Left ventricular function of the isolated, genetically obese rat's heart

1985 ◽  
Vol 248 (4) ◽  
pp. H438-H444 ◽  
Author(s):  
N. F. Paradise ◽  
C. F. Pilati ◽  
W. R. Payne ◽  
J. A. Finkelstein
Keyword(s):  
Wall Stress ◽  
Left Ventricular ◽  
Physiological Solution ◽  
Zucker Rats ◽  
Lv Function ◽  
Ether Anesthesia ◽  
Obese Female ◽  
Lean Littermate ◽  
Lv Mass ◽  
Calculated Average

We sought to determine if left ventricular (LV) function of the heart from the adult, chronically obese animal is impaired. Hearts from 50 wk-old genetically obese female Zucker rats (624 +/- 13 g) and their lean littermate controls (275 +/- 5 g) were isolated during ether anesthesia, supported metabolically by retrograde aortic perfusion (6 ml/min, 35 degrees C) with physiological solution containing suspended canine erythrocytes (hematocrit, 20%), and the ventricles were paced at 180 beats/min. A distensible, fluid-filled balloon was placed in the LV, and pressure-volume (PV) relationships were obtained. The obese and lean end-diastolic PV curves were not different, and therefore the obese and lean LV chamber compliances were similar. Comparison of the systolic PV relationships demonstrated that the obese rat's heart had a greater pressure-generating capability, which probably was a reflection of its increased LV mass (0.96 +/- 0.03 vs. 0.72 +/- 0.02 g). The calculated average meridional (or circumferential) peak systolic wall stress in the LV of the obese rat's heart, however, was significantly reduced compared with control. This diminished ability to develop systolic stress from the same end-diastolic volumes suggests that the hypertrophied LV of the middle-aged obese rat's heart is dilated or that its contractility is depressed, or both.

LV and myocyte structure and function after early recovery from tachycardia-induced cardiomyopathy

1995 ◽  
Vol 268 (2) ◽  
pp. H836-H847 ◽  
Author(s):  
F. G. Spinale ◽  
H. H. Holzgrefe ◽  
R. Mukherjee ◽  
S. R. Arthur ◽  
M. J. Child ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Contractile Function ◽  
Recovery Period ◽  
Wall Stress ◽  
Left Ventricular ◽  
Lv Function ◽  
Early Recovery ◽  
End Diastolic Volume ◽  
Lv Mass ◽  
Lv Ejection Fraction

Left ventricular (LV) function and mass were measured in six conscious dogs at weekly intervals during the progression of tachycardia-induced dilated cardiomyopathy (DCM) and during a 1-mo recovery period from DCM (post-DCM). LV end-diastolic volume and LV wall stress increased and LV ejection fraction decreased with each week of pacing. Despite the increased LV wall stress, LV mass did not change during the progression of tachycardia DCM. One week post-DCM resulted in an improved LV ejection fraction and normalization of neurohormonal profiles. However, 1 wk post-DCM was accompanied by a 26% increase in LV mass and persistent LV chamber dilation. Isolated myocyte function was examined and compared with that in six normal control dogs. Myocyte percent and myocyte velocity of shortening were 19 and 32% lower, respectively, in the post-DCM group compared with controls. Thus termination of the tachycardia subsequent to the development of DCM resulted in persistent LV chamber dilation and abnormalities in myocyte contractile function. The improved LV pump function with early recovery from tachycardia-induced DCM was mediated by LV hypertrophy and a subsequent reduction in LV wall stress rather than a normalization of LV geometry and myocyte contractile function.

