Echocardiographic Parameters Of Systolic Function Research Articles

Study of correlations between serum taurine, thyroid hormones and echocardiographic parameters of systolic function in clinically healthy Golden retrievers fed with commercial diet.

Taurine deficiency predisposes to the development of nutritional dilated cardiomyopathy and is widespread in dogs fed with non-traditional diets. However, Golden retrievers show lower plasma taurine concentration and an impaired systolic function compared to breeds of the same size and morphotype. For these reasons, it can be difficult to classify a subject from a cardiological point of view, with the risk of considering as pathological characteristics that can be completely normal in this breed. This is a cross-sectional multicenter study. The aims were 1) to identify breed-specific range of serum taurine concentration, 2) to describe a correlation between serum taurine concentration and echocardiographic parameters of systolic function in clinically healthy Golden retrievers fed with traditional diet, 3) to identify a correlation between thyroid hormones, serum taurine concentration and echocardiographic indices. Sixty clinically healthy Golden retrievers (33% males, 67% females) were included. Fifty-three dogs were fed with traditional diets and their range of serum taurine concentration was 398.2 (31.8-430) nmol/ml. Serum taurine concentration was found to be negatively correlated to systolic internal diameter of the left ventricle and systolic and diastolic left ventricular indices and volumes obtained with different methods, whereas was positively correlated to the left ventricle ejection and shortening fractions but difference was not statistically significative. A weak but significant correlation between serum taurine and T4 was demonstrated. Serum taurine median values in dogs with normal systolic function were higher than in dogs with impaired systolic function. A cut-off of serum taurine concentration of 140.6 nmol/ml had a moderate sensitivity and specificity in the identification of an impaired left ventricular systolic function (AUC 0.6, Se 78%, Sp 44%). This study showed that the median serum taurine concentration was significantly lower in dogs with impaired systolic function. Therefore, echocardiographic monitoring is recommended in all dogs with serum taurine concentration lower than 140.6 nmol/ml.

Systolic function in dogs with pulmonic stenosis of different severities and the effect of balloon valvuloplasty

Introduction/objectivesPulmonic stenosis (PS) is one of the most common congenital heart diseases in dogs leading to right ventricular (RV) pressure overload, myocardial remodeling, and potential RV dysfunction. Our objectives were to investigate the extent of RV systolic dysfunction in canine PS and to examine the immediate influence of balloon valvuloplasty (BV) on systolic function. Animals, materials and methodsThis prospective study evaluated 72 dogs with PS and 86 healthy dogs. Echocardiographic parameters of systolic function included normalized tricuspid annular plane systolic excursion (N-TAPSE), normalized systolic myocardial tissue Doppler velocity of the lateral tricuspid annulus (N-RVFW-S′), fractional area change, and speckle-tracking longitudinal endocardial RV strain. Forty-four dogs underwent BV and were re-examined after surgery. ResultsSystolic function at the basal segment of the RV was significantly lower in the PS group when compared to healthy dogs (mean N-TAPSE 4.29 ± standard deviation 1.18 mm/kg0.285 vs. 5.60 ± 1.29 mm/kg0.285; median N-RVFW-S′ 5.28 [lower-upper 25% quantile 4.35–6.43 cm/s/kg0.186] vs. 7.82 [6.73–8.79 cm/s/kg0.186]; all P<0.001). Global longitudinal RV endocardial strain showed no significant difference between the two groups (−28.50 ± 6.23% vs. 28.61 ± 4.64%; P=0.886), but segmental strain analyses revealed basal hypo- and potential compensatory hyperkinesis of the apical RVFW. Furthermore, BV affected most parameters of systolic function, but not the segmental strain values and N-TAPSE. ConclusionsRight ventricular basal longitudinal systolic function is decreased in dogs with PS in comparison to a healthy cohort. Regional and global function does not necessarily coincide.

The Echocardiographic Parameters of Systolic Function Are Associated with Specific Metabolomic Fingerprints in Obstructive and Non-Obstructive Hypertrophic Cardiomyopathy.

