Echocardiographic Left Ventricular Dimensions Research Articles

Association of QRS Duration with Echocardiographic Left Ventricular Dimensions

Background: QRS duration (QRSd) is used to diagnose left bundle branch block (LBBB) and is important for determining cardiac resynchronization therapy eligibility. Others have reported associations of left bundle branch block (LBBB) and interventricular conduction delay with left ventricular (LV) systolic and diastolic dysfunction in patients without clinical HF. Individualized QRSd thresholds may improve diagnosis and intervention strategies. The goal of this study was to assess the relations of QRS duration to echocardiographic left ventricular (LV) dimensions in individuals. Methods: This was a hospital-based cross-sectional analytical study. A total of 134 purposively selected respondents were included in the study from the patients attending the outpatient or inpatient department of cardiology, Dhaka Medical College Hospital, advised for an echocardiogram. They were divided into two groups depending on their QRS complex duration (Group I≤100 ms and Group II>100 ms). After taking informed written consent, a case record form was filled and Echo measurements were taken following standard procedure with confidentiality. Results: Among the respondents, the mean age was found 52.68 ± 14.24 years. The majority were male (68%), and around 1/3rd of the respondents were overweight or obese. Males were found to have less QRS duration than females (p<0.001) but there was no difference in age (p=0.814) between the groups. All the risk factors considering obesity, diabetes mellitus, hypertension, family history, smoking status, and dyslipidemia were found in similar proportions in both groups (p>0.05). The study found that the interventricular septum thickness and inferolateral wall thickness were higher among those having a QRS duration of more than 100 ms (Group II), but this difference was not significant (p > 0.05). On the other hand, left ventricular diastolic dimension, systolic dimension, and left ventricular mass were found to be increased significantly (p<0.05) with a reduction in ejection fraction in Group II (p<0.05). Conclusion: Left ventricular diastolic and systolic dimensions along with left ventricular mass significantly increase according to QRS duration among the patients. Meanwhile, a reduction in ejection fraction was also evident. (Bangladesh Heart Journal 2024; 39(2): 144-150

The association between taurine concentrations and dog characteristics, clinical variables, and diet in English cocker spaniels: The Canine taURinE (CURE) project.

Occurrence of low blood taurine concentrations (B-TauC) and predisposing factors to taurine deficiency in English Cocker Spaniels (ECS) are incompletely understood. Investigate the occurrence of low B-TauC in a Swedish population of ECS and evaluate the association between B-TauC and dog characteristics, clinical variables, and diet composition. One-hundred eighty privately owned ECS. Dogs were prospectively recruited and underwent physical examination, blood analyses, and echocardiographic and ophthalmic examinations. Dogs with clinical signs of congestive heart failure (CHF) also underwent thoracic radiography. Taurine concentrations were analyzed in plasma (EDTA and heparin) and whole blood. Diets consumed by the dogs at the time of the examination were analyzed for dietary taurine- (D-TauC), cysteine- (D-CysC), and methionine concentrations (D-MetC). Fifty-three of 180 dogs (29%) had low B-TauC, of which 13 (25%) dogs had clinical and radiographic signs of CHF, increased echocardiographic left ventricular (LV) dimensions and volumes, and impaired LV systolic function. Five (9%) dogs with low B-TauC had retinal abnormalities. Dietary MetC, dietary animal protein source (red/white meat), and age were associated with B-TauC in the final multivariable regression model (P < .001, R2 adj = .39). Low B-TauC suggests that taurine deficiency may play a role in the development of myocardial failure and CHF in ECS. Low D-MetC and diets with red meat as the animal protein source were associated with low B-TauC. Dogs with B-TauC below the normal reference range were older than dogs with normal concentrations.

Automated echocardiographic left ventricular dimension assessment in dogs using artificial intelligence: Development and validation.

