Abstract 567: Ivabradine Improved Cardiac Function, Fibrosis And Hyperexcitability In Rat Post-myocardial Infarction Severe Heart Failure.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Paul Milliez ◽  
Johnny Nehme ◽  
Estelle Robidel ◽  
Camille Rodriguez ◽  
JaneLise Samuel ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Sinus Node ◽  
Severe Heart Failure ◽  
Lv Function ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Adult Rats ◽  
Beneficial Effects ◽  
Lv Dysfunction

The selective sinus node I f current inhibitor Ivabradine (Iva) reduces heart rate (HR) without any other hemodynamic effects. We investigated in a rat model of post-MI severe heart failure, the effects of a chronic Iva administration on LV function, structure and electrical remodelling. Methods . MI was induced by coronary artery ligation in adult rats: echocardiography and Holter ECG were performed 2 months (m) after MI i.e. before randomization (n=12/group) into MI and MI+Iva (10 mg/kg/d) groups, and 3 m later. In ventricles, collagen was quantified after Sirius red staining of section and ACE and AT1-receptor mRNA expression (normalized to GAPDH) was assayed by RT-PCR. Results : 2m-post MI, all rats displayed severe decreased LVEF, and increased LVEDP compared to sham-operated (28%±3 vs 66%±5 and 32±2 vs 10±1 mmHg, respectively; p<0.05). In 5m-post-MI, LVEF and LVEDP were stabilized with Iva (31±1% and 24±2 mmHg), while they were worsened in MI groups (21±3% and 38±2mmHg). Blood pressure, body and heart weights were similar in MI and MI+Iva. Iva reduced HR (RR: 201±5 vs 179±3 ms in MI; p<0.05) and ventricular premature beats (514±152 vs 4717±1363/day for MI; p<0.05), and improved HR variability (SDRR: 5±1.5 vs 3.9± 0.6 for MI; p<0.05). There were no effects of Iva on duration (ms) of PR (45±3 vs 44±3), QRS (51±3 vs 46±3) and QT (106±7 vs 99±6, for MI and MI+Iva, respectively). The increased ventricular collagen in MI (4.0±0.1 vs 0.8±0.2 % in sham; p<0.05) was markedly reduced in MI+Iva (1.8±0.1%, p<0.0001 vs MI). The increases in ventricular gene expression of ACE and AT-1 receptor in MI rats (2.5 and 6 folds versus sham operated, respectively, p<0.05) were completely blunted by Iva treatment. Conclusion: Iva treatment of the post-MI heart failure: 1- markedly reduced HR and ventricular excitability and without harmful effects on conduction; 2- prevented worsening of LV dysfunction and remodelling, and 3- induced a downregulation of cardiac RAAS transcripts. Thus, through its negative chronotropic effects, Iva allowed the maintenance of cardiac function below the threshold for a tissular RAAS stimulation even in severe post-MI cardiac failure. Such beneficial effects of Iva on cardiac remodelling open new perspectives for the treatment of severe heart failure

New insights into the pathological role of TNF-α in early cardiac dysfunction and subsequent heart failure after infarction in rats

2004 ◽  
Vol 287 (1) ◽  
pp. H340-H350 ◽  
Author(s):  
C. Berthonneche ◽  
T. Sulpice ◽  
F. Boucher ◽  
L. Gouraud ◽  
J. de Leiris ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Diastolic Pressure ◽  
Subsequent Development ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Direct Role ◽  
Volume Curve ◽  
Tnf Α

A marked increase in plasma TNF-α has been described in patients with chronic heart failure (CHF). Nevertheless, little is known about the direct role of this cytokine early after myocardial infarction (MI) and its possible effects on the subsequent development of CHF. Wistar rats were subjected to permanent in vivo coronary artery ligation. At 5, 7, and 9 days after MI, cardiac function, passive compliance of the left ventricle (LV), and cardiac geometry were evaluated. The same model was used to perform pharmacological studies 7 days and 10 wk after MI in rats treated with monomeric recombinant human soluble TNF-α receptor type II (sTNF-RII, 40 μg/kg iv) or a placebo on day 3. Maximal alterations of cardiac function and geometry occurred 7 days after MI, which correlated chronologically with a peak of cardiac and serum TNF-α, as shown by immunohistochemistry and ELISA, respectively. sTNF-RII improved LV end-diastolic pressure under basal conditions and after volume overload 7 days and 10 wk after MI. Moreover, a significant leftward shift of the pressure-volume curve in the sTNF-RII-treated group 7 days after MI indicated a preservation of LV volume. Infarct expansion index was also significantly improved by sTNF-RII 7 days after MI ( P < 0.01). Nevertheless, 10 wk after MI, geometric indexes and passive pressure-volume curves were not significantly improved by the treatment. In conclusion, TNF-α plays a major role in cardiac alterations 7 days after MI in rats and contributes to hemodynamic derangement, but not to cardiac remodeling, in subsequent CHF.

