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PubMed1995

Agreement between patient self-report and clinician rating: concurrence between the BSI and the GAF among psychiatric inpatients.

Two rating scales were compared for 200 adult psychiatric inpatients at admission to, and discharge from, the hospital. Patients rated their own psychological symptoms on the Brief Symptom Inventory (BSI), and clinicians rated patients' psychological, social, and occupational functioning on the Global Assessment of Functioning (GAF) Scale. Analyses indicated no significant relationships between symptom distress reported by patients and global functioning rated by clinicians. These findings support previous research that has shown minimal congruence among criterion measures that differ in rating source.

Adolescent↗

PubMed2004

Usefulness of myocardial contrast echocardiography in predicting global left ventricular functional recovery after anterior wall acute myocardial infarction.

Although multiple recent studies have shown that myocardial contrast echocardiography (MCE) reliably differentiates between regional stunning and necrosis after acute myocardial infarction (AMI), prognosis is more closely related to measures of global left ventricular systolic function. One hundred fifteen patients underwent baseline wall motion assessment and MCE 2 days after admission and follow-up echocardiography a mean of 69 days later. Good agreement was found between perfusion score index and follow-up wall motion score index, indicating that MCE performed early after anterior wall AMI may be clinically useful in routine post-AMI risk stratification.

Aged↗

PubMed1989

Effects of primary sequence differences on the global structure and function of an enzyme: a study of pyruvate kinase isozymes.

Pyruvate kinase is an important glycolytic enzyme which is expressed differentially as four distinct isozymes whose catalytic activity is regulated in a tissue-specific manner. The kidney isozyme is known to exhibit sigmoidal kinetics, whereas the muscle isozyme exhibits hyperbolic kinetic properties. By integration of the crystallographic [Stuart, D. I., Levine, M., Muirhead, H., & Stammers, D.K. (1979) J. Mol. Biol. 134, 109-142] and primary sequence data [Noguchi, T., Inoue, H., & Tanaka, T. (1986) J. Biol. Chem. 261, 13807], it was shown that the primary sequence for the C alpha 1 and C alpha 2 regions may constitute the allosteric switching site. To provide insights into the effects of the localized sequence change on the global structural and functional behavior of the enzyme, kinetic studies under a wide spectrum of conditions were conducted for both the muscle and kidney isozymes. These conditions include measurements of enzyme activity as a function of substrate concentrations with different concentrations of allosteric inhibitors or activators. These results showed that both isozymes exhibit the same regulatory properties although quantitatively the distribution of active and inactive forms and the various dissociation constants which govern the binding of substrate and allosteric effectors with the enzyme are different. For such a majority of equilibrium constants to be altered, the localized primary sequence change must confer global perturbations which are manifested as differences in the various equilibrium constants. Structural information about these two isozymes was provided by phase-modulation measurement of the fluorescence lifetime of tryptophan residues under a variety of experimental conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2003

Performance of OSEM and depth-dependent resolution recovery algorithms for the evaluation of global left ventricular function in 201Tl gated myocardial perfusion SPECT.

UNLABELLED: It is unknown whether the use of ordered-subsets expectation maximization (OSEM) and depth-dependent resolution recovery (RR) will increase the accuracy of (201)Tl electrocardiogram-gated SPECT (GSPECT) for the measurement of global left ventricular (LV) function. METHODS: Fifty-six patients having both rest (201)Tl GSPECT and planar equilibrium radionuclide angiography (planar(RNA)) on the same day were studied. Twenty-nine patients also had LV conventional contrast angiography (Rx). LV ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) were calculated with the quantitative gated SPECT software (QGS) using 4 different processing methods: filtered backprojection (FBP), OSEM, RR + FBP, and RR + OSEM. LVEF calculated with planar(RNA) and LV EDV and ESV calculated with Rx were considered gold standards. LVEF and volumes provided with the GSPECT methods were compared with the gold standard methods. RESULTS: LVEF calculated with GSPECT methods (FBP, OSEM, RR + FBP, and RR + OSEM) were similar (not statistically significant) and correlated well with planar(RNA). On Bland-Altman analysis, the mean +/- SD of absolute difference in LVEF with GSPECT FBP, OSEM, RR + FBP, and RR + OSEM methods versus planar(RNA) were similar, with relatively large limits of agreement. LV volumes calculated with the 4 GSPECT methods were significantly lower but correlated well with Rx LV volumes. LV volumes calculated with FBP and OSEM were lower than those calculated with RR + FBP and RR + OSEM (P < 0.01). On Bland-Altman analysis, the mean +/- SD of absolute difference in LV volumes with FBP, OSEM, RR + FBP, and RR + OSEM versus Rx was, respectively, 56 +/- 45 mL (P < 0.01 vs. the other 3 methods), 57 +/- 45 mL (P < 0.01 vs. the other 3 methods), 43 +/- 48 mL, and 46 +/- 47 mL, with correspondingly large limits of agreement. The variance of random error did not differ between FBP, OSEM, RR + FBP, and RR + OSEM for either LVEF or volumes. CONCLUSION: OSEM and FBP presented similar accuracy for LVEF and volume measured with the QGS software. Their combination with depth-dependent RR provided similar LVEF but more accurate LV volumes.

