicardial vasoconstriction. Microvascular spasm was defined as symptom reproduction and ECG changes in the absence of significant epicardial vasoconstriction. Results Patients were 49±16 years old, 62% were male and left ventricular ejection fraction was 54±16%. Most frequent viruses were parvovirus B19 (PVB19, 59%) and human herpes virus 6 (HHV6, 26%), 2 patients had combined PVB19/HHV6 infection and 3 patients other herpesviruses (CMV, EBV, VZV). Epicardial spasm was observed in 10 patients (29%) during ACh testing and microvascular spasm was found in 11 patients (32%). The rate of coronary spasm (epicardial and microvascular) was higher in the PVB19 subgroup compared to HHV6 (80% vs. 33%, p=0.031). In particular, there was a higher prevalence of microvascular spasm in PVB19 compared to HHV6 (45% vs. 0%, p=0.018). Conclusion We observed a high prevalence of microvascular and epicardial spasm in patients with biopsy-proven viral myocarditis suggesting coronary spasm as a potential underlying mechanism for angina in these patients. Microvascular spasm was most often observed in patients with PVB19-associated myocarditis. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Robert-Bosch-Stiftung; Berthold-Leibinger-Stiftung

scholarly journals Does age at aortic coarctation repair have an impact on left ventricle size and function?

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
S Cardoso Torres ◽  
CX Resende ◽  
PG Diogo ◽  
P Araujo ◽  
RA Pinto ◽  
...  
Keyword(s):  
Aortic Coarctation ◽  
Surgical Repair ◽  
Myocardial Dysfunction ◽  
Global Longitudinal Strain ◽  
Negative Relationship ◽  
Late Complications ◽  
Left Ventricular ◽  
Funding Sources ◽  
The Mean ◽  
Clinical Records

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Adults with repaired aortic coarctation (CoA) require lifelong follow-up due to late complications, including left ventricular (LV) myocardial dysfunction. Age at the time of CoA repair is an important prognostic factor in these patients (pts). Purpose To evaluate LV size, ejection fraction (EF) and global longitudinal strain (GLS) values using 2D speckle tracking echocardiography (STE) in a population of adult pts with repaired CoA and to assess the relationship between these echocardiographic parameters and age at the time of CoA repair. Methods Retrospective analysis of adult pts with repaired CoA, followed in a Grown Up Congenital Heart Disease Centre. Pts with hemodynamically significant concomitant cardiac lesions were ruled out. Epidemiologic and clinical data were obtained from clinical records. Transthoracic echocardiograms were reviewed in order to assess GLS using 2DSTE (Echopac Software, GE). Results The study population consisted of 63 pts (61.9% male), with a mean age of 35.3 years at the time of the echocardiographic evaluation. The mean age at the time of the CoA repair was 117 months (95% CI 89.8-144.1 months). Surgical repair was performed in 46 pts (73%): resection with subclavian artery flap aortoplasty (n = 21); patch aortoplasty (n = 15) and head-to-head anastomosis (n = 10). In 10 pts there was no data regarding the type of surgical repair. Seven pts (11.1%) were submitted to percutaneous intervention (6 with aortic stent implantation and 1 with balloon aortic angioplasty). Mean LVEF was 63.4% (CI 95% 55.6 – 71.2%) and mean LV end-diastolic diameter (LVEDD) was 50mm (CI 95% 43-57mm). Mean GLS was - 17.3 (CI 95% 14.8- 19.8), which is inferior to the mean normal values reported for the software used. Age at the time of CoA repair had a statistically significant positive linear relationship with LVEDD (r= 0.282; p= 0.026) and a linear negative relationship with both GLS (r= -0,29; p= 0.022) and LVEF (r= -0.33; p= 0.05). Conclusion Older age at the time of CoA repair was associated with increased LVEDD and decreased GLS and LVEF. Also, GLS may be an important tool for the identification of subclinical LV dysfunction in adult pts with repaired CoA.