Beneficial effects of exercise training in heart failure are lost in male diabetic rats

2017 ◽  
Vol 123 (6) ◽  
pp. 1579-1591
Author(s):  
Dalila Boudia ◽  
Valérie Domergue ◽  
Philippe Mateo ◽  
Loubina Fazal ◽  
Mathilde Prud’homme ◽  
...  
Keyword(s):  
Heart Failure ◽  
Exercise Training ◽  
Ejection Fraction ◽  
Cardiac Function ◽  
Diabetic Rats ◽  
Diabetic Patients ◽  
Coronary Artery Ligation ◽  
Standard Diet ◽  
Beneficial Effects ◽  
Patients With Heart Failure

Exercise training has been demonstrated to have beneficial effects in patients with heart failure (HF) or diabetes. However, it is unknown whether diabetic patients with HF will benefit from exercise training. Male Wistar rats were fed either a standard (Sham, n = 53) or high-fat, high-sucrose diet ( n = 66) for 6 mo. After 2 mo of diet, the rats were already diabetic. Rats were then randomly subjected to either myocardial infarction by coronary artery ligation (MI) or sham operation. Two months later, heart failure was documented by echocardiography and animals were randomly subjected to exercise training with treadmill for an additional 8 wk or remained sedentary. At the end, rats were euthanized and tissues were assayed by RT-PCR, immunoblotting, spectrophotometry, and immunohistology. MI induced a similar decrease in ejection fraction in diabetic and lean animals but a higher premature mortality in the diabetic group. Exercise for 8 wk resulted in a higher working power developed by MI animals with diabetes and improved glycaemia but not ejection fraction or pathological phenotype. In contrast, exercise improved the ejection fraction and increased adaptive hypertrophy after MI in the lean group. Trained diabetic rats with MI were nevertheless able to develop cardiomyocyte hypertrophy but without angiogenic responses. Exercise improved stress markers and cardiac energy metabolism in lean but not diabetic-MI rats. Hence, following HF, the benefits of exercise training on cardiac function are blunted in diabetic animals. In conclusion, exercise training only improved the myocardial profile of infarcted lean rats fed the standard diet. NEW & NOTEWORTHY Exercise training is beneficial in patients with heart failure (HF) or diabetes. However, less is known of the possible benefit of exercise training for HF patients with diabetes. Using a rat model where both diabetes and MI had been induced, we showed that 2 mo after MI, 8 wk of exercise training failed to improve cardiac function and metabolism in diabetic animals in contrast to lean animals.

Central mineralocorticoid receptor blockade improves volume regulation and reduces sympathetic drive in heart failure

2001 ◽  
Vol 281 (5) ◽  
pp. H2241-H2251 ◽  
Author(s):  
Joseph Francis ◽  
Robert M. Weiss ◽  
Shun-Guang Wei ◽  
Alan Kim Johnson ◽  
Terry G. Beltz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Central Nervous System ◽  
Nervous System ◽  
Volume Regulation ◽  
Critical Role ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Water Excretion ◽  
Beneficial Effects ◽  
The Central Nervous System

The mineralocorticoid (MC) receptor antagonist spironolactone (SL) improves morbidity and mortality in patients with congestive heart failure (CHF). We tested the hypothesis that the central nervous system actions of SL contribute to its beneficial effects. SL (100 ng/h for 28 days) or ethanol vehicle (VEH) was administered intracerebroventricularly or intraperitoneally to rats with CHF induced by coronary artery ligation (CL) and to SHAM-operated controls. The intracerebroventricular SL treatment prevented the increase in sodium appetite and the decreases in sodium and water excretion observed within a week of CL in VEH-treated CHF rats. Intraperitoneal SL also improved volume regulation in the CHF rats, but only after 3 wk of treatment. Four weeks of SL treatment, either intracerebroventricularly or intraperitoneally, ameliorated both the increase in sympathetic drive and the impaired baroreflex function observed in VEH-treated CHF rats. These findings suggest that activation of MC receptors in the central nervous system plays a critical role in the altered volume regulation and augmented sympathetic drive that characterize clinical heart failure.

