Age and Ageing to introduce a new category of paper: healthcare improvement science.

Age and Ageing is now inviting papers on healthcare improvement for older people. In this article we outline the nature and scope of healthcare improvement and reference improvement models and the tools and methods of improvement science. We emphasise the issues of sustainability, including scale and spread; evaluation - including associated ethical consideration and the involvement of patients and the public in healthcare improvement and associated research. Throughout we refer to resources the authors have found useful in their own work, and provide a bibliography of sources and web-links which will provide essential guidance and support for potential contributors to this new category of submission to Age and Ageing.

Entangling moving cavities in noninertial frames.

An open question in the field of relativistic quantum information is how parties in arbitrary motion may distribute and store quantum entanglement. We propose a scheme for storing quantum information in the field modes of cavities moving in flat space-time and analyze it in a quantum field theoretical framework. In contrast with previous work that found entanglement degradation between observers moving with uniform acceleration, we find the quantum information in such systems is protected. We further discuss a method for establishing the entanglement in the first place and show that in principle it is always possible to produce maximally entangled states between the cavities.

Quantum Estimation of Parameters of Classical Spacetimes.

We describe a quantum limit to measurement of classical spacetimes. Specifically, we formulate a quantum Cramér-Rao lower bound for estimating the single parameter in any one-parameter family of spacetime metrics. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly background-independent derivation. The result is an uncertainty relation that applies to all globally hyperbolic spacetimes. Among other examples, we apply our method to detection of gravitational waves with the electromagnetic field as a probe, as in laser-interferometric gravitational-wave detectors. Other applications are discussed, from terrestrial gravimetry to cosmology.

Qualitative and quantitative contrasts in the mechanisms of lumen enlargement by coronary balloon angioplasty and directional coronary atherectomy.

OBJECTIVES: This study was designed to define and contrast the mechanisms of lumen enlargement from coronary balloon angioplasty and directional coronary atherectomy using intracoronary ultrasound imaging in vivo. BACKGROUND: The mechanisms of lumen enlargement produced by percutaneous transluminal coronary balloon angioplasty and directional coronary atherectomy are not known because the coronary artery wall has not previously been studied both before and after dilation. METHODS: We used intracoronary ultrasound to quantitate coronary lumen, vessel and plaque area both before and immediately after successful coronary angioplasty (n = 30) and directional coronary atherectomy (n = 25) at the site of most severe stenosis. RESULTS: Angioplasty increased lumen area by 2.80 +/- 0.25 mm2 (mean +/- SE, p < 0.0001). Eighty-one percent of this lumen gain resulted from an increase in vessel area and the remaining 19% from a reduction in plaque area. Lumen gain of individual lesions was separated into three groups: 67% had an increase in vessel area (vessel expansion), 13% had a decrease in plaque area and 20% had a combination of both. In contrast, vessel expansion contributed only 22% of the lumen gain with directional coronary atherectomy, with the majority (78%) of increase in lumen size coming from a reduction in plaque area. Directional coronary atherectomy increased lumen area from 2.36 +/- 0.05 to 7.00 +/- 0.28 mm2 (p < 0.0001). Plaque reduction was the sole mechanism in 60% of lesions, vessel expansion was the sole mechanism in 12% and a combination of both mechanisms occurred in 28%. Lumen enlargement of eccentric lesions treated with directional coronary atherectomy was more commonly associated with plaque reduction (p < 0.02), whereas eccentricity did not affect the mechanism of lumen enlargement with coronary angioplasty. CONCLUSIONS: This is the first study to systematically examine the coronary artery wall in vivo at the site of a severe stenosis both before and after catheter-based interventions in humans. Lumen enlargement from coronary angioplasty occurs predominantly from vessel expansion or stretching, although a reduction in plaque area contributes to the lumen gain in many patients and is the sole mechanism in a few. Lumen gain from directional coronary atherectomy is predominantly from reduction in plaque area (probably owing to tissue removal), although vessel stretching (balloon effect) occurs and is the sole mechanism in a small minority of vessels. Plaque reduction is more common in directional coronary atherectomy of eccentric lesions.

Short tandem repeat typing of bodies from a mass disaster: high success rate and characteristic amplification patterns in highly degraded samples.