The purpose of this study was to assess whether metabolomics, associated with echocardiography, was able to highlight pathophysiological differences between obstructive (OHCM) or non-obstructive (NOHCM) hypertrophic cardiomyopathy. Thirty-one HCM patients underwent standard and advanced echocardiography; a plasma sample was collected for metabolomic analysis. Results. Patients with OHCM compared with subjects with NOHCM had higher values of 2DLVEF (66.5 ± 3.3% vs. 60.6 ± 1.8%, p < 0.01), S wave (7.6 ± 1.1 vs. 6.3 ± 0.7 cm/s, p < 0.01) and 3D global longitudinal strain (17.2 ± 4.2%, vs. 13.4 ± 1.3%, p < 0.05). A 2-group PLS-Discriminant Analysis was performed to verify whether the two HCM groups differed also based on the metabolic fingerprint. A clear clustering was shown (ANOVA p = 0.014). The most discriminating metabolites resulted as follows: in the NOHCM Group, there were higher levels of threitol, aminomalonic acid, and sucrose, while the OHCM Group presented higher levels of amino acids, in particular those branched chains, of intermediates of glycolysis (lactate) and the Krebs cycle (fumarate, succinate, citrate), of fatty acids (arachidonic acid, palmitoleic acid), of ketone bodies (2-OH-butyrate). Our data point out a different systolic function related to a specific metabolic activity in the two HCM phenotypic forms, with specific metabolites associated with better contractility in OHCM.

Hemodynamic, Echocardiographic, and Sedative Effects of Oral Gabapentin in Healthy Cats.

The study objective was to evaluate sedative, hemodynamic, and echocardiographic effects of cats receiving single-dose, oral gabapentin. A prospective, double-blinded, placebo-controlled, crossover study was conducted with 10 client-owned cats. Vital parameters, physical exam, blood pressure, echocardiography, and sedation scoring were performed at each visit within 2 hr of receiving either a placebo or gabapentin capsule. Vital parameters, blood pressure recordings, and echocardiographic measurements were compared between baseline, gabapentin, and placebo; interobserver agreement for sedation scoring and correlation between variables were also evaluated. Seven of 10 cats exhibited mild sedation within 120 min after receiving gabapentin, and no adverse events occurred. Significant differences were detected with two-dimensional fractional shortening (P = .022), left ventricular internal diameter in systole using M-mode (P = .014), and left atrial volume (P < .0001). Interobserver agreement for sedation scoring was near-perfect (κ = 0.84). No significant correlation was found for gabapentin dosage and sedation score. Single-dose oral gabapentin is well tolerated in healthy cats and produces a modest decrease in several echocardiographic parameters of systolic function; however, all affected variables remained within established reference ranges. These results suggest gabapentin may be an appropriate sedative to administer before echocardiography in cats necessitating mild sedation.

Abstract 12605: Defining the Reference Range for Left Ventricular Strain by Echocardiography in Healthy Subjects: A Novel Meta-analysis Strategy

Background: Left ventricular global longitudinal strain (LVGLS), circumferential strain (LVGCS) and radial strain (LVGRS) are established echocardiographic parameters of systolic function with wide clinical applicability and prognostic implications. Despite this, the reference ranges of left ventricular (LV) strain, particularly the lower limit of normal (LLN), are not well established. This meta-analysis aims to determine the mean and LLN of two- (2D) and three-dimensional (3D) LV strain in healthy subjects and factors that may influence strain measurements. Methods: We searched Pubmed, Embase and Cochrane databases until 30 November 2019 for studies reporting left ventricular (LV) global strain in at least 50 healthy subjects. We pooled the mean and LLN of 2D and 3D LV strain using random-effects models, and performed subgroup and meta-regression analysis for 2D-LVGLS. Results: Forty-four studies were eligible totaling 8747 subjects. The pooled means and LLNs (95% confidence intervals) were -20.0% (-20.6%, -19.5%) and -15.6% (-16.2%, -15.0%) respectively for 2D-LVGLS; -22.1% (-23.7%, -20.5%) and -15.7% (-17.3%, -14.1%) respectively for 2D-LVGCS; and 48.0% (43.8%, 52.1%) and 23.2% (20.9%, 25.5%) respectively for 2D-LVGRS; all listed in Table 1. Significant heterogeneity was observed for almost all pooled LV strain analyses. The only factors associated with significant differences in both pooled mean and LLN of 2D-LVGLS were systolic blood pressure and vendor software. Conclusion: Pooled means and LLNs of 2D- and 3D- LV global strain parameters in healthy subjects were reported. Based on the pooled LLNs and their confidence intervals, the thresholds for abnormal, borderline and normal LV strains can be defined. Systolic blood pressure and vendor software were the most important parameters influencing 2D-LVGLS mean and LLN. Our novel methodology can also be applied to the meta-analysis of other echocardiographic parameters to define reference ranges.

