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Prediction of long-term effects of revascularization on regional and global left ventricular function by dobutamine echocardiography and rest Tl-201 imaging alone and in combination in patients with chronic coronary artery disease.

BACKGROUND: The aim of this study was to evaluate the accuracy of low-dose dobutamine echocardiography (DE) and resting thallium 201 single photon emission computed tomography (SPECT) alone and in combination for prediction of functional recovery at late follow-up (1 year) after revascularization. METHODS AND RESULTS: Twenty-six patients with coronary artery disease and ventricular dysfunction (ejection fraction, 42% +/- 9%) underwent DE and Tl-201 SPECT 14 +/- 9 (mean +/- SD) days before revascularization and repeated echocardiography 12 +/- 5 months thereafter. Discriminant analysis was applied to combine Tl-201 SPECT and DE data to classify dysfunctional segments as viable or nonviable. In 78 akinetic/dyskinetic revascularized segments, Tl-201 SPECT provided a sensitivity of 83% and a specificity of 55%, whereas DE showed a sensitivity of 60% and a specificity of 91%, for prediction of improvement in regional function at follow-up. The combination of data through use of discriminant analysis provided a sensitivity of 80% and a specificity of 86%, with an overall accuracy of 82%, significantly higher than DE (71%; P <.05) and Tl-201 SPECT (73%; P <.05) alone. Moreover, discriminant analysis identified 12 (75%) of 16 patients with and 8 (80%) of 10 patients without significant improvement in ejection fraction at follow-up, with an accuracy of 77%. CONCLUSIONS: The combination of Tl-201 SPECT and DE data provides higher accuracy than either technique alone for prediction of recovery of regional and global function after revascularization.

Adult↗

Comparison of pancreatic morphology and exocrine functional impairment in patients with chronic pancreatitis.

A comparative analysis of pancreatic morphology and exocrine function was performed prospectively in 48 patients. All patients had transabdominal ultrasound, computed tomography, endoscopic retrograde pancreatography, and a secretin-caerulein test. Classification of ultrasound, computed tomography, and pancreatogram findings was based on the Cambridge classification. In 10 patients, no pancreatic duct changes were detected on pancreatography. Equivocal (Cambridge I), mild to moderate (Cambridge II), and considerable ductal changes (Cambridge III) were found in 10, 12, and 16 patients, respectively. Computed tomography and ultrasound changes were found to correlate in 40-50%, 67%, and 94-100% of patients with Cambridge I, II, and III abnormal duct morphology, respectively. In patients with a normal pancreatogram, no patient had a functional impairment. Seventy per cent of the patients with equivocal pancreatic duct changes had dissociated, and 30% global, pancreatic insufficiency, while 50% of those with mild to moderate abnormal duct morphology manifested dissociated, and 50% global, functional impairment. All patients with considerable pancreatic duct changes had global pancreatic insufficiency. The results of this study confirm that normal endoscopic retrograde pancreatographic findings and Cambridge III ductal changes on endoscopic retrograde pancreatography correlate extremely well with normal pancreatic function and advanced functional insufficiency, respectively. As diagnostic tools, ultrasound and computed tomography are as sensitive as pancreatography only in chronic pancreatitis with considerable morphological changes.

Adult↗

[Magnetic resonance imaging early after acute myocardial infarction. A visual analysis of myocardial perfusion based on a 17 segment model].

Magnetic resonance imaging allows an accurate calculation of the left ventricular ejection fraction and left ventricular volumes. Additionally, it makes possible to assess myocardial perfusion after gadolinium chelate injection. Late after the injection, the presence of a myocardial hyper-enhancement can be visualized. The present study has used the 17 segment standardized nomenclature for tomographic imaging of the heart as recommended for all cardiac imaging modalities. Sixty nine patients were studied after a revascularised myocardial infarction. All patients had Timi grade 3 flow in the infarct-related artery after therapy. Regional and global function was studied using cine MR short axis slices. The gadolinium chelate first pass was scored using a 5 level scale reflecting the transmural extent of the segmental myocardial enhancement. The delayed enhancement due to gadolinium accumulation in the myocardium 10 min post injection was scored in the same manner. Left ventricular ejection fraction was 51 +/- 13%. Segmental thickening parameters (systolic thickness, absolute thickening and relative thickening) appeared statistically related to the hypoperfusion and delayed enhancement scores. Absolute myocardial thickening varied from 4.8 +/- 2.7 mm in the myocardial segments free of any delayed enhancement to 2.4 +/- 2.1 mm in segments presenting with a transmural extent of the delayed hyper-enhancement. Scores obtained after gadolinium injection were also well correlated with the global left ventricular function (r = 0.65, p < 0.01 for late enhancement). Magnetic resonance imaging of the heart allows a precise characterisation of revascularised myocardium which makes this technique very attractive for evaluating the treatments designed to improve myocardial microperfusion.