scholarly journals Ranolazine combined with enalapril or metoprolol prevents progressive LV dysfunction and remodeling in dogs with moderate heart failure

2008 ◽  
Vol 295 (5) ◽  
pp. H2149-H2155 ◽  
Author(s):  
Sharad Rastogi ◽  
Victor G. Sharov ◽  
Sudhish Mishra ◽  
Ramesh C. Gupta ◽  
Brent Blackburn ◽  
...  
Keyword(s):  
Heart Failure ◽  
Oral Treatment ◽  
Capillary Density ◽  
Cellular Level ◽  
Left Ventricular ◽  
Lv Function ◽  
Systolic Volume ◽  
Moderate Heart Failure ◽  
Beneficial Effects ◽  
Lv Dysfunction

Acute intravenous infusion of ranolazine (Ran), an anti-ischemic/antiangina drug, was previously shown to improve left ventricular (LV) ejection fraction (EF) without a concomitant increase in myocardial oxygen consumption in dogs with chronic heart failure (HF). This study examined the effects of treatment with Ran alone and in combination with metoprolol (Met) or enalapril (Ena) on LV function and remodeling in dogs with HF. Dogs ( n = 28) with microembolization-induced HF were randomized to 3 mo oral treatment with Ran alone [375 mg twice daily (bid); n = 7], Ran (375 mg bid) in combination with Met tartrate (25 mg bid; n = 7), Ran (375 mg bid) in combination with Ena (10 mg bid; n = 7), or placebo (PL; Ran vehicle bid; n = 7). Ventriculographic measurements of LV end-diastolic volume (EDV) and end-systolic volume (ESV) and LV EF were obtained before treatment and after 3 mo of treatment. In PL-treated dogs, EDV and ESV increased significantly. Ran alone prevented the increase in EDV and ESV seen in the PL group and significantly increased EF, albeit modestly, from 35 ± 1% to 37 ± 2%. When combined with either Ena or Met, Ran prevented the increase in EDV, significantly decreased ESV, and markedly increased EF compared with those of PL. EF increased from 35 ± 1% to 40 ± 1% with Ran + Ena and from 34 ± 1% to 41 ± 1% with Ran + Met. Ran alone or in combination with Ena or Met was also associated with beneficial effects at the cellular level on histomorphometric parameters such as hypertrophy, fibrosis, and capillary density as well as the expression for pathological hypertrophy and Ca2+ cycling genes. In conclusion, Ran prevented progressive LV dysfunction and global and cellular myocardial remodeling, and Ran in combination with Ena or Met improved LV function beyond that observed with Ran alone.

The nonpeptide angiotensin-(1–7) receptor Mas agonist AVE-0991 attenuates heart failure induced by myocardial infarction

2007 ◽  
Vol 292 (2) ◽  
pp. H1113-H1119 ◽  
Author(s):  
Anderson J. Ferreira ◽  
Bruno A. Jacoby ◽  
Cícero A. A. Araújo ◽  
Filipe A. F. F. Macedo ◽  
Gerluza A. B. Silva ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Heart Rate ◽  
Renin Angiotensin System ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Beneficial Effects ◽  
Isolated Hearts ◽  
Infarcted Area ◽  
Selective Ligand

The nonpeptide AVE-0991, which has been reported as a selective ligand for the angiotensin-(1–7) [ANG-(1–7)] receptor Mas, has actions similar to those attributed to the cardioprotective product of the renin-angiotensin system, ANG-(1–7). In this study, we evaluated the cardiac effects of AVE-0991 in normal and infarcted male Wistar rats. Myocardial infarction was induced by left coronary artery ligation. At the end of the treatment, the Langendorff technique was used to analyze cardiac function. Left ventricle serial sections were dyed with Gomori trichrome stain to quantify the infarcted area. In normal hearts, AVE-0991 produced a significant decrease in perfusion pressure and an increase in systolic tension, rate of tension rise and fall (±dT/d t), and heart rate. These effects were completely blocked by the perfusion of the hearts with a solution containing the selective ANG-(1–7) antagonist A-779. NG-nitro-l-arginine methyl ester treatment abolished the AVE-0991-induced vasodilation in isolated hearts. AVE-0991 significantly attenuated the decrease in systolic tension (sham operated, 13.00 ± 1.02 g; infarction, 7.18 ± 0.66 g; AVE treated, 9.23 ± 1.05 g, n = 5), +dT/d t, −dT/d t, and heart rate induced by myocardial infarction. Infarction-induced vasoconstriction was completely prevented by AVE-0991 treatment. Furthermore, AVE-0991 significantly decreased the infarcted area (6.98 ± 1.01 vs. 3.94 ± 1.04 mm2 in AVE-treated rats). These data indicate that the compound AVE-0991 produces beneficial effects in isolated perfused rat hearts involving the ANG-(1–7) receptor Mas and the release of nitric oxide. In addition, our results indicate that AVE-0991 attenuates postischemic heart failure.

