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PURPOSE: Data are unavailable for rational selection of pulse sequences to assess postinfarction myocardial viability in rodents at high field strength. We implemented a widely used clinical inversion recovery (IR) sequence at 4.7T and compared the results to a heavily T1-weighted cine FLASH sequence (T1-CF) for assessment of infarction size. MATERIALS AND METHODS: Eleven infarcted rats were examined within 24 h of infarction after injection of Gadophrin-3 contrast agent. Images were acquired using both pulse sequences and a standard cine (SC) sequence. Estimates of infarct size were compared to TTC. Global LV function was compared between the T1-CF and SC sequences. RESULTS: SNR, relative SNR, and CNR for the infarcted and normal myocardium were significantly greater for the IR sequence. Infarction size was overestimated by both sequences, but correlated highly and showed very close agreement with TTC. Global function revealed no significant differences between T1-CF and SC. CONCLUSION: Both IR and T1-CF produced reliable results for assessment of infarction size at 4.7T. While the IR sequence delivers better overall SNR and CNR, the T1-CF allows concomitant assessment of global cardiac function with a much shorter acquisition time.
AIM: We investigated the effect of coronary artery bypass grafting (CABG) surgery on global and regional myocardial function; before and immediately after coronary artery bypass grafting and 1 month after the operation. METHODS: Twenty-five patients who were undergoing elective CABG were evaluated. Transesophageal echocardiography (TEE) was used to evaluate both global and regional myocardial function. Intraoperative TEE images of the left ventricle were obtained after cannulation but before cardiopulmonary bypass (CPB), 5 and 30 minutes after the termination of CPB. Same time, hemodynamic parameters were recorded. Transesophageal echocardiography evaluation was repeated one month after the operation. RESULTS: Global left ventricular function was significantly depressed 5 minutes after CPB. At the 30 minutes after CPB, left ventricular function has returned to pre-CPB baseline levels. Global left ventricular function was significantly increased at 30 days following CABG surgery. The myocardial segments that were normal before CABG had reduced contractile functions at 5 minutes after CABG but normal segments showed a significant improvement from 5 to 30 minutes. The function of this region could not reach its initial status. The segments that had severe impairments of contractile function before the revascularization showed significant improvements at 30 minutes following CABG. CONCLUSIONS: In conclusion, a successful coronary revascularization provides an improvement in contractility in cases with chronic regional left ventricular dysfunction that is not related to irreversible necrosis.
A methodology for predicting the expected combined stochastic radiobiological effects of sequential exposure to different ionizing radiations is used to arrive at a methodology for predicting the radiobiological effects of simultaneous exposure. Both methodologies require developing additive-damage dose-effect models. Additive-damage dose-effect models are derived assuming (a) each radiation comprised by the combined exposure produces initial damage called critical damage that could lead to the radiobiological effect of interest; (b) doses of different radiations that lead to the same level of radiobiological effect (or risk) can be viewed as producing the same amount of critical damage and being indistinguishable as far as the effects of subsequently administered radiation. Derived dose-effect functions that describe the risk per individual, conditional on radiation dose, are called risk functions. The methodologies allow the use of known radiation-specific risk functions to derive risk functions for combined effects of different radiations. The risk functions for combined exposure to different radiations are called global risk functions. For sequential exposures to different ionizing radiations, the global risk functions derived depend on how individual radiation doses are ordered. Global risk functions can also differ for sequential and simultaneous exposure. The methodologies are used to account for some previously unexplained radiobiological effects of combined exposure to high and low linear-energy-transfer radiations.
