B-type natriuretic peptide in lymphedema

Lymphedema often responds to compression therapy which can also cause undesirable cardiac overload if heart failure coexists. We hypothesized that the biomarker B-type natriuretic peptide (BNP) can be used to screen lymphedema patients for undetected cardiac dysfunction. We studied unselected consecutive patients with lymphedema to determine their BNP status and compared these data with those obtained from healthy subjects without known cardiovascular diseases. Out of a total of 305 subjects with lymphedema screened, 102 (33%) consented to take part in this study. The majority (87%) were female with a mean age of 60.5 +/- 13.2 (SD) years, and 47% had just lower limb swelling. The groups were equally divided between cancer and non-cancer related causes. There were 45 females and 4 males under 60 years old, and 44 female and 9 male patients over 60 years old. Median (IQR) BNP (ng/L) were as follows: <60 years females = 17.9 (15.2) (median [RR: 3 - 64] and males = 12.4 (14.7) [RR: 0.2 - 44], >60 years females = 35.8 (57.9) [RR: 2 -247)] and males = 47.2 (44.1) [RR: 2 - 238]. For this population, the BNP concentration 100 ng/L was adopted as the value to exclude heart failure. Using this definition, 7 lymphedema subjects had BNP concentrations of 120 (19.8) ng/L, and all were found to have cardiac abnormalities on echocardiography. This study demonstrated that 93% of unselected subjects with lymphedema had BNP concentrations that exclude a diagnosis of heart failure. Those subjects with elevated BNP were found on subsequent echocardiography to have cardiac abnormalities. The use of a BNP assay is of potential value in screening patients who are more likely to have cardiac failure. Indicative factors include bilateral leg swelling, over the age of 50 years, breathlessness, where there is no known cause for the swelling. A BNP assay using a BNP concentration threshold of 100 ng/L (29 pmol/L) will identify those patients who require more detailed investigations.

Two-dimensional strain imaging: a new echocardiographic advance with research and clinical applications

Over the past two decades the quest for quantitative evaluation of left ventricular function and regional wall motion has escalated, allowing several aspects of myocardial contractile patterns to be quantified, both during stress echocardiography and in the assessment of dyssynchrony. Most of the literature to date has used Tissue Doppler Imaging (TDI) techniques to assess essentially long-axis function due to the angle dependency of Doppler based techniques. This brief review introduces the early development, validation and potential clinical applications of a new technique of quantifying two-dimensional (radial and circumferential) strains and strain rates through tracking myocardial "speckles". In-vivo and in-vitro validation of this 2D-strain imaging technique has been undertaken and reached a point where it is considered ready for more widespread investigations into clinical utility. One important advantage over TDI techniques is that it is not limited by dependency on the angle of insonation. Several recent studies looking at ventricular function in specific groups of patients have reported practical ability to distinguish the abnormally from the normally contracting regions of ventricular walls. It provides new and complementary quantitative information about ventricular dyssynchrony and regional wall motion abnormalities. More research studies are needed to determine the sensitivity and specificity of the measurements obtained using this technique and define its strengths and limitations. In particular, whether the measured values correlate well with clinical outcomes will need to be established in longitudinal interventional studies. The clinical utilities of this technique over the coming years are likely to expand rapidly.

Complementary roles of simple variables, NYHA and N-BNP, in indicating aerobic capacity and severity of heart failure

AIMS

The extent of exercise intolerance in patients with chronic heart failure (CHF) is dependent on and representative of the severity of heart failure. However, few primary care physicians have direct access to facilities for formal exercise testing. We have therefore explored whether information readily obtainable in the community can reliably predict the functional capacity of patients.

