Mitral repair best practice: proposed standards

OBJECTIVES

To define best practice standards for mitral valve repair surgery.

DESIGN

Development of standards for process and outcome by consensus.

SETTING

Multidisciplinary panel of surgeons, anaesthetists, and cardiologists with interests and expertise in caring for patients with severe mitral regurgitation.

MAIN OUTCOME MEASURES

Standards for best practice were defined including the full spectrum of multidisciplinary aspects of care.

RESULTS

19 criteria for best practice were defined including recommendations on surgical training, intraoperative transoesophageal echocardiography, surgery for atrial fibrillation, audit, and cardiology and imaging issues.

CONCLUSIONS

Standards for best practice in mitral valve repair were defined by multidisciplinary consensus. This study gives centres undertaking mitral valve repair an opportunity to benchmark their care against agreed standards that are challenging but achievable. Working towards these standards should act as a stimulus towards improvements in care.

Analysis of an adult Duchenne muscular dystrophy population

BACKGROUND

Advances in management have led to increasing numbers of patients with Duchenne muscular dystrophy (DMD) reaching adulthood. Older patients with DMD are necessarily severely disabled, and their management presents particular practical issues.

AIM

To review the management of a late adolescent and adult DMD population, and to identify areas in which the present service provisions may be inadequate to their needs.

DESIGN

Retrospective review.

METHODS

We studied 25 patients with DMD referred to an adult neuromuscular clinic over a 7-year period. Clinical details were obtained retrospectively, from case notes or direct observations.

RESULTS

There were 24 males and one symptomatic female carrier. Nine patients died during the observation period. There was no significant correlation between age of wheelchair confinement and age of death. Sixteen patients received non-invasive positive pressure support. Twelve attended mainstream schools and 12, residential special schools. All the patients lived at home for some or all of the time, when their main carers were either one or both of the parents. The most striking difficulties were with the provision of practical aids, including appropriate hoists and belts, feeding and toileting aids, and the conversion of accommodation. Patients rarely wished to discuss the later stages of their disease, and death was often more precipitate than expected. Death usually occurred outside hospital and the final cause was often difficult to establish.

DISCUSSION

Adult patients with DMD develop progressive impairment, due to respiratory, orthopaedic and general medical factors. However, the particular areas of difficulty in this study often reflected inadequate and poorly directed social and medical support, illustrating the need for improvements in the structure, co-ordination and breadth of rehabilitation services for adult patients with DMD.

A randomized comparison of the MCRI On-X and CarboMedics Top Hat bileaflet mechanical replacement aortic valves: Early postoperative hemodynamic function and clinical events

OBJECTIVE

This study compared hemodynamic function and clinical events in consecutive patients randomly assigned to receive a wholly supra-annular replacement valve or a valve with an intra-annular component.

METHODS

Fifty-two patients with an average age of 62 years (range 40-74 years) were sized for both a CarboMedics Top Hat valve (CarboMedics Inc, Austin, Tex) and an MCRI On-X valve (Medical Carbon Research Institute, LLC, Austin, Tex) before random assignment to receive either valve type. Echocardiographic and clinical assessments were performed in the immediate postoperative period and at 1 year.

RESULTS

The mean effective orifice areas were 1.41 +/- 0.42 cm2 for the Top Hat and 2.17 +/- 0.78 cm2 for the On-X (P < .0001). The mean pressure differences were 12.2 +/- 4.4 mm Hg and 6.9 +/- 3.6 mm Hg, respectively (P < .0001). New York Heart Association functional class was better with the On-X than the Top Hat valves, but there were no differences in clinical events, regression of left ventricular mass, or measures of hemolysis.

CONCLUSION

The partially intra-annular MCRI On-X valve was hemodynamically superior to the wholly supra-annular CarboMedics Top Hat valve. However, there were no differences in early clinical outcomes between the two valve types.

ATP8B1 mutations in British cases with intrahepatic cholestasis of pregnancy

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) affects approximately 0.7% of pregnancies in the UK and is associated with prematurity, fetal distress, and intrauterine death. Homozygous mutations in the ATP8B1 gene cause cholestasis with a normal serum gamma-glutamyl transpeptidase (gamma-GT), and have been reported in two forms of cholestasis: progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis (BRIC).

