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Volume Index (volume + index)
Kinds of Volume Index Selected AbstractsVolume Index 14, 2007INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 6 2007Article first published online: 9 OCT 200 First page of article [source] Association of Coronary Sinus Diameter with Pulmonary HypertensionECHOCARDIOGRAPHY, Issue 9 2008Yilmaz Gunes M.D. Background: Impaired venous drainage secondary to increased right atrial pressure (RAP) may result in coronary sinus (CS) dilatation.,Methods: Two hundred fifteen patients referred for transthoracic echocardiography were included in the study. CS diameters were measured from apical four-chamber view with the transducer being slightly tilted posteriorly to the level of the dorsum of the heart. Pulmonary artery systolic pressure (PASP) is estimated by measurement of tricuspid regurgitation velocity (v) and estimate RAP based on size and collapsibility of inferior vena cava (VCI) with the formula PASP: 4v2+RAP. Patients with PASP >35 mmHg were considered to have pulmonary hypertension (PH).,Results: CS diameter was measured in 80.3% of the patients with normal PASP (8.1 ± 2.4 mm) and 93.1% of the patients having PH (12.3 ± 2.5 mm). PASP was significantly correlated with CS diameter (r = 0.647, P < 0.001), RA volume index (r = 0.631, P < 0.001), RV volume index (r = 0.475, P < 0.001), VCI diameter (r = 0.365, P < 0.001), and left ventricular ejection fraction (LVEF) (r =,0.270, P < 0.001). CS diameter was also correlated significantly with estimated RAP (r = 0.557, P < 0.001), RA volume index (r = 0.520, P < 0.001), RV volume index (r = 0.386, P < 0.001), LVEF (r =,0.327, P < 0.001), and VCI diameter (r = 0.313, P < 0.001). Multivariate analyses, testing for independent predictive information of CS size, VCI diameter, RA and RV volume indexes, and estimated RAP for the presence of PH revealed that estimated RAP (beta = 0.465, P < 0.001) and CS size (beta = 0.402, P = 0.003) were the significant predictors.,Conclusions: Coronary sinus is dilated in patients with pulmonary hypertension. Coronary sinus diameter significantly correlates with PASP, RAP, right heart chamber volumes, LVEF, and VCI diameter. [source] Myocardial Performance Index (Tei Index) Does Not Reflect Long-Term Changes in Left Ventricular Function after Acute Myocardial InfarctionECHOCARDIOGRAPHY, Issue 1 2003Torstein Hole M.D. Aims: To evaluate whether changes in myocardial performance index (MPI or Tei index) were related to changes in other Doppler echocardiographic parameters after acute myocardial infarction, or had any independent prognostic impact in a 2-year observational study. Methods and Results: Seventy-one patients with acute myocardial infarction without heart failure were examined at baseline, 3 months, and 2 years. MPI was significantly related to end-diastolic and end-systolic volume indexes, ejection fraction, maximal velocity, and time velocity integral of early mitral filling wave at 3 months and 2 years. MPI did not contribute significantly to the prediction of any changes in the measures of diastolic or systolic function at 3 months or 2 years. Baseline MPI was significantly higher in patients who later developed heart failure(0.55 ± 0.16)than in other patients(0.43 ± 0.13, P = 0.006), but had no independent predictive power for the development of heart failure or death relative to end-systolic volume index and deceleration time of early mitral filling wave. Conclusion: MPI did not accurately reflect changes in Doppler and two-dimensional echocardiographic measures of diastolic or systolic function during a 2-year follow-up after acute myocardial infarction, and did not have any independent prognostic impact. (ECHOCARDIOGRAPHY, Volume 20, January 2003) [source] Radiographic lung density assessed by computed tomography is associated with extravascular lung water contentACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2010V. V. KUZKOV Background: We hypothesized that in acute lung injury (ALI), the volume of pulmonary tissue with aqueous density, as determined by spiral computed tomography (CT), is associated with extravascular lung water content. Our aim was to compare tissue volume index, as assessed by CT, before and after oleic acid-induced ALI, with extravascular lung water indexes (EVLWI), determined with single transpulmonary thermodilution (EVLWISTD), thermal-dye dilution (EVLWITDD), and postmortem gravimetry (EVLWIG). Methods: Seven instrumented sheep received an intravenous infusion of oleic acid 0.08 ml/kg (OA group) and four animals had vehicle only (Control group). The day before, and immediately after the experiment, sheep were anesthetized to undergo quantitative CT examinations during a short breath hold. Hemodynamics, oxygenation, EVLWISTD, and EVLWTDD were registered. Linear regression analysis was used to assess the relationships between EVLWISTD, EVLWTDD, EVLWIG, and lung tissue volume index (TVICT) determined with CT. Results: In the OA group, total lung volume increased compared with Controls. Poorly and non-aerated lung volumes increased a 3.6- and 4.9-fold, respectively, and TVICT almost doubled. EVLWISTD, EVLWITDD, and TVICT were associated significantly with EVLWIG (r=0.85, 