METHODS AND RESULTS

Ninety-six subjects with a wide range of cardiac function (10 healthy controls and 86 CHF patients with NYHA classes I-IV, LVEF 36.9+/-15.2%) were recruited into the study and had resting plasma N-BNP and cardiopulmonary exercise testing to measure peak oxygen consumption (VO2). Significantly higher N-BNP levels were found in the CHF group (299.3 [704.8] fmol/ml, median [IQR]) compared with the healthy control group (7.2 [51.2] fmol/ml), p<0.0001. There were significant correlations between peak VO2 and N-BNP levels (R=0.64, P<0.001), peak VO2 and NYHA class (R=0.76, P=0.001), but no significant correlation was seen between peak VO2 and LVEF (R=0.0788, P=0.33). Multivariate analysis identified plasma N-BNP (P<0.0001) and NYHA class (P<0.0001) as significant independent predictors of peak VO2. Logistic modelling with NYHA class and log N-BNP to predict peak VO2<20 ml/kg/min showed that the area under the curve of receiver-operating-characteristic (ROC) curve was 0.906 (95% CI 0.844-0.968). A nomogram based on the data has been constructed to allow clinicians to estimate the likelihood of peak VO2 to be <20 ml/kg/min for given values of plasma N-BNP and NYHA class.

CONCLUSIONS

By combining information from a simple objective blood test (N-BNP) and a simple scoring of functional status (NYHA), a clinician can deduce the aerobic exercise capacity and indirectly the extent of cardiac dysfunction of patients with CHF.

From CONSENSUS to CHARM—how do ACEI and ARB produce clinical benefits in CHF?

Two decades of research from CONSENSUS to CHARM using modulators of the renin-angiotensin-aldosterone system (RAAS) in chronic heart failure (CHF) patients have shown convincing clinical benefits, but the majority of clinicians prescribing these drugs are still unclear about what mechanisms are responsible for the observed benefits. Of the candidate mechanisms hitherto proposed, there emerges a theme that best fits the spectrum of known factors from pathophysiology of heart failure to how the drugs enhance longevity of patients. This concept can be summarised as follows: after the onset of heart failure, neurohormones are activated resulting in raised levels of angiotensin, aldosterone and catecholamines, which are all known cardiotoxic agents. Cumulatively over time, they are responsible for accelerated cardiomyocyte attrition, manifesting as a faster reduction of cardiac pumping reserve, leading to worsening heart failure, more neurohormonal activation, thus propagating a vicious cycle spiralling towards an earlier fatality. The vicious cycle can be interrupted by dampening the excessive neurohormonal activities, thereby minimising cardiomyocyte losses and preserving cardiac functional reserve for longer. This culminates in maintenance of a reasonable quality of life and enhanced longevity. Such a mechanistic understanding would enable clinicians to have a better perspective on how to apply data from various clinical trials involving these drugs into clinical practice, to optimise and tailor therapy to the individual patient so that each patient can gain maximal benefits.

The benefits of valsartan in the treatment of heart failure: results from Val-HeFT

Angiotensin II receptor blockers (ARBs) are the most recent class of anti-hypertensive drug to enter clinical use for chronic heart failure (CHF). In the landmark Valsartan Heart Failure Trial (Val-HeFT), valsartan reduced the risk of the combined endpoint of all-cause mortality and morbidity by 13.2% over a 2-year follow-up. Although it significantly improved a pre-specified primary endpoint, it did not improve the endpoint of all-cause mortality. Valsartan administered to patients not receiving angiotensin-converting enzyme inhibitors (ACEI) at baseline reduced the endpoint of all-cause mortality by 33% and the combined endpoint of mortality and morbidity by 44%, compared with placebo. Based on these findings, valsartan became the first ARB to be approved by the US Food and Drug Administration for the treatment of New York Heart Association class II-IV HF in patients who are intolerant of ACEIs. This review provides a summary of the key Val-HeFT results and their implications in the treatment of CHF patients.

Does balloon mitral valvuloplasty improve cardiac function? A mechanistic investigation into impact on exercise capacity