Artificial intelligence (AI) could improve accuracy and reproducibility of echocardiographic measurements in dogs. A neural network can be trained to measure echocardiographic left ventricular (LV) linear dimensions in dogs. Training dataset: 1398 frames from 461 canine echocardiograms from a single specialist center. 50 additional echocardiograms from the same center. Training dataset: a right parasternal 4-chamber long axis frame from each study, labeled by 1 of 18 echocardiographers, marking anterior and posterior points of the septum and free wall. End-diastolic and end-systolic frames from 50 studies, annotated twice (blindly) by 13 experts, producing 26 measurements of each site from each frame. The neural network also made these measurements. We quantified its accuracy as the deviation from the expert consensus, using the individual-expert deviation from consensus as context for acceptable variation. The deviation of the AI measurement away from the expert consensus was assessed on each individual frame and compared with the root-mean-square-variation of the individual expert opinions away from that consensus. For the septum in end-diastole, individual expert opinions deviated by 0.12 cm from the consensus, while the AI deviated by 0.11 cm (P = .61). For LVD, the corresponding values were 0.20 cm for experts and 0.13 cm for AI (P = .65); for the free wall, experts 0.20 cm, AI 0.13 cm (P < .01). In end-systole, there were no differences between individual expert and AI performances. An artificial intelligence network can be trained to adequately measure linear LV dimensions, with performance indistinguishable from that of experts.

Assessment of echocardiographic left ventricular dimensions with several clinical findings among healthy people

Background: The echocardiographic measurement of left ventricular dimensions and the changes of left ventricular dimensions may be important to assess cardiac as well as the cardiovascular conditions of patients. On the other hand, the QRS duration signifies the time for ventricular depolarization. Aim of the study: The aim of this study was to assess the echocardiographic left ventricular dimensions with several clinical findings among healthy people. Methods: This was an observational cross-sectional study which was conducted in the Department of Cardiology, University Cardiac Centre, Bangabandhu Sheikh Mujib Medical University, Dhaka over a period of 2 years from July 2008 to June 2010. In total 92 apparently healthy people without heart failure (HF) or myocardial infarction (MI) were included as the study population. Among them, 22 were in Referent (QRS duration &lt;100 ms), 40 in Incomplete BBB (QRS duration 100 – 119), and 30 in Complete BBB (≥ 120 ms) groups. Proper written consent was taken from all the participants and this study was approved by the ethical committee of the mentioned university. All data were processed, analyzed, and disseminated by MS Office and SPSS version as per need. Results: In this study, the left ventricular (LV) mass, left ventricular diastolic dimension, septal wall thickness, posterior wall thickness and left atrial size were significantly higher in complete BBB group than those in referent and incomplete BBB group (143.0 ± 30.2 vs. 182.6 ± 37.9 vs. 222.0 ± 61.0, p &lt; 0.001; 4.6 ± 0.3 vs. 4.9 ± 0.3 vs. 5.2±0.4, p&lt; 0.001; 0.9±0.1 vs. 1.0 ± 0.1 vs. 1.1± 0.1, p&lt;0.001; 0.9 ± 0.1 vs. 1.0 ± 0.1 vs. 1.1± 0.1, p&lt;0.001; and 3.3 ± 0.3 vs. 3.6±0.3 vs. 3.7±0.3, p&lt;0.001 respectively). However, fractional shortening and left ventricular ejection fraction were found to decrease significantly with the increase in QRS duration (p &lt; 0.001 and p &lt; 0.001 respectively). In this study the QRS duration was observed to be linearly correlated with LV mass, LV diastolic dimension, septal wall thickness, posterior wall thickness and left atrial size (r=0.577, p&lt;0.001; r=0.480, p&lt;0.001; r=0.583, p&lt;0.001; r=0.521, p&lt; 0.001 and r= 0.418, p&lt;0.001 respectively).&nbsp; However, QRS duration was found to maintain a negative correlation with fractional shortening and LVEF (r =- 0.637, p&lt;0.001 and r =- 0.701, p&lt;0.001 respectively). Conclusion: The present study revealed that longer electrocardiographic QRS duration was correlated with the increase in LV mass, LV diastolic dimensions, septal wall thickness, posterior wall thickness, and left atrial size. The association was most striking in individuals with complete BBB compared with a normal QRS duration. Meanwhile, the presence of prolonged QRS in a patient’s ECG can serve as a bedside clue to the presence of decreased fractional shortening and left ventricular ejection fraction.

