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Biomedical subjects

Greg D Gamble

Publications and source records attributed to Greg D Gamble.

At least 19 recordsLinked to original sources
PubMed2007

Annual zoledronate increases bone density in highly active antiretroviral therapy-treated human immunodeficiency virus-infected men: a randomized controlled trial.

CONTEXT: Recent studies have reported low bone mineral density (BMD) in HIV-infected patients. Annual iv administration of 4 mg zoledronate has been shown to increase BMD and suppress bone turnover in postmenopausal women. OBJECTIVE: The objective of the study was to determine whether annual administration of 4 mg zoledronate will increase BMD in HIV-infected men receiving highly active antiretroviral therapy. DESIGN AND SETTING: A 2-yr randomized placebo-controlled trial was conducted in a clinical research center. PARTICIPANTS: A total of 43 HIV-infected men were treated with highly active antiretroviral therapy for at least 3 months, with BMD T score less than -0.5. INTERVENTION: Participants received annual iv administration of 4 mg zoledronate or placebo. All participants took 400 mg/d calcium and 1.25 mg/month vitamin D. MEASUREMENTS: BMD at the lumbar spine, total hip and total body, and bone turnover markers were measured. RESULTS: At the lumbar spine, BMD increased by 8.9% over 2 yr in the zoledronate group compared with an increase of 2.6% in the control group (P<0.001). At the total hip, BMD increased by 3.8% over 2 yr in the zoledronate group compared with a decrease of 0.8% in the control group (P<0.001). At the total body, BMD increased by 2.3% over 2 yr compared with a decrease of 0.5% in the control group (P<0.001). Urine N-telopeptide decreased by 60% at 3 months in the zoledronate group and thereafter remained stable. CONCLUSIONS: Annual administration of zoledronate is a potent and effective therapy for the prevention or treatment of bone loss in HIV-infected men. The current data provide the first trial evidence of the BMD effects of annual zoledronate beyond 1 yr in any population, as well as being the first reported trial in men.

Adult↗
PubMed2007

Delayed development of Paget's disease in offspring inheriting SQSTM1 mutations.

UNLABELLED: Familial Paget's disease is associated with mutations in SQSTM1. We compared the age at diagnosis and severity of Paget's disease in parents with SQSTM1 mutations to their offspring who inherited a mutation. At any given age, the offspring were less likely to be diagnosed with Paget's disease and had less severe disease than their parents. INTRODUCTION: Mutations in sequestosome 1 (SQSTM1) occur in 25-50% of cases of familial Paget's disease and are thought to be disease-causing. We sought to determine whether there are differences in age at diagnosis and severity of disease in parents and their offspring who share the same genetic predisposition to Paget's disease. MATERIALS AND METHODS: Eighty-four offspring from 10 families (29 index patients with Paget's disease) with mutations in SQSTM1 were approached, and 58 agreed to participate. The ubiquitin-binding domain region of SQSTM1 was sequenced, and the presence or absence of the known mutation was established. The presence of Paget's disease in offspring who had inherited an SQSTM1 mutation was determined by bone scintigraphy and measurement of serum alkaline phosphatase (ALP). RESULTS: Twenty-three of 58 offspring had inherited a germline mutation in SQSTM1. The mean ALP was 77 U/liter in offspring with mutations and 72 U/liter in those without mutations (p=0.84). Scintiscans from four offspring (mean age, 45 years; mean ALP, 139 U/liter; mean skeletal involvement, 6%) showed evidence of Paget's disease but were normal in the other 19 (mean age, 44 years; mean ALP, 64 U/liter). In comparison, in the 15 parents of the 23 offspring, the mean age of diagnosis was 48 years, the mean ALP was 850 U/liter, and the mean skeletal involvement was 30%. There was a 63% reduction in the risk of being diagnosed with Paget's disease at a comparable age in the offspring compared with the parents (p=0.028). CONCLUSIONS: Only 17% of offspring inheriting an SQSTM1 mutation had evidence of Paget's disease on scintigraphy, and this was diagnosed at a later age and was less extensive than in their affected parents. SQSTM1 thus shows incomplete penetrance. The data are consistent with the hypothesis that an environmental factor is important in the pathogenesis and clinical phenotype of familial Paget's disease and that exposure to this factor may be falling.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Does rhythm matter? The prognostic importance of atrial fibrillation in heart failure.