Procedural technical success of balloon mitral valvuloplasty (BMV) is indicated by an increase in valve area and a reduction in transvalvar gradient, but there are conflicting results regarding whether these indicators correlate with subsequent improvements in exercise capacity. We conducted a study to explore the effects of valvuloplasty on cardiac function to gain insight into the mechanisms responsible for the impact on exercise ability. Sixteen patients with mitral stenosis participated in the study and the five who did not proceed to valvuloplasty served as the control group. All patients performed maximal cardiopulmonary exercise tests before and 6 weeks after valvuloplasty (without valvuloplasty in controls). Central haemodynamics including cardiac output were measured non-invasively at rest and peak exercise. At baseline, the cardiopulmonary exercise test results were similar in the two groups. Following valvuloplasty, cardiac output did not alter at rest, but increased significantly at peak exercise (8.7+/-1.7 to 10.5+/-2.1 l min(-1), P<0.01), as did peak cardiac power output (1.88+/-0.55 to 2.28+/-0.74, P<0.05) and cardiac reserve (1.07+/-0.33 to 1.45+/-0.55 watts, P<0.05). Aerobic exercise capacity improved (13.9+/-4.2 to 16.4+/-4.3 ml kg(-1) min(-1), P<0.01) as did exercise duration (354+/-270 to 500+/-266 s, P<0.01). There were no significant changes in the controls. There was a significant correlation between the changes in peak VO(2) and changes in cardiac reserve (r=0.62, P<0.01) but not with changes in resting haemodynamics. These changes did not correlate with changes in peri-procedural mitral valve haemodynamics, despite increases in mitral valve area from 1.05+/-0.16 to 1.74+/-0.4 cm(2) (P<0.0001), accompanied by falls in the transvalvar gradient and pulmonary artery pressure (12.4+/-4.7 to 4.5+/-3 mmHg, and 26.8+/-8.4 to 17.4+/-5.2 mmHg, respectively, all P<0.0001). In conclusion, we found that successful mitral valvuloplasty in our patient cohort led to improved cardiac and physical functional capacity but not resting haemodynamics. Neither indicators of technical success nor resting haemodynamics were very reliable in predicting functional improvement.

Assisted ventilation for heart failure patients with Cheyne-Stokes respiration

Patients with chronic congestive cardiac failure (CCF) frequently suffer from central sleep apnoea syndrome (CSAS). Continuous positive airway pressure (CPAP) has been suggested as a treatment. The authors hypothesised that bilevel ventilation might be easier to initiate and superior to CPAP at correcting the sleep-related abnormality of breathing in patients with CCF. After excluding those with a history suggestive of obstructive sleep apnoea, 35 patients with CCF (left ventricular ejection fraction <35%) were screened with overnight oximetry and the diagnosis of CSAS was established with polysomnography in 18. Two 14-day cycles of CPAP (0.85 kPa (8.5 mbar)) or bilevel ventilation (0.85/0.3 kPa (8.5/3 mbar)) in random order, were compared in a crossover study. Sixteen patients (13 males), mean age 62.0+/-7.4 yrs completed the study. The pretreatment apnoea/hypopnoea index of 26.7+/-10.7 was significantly reduced by CPAP and bilevel ventilation to 7.7+/-5.6 and 6.5+/-6.6, respectively. The arousal index fell from 31.1+/-10.0 per hour of sleep to 15.7+/-5.4 and 16.4+/-6.9, respectively. Significant and equal improvements with CPAP and bilevel ventilation were found for sleep quality, daytime fatigue, circulation time and New York Heart Association class. The authors conclude that continuous positive airway pressure and bilevel ventilation equally and effectively improve Cheyne-Stokes respiration in patients with congestive cardiac failure.

Central sleep apnoea syndrome in patients with chronic heart disease: a critical review of the current literature

The prevalence, prognosis, clinical presentation, pathophysiology, diagnosis, and treatment of the central sleep apnoea syndrome (CSAS) are reviewed and its relationship with congestive heart failure (CHF) is discussed. Adequately powered trials are needed with survival and health status as end points to establish whether correction of sleep related breathing abnormalities improves the outcome in patients with CHF.

Randomized controlled trial of home-based exercise training to evaluate cardiac functional gains