AIMS

To establish whether mutations in ATP8B1 are associated with ICP in British cases

PATIENTS

Sixteen well phenotyped women with ICP without raised gamma-GT were selected for sequence analysis. Subsequently, 182 patients and 120 controls were examined for the presence of the variants detected.

METHODS

All coding exons were sequenced in 16 cases. Eight ICP cases, including two women carrying a mutation, were investigated using in vivo hepatic (31)P magnetic resonance spectroscopy (MRS) RESULTS: Two heterozygous ATP8B1 transitions (208G>A and 2599C>T) that resulted in amino acid substitutions were identified; 208G>A was identified in three cases. MRS revealed an increased phosphodiester signal (Mann-Whitney U test, p = 0.03) and a decreased phosphomonoester/phosphodiester ratio (p = 0.04) in ICP cases compared with controls.

CONCLUSIONS

We were able to demonstrate ATP8B1 mutations in ICP. MRS studies suggest that susceptibility to ICP is associated with a relative rise in biliary phospholipid. These data also suggest that MRS may be used for non-invasive assessment of the liver and biliary constituents in cholestasis.

Comparison of myocardial gated single photon emission computerised tomography, planar radionuclide ventriculography and echocardiography in evaluating left ventricular ejection fraction, wall thickening and wall motion

Left ventricular ejection fraction (LVEF) and wall thickening are fundamental aspects of cardiac function. Recently, gated single photon emission computerised tomography (GSPECT) and anatomical M-mode echocardiography are new techniques, which have been introduced for the evaluation of left ventricular wall thickening and ejection fraction. These, however, have not been evaluated against established techniques, including equilibrium radionuclide ventriculography (ERNV), which remains the current gold standard for the evaluation of LVEF. We examined the concordance between LVEF, wall motion and wall thickening scores derived from GSPECT, echocardiography and ERNV, in a group of 16 patients with suspected ischaemic heart disease. Estimated ejection fraction correlated better between ERNV and gated SPECT (R2 = 0.93) than between echocardiography and either gated SPECT (R2 = 0.62) or ERNV (R2 = 0.71). There was poor correlation between gated SPECT and anatomical M-mode echocardiography in the assessment of wall thickening (83/150, 56%; kappa= 0.31, p < 0.05) and similar correlation (100/150, 66%; kappa = 0.29, p < 0.01) for wall motion analysis. In conclusion, estimations of ejection fraction by all the three studied modalities agreed to a degree sufficient for routine clinical practice. However, estimates of wall thickening from echocardiography cannot be used interchangeably with those derived from gated myocardial perfusion SPECT.

Comparison of sestamibi, thallium, echocardiography and PET for the detection of hibernating myocardium

The detection of hibernating myocardium is important because revascularisation results in improved function and prognosis in patients with hibernation but not in those with non-viable myocardium. The primary aim of this study was to compare the diagnostic accuracy of four techniques with respect to hibernation in the same study population with 6-12 months of follow-up. Twenty-five males underwent rest-stress sestamibi and delayed (>18 h) thallium scintigraphy, high-dose dobutamine stress echocardiography and nitrogen-13 ammonia/fluorine-18 fluorodeoxyglucose (NH(3)/FDG) positron emission tomography (PET). The pre-operative ejection fraction was 36.2% (+/-7.3%). Follow-up was 8.1 (+/-2.8) months. Using postoperative improvement in wall motion on echocardiography as the gold standard, 6/34 dysfunctional vascular territories were hibernating. The mean uptake of all tracers was significantly higher in hibernating than in non-viable territories ( P<0.05). Normal perfusion or mismatch on PET (FDG>NH(3) uptake) and the pattern of response to dobutamine on echocardiography were also predictive of recovery ( P<0.001 and P=0.02 respectively). Univariate logistic regression identified sestamibi, ammonia and FDG as independent predictors of hibernation. FDG-PET was, however, the only independent predictor using multivariate analysis. The nuclear techniques had high negative predictive values (NPV) of >or=95% but lower positive predictive values (PPV) of 45%-75% as compared with echocardiography, which had an NPV of 87% and a PPV of 100%. PET was the most powerful predictor of hibernation although the combination of a technique with a high PPV (echocardiography) and a high NPV (PET or sestamibi) may represent the optimal clinical choice.