Acute Disease↗

Glucoregulation has greater impact on cognitive performance than macro-vascular disease in men with type 2 diabetes: data from the Caerphilly study.

OBJECTIVE: To compare vascular and glucose related mechanisms of type 2 diabetes on cognitive performance. RESEARCH DESIGN AND METHODS: A cross-sectional observational study of type 2 diabetes defined by non insulin dependant self-report diabetes or fasting blood glucose < or = 7.0 mmol/l of 2205 men eligible for the third phase of the Caerphilly Collaborative Heart Disease Study. Men were aged 55-69 years at time of testing. Tests of cognitive function included NART (crystallised IQ), AH4 (fluid IQ), verbal fluency (executive function) Cambridge Cognitive Examination (CAMCOG) and Mini Mental State Examination (MMSE) (global function), four choice serial reaction time (psychomotor function) and memory. Men with prior stroke were omitted from the analysis. RESULTS: Men with diabetes showed cognitive deficits for verbal fluency, National Adult Reacting Test (NART) and AH4. Adjusting for vascular risk factors had minimal effect. Including blood glucose removed the deficit for verbal fluency and NART but the effect on AH4 score (-2.58; 95% CI: -5.0, -0.1, p = 0.039) was retained. More detailed analyses of AH4 score on men with diabetes showed a curvilinear relationship indicating that men with both low and high glucose levels had worse performance (AH4 = -66 + 80 log(e) glucose - 18 log(e )glucose(2); 95% CI: -29, -6; p=0.002). CONCLUSIONS: These data identify a direct effect of glucose regulation on cognitive performance associated with diabetes in a population sample. These data suggest that an effect of glucose regulation on cognitive performance in diabetes is distinct from any effect of macro-vascular disease.

Aged↗

Echocardiographic versus hemodynamic monitoring during attacks of variant angina pectoris.

Six attacks of variant angina (2 spontaneous, 4 induced by ergonovine) were studied in 6 patients by combined echocardiographic and hemodynamic monitoring. A decrease of percent systolic thickening of the ischemic wall, which occurred as early as the decrease in peak dP/dt of contraction, was detected before the onset of ST-segment elevation ("pre-electrocardiographic phase"). At this stage, no significant change in left ventricular (LV) end-diastolic pressure or end-diastolic diameter was observed. Subsequently, in the presence of clear-cut ST-segment elevation ("electrocardiographic phase"), percent systolic thickening (an index of regional function) reached its nadir, while dP/dt of contraction (an index of global function) was almost back to preischemic values. In this phase, a significant increase in LV end-diastolic diameter and end-diastolic pressure could be also detected. In the recovery phase, when the ST segment had returned to the isoelectric line ("post-electrocardiographic phase"), percent systolic thickening and dP/dt of contraction showed supernormal values, while LV end-diastolic pressure and end-diastolic diameter decreased below basal values. Thus, echocardiographic signs of impairment in LV mechanics are as early and sensitive as hemodynamic indexes during attacks of variant angina. Furthermore, information on morphologic characteristics and regional LV function, not available with hemodynamic monitoring, can be obtained by echocardiography.

Adult↗

Wall motion score index and ejection fraction for risk stratification after acute myocardial infarction.