There is evidence that multiple benefits can be obtained through exercise training that leads to increases in peak oxygen consumption (V(O(2))). It is unclear whether significant improvements can also be achieved through unsupervised low-budget home-based training regimes, especially in terms of cardiac functional gains. A randomized cross-over trial was conducted to investigate the effects of a home-based unsupervised exercise training programme of moderate intensity on aerobic capacity, cardiac reserve and peak cardiac power output in healthy middle-aged volunteers. Nine subjects with no known cardiovascular diseases performed symptom-limited treadmill cardiopulmonary exercise tests after an 8-week period of exercise training, and results were compared with those obtained after a similar 'non-exercising' control period. Cardiac output was measured non-invasively during exercise tests using the CO(2)-rebreathing method. With exercise training, resting heart rate decreased significantly from 88.3+/-3.4 to 78.7+/-3.2 beats.min(-1) (P<0.05), heart rate at a submaximal workload (V(O(2))=1.5 litres.min(-1)) decreased from 125.5+/-2.4 to 115.5+/-1.6 beats.min(-1), and peak V(O(2)) increased by 9% from 2.62+/-0.19 to 2.85+/-0.18 litres.min(-1) (P<0.01). Baseline cardiac power output was 1.11+/-0.05 W, and this remained unchanged with training. Peak cardiac power output increased by 16% from 4.1+/-0.3 to 4.7+/-0.3 W (P<0.001), and cardiac reserve increased by 21% (P<0.01). A major contribution to these increases was from the 11% increase in stroke volume, from 100.1+/-5.3 to 111.2+/-6.2 ml (P<0.001). All subjects reported more positive perceptions of their health (P<0.05), fitness (P<0.01) and levels of activity (P<0.01) after the training period. These results show that motivated subjects undergoing low-budget unsupervised home-based exercise training of moderate intensity can derive benefit in terms of symptoms, aerobic capacity and cardiac functional reserve.

Peak exercise cardiac power output; a direct indicator of cardiac function strongly predictive of prognosis in chronic heart failure

OBJECTIVES

This study assessed the prognostic value of peak cardiac power output, measured non-invasively during maximal cardiopulmonary exercise testing, against other exercise-derived haemodynamic variables in patients with chronic congestive heart failure.

METHOD AND RESULTS

Two hundred and nineteen unselected, consecutive patients with congestive heart failure (166 men, mean (+/-SD) age of 56+/-13 years) who underwent maximal symptom limited cardiopulmonary treadmill exercise testing with non-invasive estimation of cardiac output using carbon dioxide re-breathing techniques, were followed-up for a mean period of 4.64 (4.47--4.82, 95% CI) years. Cardiac power output was calculated from the product of cardiac output and mean arterial blood pressure. All cause mortality was 12.3% (27 deaths). Peak and resting cardiac power output, peak mean arterial blood pressure, peak and resting cardiac output and peak VO(2)were all predictive of outcome on univariate analyses. Peak cardiac power output, either entered continuously or categorically with a cut-off value of 1.96 watts, was the only independent predictor of mortality (P=0.0004 for values < or >1.96 watts and P=0.001 for continuous values) using multivariate analysis. A relative risk ratio of 5.08 (1.94-13.3, 95% CI) was obtained for a cardiac power output <1.96 watts.

CONCLUSION

Peak cardiac power output is an independent predictor of mortality that can be measured non-invasively using cardiopulmonary exercise testing. It can give further prognostic power to a peak VO(2)in the assessment of patients with congestive heart failure.

Left ventricular volume reduction without ventriculectomy

Partial left ventriculectomy (the Batista procedure) to achieve left ventricular volume reduction (LVVR) has been advocated as an alternative to cardiac transplantation in patients with end-stage dilated left ventricles. Here, we describe a new technique of LVVR that uses realignment of the papillary muscles, thus avoiding ventriculectomy, and report preliminary results. Eight patients (all male, mean age 49.3 [range 38 to 70] years) underwent LVVR between October 1998 and March 2000 as an adjunct to surgical coronary revascularization. Five were assessed with echocardiography and cardiopulmonary exercise testing before and after (mean follow-up time 267 [range 94 to 416] days) the operation. LVVR significantly improved left ventricular end-diastolic volume (254 +/- 32 to 218 +/- 36 mL, p = 0.03), left ventricular ejection fraction (20.14% +/- 1.36% to 31.28% +/- 2.32%, p = 0.007), and exercise duration (from 394 +/- 88 to 611 +/- 79 seconds, p = 0.03). A nonsignificant improvement in maximal oxygen consumption was also observed. This technique of LVVR is relatively simple to perform and is accomplished through a small apical cardiotomy. Preliminary results show an encouraging functional improvement following surgery. Future controlled studies are required to assess this novel technique further.