Urine Albumin to Creatinine Ratio and Echocardiographic Left Ventricular Structure and Function in Patients with Essential Hypertension

2011 ◽  
Vol 9 (2) ◽  
pp. 90 ◽  
Author(s):  
Rohola Hemmati ◽  
Mojgan Gharipour ◽  
Hasan Shemirani ◽  
Alireza Khosravi ◽  
Elham Khosravi ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Peak Velocity ◽  
Left Ventricular ◽  
Lv Function ◽  
Creatinine Ratio ◽  
Uncomplicated Hypertension ◽  
Urine Albumin ◽  
Lv Dysfunction ◽  
Mitral Annulus Velocity ◽  
Lv Mass

Background:Appearance of microalbuminuria, particularly in patients with hypertension, might be associated with a higher prevalence of left ventricular (LV) dysfunction and geometric abnormalities. This study was undertaken to determine whether high urine albumin to creatinine ratio (UACR) as a sensitive marker for microalbuminuria can be associated with LV hypertrophy (LVH) and systolic and diastolic LV dysfunction.Methods:The study population consisted of 125 consecutive patients with essential uncomplicated hypertension. Urine albumin and creatinine concentration was determined by standard methods. LVH was defined as a LV mass index >100 g/m2 of body surface area in women and >130 g/m2 in men. Echocardiographic LV systolic and diastolic parameters were measured.Results:The prevalence of microalbuminuria in patients with essential hypertension was 5.6 %. UACR was significantly no different in patients with LVH than in patients with normal LV geometry (21.26 ± 31.55 versus 17.80 ± 24.52 mg/mmol). No significant correlation was found between UACR measurement and systolic and diastolic function parameters, including early to late diastolic peak velocity (E/A) ratio (R=-0.192, p=0.038), early diastolic peak velocity to early mitral annulus velocity (E/E') ratio (R=-0.025, p=0.794), LV ejection fraction (R=0.008, p=0.929), and LV mass (R=-0.132, p=0.154). According to the receiver operator characteristic (ROC) curve analysis, UACR measurement was not an acceptable indicator of LVH with areas under the ROC curves 0.514 (95 % confidence interval 0.394–0.634). The optimal cut-off value for UACR for predicting LVH was identified at 9.4, yielding a sensitivity of 51.6 % and a specificity of 48.3 %.Conclusion:In patients with uncomplicated essential hypertension, abnormal systolic and diastolic LV function and geometry cannot be effectively predicted by the appearance of microalbuminuria.

scholarly journals Echocardiographic assessment of global left ventricular function in mice

2009 ◽  
Vol 43 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Jörg Stypmann ◽  
Markus A Engelen ◽  
Clemens Troatz ◽  
Markus Rothenburger ◽  
Lars Eckardt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Wall Stress ◽  
Left Ventricular ◽  
Lv Function ◽  
Mean Velocity ◽  
Global Left Ventricular ◽  
Mitral Inflow ◽  
Strain And Strain Rate ◽  
Echocardiographic Assessment ◽  
Murine Echocardiography

Doppler-echocardiographic assessment of cardiovascular structure and function in murine models has developed into one of the most commonly used non-invasive techniques during the last decades. Recent technical improvements even expanded the possibilities. In this review, we summarize the current options to assess global left ventricular (LV) function in mice using echocardiographic techniques. In detail, standard techniques as structural and functional assessment of the cardiovascular phenotype using one-dimensional M-mode echocardiography, two-dimensional B-mode echocardiography and spectral Doppler signals from mitral inflow respective aortal outflow are presented. Further pros and contras of recently implemented techniques as three-dimensional echocardiography and strain and strain rate measurements are discussed. Deduced measures of LV function as the myocardial performance index according to Tei, estimation of the mean velocity of circumferential fibre shortening, LV wall stress and different algorithms to estimate the LV mass are described in detail. Last but not least, specific features and limitations of murine echocardiography are presented. Future perspectives in respect to new examination techniques like targeted molecular imaging with advanced ultrasound contrast bubbles or improvement of equipment like new generation matrix transducers for murine echocardiography are discussed.

Abstract 3435: Left Ventricular Hypertrophy is Resistant to Inhibition of Expression of the R403Q Alpha-Myosin Heavy Chain Cardiac Hypertrophy-Inducing Mutant Protein

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Leah Cannon ◽  
Tadeusz Marciniec ◽  
Bryony Mearns ◽  
Robert M Graham ◽  
Diane Fatkin
Keyword(s):  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Interstitial Fibrosis ◽  
Myocardial Dysfunction ◽  
Left Ventricular ◽  
Familial Hypertrophic Cardiomyopathy ◽  
Lv Function ◽  
Dependent Manner ◽  
Cardiovascular Morbidity And Mortality ◽  
Lv Mass