OBJECTIVES: We sought to compare left ventricular (LV) function assessed with multislice computed tomography (MSCT), biplane cineventriculography (CVG), and transthoracic echocardiography (Echo), with magnetic resonance imaging (MRI) as the reference standard. BACKGROUND: With the same data as acquired for noninvasive coronary angiography, MSCT enables registration of myocardial function. METHODS: A total of 88 patients (64 men and 24 women) underwent MSCT with 16 x 0.5 mm detector collimation, CVG, and MRI, whereas Echo was retrospectively analyzed in a subset of 30 patients. RESULTS: Regarding the ejection fraction, the agreement was significantly superior for MSCT than for CVG (+/- 10.2% vs. +/- 16.8%; p < 0.001) and Echo (+/- 11.0% vs. +/- 21.2%; p < 0.001). For the end-diastolic and end-systolic volumes, the limits of agreement with CVG (p < 0.001) and Echo (p < 0.001 and p < 0.02, respectively) were also significantly larger than with MSCT. In comparison with MSCT, CVG significantly overestimated the end-diastolic and end-systolic volumes (p < 0.001). Intraobserver analysis of MSCT yielded limits of agreement for ejection fraction (+/- 4.8%), end-diastolic volume (+/- 15.6 ml) and end-systolic volume (+/- 8.0 ml), and myocardial mass (+/- 18.2 g). The accuracy in identifying patients and myocardial segments with abnormal regional function was significantly higher with MSCT (84% and 95%) than with CVG (63% and 90%; p < 0.002 and p < 0.001), whereas MSCT and Echo were not significantly different in identifying patients with abnormal regional function. CONCLUSIONS: Our results indicate that the assessment of global and regional LV function with MSCT is more accurate than with CVG, whereas MSCT is superior to Echo for global function. This suggests that MSCT allows reliable evaluation of global and regional LV function.
OBJECTIVE: We sought to investigate the geometric changes of the mitral annulus during systole in relation to global left ventricular (LV) systolic function using real-time 3-dimensional (3D) echocardiography. METHODS: Real-time 3D echocardiography was performed in 23 patients with global LV systolic dysfunction with ejection fraction of 37 +/- 19% and 9 control subjects with ejection fraction of 62 +/- 4%. Volumetric data were divided into 9 rotational apical planes (angle increment = 20 degrees) using 3D software. Nine rotational annular dimensions (ADs) were measured in all planes in early and late systole. Nonplanar angle (NPA) of the annulus between two vectors from two hinge points of the annulus in the anteroposterior plane to the center between two commissures in the commissure-commissure plane was measured during early and late systole. Fractional changes of NPA and AD were defined as changes in percentage during systole. RESULTS: NPA significantly increased during systole (early, 145 +/- 12 degrees; late, 160 +/- 9 degrees; P < .01). Among 9 ADs, 3 anteroposteriorly directed ADs showed the most prominent fractional increases during systole in all patients. Both fractional changes of NPA ( R 2 = 0.87, P < .01) and the anteroposterior dimension, AD 1 ( R 2 = 0.85, P < .01) showed significant positive correlation with global LV systolic function. CONCLUSIONS: Real-time 3D echocardiography demonstrated that saddle shape of the mitral annulus was getting enlarged and less nonplanar mainly in the anteroposterior direction during systole. These geometric changes were proportional to the global LV systolic function.
BACKGROUND: Hypertrophic cardiomyopathy is classically defined as a diastolic disease with normal systolic function. Long axis left ventricular function is an important and sensitive determinant of global ventricular function but its assessment is often difficult and complex. Tissue Doppler imaging of the mitral annulus allows the study of long axis left ventricular function. METHODS: 47 patients with non-obstructive hypertrophic cardiomyopathy and 45 healthy volunteers, matched by age and sex, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony. Data were compared among the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to normal subjects, hypertrophic cardiomyopathy patients showed: 1--Systolic function: lower velocities, longer systolic time intervals (isovolumic relaxation time, time to peak s, ejection time), higher systolic asynchrony (time to peak s, ejection time, systolic time) and lower s/shortening fraction ratio. These changes occurred despite normal indices of global systolic function. 2--Diastolic function: lower velocities (much lower rapid filling velocity, lower atrial contraction velocity, lower septal e/a), higher e/a heterogeneity index, longer protodiastolic times (isovolumic relaxation time and time to peak e), higher diastolic asynchrony (time to peak e) and lower e wave integral. Hypertrophic cardiomyopathy patients also showed higher average number of annular sides with e/a < 1 per patient and higher percentage of e/a < 1, mainly on the septal side. CONCLUSIONS: This study shows that: 1--Tissue Doppler imaging allows the detailed analysis of long axis left ventricular function in hypertrophic cardiomyopathy patients. 2--Long axis systolic function is abnormal in this disease, even in the presence of normal indices of global systolic function. 3--Long axis diastolic function is deeply disturbed in hypertrophic cardiomyopathy, at ventricular and atrial levels. 4--Long axis dysfunction occurs in annular sides contiguous to hypertrophied and non-hypertrophied walls, highlighting the role of other factors in its pathophysiology.