A method for investigating the mechanical properties of intracoronary stents using finite element numerical simulation

The proliferation of stent designs poses difficult problems to clinicians, who have to learn the relative merits of all stents to ensure optimal selection for each lesion, and also to regulatory authorities who have the dilemma of preventing the inappropriate marketing of substandard stents while not denying patients the benefits of advanced technology. Of the major factors influencing long-term results, those of patency and restenosis are being actively studied whereas the mechanical characteristics of devices influencing the technical results of stenting remain under-investigated. Each different stent design has its own particular features. A robust method for the independent objective comparison of the mechanical performance of each design is required. To do this by experimental measurement alone may be prohibitively expensive. A less costly option is to combine computer analysis, employing the standard numerical technique of the finite element method (FEM), with targeted experimental measurements of the specific mechanical behaviour of stents. In this paper the FEM technique is used to investigate the structural behaviour of two different stent geometries: Freedom stent geometry and Palmaz-Schatz (P-S) stent geometry. The effects of altering the stent geometry, the stent wire diameter and contact with (and material properties of) a hard eccentric intravascular lesion (simulating a calcified plaque) on stent mechanical performance were investigated. Increasing the wire diameter and the arterial elastic modulus by 150% results in the need to increase the balloon pressure to expand the stent by 10-fold. Increasing the number of circumferential convolutions increases the pressure required to initiate radial expansion of mounted stents. An incompressible plaque impinging on the mid portion of a stent causes a gross distortion of the Freedom stent and an hour-glass deformity in the P-S stent. These findings are of relevance for future comparative studies of the mechanical performance of stents, in designing newer stents and also in clinical practice.

Disparate results of ACE inhibitor dosage on exercise capacity in heart failure: a reappraisal of vasodilator therapy and study design

Despite manifest benefits of angiotensin converting enzyme (ACE) inhibitors on the prognosis of patients with heart failure, there is a lack of consistency in the results of trials investigating the effects of ACE inhibitors on exercise capacity. The inconsistencies cannot be readily explained by variations in effects on known neurohumoral or conventional haemodynamic factors. Drawing on insights from physiology of pump-load interactions, in a normal circulation there is an optimal extent of systemic vasodilation at which the delivery of hydraulic energy from the cardiac pump is maximal (the 'impedance matchpoint'). In heart failure, the vasoconstrictive effects shift the operating point towards mismatch at higher resistances, and optimal vasodilatory therapy would reshift the operating point to the matchpoint. Excessive dosage, however, would cause overvasodilatation leading to a reduction in cardiac power output and consequently compromising exercise ability. High levels of ACE inhibitors may not therefore improve exercise ability. Another potential reason for the observed inconsistencies is that the often used parallel-group study design (ideal for mortality studies) may not be suitable for investigating drug effects on exercise capacity because dropouts from such studies would introduce occult selection biases, thereby confounding treatment effects. In conclusion, this reappraisal of the conflicting observations reported on ACE inhibitor effects on exercise capacity has highlighted a proposition that there is an optimal dosage of ACE inhibitors which will most enhance exercise capacity, and this will require further well designed cross-over studies to elucidate.

The role of exercise testing in the evaluation and management of heart failure

The clinical syndrome of heart failure has been investigated so extensively that it may now almost be regarded as a metabolic disorder. Although an initial insult reduces cardiac pump efficacy, the resultant physiological response culminates in complex neurohormonal dysfunction. This has created confusion and prevented the acceptance of a universal definition of cardiac failure. With much current research concentrating on the pharmacological modification of neuroendocrine imbalance, it is easy to lose sight of the fundamental principles behind heart failure management, namely, to improve cardiac function. In attempting to achieve this, the issues of morbidity and mortality must be addressed jointly; they are not mutually exclusive entities. Discrepant results between mortality studies and changes in exercise capacity have undermined the value of exercise testing. Because a treatment enhances longevity we should not ignore its effect on symptomatic status, and likewise we should not discard a therapy, which improves function because adverse events result in occasional premature deaths. Informed patient choice must exist. Historically, exercise testing has been quintessential in our understanding and evaluation of heart failure. Peak oxygen consumption remains the best overall indicator of symptomatic status, exercise capacity, prognosis and hospitalisation. Unfortunately, muddling of surrogate and true end-points has confused many of these issues. Improved comprehension may be gained by applying the concept of cardiac reserve which has been described in a variety of heart conditions and used in cardiac failure patients to provide an indication of prognosis and functional capacity.