BACKGROUND: The prognostic importance of regional systolic function, as assessed by wall motion score index (WMSI), compared with global function, as assessed by left ventricular ejection fraction (LVEF), has not been assessed in large populations after acute myocardial infarction. METHODS: Echocardiograms, including the assessment of WMSI and LVEF, were performed in 767 patients with acute myocardial infarction at a median of 1 day (25th and 75th percentiles 0-2 days) after admission. Patients were followed for a median of 19 months (range 12-28 months). Cox proportional hazards models were constructed for the primary study end point (all-cause mortality) and for a secondary end point (hospitalization for congestive heart failure). RESULTS: During follow-up (median 40 months; range 32-50 months), 216 patients died and 54 patients were hospitalized for congestive heart failure. By univariate analysis, both LVEF (P < .0001) and WMSI (P < .0001) were powerful predictors of all-cause mortality. By a forward conditional Cox model, WMSI proved to be an independent predictor of death (hazard ratio 1.15 per 0.2-unit increase, 95% CI 1.10-1.21, P < .0001). When WMSI was included in the model, LVEF did not provide additional prognostic information (P = .77). Wall motion score index also proved to be an independent predictor of hospitalization for congestive heart failure (hazard ratio 1.21 per 0.2-unit increase, 95% CI 1.07-1.37, P = .002), whereas LVEF did not (P = .56). CONCLUSION: Both LVEF and WMSI provide powerful prognostic information after acute myocardial infarction; however, the predictive power of WMSI is greater.

Aged↗

Health-related quality of life assessed before and during chemotherapy predicts for survival in multiple myeloma. Nordic Myeloma Study Group.

Measurement of health-related quality of life was integrated into a randomized trial (NMSG 4/90) comparing melphalan/prednisone to melphalan/prednisone + interferon alpha-2b in newly diagnosed multiple myeloma. One of the aims of the study was to assess the prognostic significance of quality-of-life scores, using the EORTC QLQ-C30 questionnaire. Univariate analysis showed a highly significant association with survival from the start of therapy for physical functioning as well as role and cognitive functioning, global quality of life, fatigue and pain. In multivariate analysis, physical functioning and W.H.O. performance status were independent prognostic factors (P values = 0.001 for both) when analysed in a Cox regression model with the somatic variables beta-2 microglobulin, skeletal disease and age. The best prediction for survival from the start of therapy was obtained by combining the beta-2 microglobulin and physical functioning scores in a variable consisting of three risk factor levels with an estimated median survival of 17, 29 and 49 months, respectively. At a 12 months landmark analysis, the relative risk for patients with physical functioning score 0-20 v 80-100 was 5.63 (99% CI 2.76-11.49), whereas the relative risk for patients without an objective response to chemotherapy compared to those with at least a minor response was 2.32 (99% CI 1.44-3.74). Quality-of-life assessment may be an independent and valuable addition to the known prognostic factors in multiple myeloma.

Activities of Daily Living↗

Open-label study of donepezil in traumatic brain injury.

OBJECTIVE: To determine preliminarily whether donepezil will improve memory, behavior, and global function after chronic traumatic brain injury (TBI). DESIGN: Sixteen-week open-label study. SETTING: Outpatient TBI rehabilitation program. PATIENTS: Four patients with chronic, severe TBI. INTERVENTIONS: Donepezil 5mg daily for 8 weeks followed by 10mg daily for 4 weeks. MAIN OUTCOME MEASURES: Memory measures included the Rey Auditory Verbal Learning Test (RAVLT), the Complex Figure Test (CFT), items from the Rivermead Behavioural Memory Test (RBMT), and a semantic fluency task. The Neuropsychiatric Inventory (NPI) evaluated behavior and affect. Function was assessed by using the FIM instrument and a clinical global impression of change. RESULTS: On the RAVLT, the mean scores for learning and short- and long-term recall improved by 0.4, 1.04, and.83 standard deviations (SDs) above baseline, respectively. On the CFT, the mean scores for short-term recall and long-term recall improved by 1.56 and 1.38 SDs above baseline, respectively. A positive trend was observed on the RBMT and on the NPI subscales. CONCLUSIONS: Donepezil may improve some aspects of memory and behavior in persons with chronic TBI. Randomized clinical trials are required to support these preliminary findings.

Adult↗

Imaging of cardiac metabolism using radiolabelled glucose, fatty acids and acetate.

