Drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are a target for new antimicrobial technologies. Far-UVC technology is an emerging disinfection method that directly kills microorganisms using light. In contrast with conventional UV sterilization, far-UVC light has antimicrobial capabilities without apparent harm to mammalian cells.
View Article and Find Full Text PDFPhotochem Photobiol
November 2017
Analysis of the emission pattern from optical diffuser tips is vital to their usage in biomedical applications, especially as they find growing functionality beyond established phototherapy techniques. The use of ultraviolet radiation with diffuser tips increases the need to accurately characterize these devices, both for effective application and to avoid potentially dangerous exposure conditions. This study presents a new method to capture the diffusion pattern at a high resolution through the use of radiochromic film.
View Article and Find Full Text PDFRadiat Prot Dosimetry
November 2017
Measurement of ultraviolet (UV) radiation is important for human health, especially with the expanded usage of short wavelength UV for sterilization purposes. This work examines unlaminated Gafchromic EBT3 film for UV radiation monitoring. The authors exposed the film to select wavelengths in the UV spectrum, ranging from 207 to 328 nm, and measured the change in optical density.
View Article and Find Full Text PDFThe Columbia University Cardiothoracic Surgery Program dates back to the earliest days of the specialty itself, when the first pioneers ventured into the chest, and eventually the heart, to treat diseases previously believed to be beyond the reach of medicine. This spirit of innovation, creativity, and vision has grown over the ensuing century and has driven the development of advances that have defined the specialty and saved countless lives. From novel techniques for the repair of complex congenital cardiac defects and acquired cardiovascular diseases, to comprehensive management of lung and esophageal maladies, and to the marvel of minimally invasive and percutaneous interventions, the march of progress has never been stronger, more dramatic, or more consequential that it is at Columbia today.
View Article and Find Full Text PDFObjective: Right parasternal mediastinotomy with right atriotomy has been used clinically for pacemaker insertion. A similar approach might facilitate access to the coronary sinus for biventricular pacing and other manipulations when more conventional approaches are not feasible. The primary barrier to this is lack of appropriate introducers and techniques.
View Article and Find Full Text PDFObjective: Post-cardiopulmonary bypass biventricular pacing improves hemodynamics but without clearly defined predictors of response. Based on preclinical studies and prior observations, it was suspected that diastolic dysfunction or pulmonary hypertension is predictive of hemodynamic benefit.
Design: Randomized controlled study of temporary biventricular pacing after cardiopulmonary bypass.
Ventricular dyssynchrony is associated with morbidity and mortality after palliation of a single ventricle. The authors hypothesized that resynchronization with optimized temporary multisite pacing postoperatively would be safe, feasible, and effective. Pacing was assessed in the intensive care unit within the first 24 h after surgery.
View Article and Find Full Text PDFIn this article an international group of CRT specialists presents a comprehensive classification system for present and future schemes for optimising CRT. This system is neutral to the measurement technology used, but focuses on little-discussed quantitative physiological requirements. We then present a rational roadmap for reliable cost-effective development and evaluation of schemes.
View Article and Find Full Text PDFBackground: 0.5% to 10% of clean surgeries result in surgical-site infections, and attempts to reduce this rate have had limited success. Germicidal UV lamps, with a broad wavelength spectrum from 200 to 400 nm are an effective bactericidal option against drug-resistant and drug-sensitive bacteria, but represent a health hazard to patient and staff.
View Article and Find Full Text PDFIn selected patients undergoing cardiac surgery, our research group previously showed that optimized temporary biventricular pacing can increase cardiac output one hour after weaning from cardiopulmonary bypass. Whether pacing is effective after beating-heart surgery is unknown. Accordingly, in this study we examined the feasibility of temporary biventricular pacing after off-pump coronary artery bypass grafting.
View Article and Find Full Text PDFBackground: The Biventricular Pacing After Cardiac Surgery trial investigates hemodynamics of temporary pacing in selected patients at risk of left ventricular dysfunction. This trial demonstrates improved hemodynamics during optimized biventricular pacing compared with atrial pacing at the same heart rate 1 and 2 hours after bypass and reduced vasoactive-inotropic score over the first 4 hours after bypass. However, this advantage of biventricular versus atrial pacing disappears 12 to 24 hours later.