Frequency-domain simulation of MR tagging

Simulation of MR images is a useful tool for offline sequence development and as an aid to understanding image formation. One particular application of simulation is MR tagging, which is used for tracking myocardial motion. Simple spatial-domain methods cannot adequately represent effects common in these images, such as motion artifact and signal wrap. An existing frequency-domain model is shown to be inappropriate for tagged images, and an extension based on the Bloch equations and Fourier shift theorem is described to correct this. Software incorporating the new model is used to generate ideal tag intensity profiles and to accurately simulate tagged images. The shifted k-space patterns associated with tagged images, and their dependence on the order of the binomial tagging sequence, are explained. An application of the Fourier shift theorem is suggested that allows more rapid simulation of static tagged images.

Physiological cardiac reserve: development of a non-invasive method and first estimates in man

OBJECTIVE

To investigate whether physiological cardiac reserve can be measured in man without invasive procedures and whether it is a major determinant of exercise capacity.

DESIGN

Development of method of measurement and an observational study.

SETTING

A regional cardiothoracic centre.

SUBJECTS

70 subjects with a wide range of cardiac function, from heart failure patients to athletes.

METHODS

Subjects underwent treadmill, symptom limited cardiopulmonary exercise tests to measure aerobic exercise capacity (represented by VO2max) and cardiac reserve. Cardiac output was measured non-invasively using the CO2 rebreathing technique.

RESULTS

Cardiac power output (CPOmax) at peak exercise was found to be significantly related to aerobic capacity: CPOmax (W) = 0.35 + 1.5 VO2max (1/min), r = 0.87, p < 0.001. It also correlated well with exercise duration (r = 0.62, p < 0.001), suggesting that cardiac reserve is a major determinant of exercise capacity. In the study, cardiac reserve ranged from 0.27 to 5.65 W, indicating a 20-fold difference between the most impaired cardiac function and that of the fittest subject.

CONCLUSIONS

A non-invasive method of estimating physiological cardiac reserve was developed. The reserve was found to be a major determinant of exercise capacity in a population of normal subjects and patients with heart disease. This method may thus be used to provide a clearer definition of the extent of cardiac impairment in patients with heart failure.

Simulation of two-dimensional tagged MRI

MR tagging is a recent imaging development that, in cardiac applications, makes possible the tracking of points in the myocardium during the cardiac cycle. Researchers have developed semiautomated, computer-based methods for analyzing tagged images, but the images are complex and present a challenge to automated tracking systems. Simulation can provide an inexhaustible supply of images for testing and validation of tag tracking software and preview the effect of parameter changes in acquisition. SIMTAG is an interactive computer program that simulates two-dimensional tagged-MR experiments. The mathematic model used in the simulation and algorithms for simulating image noise and object deformation are described. Examples of the use of simulated images in SPAMM parameter selection, a comparison of tag contrast in signal-averaged SPAMM and CSPAMM, and simulated images as test sets for tag-tracking software are presented.

The concept of cardioreparation: Part 2. Medical implications of cardioreparation

PURPOSE

Left ventricular hypertrophy (LVH) caused by systemic hypertension, myocardial infarction and congestive heart failure is associated with pathological changes in the structure of the heart, collectively described as remodelling (see part 1 of this review). The reversal of remodelling, termed cardioreparation, might restore cardiac structure and function towards normal, thereby improving the prognosis of these conditions. We aimed to explore the medical implications of this concept.

DATA EXTRACTION

Clinical trials of angiotensin converting enzyme (ACE) inhibitors and other drugs in patients with hypertension, myocardial infarction and congestive heart failure were reviewed. The results showed that ACE inhibitors induce regression of LVH in hypertensive patients, reduce mortality in acute myocardial infarction, and reduce morbidity and mortality in patients with congestive heart failure or left ventricular dysfunction subsequent to myocardial infarction. These observations are consistent with cardioreparation by ACE inhibitors.

CONCLUSIONS

ACE inhibitors reduce morbidity and mortality in patients with myocardial infarction or congestive heart failure. Theoretical considerations and some clinical observations suggest that these benefits might result from cardioreparation.