Abstract P345: The Neuregulin Glial Growth Factor 2 (GGF2) Produces Sustained Improvement in Left Ventricular Function in Rats with Both Early and Established Heart Failure

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Anindita Ganguly ◽  
Erika Troy ◽  
Maya Srinivas ◽  
Andrea Vecchione ◽  
Patrick Sarmiere ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricular Function ◽  
Ventricular Function ◽  
Cardiac Development ◽  
Left Ventricular ◽  
Lv Function ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Sustained Improvement ◽  
Delayed Initiation

Neuregulin-1β is essential for fetal cardiac development and adult cardiac function. Previous reports indicate that neuregulins improve left ventricular function in heart failure models, however the duration of the functional improvements with early or late initiation of neuregulin treatment has not been characterized. The present studies examine the effects of early and delayed initiation of intravenous GGF2 treatment on left ventricular (LV) function in rats with myocardial infarction (MI). Rats underwent surgically-induced MI by left anterior coronary artery ligation. Treatment with vehicle or GGF2 (2.6 mg/kg) was initiated at 2 or 16 w post-MI and continued once or twice weekly or once every two weeks for the in-life duration of the study (approximately 40 weeks). LV function was assessed echocardiographically up to once weekly for the duration of the study. Early and delayed initiation of GGF2 treatment caused sustained and significant improvement (p < 0.05) in both ejection fraction (EF) and fractional shortening (FS) in all regimens tested. The greatest improvements were seen with the once weekly dosing paradigm after early initiation (average EF (%) at 40 weeks post initiation of dosing: vehicle = 44.4 ± 6.0, n = 8 rats, vs. GGF2 = 64.7±6.1. n = 9 rats) and twice weekly dosing paradigm after delayed initiation (average EF (%) at 4 weeks post initiation of dosing: vehicle = 34.18±1.6, n = 7 rats, vs. GGF2 = 50.69±4.68, n = 7 rats). In addition, LV function improved when rats were re-challenged with GGF2 following an extended wash out period. This observation indicates potential efficacy for treatment paradigms that utilize intermittent dosing. These findings suggest that GGF2 produces sustained improvement in LV function after early or delayed initiation of treatment following MI in rats.

Abstract 249: Chronic Neuregulin-1β Treatment Mitigates the Progression of Post-myocardial Infarction Heart Failure in the Setting of Type 1 Diabetes Mellitus

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Manisha Gupte ◽  
Hind Lal ◽  
Firdos Ahmad ◽  
Lin Zhong ◽  
Douglas B Sawyer ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Type 1 Diabetes ◽  
Heart Function ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Lv Function ◽  
Coronary Artery Ligation ◽  
Artery Ligation

Aim: Neuregulin-1β (NRG-1β), a growth factor critical for cardiac development as well as maintenance of heart function after injury has been shown to significantly improve heart function in preclinical rodent models. Importantly, number of studies are ongoing to test the efficacy of NRG-1β as a treatment for patients with chronic heart failure. However, the efficacy of recombinant NRG-1β in a typ1 diabetic model of heart failure due to myocardial infarction (MI) has not been investigated. The aim of the present study was to determine the efficacy of exogenous NRG-1β to improve residual cardiac function after MI in type1 diabetic rats. Methods and Results: Sprague Dawley rats were induced type 1 diabetes by a single injection of streptozotocin (STZ) (65 mg/kg). Two weeks after induction of type 1 diabetes, rats underwent left coronary artery ligation to induce MI. STZ-diabetic rats were treated with saline or NRG-1β (100 ug/kg) twice a week for 7 weeks, starting two weeks prior to experimental MI. Residual left ventricular (LV) function was significantly greater in the NRG-1β-treated STZ-diabetic MI group compared to the vehicle-treated STZ-diabetic MI group 5 weeks after MI as assessed by high-resolution echocardiography. Furthermore, NRG-1β treatment in STZ-diabetic MI rats reduced myocardial fibrosis and apoptosis as well as decreased gene expression of key oxidant-producing enzymes. Conclusion: This study demonstrates that augmentation of NRG-1β signaling in STZ-diabetic post-MI rats via therapy with exogenous recombinant NRG-1β will alleviate subsequent HF through improvements in residual LV function via protection against adverse remodeling and apoptosis.