The heart metabolizes a wide variety of substrates such as free fatty acids, glucose, lactate, pyruvate, ketone bodies and amino acids, but under normal conditions, free fatty acids and glucose are the major sources of energy. In contrast, in ischaemia with less than normal delivery of oxygen, oxidative metabolism of free fatty acids is decreased and exogenous glucose becomes the preferred substrate and the production of energy mainly depends on anaerobic glycolysis. These metabolic changes under various pathophysiological conditions of the myocardium stress the importance of metabolism for the function of the heart and allow metabolic imaging of important cardiovascular diseases. For the detection of cardiac energy metabolism, three different tracers have been developed and validated; namely radiolabelled glucose, fatty acids and acetate. [18F]-fluorodeoxyglucose (FDG) is a glucose analogue and the initial uptake of [18F]-fluorodeoxyglucose is almost identical to that of glucose. After uptake, [18F]-fluorodeoxyglucose undergoes phosphorylation but, unlike glucose-6-phosphate, FDG-6-PO4 does not undergo further metabolism and remains trapped in the myocardium. This trapping of FDG allows imaging of FDG by positron-emission-tomography and single photon emission computed tomography (SPECT) cameras. Use of FDG for assessing acute and chronic ischaemic syndromes has been studied, but it is mainly used in clinical practice to assess dysfunction of viable myocardium, which has the ability to improve in function. FDG data have been shown to adequately predict regional and global function improvement after revascularization of patients with chronic left ventricular dysfunction and coronary artery disease (CAD). They can also be a powerful predictor of prognosis in these patients. Fatty-acid metabolism can be studied after labelling with 1-123. Beta-methyl iodine phenylpentadecanoic acid is a structurally modified fatty acid, which is used to trace uptake of fatty acids in the myocardium. Similarly to the case with FDG distinct uptake patterns have been observed in patients with CAD, and preliminary data concerning detection of myocardial viability assessment of prognosis are available. Interesting data suggest that fatty-acid imaging is the most sensitive technique for assessing metabolic changes in patients with hypertrophic cardiomyopathy. [11C]-Acetate immediately enters the tricarboxylic-acid (TCA) cycle and metabolism of [11C]-acetate is dependent solely on the TCA-cycle activity. Because the TCA-cycle activity is directly coupled to myocardial oxygen consumption, clearance rates of [11C]-acetate are used to assess regional myocardial consumption of oxygen. [11C]-acetate imaging has been validated for normal subjects and patients with CAD and appears to be as effective as use of FDG for assessing viability. The unique feature of this technique is to measure the regional consumption of oxygen non-invasively. Thus myocardial metabolic imaging is a promising approach for achieving direct insight into the processes underlying functional abnormalities of the myocardium.

Acetates↗

Marchetti-Vicenzi nailing of humeral shaft fractures.

Between 1995 and 1999, 46 acute nonpathological humeral shaft fractures were treated with retrograde Marchetti-Vicenzi humeral nailing. The mean healing time of all fractures was 10.8 weeks. Forty-five fractures (97.9%) united primarily, and one needed bone grafting (2.1%). Function of the shoulder was excellent in 35 patients (76.1%) and moderate in 11 (23.9%). Elbow function was also excellent in 35 patients and moderate in 11. Global functional results were excellent in 16 patients (34.8%), good in 22 (47.8%) and fair in 8 (17.4%). There were 4 cases of 10 degrees varus malunion (8.6%), one case of 15 degrees varus malunion (2.1%), and one case of 15 degrees anterior angulation malunion (2.1%). These malunions were clinically well tolerated. Four patients required removal of the nail because of posterior elbow pain. Retrograde Marchetti-Vicenzi nailing is an acceptable alternative for the treatment of acute humeral shaft fractures with a low complication rate.

Adolescent↗

Automated quantification of myocardial ischemia and wall motion defects by use of cardiac SPECT polar mapping and 4-dimensional surface rendering.

