Effect of excitation sequence of myocardial contraction on the mechanical response of the left ventricle.

In the past two decades there has been rapid development in the field of computational cardiac models. These have included either (i) mechanical models that assumed simultaneous myocardial activation, or (ii) electromechanical models that assumed time-varying myocardial activation. The influence of these modelling assumptions of myocardial activation on clinically relevant metrics, like myocardial strain, commonly used for validation of cardiac models has yet to be systematically examined, leading to uncertainty over their influence on the predictions of these models.

Fluid-structure interaction analysis of a healthy aortic valve and its surrounding haemodynamics.

The opening and closing dynamics of the aortic valve (AV) has a strong influence on haemodynamics in the aortic root, and both play a pivotal role in maintaining normal physiological functions of the valve. The aim of this study was to establish a subject-specific fluid-structure interaction (FSI) workflow capable of simulating the motion of a tricuspid healthy valve and the surrounding haemodynamics under physiologically realistic conditions. A subject-specific aortic root was reconstructed from magnetic resonance (MR) images acquired from a healthy volunteer, whilst the valve leaflets were built using a parametric model fitted to the subject-specific aortic root geometry.

Irregular anatomical features can alter hemodynamics in Takayasu arteritis.

Objective: Takayasu arteritis (TA) is a difficult disease to deal with because there are neither reliable clinical signs, laboratory biomarkers, nor a single noninvasive imaging technique that can be used for early diagnosis and disease activity monitoring. Knowledge of aortic hemodynamics in TA is lacking. This study aimed to fill this gap by assessing hemodynamics in patients with TA using image-based computational fluid dynamics (CFD) simulations.

Time to TAVI: streamlining the pathway to treatment.

Introduction: Severe aortic stenosis is a major cause of morbidity and mortality. The existing treatment pathway for transcatheter aortic valve implantation (TAVI) traditionally relies on tertiary Heart Valve Centre workup. However, this has been associated with delays to treatment, in breach of British Cardiovascular Intervention Society targets.

A computational study of the effects of size, location, and number of tears on haemodynamics in surgically repaired type A aortic dissection.

Objective: This study aimed to comprehensively examine the roles of size, location, and number of tears in the progression of surgically repaired type A aortic dissection (TAAD) by assessing haemodynamic changes through patient-specific computational fluid dynamic (CFD) simulations.

Methods: Two patient-specific TAAD geometries with replaced ascending aorta were reconstructed based upon computed 15 tomography (CT) scans, after which 10 hypothetical models (5 per patient) with different tear configurations were artificially created. CFD simulations were performed on all the models under physiologically realistic boundary conditions.

The Use and Efficacy of FFR-CT: Real-World Multicenter Audit of Clinical Data With Cost Analysis.

Background: Fractional flow reserve-computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown.

Advanced risk prediction for aortic dissection patients using imaging-based computational flow analysis.

Patients with either a repaired or medically managed aortic dissection have varying degrees of risk of developing late complications. High-risk patients would benefit from earlier intervention to improve their long-term survival. Currently serial imaging is used for risk stratification, which is not always reliable.

Left main coronary artery atresia in a 2-year-old toddler with heart failure: Case report and review of the literature.

Congenital coronary anomalies are among the rare disorders of the otherwise normal heart. A 2-year-old toddler was evaluated for heart failure after a flu-like event 2 months before being suspicious of post-Covid-19 dilated cardiomyopathy. The cardiac magnetic resonance (CMR) technique displayed the basal to mid subendocardial to transmural scar, suggestive of an ischemic etiology.

Prediction of aortic dilatation in surgically repaired type A dissection: A longitudinal study using computational fluid dynamics.

Objective: To examine the role of a key hemodynamic parameter, namely the true and false lumen pressure difference, to predict progressive aortic dilatation following type A aortic dissection (TAAD) repair.

Methods: Four patients with surgically repaired TAAD with multiple follow-up computed tomography angiography scans (4-5 scans per patient; N = 18) were included. Through-plane diameter of the residual native thoracic aorta was measured in various aortic segments during the follow up period (mean follow-up: 49.

Fluid-Structure Interaction Simulations of Repaired Type A Aortic Dissection: a Comprehensive Comparison With Rigid Wall Models.

This study aimed to evaluate the effect of aortic wall compliance on intraluminal hemodynamics within surgically repaired type A aortic dissection (TAAD). Fully coupled two-way fluid-structure interaction (FSI) simulations were performed on two patient-specific post-surgery TAAD models reconstructed from computed tomography angiography images. Our FSI model incorporated prestress and different material properties for the aorta and graft.

Percutaneous Devices for the Treatment of Complex Native Valve Mitral Leaflet and Aortomitral Continuity Defects: Review and Case Series.

Percutaneous closure of paravalvar leaks (PVLs) was once only performed in extreme or non-surgical risk cases not suitable for redo-surgery with tissue or mechanical valves. This technique is now the treatment of choice with long term outcomes that are better than redo operations. As interventionalists become more familiar with using PVL devices, more off label device use has been reported in non-surgical cases involving complex native mitral valve regurgitation (NVMR).

Successful Conservative Treatment of a Type A Aortic Intramural Hematoma.