Effect of Regional Upper Septal Hypertrophy on Echocardiographic Assessment of Left Ventricular Mass and Remodeling in Aortic Stenosis

Transthoracic echocardiography (TTE) is the reference method for evaluation of aortic stenosis (AS), and it is extensively used to quantitate left ventricular (LV) mass and volumes. Regional upper septal hypertrophy (USH) or septal bulge is a frequent finding in patients with AS and may lead to overestimation of LV mass when using linear measurements. The objective of this study was to compare estimates of LV mass obtained by two-dimensional transthoracic echocardiographic LV dimensions measured at different levels of the LV cavity with those obtained by cardiovascular magnetic resonance (CMR). One hundred six patients (mean age, 63±15years; 68% men) with AS were included in this subanalysis of the PROGRESSA study. Two-dimensional transthoracic echocardiographic measurements of LV dimensions were obtained at the basal level (BL; as recommended in guidelines), immediately below the septal bulge (BSB), and at a midventricular level (ML). Regional USH was defined as a basal interventricular septal thickness ≥ 13mm and >1.3 times the thickness of the septal wall at the ML. Agreement between transthoracic echocardiographic and CMR measures was evaluated using Bland-Altman analysis. The distribution of AS severity was mild in 23%, moderate in 57%, and severe in 20% of patients. Regional USH was present in 28 patients (26%). In the whole cohort, two-dimensional TTE overestimated LV mass (bias: BL,+60±31g; BSB,+59±32g; ML,+54±32g; P=.02). The biplane Simpson method slightly but significantly underestimated LV end-diastolic volume (bias -10±20mL, P<.001) compared with CMR. Overestimation of LV mass was more marked in patients with USH when measuring at the BL and was significantly lower when measuring LV dimensions at the ML (P<.025 vs BL and BSB). Two-dimensional TTE systematically overestimated LV mass and underestimated LV volumes compared with CMR. However, the bias between TTE and CMR was less important when measuring at the ML. Measurements at the BL as suggested in guidelines should be avoided, and measurements at the ML should be preferred in patients with AS, especially in those with USH.

Aberrant Cardiac Long Noncoding RNA Expression Following Alterations in Thyroid Hormones

BackgroundHeart failure (HF) mortality is on the rise and altered thyroid hormone (TH) function is a major risk factor. HF can be a result of either decreased (hypothyroidism; HypoTH) or increased (hyperthyroidism; HyperTH) serum TH levels. THs regulate cardiac physiology including contractility and relaxation. We recently showed safe, cardioprotective effects with oral treatment of active form of THs in several rodent models of cardiovascular disorders. Moving forward, novel heart‐specific targets in TH pathway are warranted. About 98% of the genome is non‐protein‐coding and over 90% is transcribable. Long noncoding RNA (lncRNA; transcripts &gt;200 nucleotides) genes outnumber protein‐coding genes by several fold. Deiodinase‐3 converts active forms of THs into inactive metabolites, and its chromosomal domain also encode maternally expressed lncRNAs. However, role of lncRNAs in TH‐mediated cardiac effects is unknown. We hypothesize that alterations in TH levels will impair cardiac lncRNA expression.MethodsHypoTH was induced by feeding adult C57BL/6 mice with 0.15% propylthiouracil with 0.1% methimazole for 5 weeks. HyperTH was established by injecting TH (T4; 1 μg/g i.p.) every 48 hours. Females were used because they maintain a more stable body mass over time than males. Furthermore, women have higher incidence of thyroid anomalies. Echocardiography and heart gravimetry were performed and results analyzed by analysis of variance with Tukey's multiple comparisons test (n=3–5/group). We also performed quantitative real‐time PCR using lncRNA‐specific array of 86 different targets following pre‐amplification. Array reproducibility, reverse transcription efficiency, absence of genomic DNA contamination and normalization were ensured.ResultsSerum total T4 levels were decreased in HypoTH (p&lt;0.05) and increased in HyperTH (p&lt;0.01) [Control: 2.17±0.4; HypoTH: 0.8±0.2; HyperTH: 12.8±2.4; ug/dl]. While HypoTH hearts were atrophic (p&lt;0.05), HyperTH hearts showed significant hypertrophy (p&lt;0.0001). Heart weight to body weight ratio was 4.38±0.2 in controls, 3.8±0.1 in HypoTH and 5.9±0.1 in HyperTH. Left and right ventricular ratios also followed similar patterns (p&lt;0.05). Following HypoTH, echocardiographic left ventricular end‐systolic dimension significantly increased (p&lt;0.05) while fractional shortening decreased (p&lt;0.01). Heart rate decreased with HypoTH and increased with HyperTH (p&lt;0.01). We began investigating involvement of lncRNAs related to inflammatory and immune mechanisms that can be relevant in both TH abnormalities and HF. Quantitative real‐time PCR showed that several of these cardiac lncRNAs were differentially expressed following alterations in TH levels (p&lt;0.05). Importantly, two lncRNAs were significantly downregulated (2.9‐ and 1.73‐fold) in HypoTH, but upregulated (3.4‐ and 1.67‐fold) in HyperTH ventricles. Another lncRNA was significantly increased in HypoTH (2.1‐fold), but decreased with HyperTH (7.63‐fold).ConclusionsThis is the first report to present aberrations in cardiac lncRNAs following altered TH levels. Taken together, this demonstrates potential TH‐dependent regulation of lncRNAs in mammalian hearts that may offer clinical significance.Support or Funding InformationNYITCOM