BACKGROUND: Atrial fibrillation (AF) and congestive heart failure (HF) often coexist, but there is conflicting data regarding the association of AF with outcome in HF. To examine this further we have evaluated the prognostic effect of AF in two complementary CHF populations; a population based data set of 55,106 patients admitted to hospital with CHF, and a cohort of 197 patients recruited after a hospital admission with HF into a management clinical trial. METHODS: Firstly, data for all hospital admissions in New Zealand from 1988 to 1997 were obtained. Using coding data, 55,106 first admissions for HF were identified, the presence of AF was determined by secondary diagnosis coding, and all cause mortality was obtained. Secondly, patients enrolled in the Auckland Heart Failure Management Study were evaluated for the presence or absence of AF, and for all cause mortality at three years. RESULTS: Mortality at 30 days, 6 and 12 months was significantly lower for AF patients compared to sinus rhythm (SR) in the national admissions cohort. In the clinical trial cohort the presence of AF was also associated with lower three-year mortality, although this difference was not seen when the groups were stratified by Doppler mitral filling pattern (a restrictive filling pattern was associated with reduced longevity compared to SR, non-restrictive or AF). CONCLUSIONS: This data shows that the presence of AF in two general HF populations in New Zealand is not associated with an adverse prognosis. HF severity, and in particular a restrictive filling pattern, remain powerful predictors of mortality.

Aged↗
PubMed2006

The prognostic significance of restrictive diastolic filling associated with heart failure: a meta-analysis.

BACKGROUND: Several studies have reported that the presence of a restrictive filling pattern (RFP) is associated with poor outcome in patients with heart failure (HF). These studies, of variable sample size, have involved different HF patient groups with variable associated mortality rates and follow-up times, and while powered for effects on combined end-points such as death or hospital admission, many were underpowered to reliably determine the overall effect of the RFP on total mortality. Consequently, we performed a meta-analysis to determine the mortality associated with RFP in patients with HF. METHODS: We searched several online medical databases for prospective studies of patients with HF. All authors were requested to confirm their data. All-cause mortality was compared between RFP and non-restrictive filling patterns (Non-RFP). Review Manager version 4.2.7 software was used for the analysis. RESULTS: 3024 patients in 27 studies were identified (379 idiopathic cardiomyopathy, 2645 mixed aetiology HF). Average follow-up was between 3 months and 5 years. 1284 (42%) patients had RFP at baseline. 688 deaths occurred and the overall odds ratio for death was 4.36 (CI 3.60, 5.04); idiopathic group: 6.65 (CI 3.86, 11.47); mixed aetiology group: 4.10 (CI 3.34, 5.04). The overall odds ratio for death/transplantation was 4.87 (CI 4.04, 5.86); idiopathic group: 7.62 (CI 4.50, 12.92); mixed aetiology group: 4.56 (CI 3.74, 5.56). CONCLUSIONS: Restrictive filling pattern is associated with a four-fold increase in mortality in patients with HF and thus should be an important part of the echocardiographic assessment of such patients.

Adult↗
PubMed2006

Regional correlation of structure and function in glaucoma, using the Disc Damage Likelihood Scale, Heidelberg Retina Tomograph, and visual fields.

PURPOSE: To evaluate relationships between the Disc Damage Likelihood Scale (DDLS), global and sectoral structural parameters provided by the Heidelberg Retina Tomograph (HRT), and global and regional functional loss in visual field (VF) testing. DESIGN: Consecutive observational case series. PARTICIPANTS: One hundred ten eyes from 110 patients categorized as glaucoma, glaucoma suspect, or normal. METHODS: Participants were examined clinically to grade the DDLS score and were tested with HRT and Swedish Interactive Threshold Algorithm standard 24-2 VF tests. All tests were performed within 6 months of each other by examiners masked to the other findings. For each patient, the eye with the worse mean deviation (MD) of the VF test was enrolled in the study. Each field was divided into 6 sectors based on a published scheme, and the MD for each sector was calculated. The relationships among clinical DDLS score, HRT parameters, and VF indexes were analyzed by correlation coefficients and linear regression analysis. MAIN OUTCOME MEASURES: The relationship between the DDLS score, global and sectoral optic disc (HRT) parameters, and global and sectoral VF MDs was evaluated. RESULTS: The DDLS showed significant correlation with all global and sectoral VF indexes (r = -0.39 to -0.62, all Ps < 0.0001) and with sectoral rim area HRT measurements (r = -0.27 to -0.51, all Ps < 0.006). The DDLS correlated most strongly with superior and inferior regional data from HRT and VF, and less well with temporal and nasal data. Heidelberg Retina Tomograph rim area and rim volume were the only HRT parameters to correlate moderately with global VF MD (r = 0.30, P = 0.0018, and r = 0.28, P = 0.0030, respectively). Sectoral HRT rim area correlated moderately strongly with the corresponding sectoral VF MDs in the superior and inferior sectors (r = 0.35-0.46, P = <0.0001-0.04). CONCLUSION: Clinical disc assessment and laser tomographic data that determine the state of the neuroretinal rim are associated with sensitivity loss in VF testing in corresponding regions.

