Justin E. Davies

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BACKGROUND Coronary blood flow peaks in diastole when aortic blood pressure has fallen. Current models fail to completely explain this phenomenon. We present a new approach-using wave intensity analysis-to explain this phenomenon in normal subjects and to evaluate the effects of left ventricular hypertrophy (LVH). METHOD AND RESULTS We measured(More)
BACKGROUND Sympathetic overactivation, is reduced by renal denervation in drug-resistant hypertension. A similar role for renal denervation in heart failure remains unstudied, partly due to the concern about potential concomitant deleterious blood pressure reductions. This pilot study evaluated the safety of renal denervation for heart failure using an(More)
It has not been possible to measure wave speed in the human coronary artery, because the vessel is too short for the conventional two-point measurement technique used in the aorta. We present a new method derived from wave intensity analysis, which allows derivation of wave speed at a single point. We apply this method in the aorta and then use it to derive(More)
OBJECTIVES The purpose of this study was to develop an adenosine-independent, pressure-derived index of coronary stenosis severity. BACKGROUND Assessment of stenosis severity with fractional flow reserve (FFR) requires that coronary resistance is stable and minimized. This is usually achieved by administration of pharmacological agents such as adenosine.(More)
The augmentation index predicts cardiovascular mortality and is usually explained as a distally reflected wave adding to the forward wave generated by systole. We propose that the capacitative properties of the aorta (the arterial reservoir) also contribute significantly to the augmentation index and have calculated the contribution of the arterial(More)
Exercise hypertension independently predicts cardiovascular mortality, although little is known about exercise central hemodynamics. This study aimed to determine the contribution of arterial wave travel and aortic reservoir characteristics to central blood pressure (BP) during exercise. We hypothesized that exercise central BP would be principally related(More)
Wave intensity analysis (WIA) has found particular applicability in the coronary circulation where it can quantify traveling waves that accelerate and decelerate blood flow. The most important wave for the regulation of flow is the backward-traveling decompression wave (BDW). Coronary WIA has hitherto always been calculated from invasive measures of(More)
BACKGROUND Two ways to evaluate the symptoms of heart failure are the New York Heart Association (NYHA) classification and asking patients how far they can walk (walk distance). The NYHA system is commonly used, although it is not clear how individual clinicians apply it. AIM To investigate how useful these measures are to assess heart failure and whether(More)
PURPOSE Pain after hemorrhoidectomy appears to be multifactorial and dependent on individual pain tolerance, mode of anesthesia, postoperative analgesia, and surgical technique. Spasm of the internal sphincter is believed to play an important role. The aim of this study was to assess the role of botulinum toxin in reducing pain after Milligan-Morgan(More)
Documentation of inducible myocardial ischaemia, related to the coronary stenosis of interest, is of increasing importance in lesion selection for percutaneous coronary intervention (PCI). Fractional flow reserve (FFR) is an easily understood, routine diagnostic modality that has become part of daily clinical practice, and is used as a surrogate technique(More)