Gerbode's defect resulting from infective endocarditis

We present a report of a Gerbode's defect (left ventricular-right atrial communication) resulting from bacterial endocarditis in a 63-year-old man. Also presented is a brief overview of the literature and a possible preoperative echocardiographic diagnostic criterion relating to this unusual condition.

The relationship between mean birth weight and poverty using the Townsend deprivation score and the Super Profile classification system

Super Profiles have been used as alternative methods of characterising the deprivation of an area. Some reports suggest that Super Profiles are as accurate as established indices such as the Townsend score (TS). This was a test of this assertion.A total of 138 696 live born singleton births to Birmingham residents born between 1986 and 1996 (inclusive) were allocated to enumeration districts (EDs) by linkage from the postcode. We allocated the TS of the individual's ED. We allocated a Lifestyle and Target Market (TM) from Super Profiles by linkage to the ED. We examined the gradient between mean birth weight and the 10 Super Profile Lifestyles and compared this to the gradient between 10 Townsend groups and mean birth weight. We repeated this approach using the 40 TMs and 40 Townsend groups. We used both the median income and a census-derived deprivation measure to rank Lifestyles and TMs. The gradient between mean birth weight and area deprivation was linear for Townsend groups but not linear using either Lifestyles or TMs whichever method of ranking Lifestyles or TMs was used. Where Lifestyles or TMs were out of line with their neighbours, the TS of that group mostly explained this. As Super Profiles are generated using nationally representative data, applying the affluence ranking to small areas can lead to inaccuracies, as shown in this data. We conclude that Super Profiles are probably unsuitable as measures of deprivation of small areas.

Sildenafil for primary pulmonary hypertension: short and long-term symptomatic benefit

We report two cases of primary pulmonary hypertension (PPH) who benefited from oral sildenafil therapy. Both demonstrated a substantial improvement in exercise ability, which has been sustained at 3 and 6 months. Sildenafil acting as a phosphodiesterase 5 inhibitor may have an important role to play in the management of PPH and we believe further study to be of importance.

Prediction of symptom-onset in aortic stenosis: a comparison of pressure drop/flow slope and haemodynamic measures at rest

To compare the pressure drop/flow slope with peak and mean pressure drop, effective orifice area and aortic valve resistance for the prediction of symptom-onset we performed resting and dobutamine stress echocardiography in 49 asymptomatic patients with aortic stenosis (peak aortic velocity>2.5 m/s). The end-point was progression to symptoms requiring surgery and patients were followed for a mean 21.2 (5.2) months. A total of 23 (47%) patients progressed to symptoms requiring aortic valve replacement and 26 remained asymptomatic. There was no significant difference in age, gender, fractional shortening or the presence or absence of coronary artery disease between these groups. There were differences in peak aortic velocity (P<0.0001), peak and mean pressure drop (P<0.0001), effective orifice area (P=0.03), aortic valve resistance (P=0.001) and pressure drop/flow slope (P<0.0001). On Cox regression analysis, the pressure drop/flow slope (P<0.0001), peak aortic velocity (P=0.005) and peak pressure gradient (P=0.02) were independent predictors. Mean event-free survival at 2 years for peak velocity >4.0 m/s was 17% and for pressure drop/flow slope >0.10 mmHg/ms(-1) was 20%. Of 13 patients reporting symptoms during dobutamine stress, 10 (77%) developed spontaneous symptoms during follow-up compared with 13 of 36 (36%) with no symptoms (P=0.11). The pressure drop/flow slope is a better independent predictor of symptom onset than resistance, mean pressure difference and effective orifice area, but is similar to peak velocity.

