Exercise attenuates inflammation and limits scar thinning after myocardial infarction in mice

2015 ◽  
Vol 309 (2) ◽  
pp. H345-H359 ◽  
Author(s):  
Sarah-Lena Puhl ◽  
Andreas Müller ◽  
Michael Wagner ◽  
Yvan Devaux ◽  
Michael Böhm ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Systolic Function ◽  
Left Ventricular ◽  
Heart Weight ◽  
Lv Function ◽  
Sham Operation ◽  
Beneficial Effects ◽  
End Diastolic Volume ◽  
Underlying Mechanisms ◽  
And Function

Although exercise mediates beneficial effects in patients after myocardial infarction (MI), the underlying mechanisms as well as the question of whether an early start of exercise after MI is safe or even beneficial are incompletely resolved. The present study analyzed the effects of exercise before and reinitiated early after MI on cardiac remodeling and function. Male C57BL/6N mice were housed sedentary or with the opportunity to voluntarily exercise for 6 wk before MI induction (ligation of the left anterior descending coronary artery) or sham operation. After a 5-day exercise-free phase after MI, mice were allowed to reexercise for another 4 wk. Exercise before MI induced adaptive hypertrophy with moderate increases in heart weight, cardiomyocyte diameter, and left ventricular (LV) end-diastolic volume, but without fibrosis. In sedentary mice, MI induced eccentric LV hypertrophy with massive fibrosis but maintained systolic LV function. While in exercised mice gross LV end-diastolic volumes and systolic function did not differ from sedentary mice after MI, LV collagen content and thinning of the infarcted area were reduced. This was associated with ameliorated activation of inflammation, mediated by TNF-α, IL-1β, and IL-6, as well as reduced activation of matrix metalloproteinase 9. In contrast, no differences in the activation patterns of various MAPKs or adenosine receptor expressions were observed 5 wk after MI in sedentary or exercised mice. In conclusion, continuous exercise training before and with an early reonset after MI ameliorates adverse LV remodeling by attenuating inflammation, fibrosis, and scar thinning. Therefore, an early reonset of exercise after MI can be encouraged.

Sepiapterin enhances angiogenesis and functional recovery in mice after myocardial infarction

2011 ◽  
Vol 301 (5) ◽  
pp. H2061-H2072 ◽  
Author(s):  
Takayuki Shimazu ◽  
Hajime Otani ◽  
Kei Yoshioka ◽  
Masanori Fujita ◽  
Toru Okazaki ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Myocardial Infarction ◽  
Functional Recovery ◽  
Capillary Density ◽  
Left Ventricular ◽  
Wild Type ◽  
Beneficial Effects ◽  
End Diastolic Volume ◽  
Lv Remodeling ◽  
And Function

Uncoupling of nitric oxide synthase (NOS) has been implicated in left ventricular (LV) remodeling and dysfunction after myocardial infarction (MI). We hypothesized that inducible NOS (iNOS) plays a crucial role in LV remodeling after MI, depending on its coupling status. MI was created in wild-type, iNOS-knockout (iNOS−/−), endothelial NOS-knockout (eNOS−/−), and neuronal NOS-knockout (nNOS−/−) mice. iNOS and nNOS expressions were increased after MI associated with an increase in nitrotyrosine formation. The area of myocardial fibrosis and LV end-diastolic volume and ejection fraction were more deteriorated in eNOS−/− mice compared with other genotypes of mice 4 wk after MI. The expression of GTP cyclohydrolase was reduced, and tetrahydrobiopterin (BH4) was depleted in the heart after MI. Oral administration of sepiapterin after MI increased dihydrobiopterin (BH2), BH4, and BH4-to-BH2 ratio in the infarcted but not sham-operated heart. The increase in BH4-to-BH2 ratio was associated with inhibition of nitrotyrosine formation and an increase in nitrite plus nitrate. However, this inhibition of NOS uncoupling was blunted in iNOS−/− mice. Sepiapterin increased capillary density and prevented LV remodeling and dysfunction after MI in wild-type, eNOS−/−, and nNOS−/− but not iNOS−/− mice. Nω-nitro-l-arginine methyl ester abrogated sepiapterin-induced increase in nitrite plus nitrate and angiogenesis and blocked the beneficial effects of sepiapterin on LV remodeling and function. These results suggest that sepiapterin enhances angiogenesis and functional recovery after MI by activating the salvage pathway for BH4 synthesis and increasing bioavailable nitric oxide predominantly derived from iNOS.

