Echocardiographic assessment of cardiac function in conscious and anesthetized mice

1999 ◽  
Vol 277 (5) ◽  
pp. H1967-H1974 ◽  
Author(s):  
Xiao-Ping Yang ◽  
Yun-He Liu ◽  
Nour-Eddine Rhaleb ◽  
Nobutaka Kurihara ◽  
Henry E. Kim ◽  
...  

Using a high-frequency linear transducer (15L8), we studied 1) the feasibility of performing echocardiography in nonanesthetized mice compared with mice given pentobarbital sodium (Pento) or a mixture of ketamine and xylazine and 2) the feasibility of echocardiographic evaluation of left ventricular (LV) hypertrophy, dilatation, and function in mice with two-kidney, one-clip hypertension or myocardial infarction (MI). Heart rate (HR) in awake mice was 658 ± 9 beats/min; Pento and ketamine plus xylazine reduced HR to 377 ± 11 and 293 ± 19 beats/min, respectively, associated with a significant decrease in shortening fraction (SF), ejection fraction (EF), and cardiac output (CO) and an increase in LV end-diastolic (LVEDD) and end-systolic dimensions (LVESD). Mice with 4 wk of two-kidney, one-clip hypertension had increased LV mass (15.62 ± 0.62 vs. 22.17 ± 1.79 mg) without altered LV dimensions, SF, EF, or CO. Mice studied 4 wk post-MI exhibited obvious LV dilatation and systolic dysfunction, as evidenced by increased LVEDD and LVESD and decreased SF, EF, and CO. Our findings clearly show the adverse impact of anesthesia on basal cardiac function and the difficulty in interpreting data obtained from anesthetized mice. We believe this is the first study to demonstrate the feasibility of using echocardiography to assess cardiovascular function in the nonanesthetized mouse.

2021 ◽  
Vol 14 (10) ◽  
pp. e245963
Author(s):  
Jayanty Venkata Balasubramaniyan ◽  
Judah Nijas Arul ◽  
Jebaraj Rathinasamy ◽  
Thangavel Periyasamy

Myxomas arising from the left ventricle (LV) are extremely rare and can be easily mistaken for a thrombus. We report a case of a 35-year-old man who presented with an acute cerebrovascular accident, having had a prior history of an anterior wall myocardial infarction 2 years back with an echocardiographic evaluation showing mild LV systolic dysfunction. His present prothrombotic workup revealed hyperhomocystinaemia and elevated levels of factor VIII. Present echocardiography revealed a mass arising from a scarred LV wall. Considering the possibility of a thrombus, he was initially started on parenteral anticoagulation. Unfortunately, consequent echocardiogram evaluation showed no reduction in size of the LV mass hence surgical removal was done. Histopathological evaluation unveiled the mass to be a myxoma.


Author(s):  
Carmine Zoccali ◽  
Davide Bolignano ◽  
Francesca Mallamaci

Alterations in left ventricular (LV) mass and geometry and LV dysfunction increase in prevalence from stage 2 to stage 5 in CKD. Nuclear magnetic resonance is the most accurate and precise technique for measuring LV mass and function in patients with heart disease. Quantitative echocardiography is still the most frequently used means of evaluating abnormalities in LV mass and function in CKD. Anatomically, myocardial hypertrophy can be classified as concentric or eccentric. In concentric hypertrophy, the muscular component of the LV (LV wall) predominates over the cavity component (LV volume). Due to the higher thickness and myocardial fibrosis in patients with concentric LVH, ventricular compliance is reduced and the end-diastolic volume is small and insufficient to maintain cardiac output under varying physiological demands (diastolic dysfunction). In those with eccentric hypertrophy, tensile stress elongates myocardiocytes and increases LV end-diastolic volume. The LV walls are relatively thinner and with reduced ability to contract (systolic dysfunction). LVH prevalence increases stepwisely as renal function deteriorates and 70–80% of patients with kidney failure present with established LVH which is of the concentric type in the majority. Volume overload and severe anaemia are, on the other hand, the major drivers of eccentric LVH. Even though LVH may regress after renal transplantation, the prevalence of LVH after transplantation remains close to that found in dialysis patients and a functioning renal graft should not be seen as a guarantee of LVH regression. The vast majority of studies on cardiomyopathy in CKD are observational in nature and the number of controlled clinical trials in these patients is very small. Beta-blockers (carvedilol) and angiotensin receptors blockers improve LV performance and reduce mortality in kidney failure patients with LV dysfunction. Although current guidelines recommend implantable cardioverter-defibrillators in patients with ejection fraction less than 30%, mild to moderate symptoms of heart failure, and a life expectancy of more than 1 year, these devices are rarely offered to eligible CKD patients. Conversion to nocturnal dialysis and to frequent dialysis schedules produces a marked improvement in LVH in patients on dialysis. More frequent and/or longer dialysis are recommended in dialysis patients with asymptomatic or symptomatic LV disorders if the organizational and financial resources are available.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marianna Török ◽  
Petra Merkely ◽  
Anna Monori-Kiss ◽  
Eszter Mária Horváth ◽  
Réka Eszter Sziva ◽  
...  