Longitudinal patterns of N-terminal pro B-type natriuretic peptide, troponin T, and C-reactive protein in relation to the dynamics of echocardiographic parameters in heart failure patients.

To further elucidate the nature of the association between N-terminal pro-B type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-TnT), C-reactive protein (CRP), and clinical outcome, we examined the relationship between serial simultaneous measurements of echocardiographic parameters and these biomarkers in chronic heart failure (CHF) patients. In 117 CHF patients with ejection fraction ≤50%, NT-proBNP, hs-TnT, and CRP were measured simultaneously with echocardiographic evaluation at 6-month intervals until the end of 30 months follow-up or until an adverse clinical event occurred. Linear mixed effects models were used for data-analysis. Median follow-up was 2.2 years (interquartile range 1.5-2.6). We performed up to six follow-up evaluations with 55% of patients having at least three evaluations performed. A model containing all three biomarkers revealed that doubling of NT-proBNP was associated with a decrease in left ventricular ejection fraction by 1.83 (95% confidence interval -2.63 to -1.03)%, P < 0.0001; relative increase in mitral E/e' ratio by 12 (6-18)%, P < 0.0001; relative increase in mitral E/A ratio by 16 (9-23)%, P < 0.0001; decrease in tricuspid annular plane systolic excursion by 0.66 (-1.27 to -0.05) mm, P = 0.03; rise in tricuspid regurgitation peak systolic gradient by 2.74 (1.43-4.05) mmHg, P = 0.001; and increase in left ventricular and atrial dimensions, P < 0.05. Hs-TnT and CRP showed significant associations with some echocardiographic parameters after adjustment for clinical covariates, but after adjustment for the other biomarkers the associations were not significant. Serum NT-proBNP independently reflects changes in echocardiographic parameters of systolic function, left ventricular filling pressures, estimated pulmonary pressure, and chamber dimensions. Our results support further studies on NT-proBNP as a surrogate marker for haemodynamic congestion and herewith support its potential value for therapy guidance.

Inotropic and chronotropic effects of sotalol in healthy dogs

IntroductionSotalol is an anti-arrhythmic drug commonly used for the treatment of pathologic tachyarrhythmias in dogs. The β-adrenergic blockade associated with sotalol administration may result in reduced myocardial contractility, which is clinically relevant for treating dogs with arrhythmias and concurrent myocardial dysfunction. The inotropic properties of sotalol are not well characterized in dogs. Animals, Materials, and MethodsTen healthy, adult, large breed dogs were prospectively enrolled. All dogs underwent physical examination, blood pressure measurement, electrocardiography, 24-h Holter monitoring, and echocardiography including three-dimensional left ventricular volume measurements. Dogs were subsequently administered sotalol (1–2 mg/kg) orally twice daily for 12–16 days, and the same diagnostic tests were performed. Paired statistical analysis was used to compare parameters at baseline and after treatment with sotalol. ResultsStandard echocardiographic parameters of systolic function were reduced on sotalol compared to baseline, including ejection fraction via Simpson's method of disks which was 5.8% (95% confidence interval [CI]: 2.77–8.83%, p = 0.002) lower post-treatment. Maximum heart rate on Holter monitor was 17 bpm (95% CI: 9–37 bpm, p = 0.002) lower post-treatment than at baseline. ConclusionsSotalol has a mild negative inotropic effect in healthy dogs based on standard echocardiographic measurements. There is also a negative chronotropic effect at higher heart rates based on 24-h Holter monitoring.