Active control of the volume acquisition noise in functional magnetic resonance imaging: method and psychoacoustical evaluation

Functional magnetic resonance imaging (fMRI) provides a noninvasive tool for observing correlates of neural activity in the brain while a subject listens to sound. However, intense acoustic noise is generated in the process of capturing MR images. This noise stimulates the auditory nervous system, limiting the dynamic range available for displaying stimulus-driven activity. The noise is potentially damaging to hearing and is distracting for the subject. In an active noise control (ANC) system, a reference sample of a noise is processed to form a sound which adds destructively with the noise at the listener's ear. We describe an implementation of ANC in the electromagnetically hostile and physically compact MRI scanning environment. First, a prototype system was evaluated psychoacoustically in the laboratory, using the electrical drive to a noise-generating loudspeaker as the reference. This system produced 10-20 dB of subjective noise-reduction between 250 Hz and 1 kHz, and smaller amounts at higher frequencies. The system was modified to operate in a real MR scanner where the reference was obtained by recording the acoustic scanner noise. Objective reduction by 30-40 dB of the most intense component in scanner noises was realized between 500 Hz and 3500 Hz, and subjective reduction of 12 dB and 5 dB in tests at frequencies of 600 Hz and at 1.9 kHz, respectively. Although the benefit of ANC is limited by transmission paths to the cochlea other than air-conduction routes from the auditory meatus, ANC achieves worthwhile attenuation even in the frequency range of maximum bone conduction (1.5-2 kHz). ANC should, therefore, be generally useful during auditory fMRI.

Patent foramen ovale in elderly stroke patients

The aim of this study was to determine the incidence of echocardiographically detectable patent foramen ovale (PFO) in elderly patients who have strokes from cerebral infarction, as well as to assess the association between PFOs and other risk factors for stroke disease. Forty-three patients aged > or = 65 years admitted consecutively with cerebral infarction shown on computerised tomography of the brain were assessed using transoesophageal echocardiography. A PFO was present in 8 (19%) of the 43 patients. Four patients (50%) in this PFO group had stroke risk factors. Two were in atrial fibrillation and, of the six patients in sinus rhythm, a risk factor was present in two, both of whom had diabetes mellitus. A PFO was not detected in 35 patients. Twenty-nine (83%) of the patients in this group had risk factors, with 18 having two or more. Seven patients were in atrial fibrillation. Of the 28 patients in sinus rhythm, risk factors were present in 22 (78%).

Maternal left ventricular transverse and long-axis systolic function during pregnancy

OBJECTIVES

Circumferential fiber shortening has been the dominant basis for conventional analysis by echocardiography of left ventricular systolic function during pregnancy. Results in the literature have been conflicting due mainly to the fact that geometric assumptions for the calculation of these indices are made that may not be valid due to changes in left ventricular shape during pregnancy. Left ventricular long-axis displacement is expected to be a useful index of systolic function, independent of the changes in left ventricular geometry. The aim of this study was to compare circumferential to long-axis shortening during left ventricular contraction in pregnant women.

METHODS

This was a cross-sectional study of 125 pregnant women at 9-42 weeks of gestation and 19 non-pregnant female controls. Two-dimensional and M-mode echocardiography of the left ventricle was performed including measurement of left ventricular long-axis displacement and activation time on the lateral, septal, anterior and inferior sides of the mitral annulus. Activation time was assessed as the time from the start of the Q-wave of the electrocardiogram to the onset of left ventricular long-axis shortening.

RESULTS

Mean arterial pressure and activation time decreased during pregnancy, reaching a nadir at about 19 weeks' gestational age of 4% and 13%, respectively, below non-pregnant values; they subsequently increased towards term. Left ventricular long-axis displacement mirrored the changes in mean arterial pressure and activation time and increased with gestational age at all four sites of the atrioventricular plane reaching a peak at about 23 weeks (+ 12% compared to non-pregnant levels). The ejection fraction and fractional shortening remained stable until 30 and 32 weeks, respectively, and then decreased towards term.

CONCLUSION

Changes in left ventricular long-axis performance during pregnancy occur earlier than do measures of transverse function.

Maternal left ventricular mass and diastolic function during pregnancy

OBJECTIVE

To evaluate changes in left ventricular mass and diastolic function during normal pregnancy.

METHODS

This was a cross-sectional study of 125 pregnant women at 9-42 weeks of gestation and 19 non-pregnant female controls. Two-dimensional and M-mode echocardiography of the maternal left ventricle and left atrium was performed.