SPECT of cardiac perfusion and blood pools provides ungated 3-dimensional and gated 4-dimensional (4D) datasets of the ventricular myocardium. Modern reconstruction and review software is used to reorient the transverse thoracic slices into cardiac short-axis slices. Several validated algorithms are used to analyze these data. These programs segment out the left ventricle, determine the apical and basal limits, and then contour the endo- and epicardial surfaces. From these, 4D images of cardiac function that enable a dynamic review of wall motion are obtained. Global function in gated studies can be quantified by automatic computation of stroke volume and ejection fraction. Remapping of myocardial perfusion and wall motion into polar maps enables standardized quantification of the extent and severity of heart disease after comparison with databases of healthy hearts (normal databases). Several validated software packages make processing of these SPECT datasets comparatively easy and operator independent. The objectives of this review article are to describe the steps in the processing of a cardiac SPECT dataset for viewing and quantification, to explain the underlying algorithms used for automated processing, to compare the features of various software packages, to demonstrate how to read polar maps, and to identify and correct artifacts resulting from errors in automated processing.

Gated Blood-Pool Imaging↗

An examination of self-reported chronic conditions and health status in the 2001 Medicare Health Outcomes Survey.

OBJECTIVES: To estimate the prevalence of chronic conditions in managed care-enrolled Medicare seniors (age 65 years plus) and to examine the association between self-reported chronic conditions and health status, as measured by the SF-36. METHODS: Data were obtained from the 2001 Medicare Health Outcomes Survey (HOS). The HOS is conducted to assess the quality of care provided to Medicare beneficiaries enrolled in managed care. The survey questionnaire, which was administered by phone or mail, includes the SF-36 and items addressing demographic characteristics, depressive symptoms, and chronic conditions. The SF-36 produces eight multi-item scale scores and physical and mental component summary scores. For this analysis, an ordinary least squares regression model was conducted using the SF-36 scales and summary scores as dependent variables to estimate the association between each chronic condition and the scale scores after adjusting for demographic variables. RESULTS: More than three-fourths of the respondents had at least one chronic condition. Among the conditions, hypertension (56.6%) arthritis of the hip or knee (39.7%) and arthritis of the hand or wrist (33.3%) were the most commonly reported. Compared with other variables, age and arthritis were most highly associated with the SF-36 measures reflective of physical health. Depressive symptoms had the strongest association with the SF-36 measures most reflective of mental health. Among the chronic conditions, the adverse impact of having difficulty in controlling urination, a relatively neglected condition, was only second to depressive symptoms in its negative relationship with vitality, social-functioning, and mental health. CONCLUSION: Chronic conditions were commonly reported among the older adults. The unique associations found between chronic conditions and domains of health status demonstrate the importance of examining the burden of these conditions in terms of functioning and well-being. The findings of this study may help inform decision making at the patient, health plan, and societal levels.

Adult↗

Evaluation of post-myocardial infarction regional and global left ventricular function by monoplane ventriculography: superiority of right versus left anterior oblique projection at any infarct location.

OBJECTIVES: To study the significance of serial quantitative regional wall motion analysis, volumes, and ejection fraction findings as well as their prognostic implications derived from cineventriculography in 30 degrees right anterior oblique (RAO) projection in comparison with 60 degrees left anterior oblique (LAO) projection in post-myocardial infarction patients. Ventriculographic left ventricular parameters are accepted surrogates of mortality in myocardial infarction. Nowadays, in contrast to a biplanar approach in most institutions and clinical trials, the investigation is reduced to monoplanar ventriculography. However, it is not known whether the relevance of the two established projections might differ in different infarct topographies. DESIGN AND METHODS: Two hundred and six consecutive patients with acute myocardial infarction (infarct duration < 6 h) were treated with streptokinase (group I, n = 103) and allocated randomly additional percutaneous transluminal coronary angioplasty (group II, n = 103). Biplanar cineventriculography studies were performed at the acute stage, before discharge, and 6 months after discharge from hospital. RESULTS: Regional wall motion analysis (using an algorithm of fixed radiants) documented larger hypokinetic areas and intensities on RAO than it did on LAO projections, whereby infarct size and its improvement (stunned myocardium) was displayed more comprehensively, and a higher predictive power for survival (P = 0.0002 versus NS) was shown in anterior and inferior infarcts. No advantage of the LAO projection could be detected for evaluation of lateral infarcts due to circumflex coronary artery thrombosis either. The predictive power of the global function (ejection fraction; the algorithm of disc summation method) established by RAO projection (P = 0.007) was superior to that of LAO projection (P = 0.03). Enlargement of volumes (left ventricular remodeling) could be documented significantly only by the RAO projection; the LAO projection failed to do so. Groups I and II did not differ in any respect. CONCLUSIONS: The RAO projection has excellent diagnostic and predictive power at any infarct location. In contrast, additional LAO projection provides little information that cannot be obtained reliably from the RAO projection.