Sacubitril/Valsartan Therapy for 14 Months Induces a Marked Improvement of Global Longitudinal Strain in Patients With Chronic Heart Failure: A Retrospective Cohort Study.

BackgroundClinical efficacy of sacubitril/valsartan administered for the recommended indication of chronic heart failure (CHF) patients with New York Heart Association (NYHA) classes II-III appears to be higher than one would expect based on the drug-induced variations of the left ventricular ejection fraction (LVEF). More thorough investigations with the use of indicators of longitudinal systolic function have been therefore recommended to verify whether a part of the clinical improvement achieved with the use of sacubitril/valsartan could be supported by a reverse remodeling ensuing from changes other than a simple LVEF increase.MethodsIn the present retrospective cohort study, which collected the pertinent data from two centers devoted to clinical management of outpatients with CHF and dating back to the years 2017 and 2018, we separated patients treated with sacubitril/valsartan from those treated with conventional medical therapy, including angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs). For the rest, the therapies practiced in the two groups, patients under sacubitril/valsartan and controls, were almost identical, including similar doses of beta-blockers and mineralocorticoid receptor antagonists (MRAs) in the two cohorts, plus loop diuretics, with the latter administered at variable doses. The endpoints were the variations of LVEF and global left ventricular longitudinal strain (GLS) over a study period not shorter than 1 year.ResultsOne hundred thirty-two patients were collected within our retrospective cohort study, of whom 44 were treated with sacubitril/valsartan and 88 were subjected to conventional therapy. All patients were marked by heart failure with reduced (LVEF ≤ 40%) left ventricular ejection fraction (HFREF). The mean duration of the retrospective observation period was 14 ± 3 months. In controls, LVEF was improved after a year of therapy from 38.071 ± 5.445% (mean ± standard deviation) to 41.595 ± 5.282%. On the contrary, no significant improvement in the controls could be identified for the GLS, from -12.059 ± 4.016% to -12.250 ± 4.287%. In analogy with controls, patients assigned to sacubitril/valsartan showed a significant increase in LVEF after 1 year of treatment from 39.714 ± 4.789% to 42.119 ± 5.683% (P < 0.001). However, differently from the controls, sacubitril/valsartan group exhibited a significant improvement in GLS from -10.142 ± 3.080% to -18.238 ± 7.284% (P < 0.001).ConclusionsThe present retrospective cohort study demonstrated that the use of sacubitril/valsartan for HFREF patients, extended for a mean duration of 14 months, yields a significant improvement in the echocardiographic parameters of systolic function along the transverse (LVEF) and longitudinal (GLS) axis. For the GLS in particular, a clear superiority emerges in comparison with conventional therapy including ACE inhibitor or ARBs. From these data, the hypothesis could be derived of a possible useful role of sacubitril/valsartan also for the therapy of HFpEF. In this regard, more exhaustive clarifications ensuing from the ongoing randomized controlled trials (RCTs) are eagerly awaited.

Left ventricular end-diastolic volume as early indicator of trastuzumab-related cardiotoxicity in HER2+ breast cancer patients: results from a single-center retrospective study.