Abstract Background We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy. Methods Thirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 μm in diameter were studied using divided 50-μm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry. Results The LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-μm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-μm vessels appeared unusually close to the orifice. Conclusions Physical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.


2001 ◽  
Vol 281 (5) ◽  
pp. H1938-H1945 ◽  
Author(s):  
Chari Y. T. Hart ◽  
John C. Burnett ◽  
Margaret M. Redfield

Anesthetic regimens commonly administered during studies that assess cardiac structure and function in mice are xylazine-ketamine (XK) and avertin (AV). While it is known that XK anesthesia produces more bradycardia in the mouse, the effects of XK and AV on cardiac function have not been compared. We anesthetized normal adult male Swiss Webster mice with XK or AV. Transthoracic echocardiography and closed-chest cardiac catheterization were performed to assess heart rate (HR), left ventricular (LV) dimensions at end diastole and end systole (LVDd and LVDs, respectively), fractional shortening (FS), LV end-diastolic pressure (LVEDP), the time constant of isovolumic relaxation (τ), and the first derivatives of LV pressure rise and fall (dP/d t max and dP/d t min, respectively). During echocardiography, HR was lower in XK than AV mice (250 ± 14 beats/min in XK vs. 453 ± 24 beats/min in AV, P < 0.05). Preload was increased in XK mice (LVDd: 4.1 ± 0.08 mm in XK vs. 3.8 ± 0.09 mm in AV, P < 0.05). FS, a load-dependent index of systolic function, was increased in XK mice (45 ± 1.2% in XK vs. 40 ± 0.8% in AV, P < 0.05). At LV catheterization, the difference in HR with AV (453 ± 24 beats/min) and XK (342 ± 30 beats/min, P < 0.05) anesthesia was more variable, and no significant differences in systolic or diastolic function were seen in the group as a whole. However, in XK mice with HR <300 beats/min, LVEDP was increased (28 ± 5 vs. 6.2 ± 2 mmHg in mice with HR >300 beats/min, P < 0.05), whereas systolic (LV dP/d t max: 4,402 ± 798 vs. 8,250 ± 415 mmHg/s in mice with HR >300 beats/min, P < 0.05) and diastolic (τ: 23 ± 2 vs. 14 ± 1 ms in mice with HR >300 beats/min, P < 0.05) function were impaired. Compared with AV, XK produces profound bradycardia with effects on loading conditions and ventricular function. The disparate findings at echocardiography and LV catheterization underscore the importance of comprehensive assessment of LV function in the mouse.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Michelle A Hardyman ◽  
Stephen J Fuller ◽  
Daniel N Meijles ◽  
Kerry A Rostron ◽  
Sam J Leonard ◽  
...  