Algorithms↗

PubMed2005

Tissue-engineered myocardial patch derived from extracellular matrix provides regional mechanical function.

BACKGROUND: Extracellular matrix (ECM), a tissue-engineered scaffold, recently demonstrated cardiomyocyte population after myocardial implantation. Surgical restoration of myocardium frequently uses Dacron as a myocardial patch. We hypothesized that an ECM-derived myocardial patch would provide a mechanical benefit not seen with Dacron. METHODS AND RESULTS: Using a canine model, a full thickness defect in the right ventricle was repaired with either Dacron or ECM. A third group had no surgery and determined baseline RV function. Eight weeks later, global systolic function was assessed by the preload recruitable stroke work relationship. Regional systolic function was measured by systolic area contraction (SAC), calculated by high density mechanical mapping. Tau was used to assess global diastolic function. Recoil rate and diastolic shear were used as measures of regional diastolic function. After functional data acquisition, tissue was fixed for histological evaluation. Global systolic and diastolic functions were similar at baseline and after ECM and Dacron implantation. Regional systolic function was greater in the ECM group compared with the Dacron group (SAC: 4.1+/-0.9% versus -1.8+/-1.1, P<0.05). Regional diastolic function was also greater in the ECM group (recoil rate (degrees sec(-1)): -44+/-7 versus -17+/-2, ECM versus Dacron; P<0.05). Immunohistochemical analysis revealed cardiomyocytes in the ECM implant region, a finding not seen with Dacron. CONCLUSIONS: At 8 weeks, an ECM-derived tissue-engineered myocardial patch provides regional mechanical function, likely related to cardiomyocyte population. These results are in sharp contrast to Dacron, a commonly used myocardial patch.

Absorbable Implants↗

PubMed2005

Evaluation of Tissue Doppler Tei index for global left ventricular function in mice after myocardial infarction: comparison with Pulsed Doppler Tei index.

AIM: The Pulsed Doppler Tei index is a parameter to evaluate combined systolic and diastolic function in humans. However, one major limitation is that the parameters of Pulsed Doppler Tei index cannot be measured within one cardiac cycle. Therefore, accuracy of the Pulsed Doppler Tei index may be affected by anesthesia induced heart rate variation in mice echocardiography. Tissue Doppler Imaging (TDI) enables us to measure both relaxation and contraction velocities simultaneously. Thus, the aim of our study was to validate TDI and Pulsed Doppler Tei index and their reproducibility in mice after experimental anterior myocardial infarction (MI). METHODS AND RESULTS: Pulsed Doppler Tei index and TDI Tei index were assessed before and 4 weeks after MI. Both parameters increased significantly after MI (Pulsed Doppler: 0.4+/-0.04 to 0.7+/-0.03; P<0.001; TDI: 0.2+/-0.03 to 0.5+/-0.04; P<0.0001). In addition, TDI Tei index showed a good correlation with ejection fraction and fractional shortening, and was indicated by better reproducibility than Pulsed Doppler Tei index. CONCLUSION: Tissue Doppler Tei index is appropriate to characterize global left ventricular function in mice after MI.

Animals↗

PubMed1997

Echocardiographic Assessment of Regional and Global Left Ventricular Function Wall-Motion Scoring in Parasternal and Apical Views Versus Apical Views Alone.