scholarly journals Prognostic value of NT-proBNP for myocardial recovery in peripartum cardiomyopathy (PPCM)

2021 ◽  
Author(s):  
J. Hoevelmann ◽  
E. Muller ◽  
F. Azibani ◽  
S. Kraus ◽  
J. Cirota ◽  
...  
Keyword(s):  
Prognostic Value ◽  
Systolic Function ◽  
Point Of Care ◽  
Diagnostic Value ◽  
Left Ventricular ◽  
Peripartum Cardiomyopathy ◽  
Lv Function ◽  
Myocardial Recovery ◽  
End Diastolic Volume

Abstract Introduction Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure worldwide. Although a significant number of women recover their left ventricular (LV) function within 12 months, some remain with persistently reduced systolic function. Methods Knowledge gaps exist on predictors of myocardial recovery in PPCM. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the only clinically established biomarker with diagnostic value in PPCM. We aimed to establish whether NT-proBNP could serve as a predictor of LV recovery in PPCM, as measured by LV end-diastolic volume (LVEDD) and LV ejection fraction (LVEF). Results This study of 35 women with PPCM (mean age 30.0 ± 5.9 years) had a median NT-proBNP of 834.7 pg/ml (IQR 571.2–1840.5) at baseline. Within the first year of follow-up, 51.4% of the cohort recovered their LV dimensions (LVEDD < 55 mm) and systolic function (LVEF > 50%). Women without LV recovery presented with higher NT-proBNP at baseline. Multivariable regression analyses demonstrated that NT-proBNP of ≥ 900 pg/ml at the time of diagnosis was predictive of failure to recover LVEDD (OR 0.22, 95% CI 0.05–0.95, P = 0.043) or LVEF (OR 0.20 [95% CI 0.04–0.89], p = 0.035) at follow-up. Conclusions We have demonstrated that NT-proBNP has a prognostic value in predicting LV recovery of patients with PPCM. Patients with NT-proBNP of ≥ 900 pg/ml were less likely to show any improvement in LVEF or LVEDD. Our findings have implications for clinical practice as patients with higher NT-proBNP might require more aggressive therapy and more intensive follow-up. Point-of-care NT-proBNP for diagnosis and risk stratification warrants further investigation.

Effects of avertin versus xylazine-ketamine anesthesia on cardiac function in normal mice

2001 ◽  
Vol 281 (5) ◽  
pp. H1938-H1945 ◽  
Author(s):  
Chari Y. T. Hart ◽  
John C. Burnett ◽  
Margaret M. Redfield
Keyword(s):  
Cardiac Function ◽  
Diastolic Pressure ◽  
Systolic Function ◽  
Pressure Rise ◽  
Left Ventricular ◽  
Lv Function ◽  
Ketamine Anesthesia ◽  
The Difference ◽  
And Function ◽  
Derivatives Of

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.

Inhibition and reversal of myocardial infarction-induced hypertrophy and heart failure by NHE-1 inhibition

2004 ◽  
Vol 286 (1) ◽  
pp. H381-H387 ◽  
Author(s):  
Ling Chen ◽  
Chang Xun Chen ◽  
Xiaohong Tracey Gan ◽  
Norbert Beier ◽  
Wolfgang Scholz ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Infarct Size ◽  
Treatment Delay ◽  
Left Ventricular ◽  
Heart Weight ◽  
Coronary Artery Ligation ◽  
Treatment Protocols ◽  
Beneficial Effects ◽  
All Treatment