Adolescent↗
PubMed2006

Bone mineral density is not reduced in HIV-infected Caucasian men treated with highly active antiretroviral therapy.

OBJECTIVE: Recent studies have reported low bone mineral density (BMD) in patients infected with human immunodeficiency virus (HIV). Frequently these findings have been attributed to treatment with highly active antiretroviral therapy (HAART). We sought to determine whether BMD in HIV-infected men treated with HAART for at least 3 months is different from that in healthy controls, and, if so, what HIV-related factors might explain this finding. DESIGN: Cross-sectional analysis. PATIENTS: Fifty-nine HIV-infected Caucasian men treated with HAART, and 118 healthy community-dwelling controls. Each HIV-infected man was age-matched (within 5 years) to two controls. MEASUREMENTS: All participants had measurements of BMD and bone-related laboratory parameters. RESULTS: The mean duration of known HIV infection was 8.5 years, and of treatment with HAART was 52 months. There was no significant difference in mean BMD between groups at the lumbar spine (HIV group: 1.23 g/cm2, controls: 1.25 g/cm2; P = 0.53) or total body (HIV group: 1.18 g/cm2, controls: 1.20 g/cm2; P = 0.09). At the total hip the HIV-infected group had significantly lower BMD than the control group (HIV group: 1.03 g/cm2, controls: 1.09 g/cm2; P = 0.01). The HIV-infected group were, on average, 6.3 kg lighter than the controls. After adjusting for this weight difference, HIV infection was not an independent predictor of BMD at any site (lumbar spine P = 0.79; total hip P = 0.18; total body P = 0.76). CONCLUSIONS: HIV-infected men treated with HAART are lighter than healthy controls. This weight difference is responsible for a small decrement in hip BMD. Overall, BMD is not significantly reduced in HIV-infected Caucasian men treated with HAART.

Analysis of Variance↗
PubMed2006

Correlation of the multifocal visual evoked potential and standard automated perimetry in compressive optic neuropathies.

PURPOSE: To evaluate the relationship between abnormalities detected by the multifocal visual-evoked potential (mfVEP) compared with those detected by static achromatic automated perimetry in patients with compressive optic neuropathy. METHODS: Fifteen patients of mean age 50.8 years, with known compressive optic neuropathy from chiasmal lesions, underwent monocular mfVEP and 24-2 SITA-standard Humphrey visual field (HVF; Carl Zeiss Meditec, Dublin CA) testing in each eye. Visual field spatial agreement and extent of involvement were analyzed by assigning a severity score to each quadrant, based on pattern deviation and amplitude deviation probability plots. RESULTS: HVF mean deviation (MD) was -6.54 +/- 7.43 dB (mean), and the mfVEP mean AccuMap Severity Index (ASI; ObjectiVision Pty. Ltd., Sydney, Australia) score was 81 +/- 74. MD and ASI correlated significantly (r = -0.55, P = 0.024). Although both mfVEP and HVF reported approximately the same proportion of visual fields as abnormal (70%, 21/30, and 87%, 26/30, respectively), 19% (5/26) with abnormal HVF were labeled normal or borderline by mfVEP. The agreement for field quadrants between instruments was 69% (kappa = 0.33). mfVEP severity scores for quadrants and hemifields were higher than scores for HVF in the same eyes. The superotemporal quadrant showed the strongest correlation between techniques (r = 0.73, P = 0.002). CONCLUSIONS: In the first study to compare mfVEP to HVF in patients with compressive optic neuropathy, there was good qualitative and quantitative agreement between tests, though findings were in only modest agreement in some areas. The injury caused by compressive optic neuropathy may be usefully identified by mfVEP. Improved methods of analysis may increase the diagnostic utility of the method.