The concept of cardioreparation: Part 1. Pathophysiology of remodelling

PURPOSE

Left ventricular hypertrophy is common in patients with hypertension or congestive heart failure and in survivors of myocardial infarction. It is associated with increased risks of adverse cardiovascular events, including angina, myocardial infarction and congestive heart failure. We aimed to explain these observations in terms of changes in the structure of the heart, collectively described as remodelling.

DATA EXTRACTION

Laboratory investigations of animal models of cardiovascular diseases were reviewed. The most prominent features of remodelling are myocyte hypertrophy, excessive accumulation of collagen in the heart (myocardial fibrosis) and pathological changes in the coronary blood vessels. Remodelling disrupts the structure of the heart and impairs its pumping function and blood supply. The reversal of remodelling, termed cardioreparation, could restore cardiac structure and function towards normal and improve the prognosis of patients with cardiovascular diseases.

CONCLUSIONS

Cardioreparation implies the regression of myocyte hypertrophy and myocardial fibrosis. Myocyte hypertrophy is primarily a response to chronic pressure or volume overload of the ventricles, whereas myocardial fibrosis depends on activation of circulating and tissue renin-angiotensin-aldosterone systems. Angiotensin converting enzyme inhibitors reduce blood pressure and inhibit these systems. They might therefore induce cardioreparation.

Synchronous bilateral carcinoma of the ureter in association with unilateral incomplete duplication of the ureter

A case of bilateral synchronous ureteral tumors, in association with a unilateral incomplete duplication of ureter, is presented. This patient underwent right nephroureterectomy with removal of a cuff of bladder, partial resection of left ureter, and ileal loop interposition between renal pelvis and bladder. Followup showed no recurrence in the residual urinary tract 2-years postoperatively.

Safety and efficacy of computerized closed-loop delivery of arbutamine: a new pharmacologic myocardial stress modality for the assessment of coronary artery disease. The European Arbutamine Study Group

This study evaluated the efficacy of computer-controlled closed-loop delivery of a new synthetic catecholamine, arbutamine, when given to induce myocardial ischemia detected by electrocardiography and echocardiography with a high (10 beats/min/min) and low (6 beats/min/min) rate of increase in heart rate (heart rate slope) in 70 patients with coronary artery disease. The electrocardiographic sensitivity for the detection of myocardial ischemia was 52% for the low slope and 51% for the high slope. The corresponding figures for echocardiographic sensitivity were 83% and 79% for the low and high slopes, respectively. There were no significant differences in changes from baseline to maximum in pharmacodynamic variables, although the mean times to reach maximum heart rate and systolic blood pressure were 1.4 minutes shorter (p = 0.001) and 3.7 minutes shorter (p < 0.05), respectively, for the high-slope regimen. The duration of the infusion was shorter (p < 0.001) for the high slope. In this study, closed-loop arbutamine administration was effective and safe in the detection of coronary artery disease for both heart rate slope regimens.

Xanthogranulomatous cystitis: a case report and review of the literature

Xanthogranulomatous cystitis is a rare benign chronic inflammatory disease of unknown aetiology. We report a case of xanthogranulomatous cystitis. The patient is well more than 15 years after partial cystectomy. The relevant literature is reviewed.

Survey of postoperative pain in University Hospital Kuala Lumpur

One hundred and eighty-three patients undergoing surgery were interviewed twenty-four hours following surgery to assess the quality of pain relief they received in the immediate postoperative period. Interviews were conducted using a standard questionnaire for all patients. They were asked to (1) rate the quality of pain relief they obtained on a Visual Pain Analogue Scale (VPAS-0 being no pain and 10 being the worst imaginable pain); (2) state whether they were happy and satisfied with the pain relief they received; (3) if dissatisfied, they were asked to give their reasons. 37.7% (69 patients) had moderate to severe pain--pain score greater than 6 on the VPAS. Most of these patients had undergone abdominal or major orthopaedic surgery. 32.7% (60 patients) were unhappy with their postoperative pain control. The main reasons for complaint from the patients were that analgesic injections were either not given promptly or were not given at all. The survey also highlighted the inadequate under-administration of narcotic injections in the postoperative period despite orders being written up. It showed there is an urgent need for setting up an Acute Pain Service for better postoperative pain control. An anaesthesiology based Acute Pain Service was started in October 1992.