scholarly journals Beta-blocker use is associated with prevention of left ventricular remodeling in recovered dilated cardiomyopathy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Enzan ◽  
S Matsushima ◽  
T Ide ◽  
H Kaku ◽  
T Higo ◽  
...  
Keyword(s):  
Left Ventricular Ejection Fraction ◽  
Ejection Fraction ◽  
Beta Blocker ◽  
Primary Outcome ◽  
Protocol Analysis ◽  
Beta Blockers ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Funding Source ◽  
Ventricular Ejection Fraction

Abstract Background Withdrawal of optimal medical therapy has been reported to relapse cardiac dysfunction in patients with dilated cardiomyopathy (DCM) whose cardiac function had improved. However, it is unknown whether beta-blockers can prevent deterioration of cardiac function in those patients. Purpose We examined the effect of beta-blockers on left ventricular ejection fraction (LVEF) in recovered DCM. Methods We analyzed the clinical personal records of DCM, a national database of Japanese Ministry of Health, Labor and Welfare, between 2003 and 2014. Recovered DCM was defined as a previously documented LVEF <40% and a current LVEF ≥40%. Patients with recovered DCM were divided into two groups according to the use of beta-blockers. The primary outcome was defined as a decrease in LVEF >10% at two years of follow-up. A one to one propensity case-matched analysis was used. A per-protocol analysis was also performed. Considering intra- and inter-observer variability of echocardiographic evaluations, we also examined outcomes by multivariable logistic regression model after changing the inclusion criteria as follows; (1) previous LVEF <40% and current LVEF ≥40%; (2) previous LVEF <35% and current LVEF ≥40%; (3) previous LVEF <30% and current LVEF ≥40%; (4) previous LVEF <40% and current LVEF ≥50%. Outcomes were also changed as (1) decrease in LVEF ≥5% (2) decrease in LVEF ≥10% (3) decrease in LVEF ≥15%. The analysis of outcomes by using combination of multiple imputation and inverse probability of treatment weighting was also conducted to assess the effects of missing data and selection bias attributable to propensity score matching on outcomes. Results From 2003 to 2014, 40,794 consecutive patients with DCM were screened. Out of 5,338 eligible patients, 4,078 received beta-blockers. Propensity score matching yielded 998 pairs. Mean age was 61.7 years and 1,497 (75.0%) was male. Mean LVEF was 49.1±8.1%. The primary outcome was observed less frequently in beta-blocker group than in no beta-blocker group (18.0% vs. 23.5%; odds ratio [OR] 0.72; 95% confidence interval [CI] 0.58–0.89; P=0.003). The prevalence of increases in LVDd (11.5% vs. 15.8%; OR 0.70; 95% CI 0.54–0.91; P=0.007) and LVDs (23.1% vs. 27.2%; OR 0.80; 95% CI 0.65–0.99; P=0.041) was also lower in the beta-blocker group. Similar results were obtained in per-protocol analysis. These results were robust to several sensitivity analyses. As a result of preventing a decrease in LVEF, the deterioration to HFrEF was also prevented by the use of beta-blocker (23.6% vs. 30.6%). Subgroup analysis demonstrated that beta-blocker prevented decrease in LVEF regardless of atrial fibrillation. Conclusion Use of beta-blocker was associated with prevention of decrease in left ventricular ejection fraction in patients with recovered DCM. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Health Sciences Research Grants from the Japanese Ministry of Health, Labour and Welfare (Comprehensive Research on Cardiovascular Diseases)

scholarly journals The outcome of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) and impaired kidney function: a 3-year observational study

2021 ◽  
Author(s):  
Malgorzata Zalewska-Adamiec ◽  
Jolanta Malyszko ◽  
Ewelina Grodzka ◽  
Lukasz Kuzma ◽  
Slawomir Dobrzycki ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Incidence Rate ◽  
Kidney Function ◽  
Coronary Arteries ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Risk Of Death ◽  
Group 2 ◽  
Group 1