Evoked Potentials, Visual↗
PubMed2005

Fat mass is an important predictor of parathyroid hormone levels in postmenopausal women.

Previously, we reported that people with elevated parathyroid hormone (PTH) levels due to primary hyperparathyroidism have increased body weight compared to eucalcemic controls. We sought to determine whether the same relationship between PTH and body weight exists in eucalcemic healthy postmenopausal women, and to investigate the relationships between components of body weight, PTH, vitamin D metabolites, and metabolic indices. We performed a cross-sectional analysis of 116 healthy community-dwelling postmenopausal women. Pearson correlation analysis was used to test for univariate linear relationships between variables, and stepwise multiple regression analysis to assess for multivariate relationships. We found that PTH was significantly positively correlated with body weight, regional and total fat mass, and percent body fat, and negatively correlated with activity levels, 25 hydroxyvitamin D (25OHD), dietary calcium intake, and serum phosphate. On multivariate analysis, PTH was positively related to percent body fat (P = 0.020; partial r2 = 0.10) and negatively related to dietary calcium intake (P = 0.041; partial r2 = 0.03) and serum phosphate (P = 0.026; partial r2 = 0.04). Adjusting for vitamin D insufficiency or 25OHD levels did not affect the relationship between PTH and fat mass. For 25OHD, there were significant positive correlations with lumbar spine BMD and serum albumin, and significant negative correlations with PTH, total fat mass, trunk fat, and pelvic fat. On multivariate analysis, 25OHD was positively related to serum albumin (P = 0.008; partial r2 = 0.07) and negatively related to pelvic fat mass (P = 0.014; partial r2 = 0.05). Adjusting for PTH levels did not change the relationship between 25OHD and pelvic fat mass. We conclude that fat mass is a significant independent determinant of serum PTH levels, and that this relationship is independent of the inverse relationship between 25OHD and fat mass. This association between fat mass and PTH might contribute to the association between primary hyperparathyroidism and increased body weight.

Adipose Tissue↗
PubMed2005

Determinants of vitamin D status in older women living in a subtropical climate.

Studies performed in the Northern Hemisphere and in areas distant from the equator have demonstrated significant seasonal variation in 25-hydroxyvitamin D (25OHD) levels. Whether such variation occurs in a subtropical area such as Australasia is not clear. We performed a cross-sectional study of 1,606 healthy, postmenopausal women recruited over a 33-month period. The study had three goals: to determine the normal levels of 25OHD in healthy postmenopausal women living in Auckland, New Zealand; to determine whether seasonal variation of 25OHD occurs at this latitude; to assess the relationship between 25OHD, biochemical indices, anthropometric variables and bone mineral density (BMD). We found significant seasonal variation in 25OHD levels, with the change in monthly ultraviolet dose from summer to winter being followed 6-8 weeks later by a corresponding change in 25OHD levels. Vitamin D insufficiency (25OHD <50 nmol/l) was common. During summer, 28-58% of participants had suboptimal vitamin D status, while in winter, the frequency increased to 56-74%. 25OHD levels correlated with participants' age (r=-0.15), weight (r=-0.11), body mass index (r=-0.13), fat mass (r=-0.14), percentage body fat (r=-0.16), physical activity (r=0.10) and the month of blood sampling (all P<0.0001). Collectively, age, fat mass, physical activity, and month of sampling explained 21% of the variance in 25OHD. No significant relationships were noted between 25OHD and BMD at any site. Other variables that showed significant monthly variation were glucose (P=0.002), serum phosphate, alkaline phosphatase, and albumin (all P<0.0001). There was no monthly variation in BMD at the lumbar spine or proximal femur. In conclusion, there is significant seasonal variation in 25OHD levels, even in a subtropical climate. Furthermore, despite generous amounts of sunlight, considerable numbers of women have suboptimal vitamin D status, even in summer. Our findings support the suggestion that vitamin D supplementation should become standard practice in this population of women, particularly during winter.

Adipose Tissue↗
PubMed2005

Comparison of different methods for detection of diastolic filling abnormalities.

