Simon Redwood

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Exercise markedly influences pulse wave morphology, but the mechanism is unknown. We investigated whether effects of exercise on the arterial pulse result from alterations in stroke volume or pulse wave velocity (PWV)/large artery stiffness or reduction of pressure wave reflection. Healthy subjects (n = 25) performed bicycle ergometry. with workload(More)
OBJECTIVES The objective of this study was to compare visual and quantitative analysis of high spatial resolution cardiac magnetic resonance (CMR) perfusion at 3.0-T against invasively determined fractional flow reserve (FFR). BACKGROUND High spatial resolution CMR myocardial perfusion imaging for the detection of coronary artery disease (CAD) has(More)
BACKGROUND Transcatheter aortic valve replacement provides results comparable to those of surgery in patients at high surgical risk, but complications can impact long-term outcomes. The Lotus valve, designed to improve upon earlier devices, is fully repositionable and retrievable, with a unique seal to minimize paravalvular regurgitation (PVR). OBJECTIVES(More)
BACKGROUND The mechanisms underlying the variation in collateral formation between patients, even with similar patterns of coronary artery disease, remain unclear. This study investigates whether circulating humoral or cellular factors can provide an insight into this variation. METHODS AND RESULTS Thirty patients with isolated left anterior descending(More)
BACKGROUND The presence and extent of microvascular obstruction (MO) after acute myocardial infarction can be measured by first-pass gadolinium-enhanced perfusion cardiovascular magnetic resonance (CMR) or after gadolinium injection with early or late enhancement (EGE/LGE) imaging. The volume of MO measured by these three methods may differ because contrast(More)
AIMS The aim of this study was to identify the incidence and risk factors for acute kidney injury (AKI) after TAVI, a potentially serious complication of transcatheter aortic valve implantation (TAVI) that has been redefined by the Valve Academic Research Consortium (VARC). METHODS AND RESULTS We performed a retrospective analysis of 248 patients(More)
Two-dimensional (2D) X-ray imaging is the dominant imaging modality for cardiac interventions. However, the use of X-ray fluoroscopy alone is inadequate for the guidance of procedures that require soft-tissue information, for example, the treatment of structural heart disease. The recent availability of three-dimensional (3D) trans-esophageal(More)
A unifying definition of what constitutes high-risk percutaneous coronary intervention remains elusive. This reflects the existence of several recognized patient, anatomic, and procedural characteristics that, when combined, can contribute to elevating risk. The relative inability to withstand the adverse hemodynamic sequelae of dysrhythmia, transient(More)
OBJECTIVES The study sought a prospective multicenter nonrandomized evaluation of the Direct Flow Medical (DFM) system for the treatment of severe aortic stenosis. BACKGROUND The DFM transcatheter aortic valve system is a nonmetallic design with a pressurized support structure that allows precise positioning, retrieval, and assessment of valve performance(More)
Carotid-femoral pulse wave velocity (PWV), a measure of arterial stiffness, is determined from the time taken for the arterial pulse to propagate from the carotid to the femoral artery. Propagation time is measured variously from the foot of the waveform or point of maximum upslope. We investigated whether these methods give comparable values of PWV at(More)