Sodium/hydrogen exchange (NHE) inhibitors show promise as potential therapeutic agents for the treatment of heart failure, but it is not known whether they can reverse the maladaptive remodeling that results in heart failure. We sought to determine the effect of the NHE-1-specific inhibitor EMD-87580 (EMD) on heart failure produced by myocardial infarction in the rat and to assess whether up to 4 wk of treatment delay results in beneficial effects. Male Sprague-Dawley rats were subjected to coronary artery ligation (or a sham procedure) and followed for up to 3 mo, at which time hypertrophy and hemodynamics were determined. EMD was provided in the diet, and treatment commenced immediately or 2–4 wk after ligation. EMD significantly reduced hemodynamic abnormalities, including the elevation in left ventricular end-diastolic pressure, and diminished the loss of systolic function with all treatment protocols. Left ventricular dilatation and hypertrophy, as assessed by heart weight, cell size, and atrial natriuretic peptide (ANP) expression, were similarly reversed to sham or near-sham levels. In addition, the increased plasma ANP and pro-ANP values were reversed to levels not significantly different from sham. Surprisingly, virtually all beneficial effects were identical with all treatment protocols. These effects were observed in the absence of infarct size reduction or blood pressure-lowering effects. Our results suggest that NHE-1 inhibition attenuates and reverses postinfarction remodeling and heart failure with a treatment delay of up to 4 wk after infarction. The effect is independent of infarct size or afterload reduction, indicating a direct effect on the myocardium.

S6K inhibition renders cardiac protection against myocardial infarction through PDK1 phosphorylation of Akt

2011 ◽  
Vol 441 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Ruomin Di ◽  
Xiangqi Wu ◽  
Zai Chang ◽  
Xia Zhao ◽  
Qiuting Feng ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Cardiac Remodelling ◽  
Heart Weight ◽  
S6 Kinase ◽  
Beneficial Effects ◽  
Therapeutic Value ◽  
Specific Deletion

In the present study, we observed a rapid and robust activation of the ribosomal protein S6K (S6 kinase) provoked by MI (myocardial infarction) in mice. As activation of S6K promotes cell growth, we hypothesized that increased S6K activity contributes to pathological cardiac remodelling after MI and that suppression of S6K activation may prevent aberrant cardiac remodelling and improve cardiac function. In mice, administration of rapamycin effectively suppressed S6K activation in the heart and significantly improved cardiac function after MI. The heart weight/body weight ratio and fibrotic area were substantially reduced in rapamycin-treated mice. In rapamycin-treated mice, decreased cardiomyocyte remodelling and cell apoptosis were observed compared with vehicle-treated controls. Consistently, inhibition of S6K with PF-4708671 displayed similar protection against MI as rapamycin. Mechanistically, we observed significantly enhanced Thr308 phosphorylation and activation of Akt in rapamycin- and PF-4708671-treated hearts. Cardiomyocyte-specific deletion of PDK1 (phosphoinositide-dependent kinase 1) and Akt1/3 abolished cardioprotection after MI in the presence of rapamycin administration. These results demonstrate that S6K inhibition rendered beneficial effects on left ventricular function and alleviated adverse remodelling following MI in mice by enhancing Akt signalling, suggesting the therapeutic value of both rapamycin and PF-4708671 in treating patients following an MI.

Plasma cardiotrophin-1 following acute myocardial infarction: relationship with left ventricular systolic dysfunction

2001 ◽  
Vol 102 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Suneel TALWAR ◽  
Iain B. SQUIRE ◽  
Russell J. O'BRIEN ◽  
Paul F. DOWNIE ◽  
Joan E. DAVIES ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Acute Myocardial Infarction ◽  
Left Ventricular Systolic Dysfunction ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Clinic Visit ◽  
Left Ventricular ◽  
Lv Function ◽  
Ventricular Remodelling