RESULTS

During pregnancy left ventricular mass increased by 52%. There was an increase in left ventricular end-diastolic and end-systolic diameters (12% and 20%, respectively), left ventricular posterior wall diameter during diastole and systole (22% and 13%, respectively) and left intraventricular septum during diastole and systole (15% and 19%, respectively). Mitral valve A-wave maximum velocity increased during pregnancy by 19%, while mitral valve E-wave maximum velocity and the ratio of E-wave/A-wave velocities increased early in pregnancy by about 14% and 6%, respectively, with a subsequent decline to 4% and 10%, respectively, below non-pregnant levels.

CONCLUSION

Left ventricular mass increases during pregnancy, while left ventricular diastolic function, as demonstrated by the changes in mitral valve flow velocities, increases in the first two trimesters but declines in the third trimester.

The HCA National Disease Management Program for coronary disease detection and treatment in women

The diagnosis and treatment of heart disease in women continues to be one of the greatest challenges facing cardiovascular medicine today. Marked reductions in mortality rates during the past 2 decades did not result in improved outcomes for women. A major rate-limiting step to improving mortality rates for women is early diagnosis and initiation of effective lifesaving therapies for women. In 1999, HCA Healthcare Systems, Inc, Nashville, TN, initiated a coordinated effort among 208 hospitals in 26 states to improve the diagnosis of coronary disease and to target women who should receive aggressive risk factor modification and referral to cardiologists. We describe the initial phases of program development, including employee risk factor screening; citywide health risk assessment; nationwide educational programs for clinicians, staff, and consumers; and a dedicated outcomes assessment program for tracking women at risk for coronary disease. We believe that these efforts provide a venue for optimal care and improved outcomes for women served by HCA facilities.

Long axis excursion in aortic stenosis

OBJECTIVES

To examine long axis excursion in patients with all grades of aortic stenosis and preserved transverse systolic function, and to compare long axis excursion in symptomatic with that in asymptomatic severe aortic stenosis.

DESIGN

Prospective comparative study.

SETTING

Regional cardiothoracic centre.

PATIENTS

78 patients with all grades of aortic stenosis and normal fractional shortening and ejection fraction were studied. There were two comparison groups, 10 age matched normal subjects and 14 patients with aortic stenosis and fractional shortening < 26%.

METHODS

Aortic valve function and left ventricular mass were assessed echocardiographically. M mode measurements of long axis excursion at the septal and lateral sides of the mitral annulus were taken.

RESULTS

There were significant differences between the groups in long axis excursion at both the septal (p < 0.0001) and lateral sides of the mitral annulus (p = 0.002 by analysis of variance). Long axis excursion was independently related to both left ventricular mass index (p = 0.001) and the grade of aortic stenosis (p = 0.002). Comparing patients with severe aortic stenosis with and without symptoms, there were significant differences in effective orifice area (p = 0.02 ) and long axis excursion at the lateral side of the mitral annulus (p = 0.04), but not in fractional shortening, ejection fraction, or peak or mean pressure difference.

CONCLUSION

In patients with aortic stenosis, long axis excursion is reduced even in the presence of normal fractional shortening or ejection fraction. It is lower in patients with symptomatic compared with asymptomatic severe aortic stenosis and may be of use in predicting the onset of symptoms.

Long axis excursion in aortic stenosis

OBJECTIVES

To examine long axis excursion in patients with all grades of aortic stenosis and preserved transverse systolic function, and to compare long axis excursion in symptomatic with that in asymptomatic severe aortic stenosis.

DESIGN

Prospective comparative study.

SETTING

Regional cardiothoracic centre.

PATIENTS

78 patients with all grades of aortic stenosis and normal fractional shortening and ejection fraction were studied. There were two comparison groups, 10 age matched normal subjects and 14 patients with aortic stenosis and fractional shortening < 26%.

METHODS

Aortic valve function and left ventricular mass were assessed echocardiographically. M mode measurements of long axis excursion at the septal and lateral sides of the mitral annulus were taken.