Adjuvant trastuzumab therapy increases survival rates in patients with early HER2-positive breast cancer, although it can be potentially cardiotoxic. The aim of this study was to evaluate the prevalence of left ventricular (LV) systolic dysfunction; and the relationship between the presence of cardiovascular risk factors, cardiac therapy and/or echocardiographic parameters of systolic function at baseline and the development of cardiotoxicity in such patients. A total of 227 patients were retrospectively reviewed. Cardiotoxicity was defined as a decrease in LV ejection fraction (EF) below 50% or an absolute decrease of >10 points below the baseline value or any indication of heart failure. Each patient underwent echocardiography at baseline and at follow-up every three months. The prevalence of cardiotoxicity was 17.6% (15.4% asymptomatic, 2.2% symptomatic). Patients developing LV dysfunction presented hypertension (P=0.041) and diabetes (P=0.01) and used cardiac therapy at baseline more frequently. Smoke habit, age >50 and use of angiotensin-converting enzyme (ACE)-inhibitors, were independent predictors of cardiac damage. Furthermore, patients with LV dysfunction showed baseline LV end-diastolic volume (EDV) higher than those who did not and baseline EDV (OR=1.02; 95% CI: 1.00-1.04; P=0.027) independently predicted cardiotoxicity with 58 mL/m2 as best cut-off point (AUC=0.65, 95% CI: 0.55-0.75]). The prevalence of trastuzumab-related cardiotoxicity in patients with HER2-positive early breast cancer is relatively frequent, although asymptomatic in most cases. Baseline EDV resulted as independent predictor of cardiotoxicity suggesting that EDV may be more reliable than LVEF to identify patients at higher risk of developing cardiac damage.

Effects of Bone Marrow Mononuclear Cells Delivered through a Graft Vessel for Patients with Previous Myocardial Infarction and Chronic Heart Failure: An Echocardiographic Study of Left Ventricular Function.

The graft of stem cells to treat ischemic cardiomyopathy is popular in many clinical trials. The aim of this study was to evaluate the effectiveness of isolated coronary artery bypass graft combined with bone marrow mononuclear cells (BMMNC) delivered through graft vessels to improve left ventricular function of patients with previous myocardial infarction and chronic heart failure using echocardiography. Forty-two patients with previous myocardial infarction and chronic heart failure were randomly allocated to one of the two groups: CABG only (18 in CABG group), or CABG with BMMNC transplantation (24 in CABG+BMMNC group). Echocardiographic parameters of systolic function were measured on B-mode imaging, tissue Doppler imaging (TDI), two-dimensional (2D) strain imaging, and 8 parameters were measured totally. Echocardiographic parameters of diastolic function were measured on pulsed-wave Doppler imaging, TDI, and 2D strain rate imaging; 17 parameters were measured totally. Postoperative left ventricular ejection fraction (LVEF) versus preoperative LVEFwere 49.083±1.914% versus 36.042±1.185% (P<0.05) in CABG+BMMMNC group and 41.389±2.210% versus 34.667±1.369% (P<0.05) in CABG group, global longitudinal strain were-12.542±0.512% versus -7.083±0.583% (P<0.05) in CABG+BMMMNC group and -9.278±0.591% versus -7.000±0.673% (P<0.05) in CABG group, mLsr1 were -0.108±0.018/sec versus -0.039±0.017/sec (P<0.05) in CABG+BMMMNC group and -0.048±0.021/sec versus0.004±0.020/sec (P<0.05) in CABG group, mLsr2 were -0.055±0.013/sec versus-0.009±0.015/sec (P<0.05) in CABG+BMMMNC group and 0.004±0.015/sec versus0.024±0.017/sec (P<0.05) in CABG group, and Aa1 were 7.303±0.479cm/sec versus 5.131±0.381cm/sec (P<0.05) in CABG+BMMMNC group and 7.908±0.553cm/sec versus 6.764±0.440cm/sec (P<0.05) in CABG group. Parameters above were significantly improved postoperatively in both groups. The degree of the improvement was significantly different between the two groups with the CABG+BMMNC group improved more versus the group of CABG only (P<0.05). The improvement of left ventricular function in CABG+BMMNC group is better than CABG group. 2D strain and strain rate imaging is a more sensitive tool to evaluate left ventricular function.