Type A intramural hematoma (IMH) constitutes a variant of acute aortic syndrome. Western guidelines support an aggressive surgical approach, whereas Asian centers propose initial conservative treatment. Further expanding on this notion, we present a case of conservative subacute type A IMH management, resulting in radical hematoma resorption within 4 weeks.

Association of hemodynamic factors and progressive aortic dilatation following type A aortic dissection surgical repair.

Type A aortic dissection (TAAD) involves the ascending aorta or the arch. Acute TAAD usually requires urgent replacement of the ascending aorta. However, a subset of these patients develops aortic rupture due to further dilatation of the residual dissected aorta.

Can dynamic imaging, using F-FDG PET/CT and CT perfusion differentiate between benign and malignant pulmonary nodules?

Background: The aim of the study was to derive and compare metabolic parameters relating to benign and malignant pulmonary nodules using dynamic 2-deoxy-2-[fluorine-18]fluoro-D-glucose (F-FDG) PET/CT, and nodule perfusion parameters derived through perfusion computed tomography (CT).

Patients And Methods: Twenty patients with 21 pulmonary nodules incidentally detected on CT underwent a dynamic F-FDG PET/CT and a perfusion CT. The maximum standardized uptake value (SUV) was measured on conventional F-FDG PET/CT images.

Association of individual aortic leaflet calcification on paravalvular regurgitation and conduction abnormalities with self-expanding trans-catheter aortic valve insertion.

Background: Complication rates of paravalvular aortic regurgitation (PVR) and permanent pacemaker insertion remain high in patients undergoing trans-catheter aortic valve insertion for severe aortic stenosis. The spatial distribution of calcium between individual aortic valve leaflets, and its potential role in these complications is gaining interest. We aimed to assess the accuracy of individual aortic valve leaflet calcium quantification, and to determine its effect on the frequency of these complications.

Radiological and Laboratory Findings of Patients with COVID-19 Infection at the Time of Admission.

Background & Objective: Diagnosis of coronavirus disease 2019 (COVID-19) can be challenging, especially when the real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) is not available or it is negative. In this study, we evaluated imaging and laboratory findings in a group of patients with a multidisciplinary diagnosis of COVID-19 pneumonia.

Methods: A total of 163 patients with a clinical diagnosis of COVID-19 pneumonia admitted to a specialised respiratory centre in Tehran, Iran were enrolled in this study.

Cardiac Energetics Before, During, and After Anthracycline-Based Chemotherapy in Breast Cancer Patients Using P Magnetic Resonance Spectroscopy: A Pilot Study.

To explore the utility of phosphorus magnetic resonance spectroscopy (P MRS) in identifying anthracycline-induced cardiac toxicity in patients with breast cancer. Twenty patients with newly diagnosed breast cancer receiving anthracycline-based chemotherapy had cardiac magnetic resonance assessment of left ventricular ejection fraction (LVEF) and P MRS to determine myocardial Phosphocreatine/Adenosine Triphosphate Ratio (PCr/ATP) at three time points: pre-, mid-, and end-chemotherapy. Plasma high sensitivity cardiac troponin-I (cTn-I) tests and electrocardiograms were also performed at these same time points.

Dual-Energy CT Pulmonary Angiography (DECTPA) Quantifies Vasculopathy in Severe COVID-19 Pneumonia.

Background: The role of dual energy computed tomographic pulmonary angiography (DECTPA) in revealing vasculopathy in coronavirus disease 2019 (COVID-19) has not been fully explored.

Purpose: To evaluate the relationship between DECTPA and disease duration, right ventricular dysfunction (RVD), lung compliance, D-dimer and obstruction index in COVID-19 pneumonia.

Materials And Methods: This institutional review board approved this retrospective study, and waived the informed consent requirement.

Thrombotic complications in 2928 patients with COVID-19 treated in intensive care: a systematic review.

A prothrombotic state is reported with severe COVID-19 infection, which can manifest in venous and arterial thrombotic events. Coagulopathy is reflective of more severe disease and anticoagulant thromboprophylaxis is recommended in hospitalized patients. However, the prevalence of thrombosis on the intensive care unit (ICU) remains unclear, including whether this is sufficiently addressed by conventional anticoagulant thromboprophylaxis.

Prevalence of Thrombotic Complications in ICU-Treated Patients With Coronavirus Disease 2019 Detected With Systematic CT Scanning.

Objectives: Severe coronavirus disease 2019 is associated with an extensive pneumonitis and frequent coagulopathy. We sought the true prevalence of thrombotic complications in critically ill patients with severe coronavirus disease 2019 on the ICU, with or without extracorporeal membrane oxygenation.

Design: We undertook a single-center, retrospective analysis of 72 critically ill patients with coronavirus disease 2019-associated acute respiratory distress syndrome admitted to ICU.

Corona Virus Disease 2019 arterial and venous thrombosis in critically ill patients: a case series.

Background: Corona Virus Disease 2019 (COVID-19) pneumonitis associated with severe respiratory failure carries a high mortality. Coagulopathy has emerged as a significant contributor to thrombotic complications.

Case Summary: We describe two cases of severe COVID-19 pneumonitis refractory to conventional mechanical ventilation and proning position, transferred to our specialist centre for cardiorespiratory failure.