RESULTS

There were significant differences between the groups in long axis excursion at both the septal (p < 0.0001) and lateral sides of the mitral annulus (p = 0.002 by analysis of variance). Long axis excursion was independently related to both left ventricular mass index (p = 0.001) and the grade of aortic stenosis (p = 0.002). Comparing patients with severe aortic stenosis with and without symptoms, there were significant differences in effective orifice area (p = 0.02 ) and long axis excursion at the lateral side of the mitral annulus (p = 0.04), but not in fractional shortening, ejection fraction, or peak or mean pressure difference.

CONCLUSION

In patients with aortic stenosis, long axis excursion is reduced even in the presence of normal fractional shortening or ejection fraction. It is lower in patients with symptomatic compared with asymptomatic severe aortic stenosis and may be of use in predicting the onset of symptoms.

A cybernetic theory of morality and moral autonomy

Human morality may be thought of as a negative feedback control system in which moral rules are reference values, and moral disapproval, blame, and punishment are forms of negative feedback given for violations of the moral rules. In such a system, if moral agents held each other accountable, moral norms would be enforced effectively. However, even a properly functioning social negative feedback system could not explain acts in which individual agents uphold moral rules in the face of contrary social pressure. Dr. Frances Kelsey, who withheld FDA approval for thalidomide against intense social pressure, is an example of the degree of individual moral autonomy possible in a hostile environment. Such extreme moral autonomy is possible only if there is internal, psychological negative feedback, in addition to external, social feedback. Such a cybernetic model of morality and moral autonomy is consistent with certain aspects of classical ethical theories.

The interaction of perceived maternal and paternal parenting styles and their relation with the psychological distress and offending characteristics of incarcerated young offenders

A shortened form of the Parental Bonding Instrument (PBI) (Pederson, 1994) was used to examine the relationship between parenting styles and the psychological distress and offending patterns of a group of young male offenders held in custody in Scotland. High levels of psychological distress were linked with low parental care, but there was no association between psychological distress and parental control. Parental care was not a distinguishing factor in offending patterns, although high paternal control was linked with a younger age of first arrest. When interactions of paternal and maternal parenting styles were examined, young offenders who perceived poor parenting (i.e. neglectful parenting or affectionless control) from both parents had the highest levels of psychological distress overall.

The clinical and diagnostic features of mitral valve disease

Mitral valve disease remains common, and requires regular clinical and echocardiographic review. Surgery is indicated soon after the development of symptoms or at the first sign of left ventricular decompensation in mitral regurgitation or of the right ventricle in mitral stenosis.

Biochemical markers in the management of suspected acute myocardial infarction in the emergency department

OBJECTIVES

To compare cardiac troponin T, myoglobin, CK, CKMB activity, CKMB mass and the initial electrocardiogram in the early diagnosis of myocardial infarction in the emergency department. Methods-Biochemical markers were measured at presentation in patients with a possible diagnosis of acute myocardial infarction. Based on the clinical notes, patients were grouped as "definite myocardial infarction" (n = 50), "definite no myocardial infarction" (n = 81) and "uncertain" (n = 96). Sensitivity and specificity and positive and negative predictive values were calculated using the 131 patients with definitely present or absent myocardial infarction.

RESULTS

The initial electrocardiogram was more sensitive than any of the markers in the first six hours from symptom onset-sensitivity 74% (95%CI 61% to 88%). The positive predictive value of the initial electrocardiogram was 97% in the first six hours; the markers ranged from 47% to 67%. The negative predictive value of the initial electrocardiogram was 85% in the first six hours; the markers ranged from 61% to 70%. Four patients with non-diagnostic electrocardiograms presenting beyond six hours after pain onset had a myocardial infarct detected by at least three of the biochemical markers in each case.

CONCLUSIONS

The electrocardiogram is of more diagnostic use than biochemical markers in the first six hours after the onset of pain, but biochemical markers give additional positive diagnostic information in patients presenting later than this. The negative predictive accuracy of biochemical markers is too low for a single sample to be useful for excluding myocardial infarction in the first six hours after onset of symptoms.