Prognostic Value of Pulsed Tissue Doppler Imaging for the Assessment of Left Ventricular Systolic Function in Patients with Nonischemic Dilated Cardiomyopathy

There is still some debate regarding the prognostic significance of left ventricular longitudinal systolic dysfunction as assessed by tissue Doppler (TD) imaging in patients with chronic heart failure (HF), since previous studies have included patients with postischemic wall motion abnormalities. Thus, this study was designed to ascertain whether TD-derived longitudinal systolic dysfunction may influence the outcome of patients with nonischemic chronic HF. In 200 consecutive patients with chronic HF secondary to dilated cardiomyopathy and no history of ischemic heart disease, peak systolic mitral annular velocity (S(m) ) was measured by pulsed TD at the septal and lateral annular sites. The end points were cardiac death or hospitalization for worsening HF. Mean follow-up duration was 30 months. In a time independent analysis, averaged S(m) calculated as the average of septal and lateral S(m) , resulted to be a significant predictor of outcome in the study population (area under receiver-operator characteristic curve: cardiovascular death, 0.69, P < 0.0001; cardiovascular events, 0.64, P = 0.0005). In a time-dependent analysis, average S(m) was associated with both cardiovascular death (hazard ratio 0.832, P = 0.0019) and cardiovascular events (hazard ratio 0.904, P = 0.039), independently of other clinical risk factors and echocardiographic parameters of systolic function. Septal S(m) but not lateral S(m) was independently associated with the outcome measures. In conclusion, the assessment of systolic mitral annular velocity by pulsed TD is a useful indicator for prognostic stratification of patients with nonischemic dilated cardiomyopathy and chronic HF.

Prognostic Significance of Valvuloarterial Impedance and Left Ventricular Longitudinal Function in Asymptomatic Severe Aortic Stenosis Involving Three-Cuspid Valves

The purpose of the present study was to evaluate the role of left ventricular global afterload and various echocardiographic parameters of systolic function in a prospective cohort of 52 asymptomatic patients with severe aortic stenosis (indexed aortic valve area 0.4 ± 0.1 cm²/m²) and normal left ventricular ejection fraction (61 ± 5%). Using 2-dimensional speckle tracking echocardiography, myocardial strain, rotation, and twist were evaluated. The valvuloarterial impedance (Zva) was calculated as a measure of left ventricular global afterload. The predefined end points were the occurrence of symptoms (dyspnea, angina, syncope), aortic valve replacement, and death. At study entry, all patients had decreased longitudinal strain (LS) (-15 ± 4%) and increased circumferential strain (-22 ± 5%), twist (24 ± 7°), and Zva (5.8 ± 2 mm Hg/ml/m²). Increased Zva was closely associated with the circumferential strain increase (r = 0.59, p = 0.02) and LS decrease (r = -0.56, p = 0.016). In contrast, no relation was found between myocardial function and transaortic gradients. During follow-up (11 ± 7.5 months), on univariate Cox regression analysis, the predictors of events were the left ventricular ejection fraction (p = 0.02), mass index (p = 0.01), LS (p < 0.0001), radial strain (p = 0.04), and Zva (p = 0.0002). On multivariate Cox regression analysis, only the global LS (p = 0.03) and Zva (p = 0.03) were independently associated with the combined end point. Using receiver operating characteristic curve analysis, a LS of ≤-18% (sensitivity 96%, specificity 73%) and a Zva of ≥ 4.7 mm Hg/ml/m² (sensitivity 100%, specificity 91%) were identified as the best cutoff values to be associated with events. In conclusion, in asymptomatic patients with severe aortic stenosis, the degree of global afterload and its consequences on longitudinal function might play a role in clinical practice.

Função sistólica de pacientes com infarto miocárdico submetidos a transplante autólogo da medula óssea

Several studies have been published on the effect of bone-marrow stem cells on the left ventricle when acting on post- acute myocardial infarction remodeling. However, the results have been controversial.To carry out an echocardiographic analysis of the systolic function of patients with acute myocardial infarction after autologous mononuclear bone marrow cell transplantation (AMBMCT) as performed via the intracoronary and intravenous routes.This is an open-label, prospective, randomized study.patients admitted for ST-elevation acute myocardial infarction (MI) who had undergone mechanical or chemical reperfusion within 24 hours of the onset of symptoms and whose echocardiogram showed decreased segmental wall motion and fixed perfusion defect related to the culprit artery. Autologous bone marrow was aspirated from the posterior iliac crest under sedation and analgesia of the patients randomly assigned for the treatment group. After laboratory manipulation, intracoronary or intravenous injection of 100 x 106 mononuclear cells was performed. Echocardiography (Vivid 7) was used to assess ventricular function before and three and six months after cell infusion.A total of 30 patients were included, 14 in the arterial group (AG), 10 in the venous group (VG), and six in the control group (CG). No statistical difference was found between the groups for the echocardiographic parameters studied.Autologous mononuclear bone marrow cell transplantation did not improve the echocardiographic parameters of systolic function.

