Background: Assessment of origin of ventricular tachycardias (VTs) arising from epicardial vs endocardial sites are largely challenged by the available criteria and etiology of cardiomyopathy. Current electrocardiographic (ECG) criteria based on 12-lead ECG have varying sensitivity and specificity based on site of origin and etiology of cardiomyopathy.
Objectives: This study sought to test the hypothesis that epicardial VT has a slower initial rate of depolarization than endocardial VT.
Catheter Cardiovasc Interv
February 2024
Background: There is considerable debate about the hemodynamic effects of veno-arterial extracorporeal membrane oxygenation (VA-ECMO).
Aims: To evaluate the changes in left ventricular (LV) function, volumes, and work in patients treated with VA-ECMO using invasive LV catheterization and three-dimensional echocardiographic volumes.
Methods: Patients on VA-ECMO underwent invasive hemodynamic evaluation due to concerns regarding candidacy for decannulation.
Indian Pacing Electrophysiol J
September 2023
Premature Ventricular Complexes (PVCs) refer to electrical activity arising from ventricles resulting in ventricular contraction independent of the native rhythm. PVCs by themselves are common in the general population but based on the origin of the PVCs, either related to anatomical or electrical substrate, the disease process has a widely varied presentation and prognosis. The clinical presentation of symptoms may vary from being extremely benign, or very severe (malignant).
View Article and Find Full Text PDFParavalvular leak (PVL) is a frequent TAVR complication. Prospective identification of patients who are likely to develop PVL after TAVR would likely lead to improved outcomes. Prior studies have used geometric characteristics to predict the likelihood of PVL development, but prediction and quantification has not been done.
View Article and Find Full Text PDFBackground Intermittent fasting (IF) confers pleiotropic cardiovascular benefits including restructuring of the gut microbiome and augmentation of cellular metabolism. Pulmonary arterial hypertension (PAH) is a rare and lethal disease characterized by right ventricular (RV) mitochondrial dysfunction and resultant lipotoxicity and microbiome dysbiosis. However, the effects of IF on RV function in PAH are unexplored.
View Article and Find Full Text PDFVenous-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for acute cardiogenic shock in patients who also have acute lung injury predisposes development of a serious complication called "north-south syndrome" (NSS) which causes cerebral hypoxia. NSS is poorly characterized and hemodynamic studies have focused on cerebral perfusion ignoring the heart. We hypothesized in NSS the heart would be more likely to receive hypoxemic blood than the brain due to the proximity of the coronary arteries to the aortic annulus.
View Article and Find Full Text PDFImmune-mediated coronary spasm, called Kounis syndrome (KS), is not rare but is underdiagnosed. In this report, we present a case of KS induced by iodinated contrast resulting in cardiac arrest, requiring temporary mechanical circulatory support. We show angiographic evidence of KS and outline commonly associated clinical features that may predict KS.
View Article and Find Full Text PDFBackground: As heart failure prevalence continues to increase in the setting of a static donor supply, left ventricular assist device (LVAD) therapy for end-stage heart failure continues to grow. Anecdotal evidence suggests that malalignment of the LVAD inflow cannula may increase thrombosis risk, but this effect has not been explored mechanistically or quantified statistically. Our objective is to elucidate the impact of surgical angulation of the inflow cannula on thrombogenicity.
View Article and Find Full Text PDFBackground: Subacromial corticosteroid injections (CSI's) are a common non-surgical treatment for rotator cuff tears. Few studies have assessed the effects of pre-operative CSI's on postoperative functional outcomes.
Methods: A retrospective analysis was conducted of 132 patients with high-grade, partial-thickness rotator cuff tears (PTRCT's).
Purpose: Multiple aspects of the tumor microenvironment (TME) impact breast cancer, yet the genetic modifiers of the TME are largely unknown, including those that modify tumor vascular formation and function.