Abstract Background Myocardial infarction with nonobstructive coronary arteries (MINOCA) constitutes about 10% of the cases of acute coronary syndromes (ACS). It is a working diagnosis and requires further diagnostics to determine the cause of ACS. Methods In this study, 178 patients were initially diagnosed with MINOCA over a period of 3 years at the Department of Invasive Cardiology of the University Clinical Hospital in Białystok. The value of estimated glomerular filtration rate (eGFR) was calculated for all patients. The patients were divided into 2 groups depending on the value of eGFR: group 1—53 patients with impaired kidney function (eGFR < 60 mL/min/1.73 m2; 29.8%) and group 2—125 patients with normal kidney function (eGFR ≥ 60 mL/min/1.73 m2; 70.2%). Results In group 1, the mean age of patients was significantly higher than that of group 2 patients (77.40 vs 59.27; p < 0.0001). Group had more women than group 2 (73.58% vs 49.60%; p = 0.003). Group 1 patients had higher incidence rate of arterial hypertension (92.45% vs 60.80%; p < 0.0001) and diabetes (32.08% vs 9.60%; p = 0.0002) and smoked cigarettes (22.64% vs 40.80%; p = 0.020). Group 1 patients had higher incidence rate of pulmonary edema, cardiogenic shock, sudden cardiac arrest (13.21% vs 4.00%; p = 0.025), and pneumonia (22.64% vs 6.40%; p = 0.001). After the 37-month observation, the mortality rate of the patients with MINOCA was 16.85%. Among group two patients, more of them became deceased during hospitalization (7.55% vs 0.80%; p = 0.012), followed by after 1 year (26.42% vs 7.20%; p = 0.0004) and after 3 years (33.96% vs 9.6%; p < 0.0001). Multivariate analysis revealed that the factors increasing the risk of death in MINOCA are as follows: older age, low eGFR, higher creatinine concentration, low left ventricular ejection fraction, and ST elevation in ECG. Conclusion Impaired kidney function is diagnosed in every third patient with MINOCA. Early and late prognosis of patents with MINOCA and renal dysfunction is poor, and their 3-year mortality is comparable to patients with myocardial infarction with significant stenosis of the coronary arteries and impaired kidney function.

scholarly journals The effect of beta-blockers on hemodynamic parameters in patient-specific blood flow simulations of type-B aortic dissection: a virtual study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Amin Abazari ◽  
Deniz Rafieianzab ◽  
M. Soltani ◽  
Mona Alimohammadi
Keyword(s):  
Aortic Dissection ◽  
Clinical Decision Making ◽  
Beta Blockers ◽  
False Lumen ◽  
Specific Treatment ◽  
Left Ventricular ◽  
Patient Specific ◽  
Type B ◽  
Windkessel Model ◽  
Computed Tomography Images

AbstractAortic dissection (AD) is one of the fatal and complex conditions. Since there is a lack of a specific treatment guideline for type-B AD, a better understanding of patient-specific hemodynamics and therapy outcomes can potentially control the progression of the disease and aid in the clinical decision-making process. In this work, a patient-specific geometry of type-B AD is reconstructed from computed tomography images, and a numerical simulation using personalised computational fluid dynamics (CFD) with three-element Windkessel model boundary condition at each outlet is implemented. According to the physiological response of beta-blockers to the reduction of left ventricular contractions, three case studies with different heart rates are created. Several hemodynamic features, including time-averaged wall shear stress (TAWSS), highly oscillatory, low magnitude shear (HOLMES), and flow pattern are investigated and compared between each case. Results show that decreasing TAWSS, which is caused by the reduction of the velocity gradient, prevents vessel wall at entry tear from rupture. Additionally, with the increase in HOLMES value at distal false lumen, calcification and plaque formation in the moderate and regular-heart rate cases are successfully controlled. This work demonstrates how CFD methods with non-invasive hemodynamic metrics can be developed to predict the hemodynamic changes before medication or other invasive operations. These consequences can be a powerful framework for clinicians and surgical communities to improve their diagnostic and pre-procedural planning.

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