0.90, and 0.88, respectively; P<0.001). TVICT deviated from the reference EVLWIG values to the greatest extent with a mean bias ± 2SD of 4.0 ± 6.0 ml/kg. Conclusions: In ovine oleic acid-induced ALI, lung tissue volume, as assessed by quantitative CT, is in close agreement with EVLWI, as determined by indicator dilution methods and postmortem gravimetry, but overestimates lung fluid content. [source] Lymphocyte volume and conductivity indices of the haematology analyser Coulter® GEN.STM in lymphoproliferative disorders and viral diseasesINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2006M. SILVA Summary The haematology analyser Coulter® GEN.STM gives a set of data ,,positional parameters', defining white blood cell (WBC) populations by mean of index values (mean and standard deviation of volume, conductivity and scatter, used to identify the WBC populations). The volume and conductivity parameters related to the lymphocytes were analysed at diagnosis in patients suffering from chronic B-lymphocytic leukaemia (B-CLL), other non-CLL lymphoproliferative disorders (OLPD) and viral diseases. The standard deviation of volume index (SDVI) is significantly higher in the three groups, whereas the mean volume index (MVI) is significantly lower in B-CLL, and increased in OLPD and viral diseases. These two groups could be distinguished by their mean conductivity index (MCI), which is significantly lower in viral disease group. Cut-offs were calculated for each parameter by the mean of Receiver Operating Characteristic (ROC) analysis. The study of the detection performances showed that the combination of lymphocyte count with SDVI, MVI and MCI could be used with a good sensitivity and specificity to discriminate between the most frequent lymphocyte pathologies, even in patients with normal lymphocyte count. [source] Infusion of hypertonic saline/starch during cardiopulmonary bypass reduces fluid overload and may impact cardiac functionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010V. L. KVALHEIM Objective: Peri-operative fluid accumulation resulting in myocardial and pulmonary tissue edema is one possible mechanism behind post-operative cardiopulmonary dysfunction. This study aimed to confirm an improvement of cardiopulmonary function by reducing fluid loading during an open-heart surgery. Materials and methods: Forty-nine elective CABG patients were randomized to an intraoperative infusion of hypertonic saline/hydroxyethyl starch (HSH group) or Ringer's solution (CT group). Both groups received 1 ml/kg/h of the study solution for 4 h after baseline values were obtained (PICCO® transpulmonary thermodilution technique). Net fluid balance (NFB), hemodynamic and laboratory parameters were measured. Results: NFB was four times higher in the CT group compared with the HSH group during the first 6 h post-operatively. The total fluid gain until the next morning was lower in the HSH group, 2993.9 (938.6) ml, compared with the CT group, 4298.7 (1059.3) ml (P<0.001). Normalized values (i.e., %-changes from the baseline) of the cardiac index and the global end diastolic volume index increased post-operatively in both groups. Both parameters were significantly higher at 6 h in the HSH group compared with CT group (P=0.002 and 0.005, respectively). Normalized values of the intrathoracic blood volume index were lower in the HSH group at 6 h post-operatively when compared with the CT group. The PaO2/FiO2 ratio decreased similarly in both groups early post-operatively, but recovery tended to be more rapid in the HSH group. Although serum-sodium and serum-chloride levels were significantly higher in the HSH group, the acid,base parameters remained similar and within the normal range. Conclusions: An intraoperative infusion of HSH during cardiac surgery contributes to reduced fluid loading and an improvement in the post-operative cardiac performance. No adverse effects of the HSH infusion were observed. [source] Strong relationship between NT-proXNP levels and cardiac output following cardiac surgery in neonates and infantsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010T. BREUER Background: NT-proXNP, a new natriuretic peptide analyte, incorporates information about the concentrations of both N-terminal pro-atrial and pro-brain natriuretic peptides (NT-proANP, NT-proBNP). We aimed to investigate whether NT-proXNP is a reliable indicator of the cardiac index (CI) and the hemodynamic state in neonates and infants undergoing an open heart surgery. Methods: We enrolled 26 children under the age of 1 year into this prospective study. All patients underwent an elective cardiac operation with cardiopulmonary bypass (CPB) to achieve complete biventricular repair. Peri-operative hemodynamic parameters were assessed by transpulmonary thermodilution and natriuretic peptide levels were recorded. Results: The NT-proXNP level correlated significantly with the simultaneously measured NT-proANP level (r=0.60, P<0.001), but more strongly with the NT-proBNP level (r=0.89, P<0.001) and the arithmetic sum of both (r=0.88, P<0.001). NT-proXNP had a strong correlation with CI (r=,0.85, P<0.001), the stroke volume index (r=,0.80, P<0.001) and the global ejection fraction (r=,0.67, P<0.009) throughout the