Methods: To discover host TME modifiers, we developed a system called the Consomic/Congenic Xenograft Model (CXM). In CXM, human breast cancer cells are orthotopically implanted into genetically engineered consomic xenograft host strains that are derived from two parental strains with different susceptibilities to breast cancer.
The current study evaluates quantitatively the impact that intermittent aortic valve (AV) opening has on the thrombogenicity in the aortic arch region for patients under left ventricular assist device (LVAD) therapy. The influence of flow through the AV, opening once every five cardiac cycles, on the flow patterns in the ascending aortic is measured in a patient-derived computed tomography image-based model, after LVAD implantation. The mechanical environment of flowing platelets is investigated, by statistical treatment of outliers in Lagrangian particle tracking, and thrombogenesis metrics (platelet residence times and activation state characterized by shear stress accumulation) are compared for the cases of closed AV versus intermittent AV opening.
View Article and Find Full Text PDFThis study quantifies thrombogenic potential (TP) of a wide range of left ventricular assist device (LVAD) outflow graft anastomosis angles through state-of-the-art techniques: 3D imaged-based patient-specific models created via virtual surgery and unsteady computational fluid dynamics with Lagrangian particle tracking. This study aims at clarifying the influence of a single parameter (outflow graft angle) on the thrombogenesis associated with flow patterns in the aortic root after LVAD implantation. This is an important and poorly-understood aspect of LVAD therapy, because several studies have shown strong inter and intrapatient thrombogenic variability and current LVAD implantation strategies do not incorporate outflow graft angle optimization.
View Article and Find Full Text PDFTreatment of end-stage heart failure includes cardiac transplantation or ventricular assist device (VAD) therapy. Although increasingly prevalent, current VAD therapy has inherent complications, including thrombosis. Studies have demonstrated that VAD implantation alters intracardiac blood flow, creating areas of stagnation that predispose to thrombus formation.
View Article and Find Full Text PDFShortly after the discovery of endothelial progenitor cells (EPCs) in 1997, many clinical trials were conducted using EPCs as a cellular based therapy with the goal of restoring damaged organ function by inducing growth of new blood vessels (angiogenesis). Results were disappointing, largely because the cellular and molecular mechanisms of EPC-induced angiogenesis were not clearly understood. Following injection, EPCs must migrate to the target tissue and engraft prior to induction of angiogenesis.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
June 2015
Endothelial progenitor cells (EPCs) are a rare population of cells that participate in angiogenesis. To effectively use EPCs for regenerative therapy, the mechanisms by which they participate in tissue repair must be elucidated. This study focused on the process by which activated EPCs bind to a target tissue.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
October 2014
We previously isolated a 6.1-Mb region of SS/Mcwi (Dahl salt-sensitive) rat chromosome 12 (13.4-19.
View Article and Find Full Text PDFObjective: Diabetes Mellitus (DM) has reached epidemic levels globally. A contributing factor to the development of DM is high blood glucose (hyperglycemia). One complication associated with DM is a decreased angiogenesis.
View Article and Find Full Text PDFBone marrow-derived endothelial progenitor cells (BM-EPCs) are stimulated by vascular endothelial growth factor-A (VEGF-A) and other potent proangiogenic factors. During angiogenesis, an increase in VEGF-A expression stimulates BM-EPCs to enhance endothelial tube formation and contribute to an increase in microvessel density. Hypoxia is known to produce an enhanced angiogenic response and heightened levels of VEGF-A have been seen in oxygen deprived epithelial and endothelial cells, yet the pathways for VEGF-A signaling in BM-EPCs have not been described.
View Article and Find Full Text PDFEndothelial progenitor cells (EPCs) promote angiogenesis, and clinical trials suggest autologous EPC-based therapy may be effective in treatment of vascular diseases. Albeit promising, variability in the efficacy of EPCs associated with underlying disease states has hindered the realization of EPC-based therapy. Here we first identify and characterize EPC dysfunction in a rodent model of vascular disease (SS/Mcwi rat) that exhibits impaired angiogenesis.
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