Introduction: Raf kinases lie upstream of ERK1/2 with BRaf being the most highly expressed and having the highest basal activity. V600E BRaf mutations constitutively activate ERK1/2 and are common in cancer. The role of BRaf in the adult heart is yet to be established. ERK1/2 regulate cardiomyocyte gene expression, promoting cardiac hypertrophy and cardioprotection, but effects of ERK1/2 may depend on signal strength. Hypothesis: Our hypotheses are that BRaf is critical in regulating ERK1/2 signaling in cardiomyocytes and, whilst moderate ERK1/2 activity is beneficial, excessive ERK1/2 activity is detrimental to the heart. Methods: We generated heterozygote mice for tamoxifen- (Tam-) inducible cardiomyocyte-specific knockin of V600E in the endogenous BRaf gene. Mice (12 wks) received 2 injections of Tam or vehicle on consecutive days (n=4-10 per group). Kinase activities and mRNA expression were assessed by immunoblotting and qPCR. Echocardiography was performed (Vevo2100). M-mode images (short axis view) were analyzed; data for each mouse were normalized to the mean of 2 baseline controls. Results: V600E knockin did not affect overall BRaf or cRaf levels in mouse hearts, but significantly increased ERK1/2 activities within 48 h (1.51±0.05 fold). Concurrently, mRNAs for hypertrophic gene markers including BNP and immediate early genes (IEGs) increased signficantly. At 72 h, expression of BNP, Fosl1, Myc, Ereg and CTGF increased further, other IEGs (Jun, Fos, Egr1, Atf3) declined, and ANF was upregulated. In contrast, expression of α and β myosin heavy chain mRNAs was substantially downregulated (0.46/0.41±0.05 relative to controls). Within 72 h, left ventricular (LV) mass and diastolic LV wall thickness had increased (1.23±0.05 relative to controls), but cardiac function was severely compromised with significant decreases in ejection fraction and cardiac output (0.53/0.68±0.09 relative to controls) associated with increased LV internal diameters and cardiac volumes. Conclusions: Endogenous cardiomyocyte BRaf is sufficient to activate ERK1/2 in mouse hearts and induce cardiac hypertrophy associated with dynamic temporal changes in gene expression. However, excessive activation of ERK1/2 in isolation is detrimental to cardiac function.


Kardiologiia ◽  
2021 ◽  
Vol 61 (8) ◽  
pp. 68-75
Author(s):  
E. K. Serezhina ◽  
A. G. Obrezan

This systematic review is based on 19 studies from Elsevier, PubMed, Embase, and Scopus databases, which were found by the following keywords: LA strain (left atrial strain), STE (speckle tracking echocardiography), HF (heart failure), and HFpEF (heart failure with preserved ejection fraction). The review focuses on results and conclusions of studies on using the 2D echocardiographic evaluation of left atrial (LA) myocardial strain for early diagnosis of HFpEF in routine clinical practice. Analysis of the studies included into this review showed a significant decline of all LA functions in patients with HFpEF. Also, multiple studies have reported associations between decreased indexes of LA strain and old age, atrial fibrillation, left ventricular hypertrophy, left and right ventricular systolic dysfunction, and LV diastolic dysfunction. Thus, the review indicates significant possibilities of using indexes of LA strain in evaluation of early stages of both systolic and diastolic myocardial dysfunction. Notably, LA functional systolic and diastolic indexes are not sufficiently studied despite their growing significance for diagnosis and prognosis of patients with HFpEF. For this reason, in addition to existing models for risk stratification in this disease, including clinical characteristics and/or echocardiographic data, future studies should focus on these parameters. 


2018 ◽  
Vol 9 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Jiahui Li ◽  
Aili Li ◽  
Jiali Wang ◽  
Yu Zhang ◽  
Ying Zhou