Immunohistochemical localization of the P2Y1 purinergic receptor in Alzheimer's disease

The biological actions of extracellular nucleotides are mediated by two distinct classes of P2 receptor, P2X and P2Y. The G protein-coupled P2Y receptors comprise five mammalian subtypes, P2Y(1-11). The P2Y1 subtype is expressed abundantly throughout the human brain and is specifically localized to neuronal structures. In the present study, the distribution of the P2Y1 receptor was investigated in Alzheimer's disease (AD) brains. In contrast to control human brain, the P2Y1 receptor was localized to a number of characteristic AD structures such as neurofibrillary tangles, neuritic plaques and neuropil threads. Immunoblot analysis showed that this specific immunostaining observed over tangles was not a result of cross-reactivity between the anti-P2Y1 antiserum and abnormal tau protein, the major constituent of tangles. The significance of this altered P2Y1 cellular distribution in AD brains is at present unclear.

The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination

Significant aortic stenosis is prevalent amongst elderly people. It may be subclinical, manifesting only as a murmur, but can still cause unexpected death with little warning after symptoms develop. Recent studies have highlighted the unreliability of the classical clinical signs of severe aortic stenosis, leading to concern that some patients may not be referred appropriately for echocardiography. Here, we review the evidence for the accuracy of each sign. We suggest that the assessment of the patient with a systolic murmur should be reappraised, and offer guidelines toward improving the recognition of aortic stenosis in the community.

Does the multidimensional nature of Super Profiles help district health authorities understand the way social capital affects health?

BACKGROUND

Social capital describes the notion that the social processes in an area can lead to benefits in health. As Super Profiles describe the social character of an area and they are easy for health authorities to use, they could provide a simple method for local assessment of how social organization affects health.

METHODS

We calculated the expected mean birthweight for the enumeration districts of Birmingham based upon marital status, registration details of the child, year of birth, the mother's country of birth, fetal sex and deprivation as judged by the Townsend score using data from 138,696 live-born singleton births for the years 1986-1996 inclusive. We classified enumeration districts into Target Markets, derived from Super Profiles. For each Target Market, we calculated the observed mean birthweight and the difference and 95 per cent confidence interval between the observed and expected birthweights. We used information in Super Profiles to speculate about the social processes that led to some Target Markets having mean birthweights that were significantly different from those expected.

RESULTS

Fifteen of the 40 Target Markets had significant differences between predicted and observed mean birthweight, but these differences were less than 50 g. There were no common characteristics of Target Markets that were consistently advantageous for birthweight and none that were disadvantageous.

CONCLUSION

The information in the Super Profiles does not illuminate the way that social processes affect health, and the variation in mean birthweight between areas explained by social processes as measured by Super Profiles is small.

QT dispersion in microalbuminuric Type 1 diabetic patients without myocardial ischemia

Microalbuminuria is associated with an increased risk of cardiac death. We assessed whether urinary albumin excretion is related to abnormalities of the QT interval independently of myocardial ischemia. Thirty-four patients with type 1 diabetes who were free from ischemic heart disease on the basis of normal stress electrocardiography and echocardiography were studied. Maximal QT interval and dispersion were significantly greater in the group with microalbuminuria (n=17) compared to controls (n=17) with normal urinary albumin excretion (394 [26.1] vs. 373.8 [27.8] ms; P=.044 and 62.4 [21.8] vs. 42.7[11.6] arbitrary units; P=.009). Autonomic function was similar between the groups. Urinary albumin excretion correlated positively with QT dispersion (P=.023). These data suggest that in type 1 diabetic patients, QT abnormalities can occur independently of autonomic dysfunction or myocardial ischemia and may be related to the processes which increase urinary albumin leakage.

An echocardiographic description of the Sulzer Carbomedics Synergy ST (Labcor) porcine valve in the aortic position

BACKGROUND AND AIM OF THE STUDY

The Synergy ST (previously Labcor) valve is constructed from three separate porcine aortic cusps mounted on a scalloped, flexible, acetal copolymer stent. To date, no hemodynamic data describing this valve have been published. The aim of this study was to describe the echocardiographic findings in a population of unselected patients.

METHODS

One investigator, who was blinded to valve size, studied 84 patients (31 females, 53 males; mean age 58 years; range: 19-83 years) at four centers in Brazil. The valves were studied at a mean of 31 months after implantation (range: 1-116 months). Mean gradient was calculated using the long modified Bernoulli equation, effective orifice area (EOA) using the classical from of the continuity equation, and resistance as mean gradient/flow.