OBJECTIVE: Heart failure is associated with poor prognosis and the differentiation of patients on the basis of diastolic filling patterns helps to identify several groups of patients with incrementally higher risk. However, this is reliant on accurate definition of filling patterns. The aim of this study was to compare preload reduction with contrast-enhanced pulmonary venous Doppler recordings for the correct assessment of diastolic filling pattern. METHODS: In all, 20 patients with heart failure and 25 healthy volunteers were studied on 2 separate days. Preload reduction was achieved with the Valsalva maneuver (nonstandardized and standardized) and sublingual nitroglycerin. Responses were compared among the 3 methods and the filling patterns obtained on each day with the various methods compared. RESULTS: Although pulmonary venous Doppler improved the diastolic classification over mitral Doppler, preload reduction resulted in better classification and improved sensitivity, specificity, and positive and negative predictive values. No advantage was observed for either the standardized Valsalva or pharmacologic preload reduction. CONCLUSION: Preload reduction is an essential part of the assessment of diastolic filling grade in patients with heart failure as it can identify pseudonormal filling (mildly increased filling pressures), reversible restrictive filling (high filling pressures), and nonreversible restrictive filling pattern (very high filling pressures).

Aged↗
PubMed2005

Quantitative evaluation of regional endocardial visualisation with second harmonic imaging and contrast left ventricular opacification in heart failure patients.

AIMS: Wall motion score index (WMSI) is an important prognostic indicator in heart failure (HF) patients but requires endocardial visualisation. This study evaluated the role tissue harmonic imaging (THI) and contrast opacification (LVO) for improving endocardial visualisation and the determination of WMSI in HF patients. METHODS AND RESULTS: Thirty-one HF patients and 30 controls underwent apical echocardiography with fundamental imaging (FUND), THI and THI with contrast agent (Levovist). Visualisation and motion were graded in the six segments from each of the apical two and four chamber views. Both THI and LVO reduced the percentage of non-visualised segments (FUND 13.6%, THI 5.6%, LVO 2.8%, p=0.01) in the controls, but in HF patients, only THI improved visualisation (% segments not visualised FUND 9.7%, THI 3.5%, LVO 4.8%, p=0.06). The anterior and lateral walls were the least well visualised with FUND, but improved with LVO (anterior p=0.0026, lateral p=0.0003). No improvement was seen in the inferior wall (p=0.30) or septum (p=0.2). WMSI was similar by all methods and negatively correlated with ejection fraction (FUND r=-0.69, THI r=-0.74, LVO r=-0.77, all p<0.001). CONCLUSION: THI improved endocardial visualisation in all subjects and LVO offered additional benefit in the controls, but not in HF patients. Regional endocardial visualisation was inconsistent. Thus, both patient factors and wall segment site need to be considered when using contrast agents for endocardial visualisation.

Case-Control Studies↗
PubMed2005

Comparison of arteritis and nonarteritic anterior ischemic optic neuropathies with the Heidelberg Retina Tomograph.

OBJECTIVE: Quantitative data are not available regarding the morphological appearance of optic nerve morphology after arteritic anterior ischemic optic neuropathy (AAION) and nonarteritic anterior ischemic optic neuropathy (NAION). The purpose of this study is to evaluate the appearance of the optic nerve head in patients after AAION and NAION with the Heidelberg Retina Tomograph (HRT). DESIGN: Prospective comparative observational study. PARTICIPANTS: Thirty-eight patients with either unilateral AAION (15) or NAION (23). METHODS: Heidelberg Retina Tomograph images were taken of both affected and unaffected eyes. The quantitative changes in the optic nerve head were morphologically evaluated and compared with those of the normal contralateral eyes. MAIN OUTCOME MEASURES: Heidelberg Retina Tomograph parameters were analyzed using the uninvolved contralateral eye as a control. RESULTS: The ratio between cup area and disc area was 42% larger in the affected eyes in the NAION group than in the fellow eyes (P = 0.03, t test). In the AAION patients, the ratio between cup area and disc area was 116% larger in involved eyes than in their fellow eyes (P = 0.0003, t test). In addition, in the AAION group, relative to their fellow eyes, the rim area was 27% smaller (P = 0.0006), cup volume was 160% larger (P = 0.021, t test), mean cup depth was 29% larger, cup shape measure differed by 41% (suggesting more excavation), and mean retinal nerve fiber layer thickness was 30% less. Relative to the fellow eyes in the NAION group, the rim area was 6% smaller (P = 0.13, Student's t test), and the cup shape measure was 13% different, although these were not statistically significant. When the uninvolved eyes of the NAION and AAION groups were compared directly, there was no statistical difference between any of the HRT parameters, except mean cup depth (0.09 vs. 0.14 mm, respectively; P = 0.02). CONCLUSIONS: This study is the first to demonstrate quantitatively an enlargement and excavation of the optic cup after an event of AAION, but not NAION. The eyes affected with AAION showed significant excavation and enlargement of the optic cup when compared with contralateral uninvolved eyes. All HRT-generated parameters showed changes consistent with increased enlargement and excavation of AAION-involved eyes. These changes were not observed in eyes that experienced an event of NAION.