Donepezil (E-2020) is a reversible, noncompetitive, piperidine-type cholinesterase inhibitor. It is selective for acetylcholinesterase rather than butyrylcholinesterase. Donepezil 5 and 10 mg/day significantly improved cognition and global clinical function compared with placebo in well designed short term trials (14 to 30 weeks) in 161 to 818 patients with mild to moderate Alzheimer's disease. Beneficial effects on cognition were observed from week 3 of treatment. Donepezil 10 mg/day significantly delayed the deterioration in activities of daily living (ADL) [by 55 weeks] compared with placebo in a retrospective analysis of 1 trial, and in the largest trial significantly improved patients' abilities to perform complex tasks. However, no significant improvement in function was observed with donepezil 5 mg/day in another trial. In the 2 trials of longest duration donepezil (5 and 10 mg) significantly delayed symptomatic progression of the disease. While there was no evidence for a positive effect of donepezil on patients' quality of life, there are no validated measures of this parameter specific to patients with Alzheimer's disease. Donepezil (5 and 10 mg) significantly reduced caregiver burden. Long term efficacy data suggest that improvements in cognition, global function or ADL are maintained for about 21 to 81 weeks with donepezil (10 mg/day in most patients). Donepezil is generally well tolerated with the majority of adverse events being mild and transient. Predictably, most events were cholinergic in nature and generally related to the gastrointestinal and nervous systems. The incidence of these events was significantly higher with donepezil 10 mg than with placebo in short term clinical trials; however, this may have been due to the 7-day dose increase schedule used in these studies and can be minimised by increasing the dose after a longer (6-week) period. The incidence of serious adverse events was generally similar between donepezil 5 and 10 mg (4 to 10%) and placebo (5 to 9%) in short term trials. 26% of patients receiving donepezil (5 and 10 mg) reported serious events over a 98-week period in a long term trial. Importantly, there was no evidence of hepatotoxicity with this drug. Conclusions. Donepezil (5 and 10 mg) is an agent with a simple once-daily dosage schedule which improves cognition and global clinical function in the short (up to 24 weeks) and long term (up to about 1 year) in patients with mild to moderate Alzheimer's disease. Improvements in ADL were also observed with donepezil 10 mg/day. Adverse events associated with donepezil are mainly cholinergic. Donepezil has been extensively studied and should be considered as a first-line treatment in patients with mild to moderate Alzheimer's disease.
Functional and metabolic recovery of a female cat is described which survived for 1 year following 1 hour global cerebro-circulatory arrest at normothermia. Ischemia was produced by intrathoracal occlusion of the innominate, the left subclavian and both mammary arteries. Following ischemia the animal was kept under intensive care for 46 h. EEG and evoked potentials began to recover after 3 h following ischemia, and spontaneous respiration returned promptly on the 2nd day when the animal was weaned from the respirator. The neurological deficit score declined from a maximum of 395 immediately after ischemia to 158 during the first week and to 40 within 4 weeks. At this time the animal was slightly ataxic but she was able to walk and to feed and clean herself. One year after ischemia EEG and evoked potentials were normal. Morphological studies and the autoradiographic evaluation of protein biosynthesis revealed an almost normal pattern in cortical structures but there was almost complete atrophy of dorsal hippocampus and striatum leading to enlargement of the ventricular system. These observations demonstrate that despite these lesions the central nervous system is able to recover integrative neurological function after cerebro-circulatory arrest in normothermia of as long as 1 h.
Right ventricular (RV) dysfunction determines prognosis in patients with chronic pulmonary disease. We examined the relative prognostic potential of measures of systolic, diastolic, and global RV function in 87 patients with chronic pulmonary disease. Systolic function was evaluated by measuring RV dimensions, diastolic function by pulsed wave Doppler of the tricuspid flow profile, and global function by the Tei index. After 15.5 months follow-up, 47 patients had died. Univariate analysis demonstrated that both clinical and echocardiographic variables predicted survival. In the multivariate model both RV end-diastolic diameter index and velocity of late diastolic filling were independent predictors of survival. Receiver operator characteristic analysis demonstrated that a composite model combining these 2 measures provided the most powerful prognostic information. Echocardiographic indices of RV function identify patients with pulmonary disease at high risk and provide incremental prognostic information over and above that supplied by clinical data.