Contractility surrogates derived from three-dimensional lead motion analysis and prediction of acute haemodynamic response to CRT

BackgroundPatient-specific left ventricular (LV) lead optimisation strategies with immediate feedback on cardiac resynchronisation therapy (CRT) effectiveness are needed. The purpose of this study was to compare contractility surrogates derived from...

Relations of Central Hemodynamics and Aortic Stiffness with Left Ventricular Structure and Function: The Framingham Heart Study.

BackgroundThe differing relations of steady and pulsatile components of central hemodynamics and aortic stiffness with cardiac dimensions and function have not been fully elucidated.Methods and ResultsCentral hemodynamics and carotid‐femoral pulse wave velocity (CFPWV, a measure of aortic stiffness) were measured by arterial tonometry in 5799 participants of the Framingham Heart Study (mean age 51 years, 54% women) and related to echocardiographic left ventricular (LV) dimensions and systolic and diastolic function using multivariable‐adjusted partial Pearson correlations. Mean arterial pressure (MAP, steady component of central blood pressure) was associated positively with LV wall thickness (r=0.168; P<0.0001) but showed only a weak direct association with LV diastolic dimension (r=0.035, P=0.006). Central pulse pressure (pulsatile component of central blood pressure) showed a direct correlation with both LV diastolic dimension and LV wall thickness (r=0.08 and 0.044, both P<0.0001 in multivariable models that included MAP). CFPWV was not associated with LV structure (all P≥0.27) in MAP‐adjusted models). Both MAP and CFPWV were associated inversely with LV diastolic function (E′; r=−0.140 and −0.153, respectively; both P<0.0001), and these associations persisted after additional adjustment for LV mass and central pulse pressure (r=−0.142 and −0.108, both P<0.0001). MAP and CFPWV were not associated with LV fractional shortening (P≥0.10), whereas central pulse pressure was positively related (r=0.064, P<0.0001).ConclusionsPulsatile and steady components of central pressure are conjointly yet variably related to LV structure. CFPWV is related to LV diastolic function but not to systolic function. Additional studies are warranted to confirm these observations.

Abstract 12894: The Relations of Central Hemodynamics and Aortic Stiffness With Cardiac Structure and Function: The Framingham Heart Study

Introduction: Relations of steady and pulsatile components of central hemodynamics and aortic stiffness with cardiac dimensions and function have not been fully elucidated. Methods: We measured mean arterial pressure (MAP, steady component of blood pressure), central pulse pressure (CPP, pulsatile component of central blood pressure), and carotid-femoral pulse wave velocity (CFPWV, a measure of aortic stiffness) by arterial tonometry in 5799 Framingham Heart Study participants (mean age 51 years, 54% women). We related these to echocardiographic left ventricular (LV) dimensions and systolic and diastolic function using multivariable-adjusted partial Pearson correlations. Results: MAP was associated positively with LV wall thickness (r=0.168; p&lt;0.0001) and LV diastolic dimension (r=0.035, p=0.006). Adjusting for MAP, CPP was positively associated with LV wall thickness and LV diastolic dimension (r=0.044 and r=0.080, both p&lt;0.0001). CFPWV was not associated significantly with LV structure (all p≥0.27) in MAP-adjusted models. MAP and CFPWV were associated negatively with LV diastolic function (E’; r=-0.140 and r=-0.153, respectively; both p&lt;0.0001). The MAP relation persisted after adjustment for LV mass and CPP (r=-0.142) and the CFPWV relation persisted after adjustment for LV mass and MAP (r=-0.108, both p&lt;0.0001). MAP and CFPWV were not associated significantly with LV fractional shortening (p≥0.10), whereas CPP was positively related (r=0.064, p&lt;0.0001). The figure shows adjusted LV diastolic dimension (Panel A) and LV wall thickness (Panel B) partioned by tertiles of MAP and CPP, and E’ partitioned by CFPWV tertiles (Panel C). Conclusions: Steady and pulsatile components of central pressure are jointly yet differentially related to LV structure and function. Higher CFPWV is related to reduced LV diastolic function, but not systolic function.