Aged↗
PubMed2004

Association between primary hyperparathyroidism and increased body weight: a meta-analysis.

Although primary hyperparathyroidism is frequently asymptomatic, it has been associated with an increased prevalence of hypertension, insulin resistance, dyslipidemia, cardiovascular mortality, and cancer. Previously we reported that patients with primary hyperparathyroidism are heavier than age-matched controls. Increased body weight could contribute to the association between primary hyperparathyroidism and these extraskeletal complications. We searched MEDLINE for English language studies published between 1975 and 2003 that reported body weight or body mass index in subjects with primary hyperparathyroidism and a healthy age- and sex-comparable eucalcemic control group. Seventeen eligible studies were identified. Subjects with primary hyperparathyroidism were 3.34 kg (95% confidence interval, 1.97-4.71; P < 0.00001) heavier than controls in 13 studies reporting body weight. In four studies reporting body mass index, subjects with primary hyperparathyroidism had an increased body mass index of 1.13 kg/m(2) (-0.29 to 2.55; P = 0.12) compared with controls. Standard mean difference analysis showed that subjects with primary hyperparathyroidism had an increased weight or body mass index of 0.3 sd (0.19-0.40; P < 0.00001) compared with controls. We conclude that patients with primary hyperparathyroidism are heavier than their eucalcemic peers, and that increased body weight may contribute to the reported associations between primary hyperparathyroidism and some extraskeletal complications.

Body Weight↗
PubMed2004

Three-dimensional assessment of left ventricular systolic strain in patients with type 2 diabetes mellitus, diastolic dysfunction, and normal ejection fraction.

Left ventricular (LV) diastolic dysfunction often occurs in patients with type 2 diabetes mellitus (DM) independent of atherosclerotic coronary artery disease, myocardial ischemia, and regional wall motion anomalies. Limited information exists on LV myocardial tissue strain in this patient group. We measured 3-dimensional (3-D) parameters of LV systolic and diastolic functions in 28 patients who had type 2 DM (age 33 to 70 years), standard echocardiographic evidence of LV diastolic dysfunction, and normal LV ejection fraction, and 31 normal control subjects (age 19 to 74 years) who had no evidence of cardiac disease, with multislice cine anatomic and tagged magnetic resonance imaging. Three-dimensional analysis of the resulting images showed that peak systolic mitral valve plane displacement was 12% smaller (p = 0.040) and peak diastolic mitral valve plane velocity was 21% lower (p = 0.008) in patients who had DM than in normal controls. Peak systolic circumferential and longitudinal strains and principal 3-D shortening strain were 14%, 22%, and 10% smaller, respectively, in the DM group (p <0.001 for each). Peak diastolic rate of relaxation of circumferential and longitudinal strains and principal 3-D shortening strain were 35%, 32%, and 33% lower, respectively, in the DM group (p <0.001 for each). Thus, LV systolic circumferential, longitudinal and 3-D principal strains, and diastolic strain rates are impaired in patients who have type 2 DM, LV diastolic dysfunction, and normal LV ejection fraction.

Adult↗
PubMed2004

Association of fat-free mass and training status with left ventricular size and mass in endurance-trained athletes.