post-operative period. Conventionally measured parameters such as heart rate, mean arterial pressure and pulse-pressure product exhibited weaker correlations with CI than NT-proXNP. Among laboratory values, creatinine levels correlated significantly with CI (r=,0.77, P<0.001) and NT-proXNP (r=0.76, P<0.001) during the post-operative period. A post-operative NT-proXNP level of 3079 pmol/l was diagnostic for CI <3 l/min/m2 with 89% sensitivity and 90% specificity (area under the curve: 0.91 ± 0.05). Conclusion: NT-proXNP is a good marker of cardiac output following pediatric cardiac surgery and might be a useful tool in the recognition of a low output state. [source] Predictors of Early Outcome After Coronary Artery Surgery in Patients with Severe Left Ventricular DysfunctionJOURNAL OF CARDIAC SURGERY, Issue 2 2003Naresh Trehan The present study was undertaken to identify the prognostic factors in such patients. Methods: We analyzed the data of 176 consecutive patients (161 men, 15 women), aged 29 to 88 years (mean 58.43), with a left ventricular ejection fraction (LVEF) <30% who underwent isolated coronary artery bypass grafting. The LVEF ranged from 15% to 30% (mean 27.18%). Preoperatively, 33% had angina, 19.9% had recent myocardial infarction, and 21.6% had congestive heart failure. The mean number of grafts was 2.5/patient. The intra-aortic balloon was used prophylactically in 20.5% of patients and therapeutically in 4.0% of patients. Results: The hospital mortality was 2.3%. The complications occurred as follows: perioperative myocardial infarction in two (1.1%), intractable ventricular arrhythmias in two (1.1%), prolonged ventilation in four (2.3%) and peritoneal dialysis in 1 (0.6%). The mean ICU and hospital stay were2.46 ± 0.76and7.57 ± 2.24days, respectively. The predictors of survival on univariate analysis were New York Heart Association (NYHA) class(x2 = 14.458, p < 0.001), recent myocardial infarction(x2 = 5.852, p = 0.016), congestive heart failure (CHF)(x2 = 5.526, p = 0.019), and left ventricular end-systolic volume index (LVESVI)(x2 = 25.833, p < 0.001). However, on multivariate analysis, left ventricular end-systolic volume index was the only independent left ventricular function measurement predictive of survival(x2 = 10.228, p = 0.001). Conclusion: Left ventricular end-systolic volume index is the most important predictor of survival after coronary artery bypass surgery in patients with severe myocardial dysfunction.(J Card Surg 2003;18:101-106) [source] Substrate and Procedural Predictors of Outcomes After Catheter Ablation for Atrial Fibrillation in Patients with Hypertrophic CardiomyopathyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2008T. JARED BUNCH M.D. Background: Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) due to diastolic dysfunction, elevated left atrial pressure, and enlargement. Although catheter ablation for drug-refractory AF is an effective treatment, the efficacy in HCM remains to be established. Methods: Thirty-three consecutive patients (25 male, age 51 ± 11 years) with HCM underwent pulmonary vein (PV) isolation (n = 8) or wide area circumferential ablation with additional linear ablation (n = 25) for drug-refractory AF. Twelve-lead and 24-hour ambulating ECGs, echocardiograms, event monitor strips, and SF 36 quality of life (QOL) surveys were obtained before ablation and for routine follow-up. Results: Twenty-one (64%) patients had paroxysmal AF and 12 (36%) had persistent/permanent AF for 6.2 ± 5.2 years. The average ejection fraction was 0.63 ± 0.12. The average left atrial volume index was 70 ± 24 mL/m2. Over a follow-up of 1.5 ± 1.2 years, 1-year survival with AF elimination was 62%(Confidence Interval [CI]: 66-84) and with AF control was 75%(CI: 66-84). AF control was less likely in patients with a persistent/chronic AF, larger left atrial volumes, and more advanced diastolic disease. Additional linear ablation may improve outcomes in patient with severe left atrial enlargement and more advanced diastolic dysfunction. Two patients had a periprocedureal TIA, one PV stenosis, and one died after mitral valve replacement from prosthetic valve thrombosis. QOL scores improved from baseline at 3 and 12 months. Conclusion: Outcomes after AF ablation in patients with HCM are favorable. Diastolic dysfunction, left atrial enlargement, and AF subtype influence outcomes. Future studies of rhythm management approaches in HCM patients are required to clarify the optimal clinical approach. [source] Biventricular Versus Right Ventricular Pacing in Patients with AV Block (BLOCK HF): Clinical Study Design and RationaleJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2007ANNE B. CURTIS M.D. Background: Right ventricular (RV) pacing restores ventricular systole in patients with atrioventricular (AV) block, yet recent studies have suggested that in patients with AV block and left ventricular (LV) dysfunction, RV pacing may exacerbate the progression to heart failure (HF). BLOCK HF is a prospective, multi-center, randomized, double-blind, controlled trial designed to determine whether patients with AV block, LV dysfunction (EF , 50%), and mild to moderate HF (NYHA I-III) who require pacing benefit from biventricular (BiV) pacing, compared