We have used a PCR-based DNA-typing method, involving the coamplification of four tetrameric short tandem repeat loci, in the analysis of a large number of severely degraded tissue samples taken from the scene of a mass disaster in which bodies were exposed to extreme thermal, physical and chemical insult. Analysis of the amplified DNA in a number of the samples revealed uniquely sized artifact PCR products resulting from the amplification of degraded genomic DNA as well as characteristic patterns in the amounts of PCR products generated from differently sized loci. This system has proved to be very reliable and robust, and we were successful in typing all of the four loci in 66% of the samples tested and at least one locus in 83% of the cases. A PCR-based sex test also proved to be very effective when applied to the degraded samples.

Mechanism of altered pattern of left ventricular filling with aging in subjects without cardiac disease.

The mechanism whereby aging, in the absence of cardiac disease, may alter the pattern of left ventricular (LV) diastolic filling is unknown. Accordingly, this study was designed to examine the factors that may be in part responsible for aging's effect on the pattern of LV diastolic filling. The LV end-diastolic pressure-volume relation was analyzed in 11 elderly subjects (68 +/- 5 years, mean +/- standard deviation) and 15 normal young adults (31 +/- 7 years) without coronary artery disease, systemic hypertension, LV hypertrophy or abnormality of LV systolic function. After catheterization, the subjects underwent pulsed Doppler analysis of mitral flow. All had normal 2-dimensional echocardiograms without LV or valvular dysfunction. Peak early filling velocity in the elderly subjects was decreased in comparison with that in young adults (61 +/- 14 vs 83 +/- 8 cm/s, p less than 0.001) and the ratio of early and late diastolic filling velocity was reduced (0.81 +/- 0.26 vs 1.88 +/- 0.40, p less than 0.001). The isovolumic relaxation time did not differ between the elderly and young subjects (158 +/- 20 vs 146 +/- 22 ms, difference not significant). In the elderly, LV end-diastolic pressure was increased (15 +/- 7 vs 11 +/- 4 mm Hg, p less than 0.05) despite a smaller end-diastolic volume index (60 +/- 16 vs 74 +/- 18 ml/m2, p less than 0.05), indicating a shift of the passive diastolic pressure-volume relation. It was concluded that early diastolic filling is reduced in normal aged subjects, even in the absence of coronary artery disease and systolic dysfunction. This altered pattern of diastolic filling may result from a shift of the passive LV diastolic pressure-volume relation.

Effect of alteration in loading conditions on both normal and abnormal patterns of left ventricular filling in healthy individuals.

Doppler analysis of mitral flow provides a means of analyzing left ventricular (LV) diastolic function. While experimental studies have suggested that changes in left atrial pressure may affect the normal pattern of early diastolic filling, the effect of such changes on abnormal patterns of filling is unknown. Accordingly, the Doppler pattern of LV filling was analyzed in 20 subjects with LV hypertrophy (mean age 59 +/- 13 years, +/- standard deviation), in 25 healthy normal subjects (29 +/- 6 years) and in 11 elderly subjects (68 +/- 5 years). All underwent Doppler examination of LV inflow at rest and immediately after postural changes. In all 3 groups, head-down positioning increased early diastolic flow velocity (E) (p less than 0.001), and raised the E to late diastolic flow velocity (A) ratio (p less than 0.01). However, an abnormal E/A ratio never approached a normal resting value. Likewise, although E and the E/A ratio decreased significantly in normal subjects with head-up positioning, it did not become abnormal. The magnitude of change in E, A and E/A ratio did not differ among the 3 groups in response to postural changes. Thus, alterations of LV loading conditions alter the pattern of LV filling, whether normal or abnormal at baseline. The magnitude of change appears to be independent of the resting flow pattern. Although loading conditions may affect the Doppler pattern of filling, simple changes in venous return do not "normalize" an abnormal pattern, nor do they "abnormalize" a normal pattern.

Self-shading correction for upwelling sea-surface radiance measurements made with buoyed instruments.

Upwelling radiance measurements made with instruments designed to float at the sea surface are shaded both by the instrument housing and by the buoy that holds the instrument. The amount of shading is wavelength dependent and is affected by the local marine and atmospheric conditions. Radiance measurements made with such instruments should be corrected for this self-shading error before being applied to remote sensing calibrations or remote sensing algorithm validation. Here we use Monte Carlo simulations to compute the self-shading error of a commercially available buoyed radiometer so that measurements made with this instrument can be improved. This approach can be easily adapted to the dimensions of other instruments.