Assessment of Intraventricular Systolic Asynchrony in Patients with Atrial Fibrillation Using Triplane Tissue Doppler Imaging

Triplane tissue Doppler imaging (TDI) makes it possible to simultaneously obtain three apical view images and to measure the dyssynchrony index (DS) for 12 segments in patients with atrial fibrillation (AF). We evaluated the feasibility of using triplane TDI to assess intraventricular asynchrony in AF. In 50 patients with AF, triplane TDI was used for the analysis of myocardial velocity curves of 12 (six basal and six mid) left ventricular (LV) segments by apical two-, three-, and four-chamber views. Time to peak systolic velocity (Ts) was measured, and DS was calculated as the standard deviation (SD) of Ts over 12 segments. The DS(avg) was defined as the average of DS of eight consecutive cycles. To assess the cyclic variability of DS, the coefficient of variation of DS (CoV(DS)) was calculated as the SD of DS for eight cycles divided by DS(avg) [SD(DS)/DS(avg)]. CoV(RR), representing the variability of RR intervals, was defined as [SD(RR)/RR(avg)]. Patients with a left ventricular ejection fraction (LVEF) of 45% or more were classified as group A, and patients with an LVEF less than 45% as were classified as group B. The mean LVEF was 47% +/- 12%. Group B showed larger LV volume and lower sphericity index compared with group A. Intraobserver and interobserver variability of DS(avg) were 6% and 9%, respectively. More severe dyssynchrony was observed in group B (DS(avg); 23.5 +/- 8.5 ms in group B vs. 17.7 +/- 6.1 ms in group A, P = .008). DS(avg) was not related to RR(avg) or CoV(RR). DS(avg) negatively correlated with ejection fraction (r = -0.404, P = .004) and sphericity index (r = -0.317, P = .025) and showed positive correlation with LV volume. Analysis of asynchrony by triplane TDI was feasible in patients with AF. DS(avg) correlated with echocardiographic parameters of systolic function.

Safety and Hemodynamic Effects of Intravenous Triiodothyronine in Advanced Congestive Heart Failure

Most patients with advanced congestive heart failure have altered thyroid hormone metabolism. A low triiodothyronine level is associated with impaired hemodynamics and is an independent predictor of poor survival. This study sought to evaluate safety and hemodynamic effects of short-term intravenous administration of triiodothyronine in patients with advanced heart failure. An intravenous bolus dose of triiodothyronine, with or without a 6- to 12-hour infusion (cumulative dose 0.15 to 2.7 μg/kg), was administered to 23 patients with advanced heart failure (mean left ventricular ejection fraction 0.22 ± 0.01). Cardiac rhythm and hemodynamic status were monitored for 12 hours, and basal metabolic rate by indirect calorimetry, echocardiographic parameters of systolic function and valvular regurgitation, thyroid hormone, and catecholamine levels were measured at baseline and at 4 to 6 hours. Triiodothyronine was well tolerated without episodes of ischemia or clinical arrhythmia. There was no significant change in heart rate or metabolic rate and there was minimal increase in core temperature. Cardiac output increased with a reduction in systemic vascular resistance in patients receiving the largest dose, consistent with a peripheral vasodilatory effect. Acute intravenous administration of triiodothyronine is well tolerated in patients with advanced heart failure, establishing the basis for further investigation into the safety and potential hemodynamic benefits of longer infusions, combined infusion with inotropic agents, oral triiodothyronine replacement therapy, and new triiodothyronine analogs.