with RV pacing alone. Objective: The primary objective of this trial is to determine whether the time to first event (all-cause mortality, heart failure-related urgent care, or a , 15% increase in left ventricular end systolic volume index [LVESVI]) for patients with BiV pacing is superior to that of patients with RV pacing. Methods: Patients with AV block and LV dysfunction who require permanent pacing and undergo successful implantation of a commercial Medtronic CRT device, with or without an ICD, will be randomized to BiV or RV pacing. Patients are followed at least every 6 months until study closure. Up to 1,636 patients may be enrolled in 150 centers worldwide. Conclusion: BLOCK HF is a large, randomized, clinical study in pacing-indicated patients with AV block, mild to moderate HF symptoms, and LV dysfunction to determine whether BiV pacing is superior to RV pacing in slowing the progression of HF. [source] Study of saline wastewater influence on activated sludge flocs through automated image analysisJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2009Daniela P Mesquita Abstract BACKGROUND: In activated sludge systems, sludge settling ability is considered a critical step in effluent quality and determinant of solid,liquid separation processes. However, few studies have reported the influence of saline wastewater on activated sludge. This work aims the evaluation of settling ability properties of microbial aggregates in a sequencing batch reactor treating saline wastewaters of up to 60 g L,1 NaCl, by image analysis procedures. RESULTS: It was found that the sludge volume index (SVI) decreased with salt content up to 20 g L,1, remaining somewhat stable above this value. Furthermore, it was found that between the first salt concentration (5 g L,1) and 20 g L,1 aggregates suffered a strong deflocculation phenomenon, leading to a heavy loss of aggregated biomass. Regarding SVI prediction ability, a good correlation coefficient of 0.991 between observed and predicted SVI values was attained. CONCLUSION: From this work the deflocculation of aggregated biomass with salt addition due to pinpoint floc formation, dispersed bacteria growth and protozoa absence could be established. With respect to SVI estimation, and despite the good correlation obtained, caution is advisable given the low number of SVI data points. Copyright © 2008 Society of Chemical Industry [source] Performance assessment of a UASB,anoxic,oxic system for the treatment of tomato-processing wastesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2006Alpesh Gohil Abstract An upflow anaerobic sludge blanket (UASB),anoxic,oxic system was used to achieve biochemical oxygen demand, NH4 and total suspended solids (TSS) criteria of 15, 1 and 15 mg dm,3 at 1.17 days of system hydraulic retention time during treatment of tomato-processing waste. The incorporation of an anoxic tank was found to affect the improvement in sludge-settling characteristics, as reflected by about 25,33% reduction in the sludge volume index, along with final effluent TSS and soluble biochemical oxygen demand concentrations of 13 and 9 mg dm,3, respectively, which met the discharge criteria. Despite incomplete denitrification, sludge settleability was very good (sludge volume index < 60 cm3 g,1) owing to reduction in volatile suspended solids/TSS ratio from 0.75 to 0.6 as a result of higher alkalinity in the UASB effluent. Also in this study, phosphorus release was observed in the anoxic tank, predominantly due to abundance of acetic acid in the UASB effluent. A phosphate release of 5.4 mg P dm,3 was observed in the anoxic tank with subsequent P uptake in the following aerobic stage. Copyright © 2006 Society of Chemical Industry [source] Vasopressin decreases intestinal mucosal perfusion: a clinical study on cardiac surgery patients in vasodilatory shockACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2009A. NYGREN Background: Low to moderate doses of vasopressin have been used in the treatment of cathecholamine-dependent vasodilatory shock in sepsis or after cardiac surgery. We evaluated the effects of vasopressin on jejunal mucosal perfusion, gastric-arterial pCO2 gradient and the global splanchnic oxygen demand/supply relationship in patients with vasodilatory shock after cardiac surgery. Methods: Eight mechanically ventilated patients, dependent on norepinephrine to maintain mean arterial pressure (MAP) ,60 mmHg because of septic/post-cardiotomy vasodilatory shock and multiple organ failure after cardiac surgery, were included. Vasopressin was sequentially infused at 1.2, 2.4 and 4.8 U/h for 30-min periods. Norepinephrine was simultaneously decreased to maintain MAP at 75 mmHg. At each infusion rate of vasopressin, data on systemic hemodynamics, jejunal mucosal perfusion, jejunal mucosal hematocrit and red blood cell velocity (laser Doppler flowmetry) as well as gastric-arterial pCO2 gradient (gastric tonometry) and splanchnic oxygen and lactate extraction (hepatic vein catheter) were obtained. Results: The cardiac index, stroke volume index and systemic oxygen delivery decreased and systemic vascular resistance and systemic oxygen extraction increased significantly, while the heart rate or global oxygen consumption