Angioplasty, Balloon, Coronary↗

Effect of phenylephrine bolus administration on global left ventricular function in patients with coronary artery disease and patients with valvular aortic stenosis.

BACKGROUND: Although phenylephrine bolus administration is frequently used to increase coronary perfusion pressure in patients with coronary artery disease or valvular aortic stenosis, there are no data describing its effect on left ventricular function (LVF). METHODS: Twenty patients scheduled for elective coronary artery bypass grafting (group 1) and 18 patients scheduled for elective aortic valve replacement (group 2) entered the study. The effect of phenylephrine was compared with that of norepinephrine in those patients who developed a defined degree of arterial hypotension under general anesthesia. These patients were randomized to receive an initial bolus of either phenylephrine (1 micrograms/kg) or norepinephrine (0.05 micrograms/kg) followed by a bolus of the other drug after arterial pressure and heart rate (HR) had returned to baseline. Transesophageal echocardiography was used to evaluate LVF. Arterial pressure, HR, ejection time, and LV diameter, area, and wall thickness were recorded immediately before and for 3 min after bolus administration. Fractional diameter shortening, fractional area change, mean heart rate corrected velocity of circumferential fiber shortening (mVcfc), and LV meridional end-systolic wall stress (ESWS) were calculated. RESULTS: Both substances effectively restored arterial pressure in both groups. However, in group 1, phenylephrine administration resulted in a reduction of fractional area change from 0.51 (median) to 0.39 (P = 0.0007) and a reduction of mVcfc from 1.16 to 0.61 circ/s (P = 0.0001). End-systolic wall stress increased from 98 to 186 10(3) dyne-cm-2 (P = 0.0001). Administration of norepinephrine to group 1 and administration of either substance to the group 2 patients did not cause any significant changes of LVF. CONCLUSIONS: The results indicate that phenylephrine given as an intravenous bolus to patients with CAD anesthetized with fentanyl causes a transient impairment of LV global function and that phenylephrine bolus administration is well tolerated in patients with valvular aortic stenosis.

Aged↗

[Amputation or limb salvage? Assessing quality of life after tumor operations of the lower extremity].

The purpose of this study was to compare quality of life and subjective well-being between patients who underwent either amputation or limb-salvage procedures for lower extremity sarcomas in order to determine if this aspect can be considered in the decision on the type of surgery. Sixty-six patients were evaluated at least 1 year after surgery and systemic therapy for lower extremity sarcomas. Self-report questionnaires such as the Quality of Life Questionnaire (QLQ-C30), the Life Satisfaction Questionnaire (FLZ), and the Enneking Score (MSTS) were used. There were no differences in quality of life and subjective well-being between the two groups. Scores of the symptom scale (14.1 vs 13.2), the global quality of life (70.9 vs 71.0) as well as scores of the function scale (51.7 vs 50.3) were similar. Small differences in scores were found in social functioning but not in scores of physical, cognitive, and emotional functioning. Global subjective well-being in both groups was also similar (219.5 vs 223.7). High satisfaction was found in marital life and partnership as well as in self-assessment. The least satisfaction was found in finances. Results in functional outcome after limb-salvage procedures (77% vs 65%) were better. Although more complications were reported after limb-salvage procedures, they did not seem to have any impact on quality of life ( p=0.235, r(p)=0.112) and subjective well-being ( p=0.856, r(p)=0.140) of the patients whereas a correlation to function could be shown ( p<0.001, r(p)=0.595; p=0.015, r(p)=0.304). Additionally, a correlation between subjective well-being and the location of either amputation or reconstruction ( p=0.039, r(p)=- 0.309) could be shown. These findings demonstrate that the type of surgery has no influence on quality of life and subjective well-being after lower extremity sarcomas. Thus the decision for either limb-salvage procedures or amputation cannot be based on quality of life and subjective well-being but must be determined by oncological criteria.