Purpose: Cardiac valve calcification (VC) is very common in patients on hemodialysis. However, the definite effect of VC on left ventricular (LV) geometry and function in this population is unknown, especially when LV ejection fraction (LVEF) is normal. The aim of this study was to determine the effect of VC on LV geometry and function in long-term hemodialysis patients by conventional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE). Methods: A total of 47 hemodialysis patients (2–3 times weekly for 5 years or more) were enrolled in this study. Cardiac VC was defined as bright echoes of more than 1 mm on one or more cusps of the aortic valve or mitral valve or mitral annulus using echocardiography as the screening method. LV longitudinal global strain (GLS) was assessed on the apical four-chamber view and calculated as the mean strain of 6 segments. LV global circumferential strain was acquired on the LV short axis view at the level of papillary muscles. Results: Twenty-five patients with VC had higher mean values of interventricular septum thickness, LV posterior wall thickness, LV mass index, relative wall thickness, and LV mass/end-diastolic volume than 22 patients without VC (p < 0.05, respectively), indicating more obvious LV hypertrophy (LVH). VC patients had higher mitral annular E/E′ values, especially at the septal side representing increased LV filling pressure compatible with diastolic dysfunction, while only the E/E′ ratio of the septal side was significantly different between the 2 groups (16.7 ± 4.1 vs. 12.3 ± 4.4, p < 0.01). When assessed by GLS, LV longitudinal systolic function was also lower in in patients with VC compared with those without VC (–0.18 ± 0.03 vs. –0.25 ± 0.04; p < 0.01). Conclusions: Cardiac VC diagnosed by echocardiography when it occurs in long-term hemodialysis patients may indicate more severe LVH, myocardial damage, and worse heart function in comparison to those without VC. Tissue Doppler imaging and 2D-STE can detect the subtle change of heart function in this population in the early stage of LV dysfunction when LVEF is normal.


2018 ◽  
Vol 115 (3) ◽  
pp. 519-529 ◽  
Author(s):  
Sarah-Lena Puhl ◽  
Kate L Weeks ◽  
Alican Güran ◽  
Antonella Ranieri ◽  
Peter Boknik ◽  
...  

Abstract Aims B56α is a protein phosphatase 2A (PP2A) regulatory subunit that is highly expressed in the heart. We previously reported that cardiomyocyte B56α localizes to myofilaments under resting conditions and translocates to the cytosol in response to acute β-adrenergic receptor (β-AR) stimulation. Given the importance of reversible protein phosphorylation in modulating cardiac function during sympathetic stimulation, we hypothesized that loss of B56α in mice with targeted disruption of the gene encoding B56α (Ppp2r5a) would impact on cardiac responses to β-AR stimulation in vivo. Methods and results Cardiac phenotype of mice heterozygous (HET) or homozygous (HOM) for the disrupted Ppp2r5a allele and wild type (WT) littermates was characterized under basal conditions and following acute β-AR stimulation with dobutamine (DOB; 0.75 mg/kg i.p.) or sustained β-AR stimulation by 2-week infusion of isoproterenol (ISO; 30 mg/kg/day s.c.). Left ventricular (LV) wall thicknesses, chamber dimensions and function were assessed by echocardiography, and heart tissue collected for gravimetric, histological, and biochemical analyses. Western blot analysis revealed partial and complete loss of B56α protein in hearts from HET and HOM mice, respectively, and no changes in the expression of other PP2A regulatory, catalytic or scaffolding subunits. PP2A catalytic activity was reduced in hearts of both HET and HOM mice. There were no differences in the basal cardiac phenotype between genotypes. Acute DOB stimulation induced the expected inotropic response in WT and HET mice, which was attenuated in HOM mice. In contrast, DOB-induced increases in heart rate were unaffected by B56α deficiency. In WT mice, ISO infusion increased LV wall thicknesses, cardiomyocyte area and ventricular mass, without LV dilation, systolic dysfunction, collagen deposition or foetal gene expression. The hypertrophic response to ISO was blunted in mice deficient for B56α. Conclusion These findings identify B56α as a potential regulator of cardiac structure and function during β-AR stimulation.


2018 ◽  
Vol 36 (6) ◽  
pp. 1318-1325 ◽  
Author(s):  
Piotr Dobrowolski ◽  
Magdalena Januszewicz ◽  
Anna Klisiewicz ◽  
Aleksander Prejbisz ◽  
Ewa Warchoł-Celińska ◽  
...  

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