Validation of echocardiographic methods for assessing left ventricular dysfunction in rats with myocardial infarction

2004 ◽  
Vol 287 (5) ◽  
pp. H2049-H2053 ◽  
Author(s):  
Eric E. Morgan ◽  
Michael D. Faulx ◽  
Tracy A. McElfresh ◽  
Theodore A. Kung ◽  
Michael S. Zawaneh ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Index ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Lv Function ◽  
Coronary Artery Ligation ◽  
Sham Operation ◽  
Artery Ligation ◽  
Peak Rate ◽  
Fractional Shortening

The rat infarct model is widely used in heart failure research, but few echocardiographic indexes of left ventricular (LV) function are validated in this model. Accordingly, the objective of this study was to validate a 13-segment LV wall motion score index (WMSI) and the myocardial performance index (MPI) in infarcted rats. Twenty-nine male Wistar rats underwent left coronary artery ligation or sham operation and were evaluated with two-dimensional and Doppler flow echocardiography 8 wk later. After echocardiography, invasive indexes were obtained using a high-fidelity catheter. WMSI and MPI were correlated with the invasive and noninvasive measurements of LV function. WMSI and MPI significantly correlated directly with end-diastolic pressure ( r = 0.72 and 0.42 for WMSI and MPI, respectively) and the time constant of isovolumic relaxation ( r = 0.68 and 0.48) and inversely with peak rate of rise of LV pressure (+dP/d t; r = −0.68 and −0.50), peak rate of decline in LV pressure ( r = −0.57 and −0.44), LV developed pressure ( r = −0.58 and −0.42), area fractional shortening ( r = −0.85 and −0.53), and cardiac index ( r = −0.74 and −0.74). Stepwise linear regression analyses revealed that LV end-diastolic pressure, +dP/d t, area fractional shortening, and cardiac index were independent determinants of WMSI ( r = 0.994) and that cardiac index and +dP/d t were independent determinants of MPI ( r = 0.781). We conclude that the 13-segment WMSI and MPI are reproducible and correlate strongly with established echocardiographic and invasive indexes of systolic and diastolic function. These findings support the use of WMSI and MPI as indexes of global LV function in the rat infarction model of heart failure.

Peripheral artery structure and endothelial function in heart failure: effect of ACE inhibition

1996 ◽  
Vol 271 (2) ◽  
pp. H469-H477 ◽  
Author(s):  
P. Mulder ◽  
L. Elfertak ◽  
V. Richard ◽  
P. Compagnon ◽  
B. Devaux ◽  
...  
Keyword(s):  
Heart Failure ◽  
Endothelial Dysfunction ◽  
Morphological Changes ◽  
Ace Inhibition ◽  
Mesenteric Arteries ◽  
Coronary Artery Ligation ◽  
Resistance Arteries ◽  
Artery Ligation ◽  
Cross Sectional ◽  
Beneficial Effects

Chronic heart failure (CHF) induces peripheral vasoconstriction and impairs endothelium-dependent relaxation of large arteries. We investigated in a rat model of CHF (coronary artery ligation) 1) whether endothelial dysfunction also exists in resistance arteries, 2) whether this is associated with vascular morphological changes, and 3) the effect of angiotensin-converting enzyme (ACE) inhibition on these parameters. After 1 mo or 1 yr, CHF reduced the vasodilatory response to acetylcholine of isolated, perfused femoral and mesenteric artery segments. This impairment was more marked in femoral than in mesenteric arteries. However, CHF did not induce any arterial remodeling. Chronic treatment with the ACE inhibitor perindopril improved the response to acetylcholine and reduced media cross-sectional area and collagen density. Thus at the level of small peripheral arteries, CHF induces an endothelial dysfunction but does not affect vascular structure. ACE inhibition prevents the CHF-induced endothelial dysfunction and induces vascular remodeling. These changes could contribute to the observed beneficial effects of ACE inhibitors on hemodynamics and survival in CHF.

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