did not change with increasing vasopressin dose. Jejunal mucosal perfusion decreased and the arterial-gastric-mucosal pCO2 gradient increased, while splanchnic oxygen or lactate extraction or mixed venous,hepatic venous oxygen saturation gradient were not affected by increasing infusion rates of vasopressin. Conclusions: Infusion of low to moderate doses of vasopressin in patients with norepinephrine-dependent vasodilatory shock after cardiac surgery induces an intestinal and gastric mucosal vasoconstriction. [source] Pulse pressure variation and stroke volume variation during different loading conditions in a paediatric animal modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2008J. RENNER Background: Previous studies in adult patients and animal models have demonstrated that pulse pressure variation (PPV) and stroke volume variation (SVV) can be used to predict the response to fluid administration. Currently, little information is available on the performance of these variables in infants and neonates. The aim of our study was to assess whether PPV and SVV can predict fluid responsiveness in an animal model and to investigate the influence of different tidal volumes applied. Methods: PPV and SVV were monitored by pulse contour analysis in 19 anaesthetized and paralysed piglets during ventilation with tidal volumes (VT) of 5, 10 and 15 ml/kg both before and after fluid loading with 25 ml/kg of hydroxy-ethyl starch 6% (HES). Cardiac output was measured by pulmonary artery thermodilution and a positive response to HES infusion was defined as ,20% increase in the stroke volume index (SVI). Results: Before HES infusion, PPV and SVV were significantly greater during ventilation with a VT of 10 and 15 ml/kg than during ventilation with a VT of 5 ml/kg (P<0.05). After HES infusion, only ventilation with VT 15 ml/kg resulted in a significant increase in PPV and SVV. As assessed by receiver operating characteristic curve analysis, SVV during ventilation with VT 10 ml/kg was the best predictor of a positive response to fluid loading (AUC=0.87). Conclusions: In this paediatric animal model, we found that SVV during ventilation with 10 ml/kg was a sensitive and specific predictor of the response to fluid loading. [source] Effects of Norepinephrine and Combined Norepinephrine and Fenoldopam Infusion on Systemic Hemodynamics and Indices of Renal Function in Normotensive Neonatal FoalsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2008A.R. Hollis Background: Norepinephrine increases arterial blood pressure but may have adverse effects on renal blood flow. Fenoldopam, a dopamine-1 receptor agonist, increases urine output in normotensive foals. The combination of norepinephrine and fenoldopam may lead to improved renal perfusion compared with an infusion of norepinephrine alone. The combined effects of these drugs have not been reported in the horse. Hypothesis: Norepinephrine will alter the hemodynamic profile of foals without affecting renal function. Addition of fenoldopam will change the renal profile during the infusions without changing the hemodynamic profile. Animals: Five conscious pony foals. Methods: Each foal received norepinephrine (0.3 ,g/kg/min), combined norepinephrine (0.3 ,g/kg/min) and fenoldopam (0.04 ,g/kg/min), and a control dose of saline in a masked, placebo-controlled study. Heart rate (HR), arterial blood pressure (direct), and cardiac output (lithium dilution) were measured, and systemic vascular resistance (SVR), stroke volume, cardiac index (CI), and stroke volume index were calculated. Urine output, creatinine clearance, and fractional excretion of electrolytes were measured. Results: Norepinephrine and a combined norepinephrine and fenoldopam infusion increased arterial blood pressure, SVR, urine output, and creatinine clearance and decreased HR and CI compared with saline. The combination resulted in higher HR and lower arterial blood pressure than norepinephrine alone. Conclusions and Clinical Importance: Norepinephrine might be useful for hypotensive foals, because in normal foals, this infusion rate increases SVR without negatively affecting renal function (creatinine clearance increased). Fenoldopam does not provide additional benefit to renal function. These findings warrant further investigation. [source] Clinical, Echocardiographic, and Neurohormonal Effects of a Sodium-Restricted Diet in Dogs with Heart FailureJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2000John E. Rush The use of low-sodium diets in dogs with heart failure is common practice, but randomized, double-blind studies have not been conducted to examine the benefits or problems with this approach. The purpose of this study was to determine the effects of a low-sodium diet on clinical, echocardiographic, and neurohormonal parameters in dogs with heart failure. Dogs with stable chronic heart failure were fed exclusively a low-sodium (LS) and a moderate-sodium (MS) diet for 4 weeks each in a randomized, double-blind, crossover design. At days 0, 28, and 56, echocardiography and thoracic radiography were performed, and blood was analyzed for electrolytes and neurohormones. Fourteen dogs completed the study (9 with chronic valvular disease and 5 with dilated cardiomyopathy). Electrolyte