The immediate effect of coronary artery bypass surgery on global and regional myocardial function using the internal mammary artery (IMA) versus saphenous vein (SV) was studied intraoperatively using transesophageal echocardiography (TEE). Thirty-two patients received an IMA and 10 patients only SV. Transesophageal echocardiography was recorded before thoracotomy, 5 minutes after the end of cardiopulmonary bypass (CPB) and after chest closure. Global and regional left ventricular function were expressed as a percent of the short axis area change (%SAAC) and a percent of the fractional area change (%FAC), respectively. Segments were classified according to their baseline function as normal, %FAC greater than 40%, or dysfunctional, %FAC less than 40%. Only normal segments were considered in this study. No significant change in %SAAC in either group was observed in this study. Internal mammary artery revascularized segments showed a significant decrease in %FAC from 57 +/- 1 before thoractomy to 53 +/- 2 5 minutes after CPB, whereas SV segments showed a significant improvement in %FAC from 56 +/- 1 to 61 +/- 1. Applying strict criteria derived from intraobserver and cycle-to-cycle variability, 17% of IMA segments had deteriorated by more than 36% whereas only 4% of SV segments showed such deterioration. Conversely, 17% of SV segments showed an increase in %FAC by more than 36% and only 3% of IMA segments improved similarily. The observed changes were of short duration and had largely resolved by chest closure.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to investigate whether dopamine combined with bunazosin improves cardiac function, the global and regional cardiac function and regional blood flow of 7 anesthetized dogs were analyzed before and after occlusion of the left anterior descending coronary artery (LAD), then after 10 micrograms/kg/min dopamine infusion following the LAD occlusion, and again after a bolus infusion of bunazosin 250 micrograms/kg. Dopamine with bunazosin reduced left atrial pressure from 4.9 +/- 0.9 to 3.1 +/- 0.5 mmHg (p less than 0.05) and improved cardiac output from 1.22 +/- 0.15 to 1.50 +/- 0.14 L/min (p less than 0.05), maximum positive left ventricular dp/dt from 1721 +/- 202 to 3600 +/- 663 mmHg/sec (p less than 0.05) and the time constant from 45.2 +/- 5.0 to 27.5 +/- 4.6 msec (p less than 0.01). Bunazosin added to the dopamine reduced the elevated left ventricular peak systolic pressure caused by dopamine from 130 +/- 7 to 113 +/- 8 mmHg (p less than 0.01). With regard to the regional wall motion, the impaired LAD-delta L (the segment systolic shortening) and LAD-Elmax (the slope of peak systolic pressure--endsystolic length relation) following the LAD occlusion improved from 0.5 +/- 2.5 per cent to 5.9 +/- 2.6 per cent (p less than 0.01) and from 50 +/- 9 to 82 +/- 14 mmHg/mm (p less than 0.01) after the infusion of dopamine with bunazosin. Dopamine greatly increased the Rate Pressure Product (RPP) from 12610 +/- 1120 after LAD occlusion to 16950 +/- 1420, whereas dopamine in combination with bunazosin did not increase the RPP due to a drop of LV-PSP with little change in regional myocardial blood flow. It was concluded that combining dopamine with bunazosin was useful for improving both the global and regional cardiac functions of the ischemic heart.
We hypothesized that intermittent coronary sinus retroperfusion (ICSR) would improve cardiac function after an in situ ischemic insult. To test this, we analyzed the global and regional ventricular function of anesthetized open-chest dogs. The left anterior descending coronary artery (LAD) was occluded for 135 minutes before the animals were killed. ICSR was performed for the 120 minutes (from 5 minutes to 135 minutes after ligation of the LAD) using balloon catheter which is placed at the coronary sinus via right atrium artery. Measurements were performed before, and seven specific times after occlusion of the LAD. Values were expressed as 100% at 15 minutes after LAD ligation. We found that percent recovery of the max volume of the instantaneous pressure-volume ratio (Emax) demonstrated a significant change between the ICSR group (n = 7) and the control group (n = 7) at 60 minutes after the beginning of ICSR (ICSR group: 126.6 +/- 23, control group: 84.5 +/- 40, p < 0.05). Also left ventricular systolic pressure and maximum negative dp/dt improved in ICSR group compared with control group 75 minutes after LAD occlusion (p < 0.01). Other cardiac functions were a trend toward improvement by ICSR though there was no significant difference between any groups. However in the control group, cardiac function was worse after occlusion. We concluded that retrograde perfusion with ICSO improved both global and regional cardiac functions in the acute myocardial infarction.