Derivative analysis of absorption features in hyperspectral remote sensing data of carbonate sediments.

This study uses derivative spectroscopy to assess qualitative and quantitative information regarding seafloor types that can be extracted from hyperspectral remote sensing reflectance signals. Carbonate sediments with variable concentrations of microbial pigments were used as a model system. Reflectance signals measured directly over sediment bottoms were compared with remotely sensed data from the same sites collected using an airborne sensor. Absorption features associated with accessory pigments in the sediments were lost to the water column. However major sediment pigments, chlorophyll a and fucoxanthin, were identified in the remote sensing spectra and showed quantitative correlation with sediment pigment concentrations. Derivative spectra were also used to create a simple bathymetric algorithm.

Ocean PHILLS hyperspectral imager: design, characterization, and calibration.

The Ocean Portable Hyperspectral Imager for Low-Light Spectroscopy (Ocean PHILLS) is a hyperspectral imager specifically designed for imaging the coastal ocean. It uses a thinned, backsideilluminated CCD for high sensitivity and an all-reflective spectrograph with a convex grating in an Offner configuration to produce a nearly distortionfree image. The sensor, which was constructed entirely from commercially available components, has been successfully deployed during several oceanographic experiments in 1999-2001. Here we describe the instrument design and present the results of laboratory characterization and calibration. We also present examples of remote-sensing reflectance data obtained from the LEO-15 site in New Jersey that agrees well with ground-truth measurements.

Candida endocarditis. A treatable form of pacemaker infection.

Fungal endocarditis is a rare complication of permanent pacemaker implantation. In all reports we have identified, this infection has been fatal, diagnosed postmortem. We present a patient in whom early echocardiographic diagnosis resulted in curative surgical and antimicrobial therapy. Fungal endocarditis is an unusual, but treatable complication of permanent pacemakers.

Magnetic resonance imaging evaluation of recipient for cryopreserved aortic allograft.

Aortic valve replacement with a cryopreserved aortic allograft is the procedure of choice for many patients with aortic valvular heart disease. We have used magnetic resonance imaging preoperatively to determine annular size and coronary artery orientation in the recipient, which not only has enabled us to select an allograft of appropriate size from a distant tissue bank, but also has helped us to identify preoperatively the recipient with a truly bicuspid valve in which the coronary arteries are oriented 180 degrees apart. Sixteen consecutive patients were evaluated preoperatively, the aortic annulus being measured with both magnetic resonance imaging and echocardiography. Cryopreserved aortic allografts were ordered on the basis of the magnetic resonance imaging measurement. Annular size was then measured intraoperatively with calibrated sizers. Magnetic resonance imaging annular measurements correlated highly with those found at operation (r = 0.92), whereas echocardiographic measurements correlated less well (r = 0.69). Coronary orientation was accurately predicted in every case (r = 1.0). Therefore, we have found magnetic resonance imaging to be useful in the preoperative evaluation of patients for aortic valve replacement with a cryopreserved aortic allograft.

Perforation of the anterior mitral leaflet caused by aortic valve endocarditis: diagnosis by two-dimensional, transesophageal echocardiography and color flow Doppler.

Perforation of the mitral valve as a result of aortic valve endocarditis is rare. Recognition of such abnormality is very important before surgical intervention. Diagnosis is very difficult by either invasive or noninvasive techniques. This report stresses the role of echocardiography in evaluating this rare abnormality. Perforation of the anterior mitral valve leaflet developed in our patient as a complication of aortic valve endocarditis. The perforation was suggested by the surface echocardiogram (as an interruption of the leaflet continuity) and by the color flow Doppler (which suggested turbulent flow at the area of suspected interruption). The perforation was confirmed during surgery by transesophageal echocardiography and alerted the surgeon to repair, rather than replace, the valve.

Mechanism of physiologic and pathologic S3 gallop sounds.