Activities of Daily Living↗

Assessment of various parameters in the estimation of differential renal function using technetium-99m mercaptoacetyltriglycine.

Differential renal function (DRF) is an important parameter that should be assessed from virtually every dynamic renogram. With the introduction of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3), a tracer with a high renal extraction, the estimation of DRF might hopefully become accurate and reproducible both between observers in the same institution and also between institutions. The aim of this study was to assess the effect of different parameters on the estimation of DRF. To this end we investigated two groups of children: group A, comprising 35 children with a single kidney (27 of whom had poor renal function), and group B, comprising 20 children with two kidneys and normal global function who also had an associated 99mTc-dimercaptosuccinic acid scan (99mTc-DMSA). The variables assessed for their effect on the estimation of DRF were: different operators, the choice of renal regions of interest (ROIs), the applied background subtraction, and six different techniques for analysis of the renogram. The six techniques were based on: linear regression of the slopes in the Rutland-Patlak plot, matrix deconvolution, differential method, integral method, linear regression of the slope of the renograms, and the area under the curve of the renogram. The estimation of DRF was less dependent upon both observer and method in patients with two normally functioning kidneys than in patients with a single kidney. The inter-observer comparison among children in either group was not dependent on either ROI or background subtraction. However, in patients with poor renal function the method of choice for the estimation of DRF was dependent on background subtraction, though not ROI. In children with two kidneys and normal renal function, the estimation of DRF from the 24 techniques gave similar results. Methods that produced DRF values closest to expected results, from either group of children, were the Rutland-Patlak plot and matrix deconvolution methods.

Area Under Curve↗

Stem cells and regeneration of the cardiovascular system: facts, fictions, and uncertainties.

The data reviewed here support the view that bone marrow (BM) stem cells can migrate to infarcted myocardium and differentiate into mature, functional cardiomyocytes. Cytokines can mobilize BM stem cells from marrow leading to homing of progenitor cells to infarcted myocardium. Interestingly, contractile performance in these studies appears greater than the capacity of the regenerated cell mass and its biomechanial organization predict, suggesting that the function of the regenerated cell per se may not alone account for global functional recovery.

Bone Marrow Cells↗

Effects of surgery for postinfarction ventricular tachycardia on parameters of left ventricular function.

Heart failure is the leading cause of death in patients after surgery for ventricular tachycardia. This study examines the effects of antiarrhythmic surgery on 4 parameters of left ventricular (LV) function. Global ejection fraction, segmental wall motion score, homogeneity of contraction, and diastolic function were measured in 32 patients by technetium-99m radionuclide ventriculography. Ejection fraction was measured from the left anterior oblique image. Wall motion score was assessed semiquantitatively for 11 LV segments from 3 projections. Homogeneity of contraction was expressed as the SD of the LV phase analysis curve during systole from the left anterior oblique image. Diastolic function was expressed in terms of peak and mean first time derivative of the action potential (dV/dt) of the LV function curve. Subgroup analyses were performed to distinguish the effects of aneurysmectomy, coronary artery bypass grafting, and changes in angiotensin converting enzyme inhibitor therapy. Mean systolic function improved after surgery (ejection fraction 22% vs 32%, p <0001; wall motion score 20 vs 13, p <0.0001; phase analysis 18 vs 12, p <0.03). Mean diastolic function also improved (peak dV/dt 0.83 +/- 0.32 vs 1.49 +/- 0.39, p = 0.006; mean dV/dt 0.41 +/- 0.15 vs 0.76 +/- 0.27, p = 0.006). Improvements were not confined to those who had aneurysmectomy or coronary bypass grafting and were not explained by changes in vasodilator therapy. Thus, antiarrhythmic surgery does not inherently damage LV function. Significant improvements were observed in most patients. Failure to improve indicated a poor longer term prognosis.

Aged↗