Left ventricular hypertrophy (LVH) develops as a compensatory response to myocardial dysfunction due to diverse causes, but is nonetheless a major risk factor for premature cardiovascular morbidity and mortality. It is thus unclear if regressing LVH is beneficial or may worsen patient outcome. To evaluate the effects of LVH regression, we developed a transgenic mouse model in which the expression of a familial hypertrophic cardiomyopathy (FHC)-inducing mutation (R403Q alpha-MHC) can be regulated in a temporal and dose-dependent manner. In this model, transgene expression can be shut off by feeding with a tetracycline analogue (doxycycline). Serial echocardiography and histology studies were performed in a cohort of mice expressing the FHC mutant (“gene-on”) and in wildtype (WT) littermates. A second cohort of WT and 403/+ mice was randomised to placebo or doxycycline (“gene off”) from 6 (Dox6) or 20 weeks (Dox20) and evaluated at 40 weeks of age. Compared to WT littermates, “gene on” 403/+ mice showed increased LV mass, LV end-diastolic diameter (LVDD) and left atrial diameter (LAD), and reduced fractional shortening (LVFS), with changes evident from 12 weeks of age. LV sections from 403/+ mice showed typical features of FHC: myofibre disarray and interstitial fibrosis. LV mass, LV function and myocardial histology were unchanged in both male and female placebo- vs Dox6 or Dox20 mice at 40 weeks (Table 1 ). Thus, consistent with the major LV thickening in FHC humans occurring in adolescence, overexpression of R403Q for only 6 weeks is sufficient to trigger the complete LVH phenotypic response. Moreover, switching off the genetic trigger for LVH in 403/+ mice at 6 weeks (prior to overt disease manifestation) or 20 weeks (established disease) does not induce regression of LVH or exacerbate contractile dysfunction. Interventions to induce LVH regression may, therefore, need to be directed at downstream factors in hypertrophic pathways. Table 1. Echo data for male WT and 403/+ mice aged 40 weeks

Abstract 12952: Global Longitudinal Strain is Simple, Effective & Sensitive Assessment of Cardiac Chamber Function in Patients With Acute-phase Myocarditis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Shaun Khanna ◽  
Aditya Bhat ◽  
Henry H Chen ◽  
Kennith Gu ◽  
Gary Gan ◽  
...  
Keyword(s):  
Acute Phase ◽  
Longitudinal Strain ◽  
Myocardial Dysfunction ◽  
Global Longitudinal Strain ◽  
Disease Process ◽  
Left Ventricular ◽  
Lv Function ◽  
Lv Mass ◽  
Echocardiographic Parameters ◽  
Cardiac Therapy

Introduction: Myocarditis is an inflammatory disease process with growing clinical relevance in the current COVID-19 pandemic. Acute-phase myocarditis is known to result in subclinical changes in left ventricular (LV) function despite normal LV ejection fraction (LVEF), as assessed by myocardial deformation indices. The presence of right ventricular (RV) and left atrial (LA) subclinical dysfunction however has not been well described in current literature. Hypothesis: Myocarditis patients have subclinical impairment of LV, RV and LA function as assessed by global longitudinal strain (GLS) on speckle tracking echocardiography. Methods: Consecutive patients with clinical diagnosis of myocarditis admitted to our institution during 2013-2018 were assessed (n=76). Patients who did not meet appropriate diagnostic criteria (n=14), had impaired LVEF or prior cardiac disease (n=8) or poor transthoracic echocardiogram images (n=14) were excluded from analysis. Clinical and echocardiographic parameters were compared to age- , gender- and risk factor- matched controls. GLS was performed by two independent observers using vendor independent software (TomTec Arena, Germany v4.6). Results: The final cohort consisted 40 patients with myocarditis (age 44.3±16.7, 60% male) and 40 matched controls (44.5±16.6, 60% male). No significant differences in baseline clinical characteristics were observed between groups. No differences in LVEF, indexed LV mass, RV fractional area change, indexed LA volume or TR pressure gradient (p>0.05 for all) were demonstrated between the two groups. Patients with myocarditis had a lower mean LV strain (GLS%: -16.4±2.9 vs -19.7±2.7, p=0.0001), a lower mean RV Free Wall Strain (FWS) (GLS%: -22.1±4.1 vs -26.2±6.9, p=0.03) and a lower mean LA reservoir strain (GLS%: 27.5±4.6 vs. 33.7±6.3, p<0.0001) when compared to controls. Conclusions: Our results demonstrate the presence of significant subclinical global myocardial dysfunction despite normal traditional echocardiographic indices, in patients with acute-phase myocarditis. Routine assessment of GLS may identify such patients for early targeted cardiac therapy.

Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy

2007 ◽  
Vol 85 (8) ◽  
pp. 790-799 ◽  
Author(s):  
P. Alter ◽  
H. Rupp ◽  
M.B. Rominger ◽  
A. Vollrath ◽  
F. Czerny ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Wall Stress ◽  
Left Ventricular ◽  
Ventricular Wall ◽  
Resonance Imaging ◽  
Sphere Model ◽  
Lv Mass ◽  
Systolic Wall Stress

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.

Evaluation of diastolic LV function

2015 ◽  
pp. 323-335
Author(s):  
Johan De Sutter ◽  
Jean-Louis J. Vanoverschelde
Keyword(s):  
Diastolic Function ◽  
Daily Practice ◽  
Tissue Doppler ◽  
Left Ventricular ◽  
Doppler Imaging ◽  
Lv Function ◽  
Prognostic Information ◽  
Heart Failure Patients ◽  
Lv Mass ◽  
Deformation Measurements

The evaluation of diastolic function in patients with reduced (HFREF) or preserved (HFPEF) left ventricular (LV) ejection fraction is important as it carries both diagnostic and prognostic information. In daily practice, this is most frequently done by standard echocardiographic techniques, including the evaluation of LV mass and LA volumes, as well as transmitral and pulmonary venous PW Doppler, CW Doppler for evaluation of the IVRT, and tissue Doppler imaging of the septal and lateral annular velocities. This permits grading the severity of diastolic dysfunction, which is related to outcome and may be used to estimate LV filling pressures. The latter needs further validation, especially in patients with HFPEF. Newer echocardiographic and cardiac magnetic resonance techniques, including myocardial deformation measurements during diastole, LV twist and untwisting, and parameters of left atrial function, are promising and will hopefully in the future help clinicians to make a more precise evaluation of diastolic function and filling pressures in heart failure patients.

Ventricular performance and myocardial water content during hemodilution in dogs

1978 ◽  
Vol 235 (6) ◽  
pp. H767-H775 ◽  
Author(s):  
G. A. Geffin ◽  
M. A. Vasu ◽  
D. D. O'Keefe ◽  
D. G. Pennington ◽  
A. J. Erdmann ◽  
...  
Keyword(s):  
Water Content ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Lv Function ◽  
Stroke Work ◽  
Ventricular Performance ◽  
End Diastolic Volume ◽  
Lv Mass ◽  
Right Heart Bypass ◽  
Water Gain

In dogs anesthetized with chloralose-urethan on right heart bypass, left ventricular (LV) performance was assessed at constant LV stroke work before and for up to 2.5 h after crystalloid hemodilution was established. Lowering the hematocrit from 43.3 +/- 1.3% to 13.6 +/- 1.7% (SE) did not significantly change LV end-diastolic pressure (LVEDP) initially. After 80 min LVEDP increased slightly by 1.7 +/- 0.6 cmH2O (P less than 0.05) at a stroke work of 17.3 +/- 2.3 g.m. The value of dP/dt did not change significantly throughout. When LV function curves were generated by increasing cardiac output, the stroke work attained at an LVEDP of 10 cmH2O decreased with hemodilution from 23.9 +/- 3.5 to 20.8 +/- 3.9 g.m (NS). LV wall water content increased with hemodilution, from which it could be calculated that there was an 18.6% increase in LV mass. Thus, despite an increase in LV external girth demonstrated by LV circumferential gauges, it is possible that increased wall thickness due to the water gain resulted in little change or an actual decrease in LV end-diastolic volume. Thus, profound hemodilution can be attained with only slight depression of LV performance.