Cardiac Troponin‐I Concentration, Myocardial Arteriosclerosis, and Fibrosis in Dogs with Congestive Heart Failure because of Myxomatous Mitral Valve Disease

Few previous studies have investigated the association between biomarkers and cardiac disease findings in dogs with naturally occurring myxomatous mitral valve disease (MMVD). To investigate if histopathological changes at necropsy could be reflected by in vivo circulating concentrations of cTnI and aldosterone, and renin activity, in dogs with naturally occurring congestive heart failure because of MMVD. Fifty privately owned dogs with MMVD and heart failure. Longitudinal Study. Dogs were prospectively recruited and examined by clinical and echocardiographical examination twice yearly until time of death. Blood was stored for batched analysis of concentrations of cTnI and aldosterone, and renin activity. All dogs underwent a standardized necropsy protocol. cTnI were associated with echocardiographic left ventricular end-diastolic dimension (P < .0001) and proximal isovolumetric surface area radius (P < .004). Furthermore, in vivo cTnI concentrations reflected postmortem findings of global myocardial fibrosis (P < .001), fibrosis in the papillary muscles (P < .001), and degree of arterial luminal narrowing (P < .001) Aldosterone or renin activity did not reflect any of the cardiac disease variables investigated. Cardiac fibrosis and arteriosclerosis in dogs with MMVD are reflected by circulating cTnI concentration, but not by aldosterone concentration or renin activity. Cardiac troponin I could be a valuable biomarker for myocardial fibrosis in dogs with chronic cardiac diseases.

Tricuspid Valve Repair: Devega’s Tricuspid Annuloplasty in Moderate Secondary Tricuspid Regurgitation

Moderate secondary tricuspid incompetence has variable natural history if left unattended during mitral valve surgery. Recent data suggest progression of the secondary tricuspid incompetence over time.Secondary moderate tricuspid regurgitation in rheumatic mitral valve disease may regress after mitral valve surgery without direct intervention. The present study was done to assess early result of DeVega tricuspid valve annuloplasty amongst those with moderate tricuspid regurgitation due to rheumatic mitral valve disease. Group I(mitral value replacement with tricuspid repair) and group II (mitral value replacement only).The two groups were followed up at three months post-operatively and evaluated for their functional class and echocardiography variables. There were 43 patients who underwent mitral valve replacement with moderate tricuspid regurgitation. 23 underwent mitral valve replacement with tricuspid repair group (Group 1). Most of the patients were women (28/43). The mean age was 31.4 + 14.8 and 25.13 + 9.4 years. Group I had 21(91.3%) and Group II had 17 (85%) in NYHA class III and IV. The pre-operative echocardiographic cardiac left ventricular and left atrial dimensions, Left ventricular function and valve lesions were statistically similar for both groups, except PASP was higher amongst tricuspid repair (Group 1: 38.60 + 12.75 mHg, Group 2: 61.52 + 19.76 mmHg; p equals or less than 0.05). At three month review after surgery, four patients were in NYHA II amongst those without tricuspid repair (Group II), whilst the rest were in NYHA I. Left ventricular dimensions, Left Ventricular function and valve prosthetic valve function were similar between groups. Eleven (47.8%) patients in Group I and only five (25%) of Group II had trace or less TR at the follow-up. This was found to be statistically significant on chi square test (p less than 0.05). There were 7 (16.2%) patients who had persistent moderate TR. Higher PASP and larger LV dimensions at three months were predictive of persistent moderate TR. Mitral valve replacement does decrease the severity of tricuspid regurgitation amongst those with secondary moderate tricuspid regurgitation by at least one grade, but DeVega's annuloplasty confers a better repair result.

A Randomised, Placebo-controlled Trial of Carvedilol in Early Familial Dilated Cardiomyopathy