AIMS: To investigate regional systolic function of the left ventricle, to test the hypothesis that "pure" diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction > or = 50%) is associated with longitudinal systolic dysfunction. METHODS AND RESULTS: One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart failure, 30 with systolic heart failure; and 39 age-matched normal volunteers) were studied by conventional and tissue Doppler echocardiography. Global diastolic function was assessed using the flow propagation velocity, and by estimating left ventricular filling pressure from the ratio of transmitral E and mitral annular E(TDE) velocities (E/E(TDE)); and global systolic function by measurement of ejection fraction. Radial and longitudinal functions were assessed separately from posterior wall and mitral annular velocities. Global and radial systolic function were similar in patients with "pure" diastolic dysfunction and normal subjects, but patients with either asymptomatic diastolic dysfunction or diastolic heart failure had impaired longitudinal systolic function (mean velocities: 8.0+/-1.2 and 7.7+/-1.5 cm/s, respectively, versus 10.1+/-1.5 cm/s in controls; p<0.001). In subjects with normal ejection fraction, global diastolic function correlated with longitudinal systolic function (r=0.56 for flow propagation velocity, and r=-0.53 for E/E(TDE) ratio, both p<0.001), but not with global systolic function. CONCLUSION: Worsening global diastolic dysfunction of the left ventricle is associated with a progressive decline in longitudinal systolic function. Diastolic heart failure as conventionally diagnosed is associated with regional, subendocardial systolic dysfunction that can be revealed by tissue Doppler of long-axis shortening. Diagnostic algorithms and definitions of heart failure need to be revised.
PURPOSE OF THE STUDY: This study was performed to analyse the clinical and radiological results obtained after the treatment of femoral fractures after total hip arthroplasties by a Charnley's extra long-stem prosthesis, and to compare these results with those obtained by alternative treatments proposed by various authors. MATERIALS: 18 patients, whose mean age was 68.5 years (extremes: 45 to 86 years). Cooke and Newman fractures classification showed a clear prominence of type III. In 8 cases we found a femoral loosening, prior to the fracture, divided as follows: 4 in grade III and 4 in grade IV, using Vives classification. Type I fractures were always associated to complete femoral loosening. METHOD: Clinical results were analysed by Merle d'Aubigné's scoring system, giving a pre-fracture global score of 13.5. Post-operative radiological analysis was made on the appearance of femoral radiolucent lines and/or modification of the femoral implant. RESULTS: 17 patients were followed, with a mean of 5 years (extremes: 1 to 14 years). Consolidation was always obtained. The global mean functional results were of 15.2, with score improvement, essentially, of soreness and stability. We found 12 good and very good results, 4 poor and 1 bad. Age (< 75 years) and fracture type (II and III) appeared to be important factors influencing the functional result, contrary to the lesional mechanism. 6 non-evolutive bone-cement radiolucent lines appeared, in immediate post-operative phase. One cement-prosthesis radiolucent line appeared later, leading to loosening and rupture of the implant. We deplore 3 stem twistings, of which only one led to implant rupture. Walking with support was possible at the 5th postoperative days. DISCUSSION: Our functional results are encouraging (12 good results, i.e. 71 per cent), compared with other treatments. This technique improved the global functional score. This is due to the simultaneous treatment of the fracture and of the eventual pre-traumatic associated femoral loosening. The technique allows a quick resumption of autonomy, a short hospitalization time for these elderly patients. The main disadvantage of the orthopaedic treatment is the prolonged decubitus and the important risk of secondary loosening. Osteosynthesis by plate has the advantage of keeping a maximum of osseous stock, but delays weight bearing, favours the non union by a large loss of periosteum. It never permits the treatment of the associated loosening during the same operation. It is also at the origin of a cement weakening, while fixing the proximal screws, leading to the difficulty of placing the prosthesis. Major disadvantage of proposed method is the use of a high quantity of cement to ensure stability of the implants; but this has never had negative consequences in our study. CONCLUSION: This surgical technique seems to be a satisfying alternative to the treatment of femoral fractures on total hip arthroplasty, due to the advantages obtained. It is reserved for elderly patients. However, these findings should be taken with caution, due to our small series.
The global behavior of interactions between genes can be investigated by forming the network of functionally-related genes using the annotations based on the Gene Ontology. We define two genes to be connected when the pair of genes is involved in the same biological process. There has been other work on the analysis of different kinds of cellular and metabolic networks, such as gene coexpression network, in which genes are paired when they are found to be coexpressed in the microarray experiments. We observe that our functionally-related gene networks among humans, fruit flies, worms and yeast exhibit the small-world property, but all except the network of worms show the existence of the scale-free property.