Although the S3 gallop sound has long been used clinically as an indicator of left ventricular systolic dysfunction, the mechanism responsible for its production remains controversial. The same sound is often found in young healthy individuals, and whether a similar mechanism is responsible is also unknown. The relationship of the S3 gallop sound to the dynamics of left ventricular filling was compared in 18 healthy young triathletes and 15 older subjects with cardiac disease. Twenty healthy normal subjects without an S3 were included as controls. Phonocardiographic, two-dimensional echocardiographic, and Doppler echocardiographic analysis of left ventricular inflow were evaluated. The S3 in both groups always occurred close to peak early filling velocity (E), during early flow deceleration. Mean E deceleration rate was higher in the subjects with S3 (726 +/- 153 cm/sec2 in the triathletes and 819 +/- 274 cm/sec2 in those with cardiac disease) than in control subjects (563 +/- 131 cm/sec2, p less than 0.001 in both cases). Ten triathletes underwent examination both before and immediately after 30 degrees head-up tilt. E deceleration rate dropped significantly with head-up tilt (720 +/- 137 vs 590 +/- 174 cm/sec2, p less than 0.01), while concurrently the S3 disappeared or was diminished in amplitude. Similar changes were seen in subjects with cardiac disease. We conclude that both the "pathologic" and "physiologic" S3 are related to abnormally rapid deceleration of early diastolic left ventricular inflow. Although the presence of the S3 is not dependent on the state of left ventricular systolic function, diastolic filling is characterized by a predominance of early inflow with a rapid flow deceleration rate.

Outpatient cholecystectomy simulated in an inpatient population.

This prospective clinical trial evaluates the feasibility and safety of elective cholecystectomy in a simulated outpatient protocol in 40 patients. Results were compared with a 19-patient control group managed by conventional postoperative methods. Oral liquids were begun in the recovery room, intravenous fluids were discontinued 4 hours after surgery, and enteral analgesics and antiemetics were provided on the ward. Protocol patients were randomized in a double-blind fashion to receive metoclopramide or placebo after surgery to assess its influence on the early tolerance of oral intake. In the protocol group, nausea without emesis occurred in nine patients (23%); 11 others (28%) had nausea with emesis. This was not significantly different from the control group. Metoclopramide-treated patients did not demonstrate a lower incidence of nausea or emesis but did tolerate oral liquids earlier after surgery than the placebo group (P less than 0.05). After release from recovery, eight protocol patients (20%) requested parenteral narcotics for relief of pain. Postoperative urinary catheterization was required in nine protocol patients (23%) and five control patients (26%). No major complications occurred. Outpatient cholecystectomy is both feasible and safe. Metoclopramide may allow earlier tolerance of enteral liquids postoperatively.

Immediate angioplasty for acute myocardial infarction: a community hospital's experience.

This study describes prospective outcome data from 100 consecutive patients presenting with acute myocardial infarction and treated with immediate angioplasty in a community hospital setting. Successful angioplasty was achieved in 86% of patients with a mean reperfusion time of 77.5 minutes. Only 4 patients did not survive initial hospitalization; three of these initially presented with cardiogenic shock. The survival rate in noncardiogenic shock patients was 98.9%. Four patients underwent repeat angioplasty of the infarct-related artery and 6 patients were referred for coronary artery bypass surgery during initial hospitalization. During the 6 month follow-up, nine patients required repeat hospitalization. Seven of these patients presented with recurrent ischemia; four underwent repeat angioplasty and 3 coronary artery bypass surgery. There were no subsequent deaths or reinfarctions during the 6 month follow-up. The angioplasty success rate and clinical outcomes in this study compare favorably to previous trials performed in select interventional centers and suggest that immediate angioplasty can be the preferred reperfusion therapy in a community hospital setting.

The underlying coronary lesion in myocardial infarction: implications for coronary angiography.

Myocardial infarction is usually caused by sudden thrombotic occlusion of a coronary artery at the site of a fissured atherosclerotic plaque. Recent evidence suggests that coronary angiography may be insensitive in detecting and quantitating atherosclerosis. Serial angiographic studies demonstrate that the majority of myocardial infarctions occur due to occlusion of arteries that previously did not contain angiographically significant (greater than 50%) stenoses. Similarly, quantitative angiography performed after thrombolytic therapy indicates that the coronary lesion underlying the clot is frequently not severely stenotic. Thus, an angiographically apparent stenosis is not necessary for the development of a thrombotic occlusion resulting in an MI. These observations suggest that coronary angiography does not accurately predict the site of a subsequent occlusion that will produce a myocardial infarction.