Screening of asymptomatic relatives of patients with dilated cardiomyopathy (DCM) has identified a population of individuals with left ventricular dilatation and/or minimally impaired contraction who are believed to have early disease. A proportion of these individuals with early disease progress to overt cardiomyopathy, however to our knowledge there have been no studies that have examined the impact of early intervention on disease progression. We evaluated 424 asymptomatic relatives in 110 families of probands with DCM and identified 102 individuals (24%) with suspected "early disease" (EDCM). Thirty-two EDCM subjects were randomised into a six-month placebo-controlled trial of the β-blocker, carvedilol. Transthoracic echocardiography and plasma nt-proBNP levels were measured at baseline and repeated at six months. The primary trial endpoint was change in left ventricular end-systolic diameter after six months. Subjects completing six months of blinded trial therapy were offered open-label carvedilol and then observed over an extended period with repeated clinical evaluation and echocardiography. At baseline, left ventricular dimensions, systolic function and plasma nt-proBNP levels were similar in carvedilol and placebo groups. There were no significant changes observed in these parameters in either treatment group after six months, however reductions in end-diastolic diameter (% predicted) were observed in carvedilol-treated subjects (P=0.002) during an open-label median follow-up of 32 months (range: 13-56 months). In an asymptomatic population of individuals with EDCM, treatment with carvedilol for six months had no effect on echocardiographic left ventricular dimensions or systolic function, however longer-term treatment may reverse left ventricular remodelling (Australian Clinical Trials Registry N012605000204640).

Utility of QRS width and echocardiography parameters in an integrative algorithm for selecting heart failure patients with cardiac dyssynchrony

Background Cardiac resynchronization therapy (CRT) is an effective treatment in dilated cardiomyopathy (DCM). However, it has been demonstrated that mechanical dyssynchrony is not related to electrical dyssynchrony. We hypothesized that a new QRS width cutoff could be easier to use as a first step in the selection of patients with inter- and intraventricular dyssynchrony. Methods We included 58 patients with DCM. Electrocardiographic (PR interval and QRS width) and echocardiographic (left ventricular dimensions, systolic and diastolic function, dyssynchrony parameters) data were evaluated in all patients. Results According to QRS width, we divided the study population in two groups: Group 1, 25 patients having a narrow QRS (≤ 120 ms), and Group 2, 33 patients having a wide QRS (> 120 ms). Patients in Group 2 had larger left ventricles, with similar systolic function and more severe diastolic dysfunction than patients with narrow QRS. Interventricular dyssynchrony was more frequent in group 2 (54.5% vs 20%, p = 0.01), while intraventricular dyssynchrony was highly prevalent in both groups (82.1% vs 72%, p = 0.48). A QRS > 140 ms best predicted the presence of interventricular dyssynchrony (sensitivity 78.2% and specificity 63.6%), while a QRS > 150 ms best predicts intraventricular dyssynchrony (sensitivity 48.6% and specificity 80%). Conclusions Intraventricular dyssynchrony has a high prevalence in patients with DCM, irrespective of the QRS width. Using a higher QRS width cutoff (150 ms) might help in patient selection for CRT. Electrocardiography and echocardiography can be combined into a selection algorithm for patients receiving resynchronization therapy.

Prospective screening for occult cardiomyopathy in dogs by measurement of plasma atrial natriuretic peptide, B-type natriuretic peptide, and cardiac troponin-I concentrations

To evaluate the use of measuring plasma concentrations of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and cardiac troponin-I (cTnI) to detect dogs with occult dilated cardiomyopathy (DCM). 118 client-owned dogs. Dogs were prospectively examined by use of ECG; echocardiography; and evaluation of concentrations of ANP, BNP, and cTnI. Occult DCM was diagnosed by evaluation of echocardiographic left ventricular dimensions and detection of ventricular arrhythmias on ECG. Sensitivity and specificity of assays for measurement of plasma concentrations of ANP, BNP, and cTnI to detect dogs with occult DCM were determined. Occult DCM was diagnosed in 21 dogs. A concentration of > 6.21 pg/mL for BNP had a sensitivity of 95.2% and specificity of 61.9% for identifying dogs with occult DCM. In contrast, concentrations of ANP and cTnI had relatively low predictive values. Blood-based screening for occult DCM in dogs can be accomplished by use of a BNP assay. Additional studies should be performed to optimize this method of screening dogs to detect occult DCM.

Cross-Sectional Correlates of Serum Heat Shock Protein 70 in the Community

Recent studies of referral samples suggest that heat shock proteins play a key role in the pathogenesis of high BP and cardiovascular diseases (CVD) including heart failure. It is unclear whether circulating heat shock protein 70 (HSP70) levels are related to CVD risk factors, echocardiographic indexes of left ventricular (LV) remodeling, and prevalent CVD in the population. We evaluated the cross-sectional relations of serum HSP70 to established CVD risk factors (including hypertension), markers of oxidative stress (urinary 8-epi-PGF(2alpha)) and inflammation (plasma interleukin-6, C-reactive protein, monocyte chemoattractant protein-1 MCP-1, and soluble intercellular adhesion molecule sICAM-1), echocardiographic LV dimensions and prevalent CVD in 456 Framingham Offspring Study participants (mean age 61 years, 42% women). In multivariable analyses, serum HSP70 was not associated with age, sex, vascular risk factors (including hypertension), echocardiographic LV mass or prevalent CVD. Also, serum HSP70 was not related to any of the biomarkers evaluated (p> or = 0.10 for all). In our community-based sample, serum HSP70 was similar in men and women, and not significantly related to traditional or novel risk factors, to LV mass or to prevalent CVD. Our data suggest that blood levels may not adequately reflect the important role of heat shock proteins in prevalent CVD.