OBJECTIVES: We sought to study the relationship between left ventricular (LV) size and body composition in male endurance athletes and age-matched control subjects. BACKGROUND: Endurance training is associated with increases in both left ventricular mass (LVM) and left ventricular end-diastolic dimension (LVEDD) in athletes. In other populations, LVM is independently predicted by fat-free mass (FFM). We hypothesized that the increase in LV size and mass observed with training may be a normal response to increased FFM. METHODS: Twelve young and 18 older male endurance athletes and 10 young and 18 older untrained men underwent exercise testing, echocardiography, and dual-photon x-ray absorptiometry body composition analysis. Univariate correlates (Spearman) and multivariate determinants of LVM and LVEDD were sought from: height, height(1.4), height(2.7), height(3.0), body surface area (BSA), FFM, weight, and body mass index. Un-indexed and indexed LVM and LVEDD were then compared. RESULTS: Athletes were of a similar age, weight, and height, but had higher FFM and maximum oxygen uptake than untrained men. Both LVM and LVEDD were correlated with body size, including FFM, BSA, weight, and height (all p < 0.05). On multivariate analysis, FFM was the only independent predictor of both LVM (R(2) = 0.36, p < 0.001) and LVEDD (R(2) = 0.35, p < 0.001). Furthermore, LVM and LVEDD (un-indexed and indexed to BSA and height) were different between athletes and non-athletes, but not when indexed to height(2.7) or FFM. CONCLUSIONS: Both LVM and LVEDD are predicted by FFM in endurance athletes, and when indexed to FFM, no training-related differences were observed. Thus, the extent of LV remodeling (athletic heart) in trained individuals may reflect a normal physiologic response to increased FFM induced by training.

Absorptiometry, Photon↗
PubMed2004

Effects of carvedilol on left ventricular remodeling after acute myocardial infarction: the CAPRICORN Echo Substudy.

BACKGROUND: The CAPRICORN trial has shown that carvedilol improved outcome in patients with left ventricular dysfunction after acute myocardial infarction treated with ACE inhibitors. The aim of this substudy was to determine the effects of carvedilol on left ventricular remodeling in this patient group. METHODS AND RESULTS: Patients entering the CAPRICORN trial from 13 centers in New Zealand, Australia, and Spain were recruited for this echocardiographic substudy. In 127 patients, quantitative 2D echocardiography was performed according to a standard protocol before randomization and repeated after 1, 3, and 6 months of treatment with carvedilol or placebo. Left ventricular volumes, ejection fraction (Simpson's method), and wall motion score index were determined in a blinded analysis at the Core Echo Laboratory. At 6 months, left ventricular end systolic volume was 9.2 mL less in the carvedilol group than in the placebo group (P=0.023), and left ventricular ejection fraction was 3.9% higher (P=0.015). Left ventricular end diastolic volume and wall motion score index were not statistically different between the 2 groups at 6 months. CONCLUSIONS: In patients with left ventricular dysfunction after acute myocardial infarction treated with ACE inhibitors, carvedilol had a beneficial effect on ventricular remodeling, which may, in part, mediate the substantial clinical beneficial effects of carvedilol in this patient population.

Adrenergic beta-Antagonists↗
PubMed2004

Effect of tissue harmonic imaging and contrast upon between observer and test-retest reproducibility of left ventricular ejection fraction measurement in patients with heart failure.

AIMS: To investigate the effects of tissue harmonic imaging (THI) and contrast chamber opacification (LVO) upon measurement variability and reproducibility of echocardiographic left ventricular (LV) volume and ejection fraction (EF) measurements in patients with heart failure (HF). BACKGROUND: Echocardiography is often used in HF patients to determine LV volumes and EF. However, current echo methods are variable and may not be applicable for repeat testing in individual patients. THI and LVO have both been shown to improve endocardial visualisation, but it remains to be determined whether this results in better measurement reproducibility. METHODS: Thirty-one HF patients and 30 control subjects underwent echocardiography on two separate days. LV volumes were measured under four different imaging conditions: fundamental, THI, LVO and LVO with ECG-triggered Power Doppler. Chamber opacification, pulmonary transit time (PTT), endocardial enhancement, reproducibility and bias were assessed. RESULTS: Chamber opacification was inferior and the PTT longer in the HF patients. PTT was related to LV volumes, EF, jugular venous pressure and mitral filling pattern. THI improved endocardial visualisation, and although LVO improved endocardial visualisation in the controls, it offered no benefit over THI in the HF patients. LV volumes and EF were different for each method and THI was the least variable method for repeat measurements. CONCLUSIONS: THI improved endocardial visualisation and was the least variable of the techniques. LVO offered no further advantage in patients with HF and thus cannot be routinely advocated and since LV volumes and EF were different for each, these methods are neither comparable nor interchangeable for follow-up assessments.

Contrast Media↗