The aim of the study was to examine the value of echocardiographic wall-motion scoring in apical views as compared to a conventional combination of apical and parasternal views. In 50 consecutive patients referred to coronary arteriography for potential revascularization, echocardiographic digital image loops of the left ventricle (LV) were recorded in parasternal long- and short-axis views and in apical long-axis, two-, and four-chamber views. Eight of 16 standardized LV segments appear both in the apical and in the parasternal views (group 1 segments). The remaining eight segments are visualized in the apical views only (group 2). Using a cross-over design, two cardiologists independently performed regional wall-motion scoring based on apical views, respectively, based on the combination of parasternal and apical views. Using the conventional approach (parasternal and apical views) 98% of the total 800 segments were scored as compared to 95% when using the mere apical approach (P < 0.05); 94% of the 800 segments were scored from both approaches. The regional wall-motion score was identical in 76% of group 1 segments and in 77% of group 2 segments. It diverged, at most, one score in 94% of group 1 segments and in 91% of group 2 segments (P > 0.05). LV ejection fraction (EF) calculated on the basis of average wall-motion score exclusively assessed from the apex differed little from angiographic EF (mean difference 2.0%, 95% confidence limits +/- 6.6%). Intraobserver variability of wall-motion scores (n = 25 patients) was small and almost identical for the two cardiologists. Similarly, interobserver variability was small and identical for apical views and conventional views. We conclude that there is no substantial loss of information when echocardiographic evaluation of regional and global left ventricular function is performed solely from the apical approach.

Journal Article↗

PubMed2005

Protein-energy malnutrition impairs functional outcome in global ischemia.

We investigated whether protein-energy malnutrition (PEM) exacerbates brain injury in global ischemia. It was hypothesized that PEM would increase secondary brain damage by worsening ischemia-induced depletion of glutathione (GSH) and increasing oxidative stress. Adult male gerbils were fed an adequate protein (12.5%; C) or low protein (2%; PEM) diet for 4 weeks and subjected to 5 min of bilateral carotid artery occlusion (Ischemia) or sham surgery (Sham). At 12 h post-ischemia, GSH and markers of oxidative stress were measured in hippocampus and neocortex. The remaining gerbils were tested in the open field on days 3, 7, and 10, with viable hippocampal CA1 neurons assessed on day 10. Although the habituation of C-Ischemia gerbils in the open field was normal by day 7, PEM-Ischemia gerbils failed to habituate even by day 10 and spent greater time in the outer zone (P < 0.05). Mean (+/-SEM) total number of viable CA1 neurons at 10 days post-ischemia were C-Sham = 713 (13), C-Ischemia = 264 (48), PEM-Sham = 716 (12), and PEM-Ischemia = 286 (66). Although PEM did not increase CA1 neuron loss caused by ischemia, a subset (4/12) of PEM-Ischemia gerbils showed dramatic reactive gliosis accompanied by extensive neuronal loss. Hippocampal protein thiols were decreased by PEM and ischemia. Although the mechanism is yet to be established, the finding that PEM worsens functional outcome following global ischemia is clinically relevant since 16% of elderly are nutritionally compromised at the time of admission for stroke.

Animals↗

PubMed1995

Role of bradykinin in cardiac functional protection after global ischemia-reperfusion in rat heart.

We have reported that cardiac preconditioning against ischemia-reperfusion (IR) can be induced by transient ischemia (TI) and alpha 1-adrenoreceptor stimulation, both mediated by protein kinase C (PKC) (Mitchell, M., X. Meng, C. Parker, E. Brew, A. Harken, and A. Banerjee. Circ. Res. 76: 73-81, 1995). Our study objective was to explore the mechanism of endogenous preconditioning and address the role of PKC activation in bradykinin-mediated cardiac functional protection. Isolated rat heart was used to assess the effects of exogenous bradykinin, TI, selective B2-receptor blocker, and PKC antagonism on cardiac functional recovery after a global IR injury. Final recovery of developed pressure was improved in hearts treated with bradykinin and TI compared with controls. Bradykinin- and TI-mediated preconditioning was eliminated with coinfusion of the B2-receptor antagonist. Further evaluation of bradykinin-mediated preconditioning revealed that PKC blockade also eliminated functional protection. Immunofluorescent stains of bradykinin-treated hearts demonstrated translocation and activation of specific PKC isoforms in the preconditioned heart. We conclude that TI-mediated preconditioning involves intrinsic cardiac bradykinin receptor stimulation. Bradykinin, through the B2 receptor, initiates a series of intracellular events culminating in the activation of PKC.

Animals↗

PubMedDate not supplied

[Biventricular functional adaptation during a prolonged race. An analysis of global and regional ventricular function].