Cross-sectional relations of electrocardiographic QRS duration to left ventricular dimensions: The Framingham Heart Study

The goal of this study was to assess the relations of electrocardiographic QRS duration to left ventricular (LV) measurements in individuals without heart failure (HF) or prior myocardial infarction (MI). Increased electrocardiographic QRS duration (>/=120 ms) is a marker of ventricular dyssynchrony. We evaluated the relations of maximal electrocardiographic QRS duration to echocardiographic LV dimensions in 4,534 Framingham Heart study participants (mean age 54 years, 57% women) without prior HF or MI. QRS duration was analyzed as a continuous variable and as categories (<100, 100 to 119, and >/=120 ms). In linear regression models, LV mass, end-diastolic dimension, and septal and posterior wall thicknesses were positively related to log-QRS duration, whereas fractional shortening (FS) was inversely related (p < 0.001). There was a significant trend for increasing LV mass and dimensions, and decreasing FS across categories of QRS duration (p < 0.001). Left bundle branch block was associated with higher LV mass and lower FS compared with a normal QRS duration (p < 0.001). In our community-based sample of individuals free of HF and MI, increasing electrocardiographic QRS duration was positively related to LV mass and dimensions, and inversely associated with LV FS. Additional investigations are warranted to elucidate the mechanisms underlying the observed associations.

Relationship of QT Dispersion to Echocardiographic Left Ventricular Function, Dimension and Mass in Patients with Coronary Artery Disease

Background：Previous studies showed that increased QT dispersion has been observed during episodes of myocardial ischemia or infarction and identified the patients at risk of arrhythmia or sudden death. The aim of this study was to investigate the relation between QT dispersion and left ventricular (LV function (systolic and diastolic, dimension and mass as well as to analyze the differences of this relationship according to the extent of angiographic coronary stenosis in patients with coronary artery disease. Methods：The study population included 262 patients (male 129, female 133；average age 60 years. Echocardiography was done for the measurement of left ventricular function, dimension and mass on admission. Electrocardiography for QT and QTc (corrected QT dispersion were recorded 25 mm/sec paper speeds before the coronary angiography. Patients were divided into two groups； Group A where angiographic coronary stenosis <50%, and Group B where angiographic coronary stenosis ≥50%. Results：The results were as follows：1 QT dispersion was higher in those with depressed LV systolic function (EF<55% than in those with normal LV systolic function among Group A (p<0.05. 2 QT dispersion was higher in those with abnormal IVRT (isovolumic relaxation time than in those with normal IVRT among Group A (p<0.05. But, there was no correlation between QT dispersion and other diastolic parameters in Group A. 3 QT dispersion was positively correlated with increased LVDd (diastolic left ventricular dimension, LVDs (systolic left ventricular dimension, LAD (left atrial dimension and IVS (interventricular septum in those in Group A. But, there found no correlation between QT dispersion and LV dimension parameters in Group B. 4 QT dispersion also had a positive correlation with LV mass in all patients and in those in Group A (all patients p<0.01；Group A p<0.001. But, there found no correlation between QT dispersion and LV mass in Group B. 5 On multiple logistic regression analysis, sex, abnormal IVRT and significant stenosis (≥50% of the coronary artery were independent prognostic factors of prolonged QT dispersion (p<0.05. 6 QTc dispersion showed the same result as QT dispersion. Conclusion：LV systolic function (EF, some diastolic function (IVRT, dimension (LVDd, LVDs, LAD IVS, and mass are associated with the increased QT dispersion in patients with coronary artery disease, especially minimal angiographic stenosed (<50% patients. So, we consider echocardiography is an important tool to predict the QT dispersion in patients with coronary artery disease.

Left ventricular mass index in aortic valve surgery: a new index for early valve replacement?