RESULTS

There were no significant differences in peak transaortic velocity and mean gradient between valves of different annulus size. However, EOA was directly related (p = 0.0075) and resistance indirectly related to valve size (p = 0.021, ANOVA). Trivial or mild regurgitation was seen in 31 patients (37%), moderate in three (4%) and severe in two (2%). The regurgitation was solely paraprosthetic in five patients, solely through the valve in 23, and both in seven. Regurgitation through the valve usually occurred adjacent to the commissures.

CONCLUSION

The Synergy ST porcine valve has hemodynamics of forward flow similar to that of other stented porcine valves.

Regional and cellular distribution of the P2Y(1) purinergic receptor in the human brain: striking neuronal localisation

The biological actions of extracellular nucleotides are exerted via two families of P2 receptors, P2X and P2Y. The metabotropic P2Y receptors comprise at least 7 distinct subtypes, which have been cloned from a number of species. However, none of the P2Y receptor proteins have been visualised yet in human brain. In the present study, the regional and cellular distribution of the P2Y(1) receptor was investigated in the human brain by using immunohistochemistry. Polyclonal antibodies were raised against a synthetic peptide from the C-terminus of the P2Y(1) protein. Immunoblot analysis demonstrated that P2Y(1) antiserum specifically recognised a 63-kDa band in human and rat brain membranes. Similarly, the antiserum specifically detected the human P2Y(1) receptor in transfected 1321N1 cells. Immunohistochemical analysis on perfusion-fixed human brain tissue showed a widespread distribution for this receptor throughout the brain. At the cellular level, the P2Y(1) receptor was strikingly localised to neuronal structures of the cerebral cortex, cerebellar cortex, hippocampus, caudate nucleus, putamen, globus pallidus, subthalamic nucleus, red nucleus, and midbrain. Expression of the P2Y(1) receptor was not detected in other non-neuronal cell types. These results provide the first characterisation of the cellular distribution of a P2Y receptor in the human brain. The widespread and abundant distribution of the P2Y(1) receptor suggests its involvement in a number of important functions within the human brain. The neuronal localisation of this receptor points towards a possible role in neurotransmission, and also highlights a major role for extracellular nucleotides as signaling molecules within the brain.

When is an aortic valve prosthesis too small? The need for dobutamine stress echocardiography

We describe a patient who had undergone aortic valve replacement with a small prosthesis 10 years previously and who presented with exertional breathlessness. The resting transaortic pressure gradient was only 30 mmHg but increased to 165 mmHg on dobutamine stress. Conventional resting echocardiography may fail to demonstrate abnormal prosthetic aortic valve function; in the presence of symptoms, dobutamine stress echocardiography should be considered.

Heterozygous MDR3 missense mutation associated with intrahepatic cholestasis of pregnancy: evidence for a defect in protein trafficking

Intrahepatic cholestasis of pregnancy (ICP) is a liver disease of pregnancy with serious consequences for the mother and fetus. Two pedigrees have been reported with ICP in the mothers of children with a subtype of autosomal recessive progressive familial intrahepatic cholestasis (PFIC) with raised serum gamma-glutamyl transpeptidase (gamma-GT). Affected children have homozygous mutations in the MDR3 gene (also called ABCB4 ), and heterozygous mothers have ICP. More frequently, however, ICP occurs in women with no known family history of PFIC and the genetic basis of this disorder is unknown. We investigated eight women with ICP and raised serum gamma-GT, but with no known family history of PFIC. DNA sequence analysis revealed a C to A transversion in codon 546 in exon 14 of MDR3 in one patient, which results in the missense substitution of the wild-type alanine with an aspartic acid. We performed functional studies of this mutation introduced into MDR1, a closely related homologue of MDR3. Fluorescence activated cell sorting (FACS) and western analysis indicated that this missense mutation causes disruption of protein trafficking with a subsequent lack of functional protein at the cell surface. The demonstration of a heterozygous missense mutation in the MDR3 gene in a patient with ICP with no known family history of PFIC, analysed by functional studies, is a novel finding. This shows that MDR3 mutations are responsible for the additional phenotype of ICP in a subgroup of women with raised gamma-GT.