abnormalities were common during the study, and serum sodium and chloride concentrations decreased significantly on the LS diet. Neurohormones did not change significantly between diet groups. Maximum left atrial (P= .05) and standard left atrial (P= .09) size decreased on the LS diet. For dogs with chronic valvular disease, vertebral heart score (P= .05), left ventricular internal dimension in diastole (P= .006) and systole (P= .02), standard left atrial dimension (P = .03), maximum left atrial dimension (P= .02), end-diastolic volume index (P= .02), and end-systolic volume index (P= .04) decreased significantly on the LS diet compared to the MS diet. Although analysis of these data suggests some benefits of a low-sodium diet, future studies with improved study design are needed to further evaluate the advantages and disadvantages of sodium restriction in dogs with heart failure. [source] The role of cellular polysaccharides in the formation and stability of aerobic granulesLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2001J.-H. Tay Aims:,This paper attempts to investigate the role of cellular polysaccharides in the formation and stability of aerobic granules. Methods and Results:,Three column sequential aerobic sludge blanket reactors (R1, R2 and R3) were operated at a superficial air upflow velocity of 0·3 cm s,1, 1·2 cm s,1 and 2·4 cm s,1, respectively. Aerobic granules appeared at cycle 42 in R2 and R3 with a mean size of 0·37 mm in R2 and 0·35 mm in R3, however, aerobic granulation was not observed in R1. After the formation of aerobic granules, the sludge volume index (SVI) decreased to 55 ml g,1 in R2 and 46 ml g,1 in R3. Aerobic granulation was concurrent with a sharp increase of cellular polysaccharides normalized to cellular proteins, which increased from 5·7 to 13·0 mg per mg proteins in R2, and 7·5,13·9 mg per mg protein in R3. The content of polysaccharides in aerobic granules was 2,3 times higher than that in the bioflocci cultivated in R1. The disappearance of aerobic granules in R2 was tightly coupled to a drop in cellular polysaccharides. After the reappearance of bioflocci in R2, the content of cellular polysaccharides were found to be restored to the level observed in R1. Conclusions:,It appears that the production of cellular polysaccharides could be stimulated by hydrodynamic shear force and contributes to the formation and stability of aerobic granules. Significance and Impact of the Study:,It is expected that this study would provide useful information for better understanding the mechanisms of aerobic granulation. [source] Haemodynamic changes during positive-pressure ventilation in childrenACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2005A. Kardos Background:, Positive-pressure ventilation may alter cardiac function. Our objective was to determine with the use of impedance cardiography (ICG) whether altering airway pressure modifies the central haemodynamics in mechanically ventilated children with no pulmonary pathology. Central venous saturation (ScvO2) was measured as an indicator of tissue perfusion. Methods:, Twelve children between 7 and 65 months of age, requiring mechanical ventilation as a consequence of a non-pulmonary disease, were enrolled in the study. All patients had a central venous line as a part of their routine management. Using pressure controlled ventilation (PCV) the baseline PEEP value of 5 cmH2O (Pb5) was increased to 10 cmH2O (Pi10) and then to 15 cmH2O (Pi15). After Pi15, PEEP was decreased to 10 (Pd10) and then to 5 cmH2O (Pd5). Each time period lasted 5 min heart rate (HR), mean arterial blood pressure (MABP), central venous pressure (CVP), end-tidal carbon dioxide (ETCO2), mean airway pressure (Paw), stroke volume index (SVI), cardiac index (CI) and central venous oxygen saturation (ScvO2) were recorded at the end of the five periods. Results:, The values of CI did not change when 10 and 15 cmH2O of PEEP were applied. Elevation of PEEP and thus Paw caused slight but not significant reductions in SVI and ScvO2 as compared to the baseline (Tb5). After reducing PEEP in Td5 we found statistically significant elevations of SVI and CI, as compared to Ti15 heart rate, ETCO2 and MABP remained unchanged. Conclusion:, We did not find significant haemodynamic changes following PEEP elevation in ventilated children, as measured using impedance cardiography. Reducing the value of PEEP to 5 cmH2O resulted in statistically significant SVI elevations. The values of ScvO2 remained unaffected. [source] Coenzyme Q10 improves contractility of dysfunctional myocardium in chronic heart failureBIOFACTORS, Issue 1-4 2005Romualdo Belardinelli Abstract Background: There is evidence that plasma CoQ10 levels decrease in patients with advanced chronic heart failure (CHF). Objective: To investigate whether oral CoQ10 supplementation could improve cardiocirculatory efficiency in patients with CHF. Methods: We studied 21 patients in NYHA class II and III (18M, 3W, mean age 59 ±9 years) with stable CHF secondary to ischemic heart disease (ejection fraction 37 ± 7%), using a double-blind, placebo-controlled cross-over design. Patients were assigned to oral CoQ10 (100 mg tid) and to placebo for 4 weeks, respectively. Results: CoQ10 supplementation resulted in a threefold increase in plasma CoQ10 level (P<0.0001 vs placebo). Systolic wall thickening score index (SWTI) was improved both at rest and peak dobutamine stress echo after CoQ10 supplementation (+12.1 and 15.6%, respectively, P<0.05 vs placebo). Left ventricular ejection fraction improved significantly also at peak dobutamine (15% from study entry P<0.0001) in relation to a decrease in LV end-systolic volume index (from 57 ± 7 mL/m2 to 45 mL/m2, P<0.001). Improvement in the contractile response was more evident among initially akinetic (+33%) and hypokinetic (+25%) segments than dyskinetic ones (+6%). Improvement in SWTI was correlated with changes in plasma CoQ10 levels (r=,0.52, P<0.005). Peak VO2 was also improved after CoQ10 as compared with placebo (+13%, <0.005). No side effects were reported with CoQ10. Conclusions: Oral CoQ10 improves LV contractility in CHF without any side effects. This improvement is associated with an enhanced functional capacity. [source] A simple method to estimate the contribution of biological floc and reactor-solution to mass transfer of oxygen in activated sludge processesBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2005Venkatram Mahendraker Abstract In this study, the mass transfer coefficient of biological floc (KLabf) was estimated from the mass transfer coefficient of the mixed-liquor (KLaf) and the reactor-solution (KLae). The biological floc resistance (BFR) and reactor-solution resistance (SR) were defined as the reciprocal of KLabf and KLae, respectively, by applying the concept of serial-resistance originally presented in two-film theory (Lewis and Whitman (1924) Ind Eng Chem 16:1215,1220). The specific biological floc resistance (SBFR) was defined as biological floc resistance per unit biomass concentration. The data indicated that an activated sludge process yielding low BFR/MLR and BFR/SR tended to produce higher oxygen transfer efficiency. Surprisingly, the reactor-solution posed the same level of resistance as clean water in all experiments, except in a 5-day SRT, non-nitrifying, completely mixed activated sludge (CMAS) process run. Furthermore, SBFR successfully represented biological floc and showed a positive correlation to sludge volume index (SVI). In addition, SBFR/SR and oxygen transfer efficiency (OTEf) followed an exponential relationship for the complete data set. The method of separating the mixed-liquor into biological floc and reactor-solution improved the understanding of oxygen transfer under process conditions, without resorting to intrusive techniques or direct handling of fragile biological floc. © 2005 Wiley Periodicals, Inc. [source] Myocardial iron clearance during reversal of siderotic cardiomyopathy with intravenous desferrioxamine: a prospective study using T2* cardiovascular magnetic resonanceBRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2004Lisa J. Anderson Summary Heart failure from iron overload causes 71% of deaths in thalassaemia major, yet reversal of siderotic cardiomyopathy has been reported. In order to determine the changes in myocardial iron during treatment, we prospectively followed thalassaemia patients commencing intravenous desferrioxamine for iron-induced cardiomyopathy during a 12-month period. Cardiovascular magnetic resonance assessments were performed at baseline, 3, 6 and 12 months of treatment, and included left ventricular (LV) function and myocardial and liver T2*, which is inversely related to iron concentration. One patient died. The six survivors showed progressive improvements in myocardial T2* (5·1 ± 1·9 to 8·1 ± 2·8 ms, P = 0·003), liver iron (9·6 ± 4·3 to 2·1 ± 1·5 mg/g, P = 0·001), LV ejection fraction (52 ± 7·1% to 63 ± 6·4%, P = 0·03), LV volumes (end diastolic volume index 115 ± 17 to 96 ± 3 ml, P = 0·03; end systolic volume index 55 ± 16 to 36 ± 6 ml, P = 0·01) and LV mass index (106 ± 14 to 95 ± 13, P = 0·01). Iron cleared more slowly from myocardium than liver (5·0 ± 3·3% vs. 39 ± 23% per month, P = 0·02). These prospective data confirm that siderotic heart failure is often reversible with intravenous iron chelation with desferrioxamine. Myocardial T2* improves in concert with LV volumes and function during recovery, but iron clearance from the heart is considerably slower than from the liver. [source] Elevated augmentation index derived from peripheral arterial tonometry is associated with abnormal ventricular,vascular couplingCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2010Kevin S. Heffernan Summary Background:, Although typically derived from the contour of arterial pressure waveform, augmentation index (AIx) may also be derived from the digital pulse volume waveform using finger plethysmography (peripheral arterial tonometry, PAT). Little is known regarding the physiologic correlates of AIx derived from PAT. In this study, we investigated the relation of PAT-AIx with measures of ventricular,vascular coupling. Methods:, Pulse volume waves were measured via PAT and used to derive AIx. Using 2-dimensional echocardiography, effective arterial elastance index (EaI) was estimated as end-systolic pressure/stroke volume index. Left ventricular (LV) end-systolic elastance index (ELVI) was calculated as