The glycoprotein 130 (gp130) signalling pathway is important in the development of heart failure. Cardiotrophin-1 (CT-1), a cytokine acting via the gp130 pathway, is involved in the process of ventricular remodelling following acute myocardial infarction (AMI) in animals. The aims of the present study were to examine the profile of plasma CT-1 following AMI in humans, and its relationship with echocardiographic parameters of left ventricular (LV) systolic function. Serial measurements of plasma CT-1 levels were made in 60 patients at 14-48h, 49-72h, 73-120h and 121-192h following AMI and at a later clinic visit. LV function was assessed using a LV wall motion index (WMI) score on admission (WMI-1) and at the clinic visit (WMI-2). Compared with values in control subjects (29.5±3.6fmol/ml), the plasma CT-1 concentration was elevated in AMI patients at 14-48h (108.1±15.1fmol/ml), 49-72h (105.2±19.7fmol/ml), 73-120h (91.2±14.9fmol/ml) and 121-192h (118.8±22.6fmol/ml), and at the clinic visit (174.9±30.9 fmol/ml) (P < 0.0001). Levels were higher following anterior compared with inferior AMI. For patients with anterior AMI, CT-1 levels were higher at the clinic visit than at earlier times. WMI-1 correlated with CT-1 at all times prior to hospital discharge (P < 0.05). On best subsets analysis, the strongest correlate with WMI-1 was CT-1 level at 49-72h (R2 = 20%, P < 0.05). In conclusion, plasma levels of CT-1 are elevated soon after AMI in humans and rise further in the subsequent weeks in patients after anterior infarction. CT-1 measured soon after AMI is indicative of LV dysfunction, and this cytokine may have a role in the development of ventricular remodelling and heart failure after AMI.

Disproportionate secondary mitral regurgitation: myths, misconceptions and clinical implications

Heart ◽  
2020 ◽  
pp. heartjnl-2020-316992
Author(s):  
Paul A Grayburn ◽  
Milton Packer ◽  
Anna Sannino ◽  
Gregg W Stone
Keyword(s):  
Mitral Regurgitation ◽  
Ejection Fraction ◽  
Medical Therapy ◽  
Mean Value ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Lv Function ◽  
End Diastolic Volume ◽  
Regurgitant Orifice Area ◽  
And Function

Secondary (functional) mitral regurgitation (SMR) most commonly arises secondary to left ventricular (LV) dilation/dysfunction. The concept of disproportionately severe SMR was proposed to help explain the different results of two randomised trials of transcatheter edge-to-edge mitral valve repair (TEER) versus medical therapy. This concept is based on the fact that effective regurgitant orifice area (EROA) depends on LV end-diastolic volume (LVEDV), ejection fraction, regurgitant fraction and the velocity-time integral of SMR. This review focuses on the haemodynamic framework underlying the concept and the myths and misconceptions arising from it. Each component of EROA/LVEDV is prone to measurement error which can result in misclassification of individual patients. Moreover, EROA is typically measured at peak systole rather than its mean value over the duration of MR. This can result in physiologically impossible values of EROA or regurgitant volume. Although the EROA/LVEDV ratio (1) emphasises that grading MR severity needs to consider LV size and function and (2) helps explain the different outcomes between COAPT and MITRAFR, there are important factors that are not included. Among these are left atrial compliance, LV pressure and ejection fraction, pulmonary hypertension, right ventricular function and tricuspid regurgitation. Because medical therapy can reduce LV volumes and improve both LV function and SMR severity, the key to patient selection is forced titration of neurohormonal antagonists to the target doses that have been proven in clinical trials (along with cardiac resynchronisation when appropriate). Patients who continue to have symptomatic severe SMR after doing so should be considered for TEER.

scholarly journals Darbepoetin-α prevents progressive left ventricular dysfunction and remodeling in nonanemic dogs with heart failure