To determine the effects of a six-hour competitive race on left and right ventricular performance, 99mTc gated blood pool scans were performed to 6 long distance runners before the race (rest), each hour during the race and one hour after concluding the exercise (recovery). Heart rate increased during the race, peaking at 4th hour of competition (55 +/- 3 to 110 +/- 9 lpm; p = 0.001). Evolution of right ventricular ejection fraction showed a similar behavior with the evolution of left ventricular ejection fraction during the competition (r = 0.39; p = 0.006). Blood volume in the lungs increased at the end of the race (index 1.13 +/- 0.14) normalizing at recovery (index 1.03 +/- 0.03). Left and right ventricular peak filling rate had an inverse correlation with pulmonary blood volume (r = -0.31; p = 0.041 and r = -0.47; p = 0.001 respectively). Both left and right ventricular ejection fraction had an inverse correlation with pulmonary blood volume (r = -0.38; p = 0.006 and r = -0.34; p = 0.01 respectively). The anteroseptal regional ejection fraction showed an inverse correlation with end-systolic and end-diastolic volume (r = -0.32; p = 0.03 and r = -0.4; p less than 0.01 respectively). The posterolateral region showed a parallel evolution with the global ejection fraction for both left and right ventricles (r = 0.57; p less than 0.0001 and r = 0.38; p = 0.009 respectively). In conclusion, a transient biventricular functional adaptation during a prolonged race is related to pulmonary blood volume redistribution and to a higher preload for both ventricles and a greater afterload for the right ventricle. The posterolateral and inferoapical regions show a similar behavior as both left and right ventricular ejection fraction, response that does not occur with the anteroseptal regional ejection fraction.

Adaptation, Physiological↗

PubMed2002

Criteria for definition of regional functional improvement on quantitative post-stress gated myocardial SPET after bypass surgery in patients with ischaemic cardiomyopathy.

Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56 +/- 13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF < or = 35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% ( n = 15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml ( n = 2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (DeltaRWT), regional wall motion improvement (DeltaRWM) and regional resting (DeltaRP) and stress perfusion improvement (DeltaRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25% +/- 6% to 34% +/- 11% after CABG. A total of 229 segments were dysfunctional (wall motion < or = 2 mm, thickening < or = 20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of DeltaRWT and DeltaRWM were 0.717 and 0.620, respectively. The AUC of DeltaRWT was significantly larger than that of DeltaRWM ( P = 0.009) and the optimal cut-off value of DeltaRWT was 15%. The AUCs of DeltaRP and DeltaRstrP were not significant. The correlation coefficients between summed DeltaRWT and DeltaRWM and LVEF improvement were 0.591 and 0.472, respectively. The number of segments with a DeltaRWT of more than 15% correlated with LVEF improvement (rho = 0.533 by Spearman rank correlation). Regional wall thickening improvement showed the best correlation with global LV functional improvement after CABG. The most reliable regional criterion of myocardial viability was improvement in regional wall thickening by > or = 15% on quantitative gated SPET.

Cardiac Volume↗

PubMed1997

ProC Global: the first functional screening assay for the complete protein C pathway.

In clinical practice, venous thromboembolic complications are much more frequent than bleeding disorders. In fact, disturbances within the protein C pathway due to coagulation factor V (FV) Leiden mutation and deficiency of protein C or protein S are the most frequent abnormalities in hereditary thrombophilia. Furthermore, acquired dysfunctions of the protein C system may predispose the single individual to an increased thrombotic risk. A routine-suited screening assay that would allow the monitoring of the proper interplay of factors in the protein C pathway could add an important factor to the basic coagulation profile. This consists of the prothrombin time and of the activated partial thromboplastin time, which currently allow only a screening for increased risk for bleeding but not for venous thromboembolism. A new functional screening test for the protein C system such as the presented ProC Global should therefore facilitate detection of FV Leiden as well as deficiency of protein C and protein S. The results of the present evaluation indicate that ProC Global is highly sensitive to activated protein C resistance/FV Leiden (100%) and protein C deficiency (90%) and sensitive to protein S deficiency (63%). Furthermore, the assay gives a quantitative measure of the net potential of the protein C pathway in relation to the intrinsic procoagulant system. The use of this assay for a prospective assessment of thromboembolic risk is the subject of current studies.

Blood Coagulation Disorders↗

PubMed2007

Global analysis of functional surfaces of core histones with comprehensive point mutants.