scholarly journals Genetic relevance and determinants of mitral leaflet size in hypertrophic cardiomyopathy

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Hyemoon Chung ◽  
Yoonjung Kim ◽  
Chul-Hwan Park ◽  
Jong-Youn Kim ◽  
Pil-Ki Min ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Nuclear Dna ◽  
Wall Stress ◽  
Left Ventricular ◽  
Mitral Leaflet ◽  
Systolic Volume ◽  
Left Atrial Wall ◽  
Lv Mass ◽  
End Systolic Volume ◽  
Sarcomeric Genes

Abstract Background Whether mitral leaflet elongation is a primary phenotype of hypertrophic cardiomyopathy (HCM) is controversial. We investigated the genetic relevance and determinants of mitral leaflet size by performing extensive gene analyses in patients with HCM. Methods Anterior mitral leaflet (AML) lengths were measured in HCM patients (n = 211) and age- and sex-matched controls (n = 30) using echocardiography with hemodynamic and chamber geometric assessments. We analyzed 82 nuclear DNA (8 sarcomeric genes, 74 other HCM-associated genes) and mitochondrial DNA. Cardiac magnetic resonance imaging (CMR) was performed in the 132 HCM patients. Results Average indexed AML was significantly longer for HCM than for controls (17.2 ± 2.3 vs. 13.3 ± 1.6 mm/m2, P <  0.001). Average AML length correlated with body surface area (BSA), left ventricular (LV) end-systolic volume (P <  0.001) and LV mass by CMR (P < 0.001). Average indexed AML by BSA of pure-apical HCM was significantly shorter than other typed HCM (16.6 ± 2.0 vs. 17.4 ± 2.4 mm/m2, P = 0.025). Indexed AML was independently correlated with left atrial wall stress. The thin filament mutation group showed larger average AML (31.9 ± 3.8 vs. 29.6 ± 3.8 mm, P = 0.045), but this was not significant with the indexed value. No difference in AML size among subgroups was observed based on the presence of sarcomere protein or mitochondria-related gene variants (P > 0.05). Conclusion AML elongation was a unique finding of HCM. However, the leaflet size was more related to chamber geometry and hypertrophy pattern rather than genetic factors within overt HCM.

Colchicine attenuates left ventricular hypertrophy but preserves cardiac function of aortic-constricted rats

2003 ◽  
Vol 94 (4) ◽  
pp. 1627-1633 ◽  
Author(s):  
Beatriz S. Scopacasa ◽  
Vicente P. A. Teixeira ◽  
Kleber G. Franchini
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Colchicine Treatment ◽  
Average Diameter ◽  
Left Ventricular ◽  
Lv Function ◽  
Right Ventricular Mass ◽  
Lv Mass ◽  
Phenylephrine Infusion

To investigate the effects of colchicine on left ventricular (LV) function and hypertrophy (LVH) of rats subjected to constriction of transverse aorta (TAoC), we evaluated SO (sham operated, vehicle; n = 25), SO-T (sham operated, colchicine 0.4 mg/kg body wt ip daily; n = 38), TAoC (vehicle; n = 37), and TAoC-T (TAoC, colchicine; n = 34) on the 2nd, 6th, and 15th day after surgery. Colchicine attenuated LVH of TAoC-T compared with TAoC rats, as evaluated by ratio between LV mass (LVM) and right ventricular mass, LV wall thickness, and average diameter of cardiac myocytes. Systolic gradient across TAoC (∼45 mmHg), LV systolic pressure, LV end-diastolic pressure, and rate of LV pressure increase (+dP/d t) were comparable in TAoC-T and TAoC rats. However, the baseline and increases of LV systolic pressure-to-LVM and +dP/d t-to-LVMratios induced by phenylephrine infusion were greater in TAoC-T and SO-T compared with SO rats. Baseline and increases of +dP/d t-to-LVM ratio were reduced in TAoC compared with SO rats. TAoC rats increased polymerized fraction of tubulin compared with SO, SO-T, and TAoC-T rats. Our results indicate that colchicine treatment reduced LVH to pressure overload but preserved LV function.

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