Increased left ventricular mass index has been associated with higher mortality. We analyze the effect of increased left ventricular mass index on outcomes in patients undergoing aortic valve replacement. Echocardiographic left ventricular dimensions were used to calculate left ventricular mass index in 614 patients who underwent aortic valve replacement between June 1993 and November 2001. Left ventricular mass index was considered increased if higher than the value of the superior decile (277 g/m(2) in males and 251 in females). Mean left ventricular mass index was: 178+/-111 g/m(2), and increased index was considered in 9.9% of patients. Postoperative complications (low cardiac output syndrome, respiratory failure, arrhythmias, pneumonia and mediastinitis), median length of hospital stay: 12 days (6-57) versus 11 days (5-51), and in-hospital mortality (11.4, 3.2%, P<0.01) were higher in patients with increased left ventricular mass index. Multivariable analysis identified increased left ventricular mass index (odds ratio: 5.6; 95% confidence interval: 1.2-25.0; P=0.02) and other three variables: age (P=0.04), history of chronic renal failure (P=0.03) and cardiopulmonary bypass time (P=0.004), as independent predictors of early mortality. Increased left ventricular mass index is associated with an in-hospital adverse outcome and a significantly higher in-hospital mortality in patients undergoing aortic valve replacement. Outcomes in asymptomatic patients could be improved before a clinically significant increase in left ventricular mass index. Further studies should be performed to determine the usefulness of this index in selecting patients for earlier aortic valve replacement.

Implications of increased left ventricular mass index on in-hospital outcomes in patients undergoing aortic valve surgery

Background: Increased left ventricular mass index has been shown to be associated with higher mortality in epidemiologic studies. However, the effect of increased left ventricular mass index on outcomes in patients undergoing aortic valve replacement is unknown. Methods: We studied 473 consecutive patients undergoing elective aortic valve replacement to assess the influence of left ventricular mass index on outcomes in patients having this procedure. Echocardiographic left ventricular dimensions were used to calculate left ventricular mass index (considered increased if >134 g/m2 in male patients and >110 g/m2 in female patients). Results: Left ventricular mass index was increased in 24% of patients undergoing aortic valve replacement. Postprocedural complications (respiratory failure, renal insufficiency, congestive heart failure, and atrial and ventricular arrhythmias), length of stay in the intensive care unit, and in-hospital mortality were increased in patients with increased left ventricular mass index. Multivariable analysis identified prior valve surgery (odds ratio, 4.3; 95% confidence interval, 1.2-15.7; P =.030), left ventricular ejection fraction (odds ratio, 1.07; 95% confidence interval, 1.01-1.14; P =.020), history of hypertension (odds ratio, 8.2; 95% confidence interval, 2.2-30.4; P =.002), history of liver disease (odds ratio, 50.4; 95% confidence interval, 4.2-609.0; P =.002), and increased left ventricular mass index (odds ratio, 38; 95% confidence interval, 9.3-154.1; P ||.001) as independent predictors of in-hospital mortality. Furthermore, low output syndrome was identified as the most common mode of death (36%) after aortic valve replacement in patients with increased left ventricular mass index. Conclusions: Increased left ventricular mass index is associated with increased adverse in-hospital clinical outcomes in patients undergoing aortic valve replacement. Although this finding warrants special modification in perioperative management, further studies are needed to address whether outcomes in asymptomatic patients with aortic valve disease could be improved by earlier aortic valve replacement before a significant increase in left ventricular mass index.J Thorac Cardiovasc Surg 2001;122:919-28

Persistently increased serum concentrations of cardiac troponin T in patients with idiopathic dilated cardiomyopathy are predictive of adverse outcomes

Background—The measurement of serum concentrations of cardiac troponin T (TnT) is a simple, useful method to detect myocyte injury that may be repeated multiple times to follow patients without interobserver variability. Methods and Results—Multiple measurements of TnT with a second-generation assay were performed in 60 patients with dilated cardiomyopathy confirmed by coronary angiography and endomyocardial biopsy between April 1996 and December 1999. Three evolutionary patterns of TnT concentrations were identified. Thirty-three patients had concentrations of TnT <0.02 ng/mL throughout the follow-up period (group 1). The remaining 27 patients had high initial serum concentrations of TnT (≥0.02 ng/mL). In 10 of these 27 patients, TnT decreased to <0.02 ng/mL during follow-up (group 2), whereas 17 had persistently high serum TnT concentrations despite being conventionally treated for chronic congestive heart failure (group 3). Although the initial echocardiographic left ventricular diastolic dimension (LV...