View Article and Find Full Text PDFObjectives: Effects of temporary biventricular pacing after cardiopulmonary bypass are unpredictable, and the utility of speckle-tracking echocardiography in this setting is unclear. Accordingly, speckle-tracking analysis of transgastric echocardiograms taken during cardiac surgery was assessed as a potential tool to measure strain, synchrony, and twist as indices to predict response.
Design: Prospective observational study, in part, with a randomized controlled study of temporary permanent biventricular pacing after cardiopulmonary bypass.
Background: Biventricular pacing (BiVP) improves cardiac output (CO) in selected cardiac surgery patients, but response remains variable, necessitating a better understanding of the mechanism. Accordingly, we used speckle tracking echocardiography (STE) to analyze BiVP during acute right ventricular pressure overload (RVPO).
Materials And Methods: In nine pigs, the inferior vena cava (IVC) was snared to decrease CO and establish a control model.
Background: This study sought to determine whether optimized biventricular pacing increases cardiac index in patients at risk of left ventricular dysfunction after cardiopulmonary bypass. Procedures included coronary artery bypass, aortic or mitral surgery and combinations. This trial was approved by the Columbia University Institutional Review Board and was conducted under an Investigational Device Exemption.
View Article and Find Full Text PDFObjectives: Biventricular pacing may ameliorate symptoms of acute heart failure. Speckle-tracking echocardiography can assess cardiac function to elucidate mechanisms of benefit. Accordingly, radial and circumferential strain and radial and circumferential strain synchrony were measured with speckle-tracking echocardiography during biventricular pacing in a model of left ventricular (LV) volume overload.
View Article and Find Full Text PDFPacing Clin Electrophysiol
June 2013
Background: Transtelephonic monitoring (TTM) of pediatric patients with cardiac pacemakers (PMs) has been shown to have high sensitivity and specificity in identifying PM malfunction. The objective of this study is to determine if there is a difference in the rate of abnormal TTM findings in transvenous versus epicardial PM systems.
Methods: Our TTM database was reviewed.
Pulmonary thromboendarterectomy (PTE) reverses chronic thromboembolic pulmonary hypertension, decreasing pulmonary vascular resistance and pressure overload failure of the right ventricle (RV). Suboptimal cardiac function early after PTE on cardiopulmonary bypass (CPB) may require inotropic or mechanical support. Our laboratory demonstrated increased cardiac output (CO) with temporary biventricular pacing (BiVP) in an RV pressure overload pig model.
View Article and Find Full Text PDFIncreased thresholds in permanent epicardial leads pose a special challenge in the postoperative period. We present a case of complete heart block after surgical correction of a congenital heart defect that required conversion of an axial bipolar lead to unipolar lead to avoid lead replacement. We review the options for repair and describe our approach to this patient.
View Article and Find Full Text PDFObjectives: We have previously demonstrated that biventricular pacing increased cardiac output within 1 hour of weaning from cardiopulmonary bypass in selected patients. To assess the possible sustained benefit, we reviewed in the present study the effects of biventricular pacing on the mean arterial pressure after chest closure.
Methods: A total of 30 patients (mean ejection fraction 35% ± 15%, mean QRS 119 ± 24 ms) underwent coronary bypass and/or valve surgery.
Objective: Vasoactive medications improve hemodynamics after cardiac surgery but are associated with high metabolic and arrhythmic burdens. The vasoactive-inotropic score was developed to quantify vasoactive and inotropic support after cardiac surgery in pediatric patients but may be useful in adults as well. Accordingly, we examined the time course of this score in a substudy of the Biventricular Pacing After Cardiac Surgery trial.
View Article and Find Full Text PDFBackground: We used speckle-tracking echocardiography to test the hypothesis that regional left ventricular (LV) strain would improve during optimized biventricular pacing (BiVP) in acute right ventricular (RV) pressure overload (PO).
Materials And Methods: Complete heart block and RVPO were induced in five open-chest fully anesthetized pigs. BiVP was optimized by adjusting atrioventricular and interventricular delays to maximize cardiac output derived from an aortic flow probe.
Biventricular pacing (BiVP) improves cardiac output (CO) and mean arterial pressure (MAP) after cardiopulmonary bypass (CPB) in selected patients at risk for acute left heart failure after cardiac surgery. Optimization of atrioventricular delay (AVD) and interventricular delay (VVD) to maximize the hemodynamic effect of pacing requires rapid and accurate data processing. Conventional post hoc data processing (PP) is accurate but time-consuming, and infeasible in the intraoperative setting.
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