The core histones are essential components of the nucleosome that act as global negative regulators of DNA-mediated reactions including transcription, DNA replication and DNA repair. Modified residues in the N-terminal tails are well characterized in transcription, but not in DNA replication and DNA repair. In addition, roles of residues in the core globular domains are not yet well characterized in any DNA-mediated reactions. To comprehensively understand the functional surface(s) of a core histone, we constructed 320 yeast mutant strains, each of which has a point mutation in a core histone, and identified 42 residues responsible for the suppressor of Ty (Spt(-)) phenotypes, and 8, 30 and 61 residues for sensitivities to 6-azauracil (6AU), hydroxyurea (HU) and methyl-methanesulfonate (MMS), respectively. In addition to residues that affect one specific assay, residues involved in multiple reactions were found, and surprisingly, about half of them were clustered at either the nucleosome entry site, the surface required for nucleosome-nucleosome interactions in crystal packing or their surroundings. This comprehensive mutation approach was proved to be powerful for identification of the functional surfaces of a core histone in a variety of DNA-mediated reactions and could be an effective strategy for characterizing other evolutionarily conserved hub-like factors for which surface structural information is available.

Amino Acid Sequence↗

PubMed1994

Stunning, preconditioning, and functional recovery after global myocardial ischemia.

Stunning (reversible myocardial ischemia without necrosis) occurs with induced global ischemia during cardiac operations and depresses the ability of the heart to utilize oxygen efficiently because less contractile work is developed per unit of oxygen utilized. Interestingly, regional studies have demonstrated dramatic infarct size reduction with stunning episodes before prolonged ischemia, a phenomenon known as myocardial preconditioning. It is postulated that the postischemic contractile dysfunction noted after stunning causes reduced energy demands, which "preconditions" myocardium to withstand a subsequent longer ischemic episode. Some evidence from regional studies suggests that preconditioning may improve functional recovery after ischemia. This study examined the complex relationship between stunning and preconditioning to functional recovery in a surgical setting of global ischemia. To study the effect of stunning, myocardial oxygen consumption, oxygen extraction, and functional indices of contractility were measured before and after isolated rabbit hearts were subjected to 10, 20, or 45 minutes of normothermic 37 degrees C global ischemic stun intervals. This demonstrated that while oxygen consumption and extraction quickly recover to prestun levels, contractility remains depressed well beyond the stun interval. To study the effect of preconditioning using stunning, isolated hearts were then subjected to 120 minutes of 34 degrees C cardioplegic-induced ischemia after preconditioning. Hearts received either modified St. Thomas cardioplegic solution as a control or cardioplegia administered after preconditioning with 37 degrees C ischemic stunning for 5, 10, 15, 20, or 45 minutes or multiple 5- or 10-minute stuns, with reperfusion before cardioplegic-induced ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1984

[Quantitative functional scintigraphy of the salivary glands. I. Determination of global and regional gland function].

A method for quantifying the function of the salivary glands using the dynamic scintigraphy with 99mTc is presented. After a special back-ground subtraction, the net-time-activity curves of the glands are characterized by 4 quantitative parameters, describing the ability of the glands to accumulate and to excrete the tracer. As a basis for clinical application, normal values are determined and their reproducibility is discussed. To demonstrate also regional functional differences within a single gland, phase-and gradient images are suggested.

Humans↗

PubMed1986

Recovery of left ventricular function after hypothermic global ischemia. Age-related differences in the isolated working rabbit heart.

The immature myocardium has a greater tolerance for ischemia than does the mature heart. The effect of ischemia when combined with hypothermia on the newborn heart is poorly understood but has important clinical applications. This study examined the metabolic and functional recovery after 90 minutes of global ischemia at 20 degrees C in neonatal (1 week), immature (1 month), and mature (4 month) isolated working rabbit hearts. Following ischemia, aortic flow, cardiac output, heart rate, and stroke work remained at baseline values for neonatal hearts. Only coronary flow was significantly reduced from a control level of 4.5 +/- 1.4 (standard error of the mean) to 3.3 +/- 1.1 ml/min, p less than 0.05. In the immature group, hemodynamic parameters were below baseline, although no statistical differences were noted. Among mature hearts, however, all hemodynamic values were significantly below preischemic control. Water content was significantly higher in immature (73.2% +/- 1.4%) and mature (75.3% +/- 2.5%) hearts when compared with the neonatal group (46.8% +/- 4.6%), p less than 0.001. Coronary sinus creatine kinase was unchanged from baseline at 10 and 30 minutes following ischemia in the neonatal group. Although demonstrating substantial increases from baseline, statistical significance was not seen in the immature group because of the wide variation about the mean. In the mature group, creatine kinase rose significantly from preischemic levels of 15.4 +/- 4.3 IU/L/gm to 184.2 +/- 51.6 IU/L/gm at 10 minutes (p less than 0.01) and 123.7 +/- 31.9 IU/L/gm at 30 minutes (p less than 0.05). This study demonstrated improved tolerance to prolonged hypothermic ischemia in neonatal rabbit hearts when compared with older hearts subjected to the same conditions. The role of cardioplegic solutions in protecting the neonatal heart during cardiac operations when deep hypothermia is used may be of lesser importance than in the older patient.