Moderate sodium restriction does not alter lower body negative pressure tolerance.

HYPOTHESIS: Space travel with exposure to microgravity leads to a significant reduction in orthostatic tolerance on return to Earth, for which countermeasures are only partially successful. The purpose of this study was to examine the effect of moderate dietary sodium restriction on tolerance to LBNP. METHODS: Eight healthy men, age 25.1+/-1.3 yr, volunteered for the study. Subjects were exposed to presyncopal LBNP after consuming their "typical" diet (C) for 5 d and after consuming a sodium restricted (SR) diet for 5 d. Diet sequence was randomized and adherence was verified by 24-h urine collection on the 4th and 5th days of each diet. RESULTS: All subjects reached presyncope during the LBNP, regardless of diet. Urinary sodium excretion was 3390+/-950 mg on the C diet and 1174+/-560 mg on the SR diet. Urinary potassium was not different between the diets. Cumulative stress index scores were 655+/-460 (mm Hg x min) on the C diet and 639+/-388 (mm Hg x min) during SR. Cardiac volumes, BP and total peripheral resistance were not different at any stage of the LBNP between the diets, nor were catecholamines. Plasma renin activity, determined by radioimmunoassay, was significantly higher during SR at rest, and during all stages of LBNP in comparison with the control diet. CONCLUSION: Moderate dietary sodium restriction is not detrimental to orthostatic tolerance.

Validation of impedance cardiography during lower body negative pressure.

BACKGROUND: Both echocardiographic and impedance cardiographic techniques have been used individually for the determination of stroke volume (SV) during lower body negative pressure (LBNP). Impedance cardiography has not been validated during LBNP. HYPOTHESIS: The purpose of this study was to determine both the absolute values for SV and the change in SV for each stage of LBNP using both impedance and echocardiographic techniques during staged LBNP to presyncope. The hypothesis was that there would be no difference between the two techniques for either the absolute values of SV or for the change in SV with each stage of LBNP. METHODS: There were 16 men who volunteered to undergo LBNP. LBNP was lowered in 10 mmHg stages for 5 min per stage until presyncope was reached. Left ventricular SV was determined by two-dimensional echocardiography and impedance cardiography. Both the absolute values for SV and the change in SV from baseline at each stage of LBNP were compared for the two methods. RESULTS: There were no significant differences between the two techniques for the measurement of either the absolute SV or the change in SV with LBNP. The two methods correlated highly with r = 0.89 for the absolute SV values and r = 0.93 for the change in SV. Graphical analysis with the Bland-Altman analysis showed little bias in the impedance measurement for SV (-0.031 ml) and the change in SV (-2.7 ml). CONCLUSIONS: Impedance cardiography was a reliable measure of SV, as well as the change in SV, during LBNP stress to presyncope.

The heart is not necessarily empty at syncope.

BACKGROUND: Although extensively investigated, the mechanism(s) of post-spaceflight orthostatic intolerance has not been elucidated. Several researchers have proposed that the "trigger" for syncope is an empty ventricle, initiated when a hypercontractile state, possibly due to a sudden surge in epinephrine, causes the walls of the left ventricle to touch leading to a profound sympatho-inhibition and intense vagal stimulation. HYPOTHESIS: A markedly reduced left ventricular end systolic volume (LVESV) achieved during progressive, presyncopal-limited lower body negative pressure (LBNP) is the trigger for syncope. METHODS: Eight healthy men, age 25.1+/-1.3 yr, volunteered for the study. Changes in left ventricular end-diastolic volume and LVESV were measured, using two-dimensional echocardiography, at each stage of LBNP from rest up to presyncope (PS). Plasma venous catecholamine concentrations were measured at the end of each stage by high performance liquid chromatography (HPLC) with electrochemical detection. RESULTS: All subjects reached PS. Three men became bradycardic at presyncope while five remained tachycardic. LVESV decreased by 28% at PS with no evidence of ventricular cavity obliteration. Norepinephrine increased by 44% from rest to PS, but no epinephrine surge was detected (35% increase from rest to PS). CONCLUSION: These data indicate that it is possible to initiate syncope with only a 28% decrease in LVESV, and that sympatho-inhibition and bradycardia are not required elements for syncope to occur.