end-systolic pressure/end-systolic volume index. Ventricular,vascular coupling ratio was defined as EaI/ELVI. Results:, Given the bi-directional nature of ventricular,vascular uncoupling as measured by echocardiography, patients were separated into three groups: low EaI/ELVI (<0·6, n = 21), optimal EaI/ELVI (mean 0·6,1·2, n = 16) and high EaI/ELVI (>1·2, n = 10). Adjusting for potential confounders (age, mean arterial pressure, height and heart rate), patients with optimal EaI/ELVI had lower AIx (1 ± 4%, P<0·05) compared to those with low EaI/ELVI (13 ± 4%) and high EaI/ELVI (19 ± 5%). Conclusions:, Abnormal ventricular,vascular coupling, arising from either increased effective arterial elastance or increased ventricular elastance, is associated with increased AIx as measured by PAT. Additional research is needed to examine other vascular correlates of PAT-AIx. [source] Influence of right ventricular pre- and afterload on right ventricular ejection fraction and preload recruitable stroke work relationCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2001Wolfram Burger When right ventricular (RV) afterload is abnormally increased, it correlates inversely with right ventricular ejection fraction (RVEF). We tested, whether this would be different with normal afterload. Additionally, we investigated whether previous studies on the slope of RV preload recruitable stroke work (SW) relation, which used rather non-physiological measures to change RV preload, could be transferred to more physiological loading conditions. RV volumes were determined by thermodilution in 16 patients with stable coronary artery disease and normal pulmonary artery pressure (PAP) at rest. Pre- and afterload were varied by body posture, nitroglycerin (NTG) application and by exercise at different body positions. At rest, the change from recumbent to sitting position decreased PAP, cardiac index (Ci), RV diastolic and systolic volumes, and RVEF. Additionally, mean pulmonary artery pressure (MPAP) correlated positively with both RVEF and cardiac index. After correction for mathematical coupling, the RV preload recruitable SW relation was: right ventricular stroke work index (RVSWi) (103 erg m,2)= 8·1 × (RV end-diastolic volume index ,4·9), with n=96, r=0·57, P,0·001. Exercise abolished this correlation and led to an inverse correlation between RV end-systolic volume (ESV) and RVSW. In conclusion, (i) RVEF correlates positively with RV afterload when afterload varies within normal range; (ii) the slope of the RV preload recruitable SW relation, which is obtained at steady state under normal loading conditions, is substantially flatter than previously described for dynamic changes of RV preload. With increasing afterload, preload loses its determining effect on RV performance, while afterload becomes more important. This puts earlier assumptions of an afterload independent RV preload recruitable SW relation into question. [source] Interplanner variability in carrying out three-dimensional conformal radiation therapy for non-small-cell lung cancerJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 3 2008S Everitt Summary This study evaluated the variability among six radiation therapy planners in planning radiation treatment for four patients with lung cancer using two treatment protocols. The interplanner variability for target conformity and homogeneity was smaller than the variability among the patients and planning approaches. The same was found for the dose volume indices achieved for most critical structures, indicating that interplanner variability is not likely to be an important source of variation in radiotherapy studies if concise treatment protocols are followed. [source] Flow,volume curve changes in patients with obstructive sleep apnoea and brief upper airway dysfunctionRESPIROLOGY, Issue 1 2000Alastair H Campbell Objective: Patients with obstructive sleep apnoea (OSA) and those with brief upper airway dysfunction (BUAD) have been reported to have abnormalities of maximal flow,volume curves. This study was designed to assess the ability of flow,volume curves to predict the presence of OSA or BUAD. Methodology: Four maximal flow,volume manoeuvres performed by 33 OSA patients and 16 BUAD patients were compared with those of 36 normal subjects. Flow,volume indices, their variability, saw-toothing in the curve and an algorithm based on the flow ratios and shape of the curves were assessed. Results: When the confounding factors, body mass index (BMI), age, gender and smoking status were taken into account, there was no significant difference in a variety of indices derived from the flow,volume curves between OSA and normal subjects. No BUAD patient had normal flow,volume curves as determined with the algorithm. After BMI, age, gender and smoking status were accounted for, decreased forced expiratory volume in 1 s (FEV1), and increased variability of peak expiratory flow (PEF)/peak inspiratory flow (PIF) and FEV1/PEF remained significantly associated with BUAD. Conclusions: These findings suggest that flow,volume curve indices have no value in predicting OSA. Some abnormalities are found in patients with BUAD; a normal flow,volume curve makes the diagnosis of BUAD unlikely. [source] | |||||||||||||