Aging↗

PubMed1986

Effects of intracoronary thrombolysis on global left ventricular function assessed by an automated edge detection technique.

Three hundred and two patients with acute myocardial infarction were enrolled in a randomized multicenter trial to compare conventional treatment with attempted recanalization by intracoronary streptokinase. In a subgroup of patients, the effects of thrombolysis on left ventricular function were evaluated within 48 hr, at 2 wk, and at 3 mo after admission. Global left ventricular ejection fraction (LVEF) was obtained by radionuclide angiography and analyzed with an automatic detection program. Paired data were determined in 160 patients (control 78, thrombolysis 82) within 48 hr and at 2 wk, and in 143 patients (control 71, thrombolysis 72) at 48 hr, 2 wk, and 3 mo. It was shown that LVEF significantly improved in the thrombolysis group as compared with controls both at 2 wk (delta LVEF thrombolysis 3.9 +/- 7.9%, p less than 0.001 compared with delta LVEF control 0.6 +/- 9.7%, p = N.S.) and at 3 mo (delta LVEF thrombolysis 3.1 +/- 12.4%, p less than 0.05 compared with delta LVEF control 2.1 +/- 12.2%, p = N.S.). When patients were divided according to infarct site, however, significant improvement at 3 mo was only observed in the patients with anterior infarction (delta LVEF thrombolysis 5.5 +/- 13.1%, p less than 0.05 compared with delta LVEF control 3.3 +/- 10.4%, p = N.S.). It was shown that acute intervention with intracoronary streptokinase has a potentially favorable and lasting effect on left ventricular function in patients with anterior myocardial infarction. This improvement might be related to the rather rapid administration of thrombolytic therapy with a median time of approximately 4 hr after onset of symptoms.

Adult↗

PubMed1996

Assessment of left ventricular function after radiofrequency and direct current atrioventricular node ablation.

BACKGROUND: There is limited information available regarding the effect of catheter ablation of the antioventricular (AV) junction on left ventricular (LV) function. Both deterioration and improvement in LV function have been reported following direct current (DC) ablation of the AV junction. The deterioration of LV function following DC ablation of the AV junction may be due to the accompanying barotrauma, DC arcing and direct coagulation, or even the effects of chronic ventricular pacing. If this deterioration of LV function was a result of the accompanying effects of DC shock, the use of radiofrequency ablation (RF) should not result in deterioration of LV function. AIM: To study LV function before and after different methods of AV junction ablation and in patients with chronic ventricular pacing without AV junction ablation. MATERIAL: This study assessed LV function in patients following RF ablation, low energy DC ablation of the AV junction and compared the results with our previously reported finding in patients who had AV junction ablation using high energy DC shock. A group of patients undergoing permanent single chamber ventricular pacemaker implantation without AV junction ablation were selected as controls. METHODS: All patients were paced in the ventricle at 110 beats/minute during LV function assessment by radionuclide angiography. Global LV function and segmental wall motion abnormalities were assessed before, immediately following and three months after ablation. RESULTS: In the high energy DC ablation group, a fall in global LV function (50 +/- 3.0% to 43 +/- 3.0%, p = 0.02) and impairment of segmental wall motion were detected. Low energy DC ablation resulted in segmental wall motion impairment similar to high energy DC but without affecting global ejection fraction (47.0% +/- 6.7 to 45.5% +/- 3.1, p > 0.05). Neither RF ablation (44.0% +/- 3.3 to 45.3% +/- 3.5, p > 0.05), nor chronic pacing (46.7% +/- 4.9 to 47.0% +/- 2.9 p > 0.05) had any effect on global or segmental LV function. CONCLUSIONS: Low energy DC or RF ablation of the AV junction does not affect global LV ejection fraction. The deterioration of global LV function after high energy DC shock ablation appears to be related to the accompanying effects of DC energy and not to the effects of chronic ventricular pacing.

Adult↗