2008 ◽  
Vol 295 (6) ◽  
pp. H2475-H2482 ◽  
Author(s):  
Sharad Rastogi ◽  
Makoto Imai ◽  
Victor G. Sharov ◽  
Sudhish Mishra ◽  
Hani N. Sabbah
Keyword(s):  
Heart Failure ◽  
Caspase 3 ◽  
Hypoxia Inducible Factor ◽  
Left Ventricular ◽  
Stem Cell Marker ◽  
Lv Function ◽  
Systolic Volume ◽  
Beneficial Effects ◽  
End Diastolic Volume ◽  
End Systolic Volume

In anemic patients with heart failure (HF), erythropoietin-type drugs can elicit clinical improvement. This study examined the effects of chronic monotherapy with darbepoetin-α (DARB) on left ventricular (LV) function and remodeling in nonanemic dogs with advanced HF. HF [LV ejection fraction (EF) ∼25%] was produced in 14 dogs by intracoronary microembolizations. Dogs were randomized to once a week subcutaneous injection of DARB (1.0 μg/kg, n = 7) or to no therapy (HF, n = 7). All procedures were performed during cardiac catheterization under general anesthesia and under sterile conditions. LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF were measured before the initiation of therapy and at the end of 3 mo of therapy. mRNA and protein expression of caspase-3, hypoxia inducible factor-1α, and the bone marrow-derived stem cell marker c-Kit were determined in LV tissue. In HF dogs, EDV and ESV increased and EF decreased after 3 mo of followup. Treatment with DARB prevented the increase in EDV, decreased ESV, and increased EF. DARB therapy also normalized the expression of HIF-1α and active caspase-3 and enhanced the expression of c-Kit. We conclude that chronic monotherapy with DARB prevents progressive LV dysfunction and dilation in nonanemic dogs with advanced HF. These results suggest that DARB elicits beneficial effects in HF that are independent of the presence of anemia.

Hyperhomocysteinemia leads to pathological ventricular hypertrophy in normotensive rats

2003 ◽  
Vol 285 (2) ◽  
pp. H679-H686 ◽  
Author(s):  
Jacob Joseph ◽  
Lija Joseph ◽  
Nawal S. Shekhawat ◽  
Sulochana Devi ◽  
Junru Wang ◽  
...  
Keyword(s):  
Cardiac Remodeling ◽  
Ventricular Hypertrophy ◽  
Ventricular Remodeling ◽  
Systolic Function ◽  
Left Ventricular ◽  
Lv Function ◽  
Wall Thickening ◽  
Cardiovascular Morbidity And Mortality ◽  
And Function

A recent report indicated that hyperhomocysteinemia (Hhe), in addition to its atherothrombotic effects, exacerbates the adverse cardiac remodeling seen in response to hypertension, a powerful stimulus for pathological ventricular hypertrophy. The present study was undertaken to determine whether Hhe has a direct effect on ventricular remodeling and function in the absence of other hypertrophic stimuli. Male Wistar-Kyoto rats were fed either an amino acid-defined control diet or an intermediate Hhe-inducing diet. After 10 wk of dietary treatment, rats were subjected to echocardiographic assessment of left ventricular (LV) dimensions and systolic function. Subsequently, blood was collected for plasma homocysteine measurements, and the rats were killed for histomorphometric and biochemical assessment of cardiac remodeling and for in vitro cardiac function studies. Significant LV hypertrophy was detected by echocardiographic measurements, and in vitro results showed hypertrophy with significantly increased myocyte size in the LV and right ventricle (RV). LV and RV remodeling was characterized by a disproportionate increase in perivascular and interstitial collagen, coronary arteriolar wall thickening, and myocardial mast cell infiltration. In vitro study of LV function demonstrated abnormal diastolic function secondary to decreased compliance because the rate of relaxation did not differ between groups. LV systolic function did not vary between groups in vitro. In summary, in the absence of other hypertrophic stimuli short-term intermediate Hhe caused pathological hypertrophy and remodeling of both ventricles with diastolic dysfunction of the LV. These results demonstrate that Hhe has direct adverse effects on cardiac structure and function, which may represent a novel direct link between Hhe and cardiovascular morbidity and mortality, independent of other risk factors.

Sign in / Sign up

Export Citation Format

Share Document