Neurohormones in an ovine model of compensated postinfarction left ventricular dysfunction

2000 ◽  
Vol 278 (3) ◽  
pp. H731-H740 ◽  
Author(s):  
Miriam T. Rademaker ◽  
Vicky A. Cameron ◽  
Christopher J. Charles ◽  
Eric A. Espiner ◽  
M. Gary Nicholls ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Ejection Fraction ◽  
Natriuretic Peptide ◽  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Plasma Concentrations ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation

Clinical heart failure, often the result of myocardial infarction, may be preceded by a period of compensated left ventricular impairment. There is substantial need for an experimental model that reflects this human condition. In sheep, coronary artery ligation produced consistent left ventricular anteroapical myocardial infarctions resulting in chronic (5 wk), stable hemodynamic changes compared with sham controls, including reductions in ejection fraction (51 ± 2 vs. 30 ± 5%, P < 0.001), cardiac output (6.3 ± 0.2 vs. 5.1 ± 0.2 l/min, P< 0.01), and arterial pressure (93 ± 2 vs. 79 ± 3 mmHg, P< 0.001), and increases in cardiac preload (left atrial pressure, 3.3 ± 0.1 vs. 8.3 ± 1.3 mmHg, P < 0.001). These changes were associated with acute and sustained increases in plasma concentrations of atrial natriuretic peptide (ANP; 5 wk, 11 ± 2 vs. 27 ± 5 pmol/l, P < 0.001), brain natriuretic peptide (BNP; 3 ± 0.2 vs. 11 ± 2 pmol/l, P < 0.001), and amino-terminal pro-brain natriuretic peptide (NT-BNP; 17 ± 3 vs. 42 ± 12 pmol/l, P < 0.001). Significant correlations were observed between plasma levels of the natriuretic peptides (ANP, day 7 to week 5 samples; BNP and NT-BNP, day 1 to week 5samples) and changes in left ventricular volumes and ejection fraction. In contrast, renin activity, aldosterone, catecholamines, and endothelin were not chronically elevated postinfarction and were not related to indexes of ventricular function. Coronary artery ligation in sheep produces the pathological, hemodynamic, and neurohormonal characteristics of compensated left ventricular impairment secondary to myocardial infarction. Plasma concentrations of the cardiac natriuretic peptides are sensitive markers of left ventricular dysfunction. This is a reproducible model that reflects the clinical condition and should prove suitable for investigating the pathophysiology of, and experimental therapies in, early left ventricular dysfunction.

scholarly journals Right coronary artery ligation in mice: a novel method to investigate right ventricular dysfunction and biventricular interaction

2019 ◽  
Vol 316 (3) ◽  
pp. H684-H692 ◽  
Author(s):  
Pierre Sicard ◽  
Timothée Jouitteau ◽  
Thales Andrade-Martins ◽  
Abdallah Massad ◽  
Glaucy Rodrigues de Araujo ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Infarct Size ◽  
Right Ventricular ◽  
Right Coronary Artery ◽  
Ventricular Dysfunction ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Inferior Myocardial Infarction ◽  
Acute Inferior Myocardial Infarction

Right ventricular (RV) dysfunction can lead to complications after acute inferior myocardial infarction (MI). However, it is unclear how RV failure after MI contributes to left-sided dysfunction. The aim of the present study was to investigate the consequences of right coronary artery (RCA) ligation in mice. RCA ligation was performed in C57BL/6JRj mice ( n = 38). The cardiac phenotypes were characterized using high-resolution echocardiography performed up to 4 wk post-RCA ligation. Infarct size was measured using 2,3,5-triphenyltetrazolium chloride staining 24 h post-RCA ligation, and the extent of the fibrotic area was determined 4 wk after MI. RV dysfunction was confirmed 24 h post-RCA ligation by a decrease in the tricuspid annular plane systolic excursion ( P < 0.001) and RV longitudinal strain analysis ( P < 0.001). Infarct size measured ex vivo represented 45.1 ± 9.1% of the RV free wall. RCA permanent ligation increased the RV-to-left ventricular (LV) area ratio ( P < 0.01). Septum hypertrophy ( P < 0.01) was associated with diastolic septal flattening. During the 4-wk post-RCA ligation, LV ejection fraction was preserved, yet it was associated with impaired LV diastolic parameters ( E/ E′, global strain rate during early diastole). Histological staining after 4 wk confirmed the remodeling process with a thin and fibrotic RV. This study validates that RCA ligation in mice is feasible and induces RV heart failure associated with the development of LV diastolic dysfunction. Our model offers a new opportunity to study mechanisms and treatments of RV/LV dysfunction after MI. NEW & NOTEWORTHY Right ventricular (RV) dysfunction frequently causes complications after acute inferior myocardial infarction. How RV failure contributes to left-sided dysfunction is elusive because of the lack of models to study molecular mechanisms. Here, we created a new model of myocardial infarction by permanently tying the right coronary artery in mice. This model offers a new opportunity to unravel mechanisms underlying RV/left ventricular dysfunction and evaluate drug therapy.

Comparison of Myocardial Infarction with Sequential Ligation of the Left Anterior Descending Artery and Its Diagonal Branch in Dogs and Sheep

2003 ◽  
Vol 26 (4) ◽  
pp. 351-357 ◽  
Author(s):  
W.G. Kim ◽  
Y.C. Shin ◽  
S.W. Hwang ◽  
C. Lee ◽  
C.Y. Na
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Suitable Model ◽  
Artery Ligation ◽  
Diagonal Branch ◽  
Left Anterior Descending Artery ◽  
Arterial Blood

We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial fibrosis were observed in the dog hearts. In conclusion, this study confirms that the dog is not a suitable model for myocardial infarction with failure by coronary artery ligation despite negligent operative mortality, when compared directly with an ovine model.

Assessment of the stability of N-terminal pro-brain natriuretic peptide in vitro: implications for assessment of left ventricular dysfunction

1999 ◽  
Vol 97 (3) ◽  
pp. 255-258 ◽  
Author(s):  
P. F. DOWNIE ◽  
S. TALWAR ◽  
I. B. SQUIRE ◽  
J. E. DAVIES ◽  
D. B. BARNETT ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Left Ventricular Dysfunction ◽  
Room Temperature ◽  
Ventricular Dysfunction ◽  
Plasma Concentrations ◽  
Left Ventricular ◽  
Blood Samples ◽  
The Stability

Plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) are raised in patients with left ventricular dysfunction. Measurement of this peptide has a potential diagnostic role in the identification and assessment of patients with heart failure. The stability of this peptide over time periods and conditions pertaining to routine clinical practice has not been reported previously. Blood samples were obtained from 15 subjects. One aliquot was processed immediately, and the remaining portions of the blood samples were stored for 24 h or 48 h at room temperature or on ice prior to processing. Plasma concentrations of NT-proBNP were measured with a novel immunoluminometric assay developed within our laboratory. Mean plasma concentrations of NT-proBNP were not significantly different whether blood samples were centrifuged immediately and stored at -70 °C or kept at room temperature or on ice for 24 h or 48 h. The mean percentage differences from baseline (reference standard) were +5.2% (95% confidence interval +18.2 to -7.8%) and +0.8% (+15.2 to -13.7%) after storage for 24 h at room temperature or on ice respectively, and +8.9% (+24.2 to -6.5%) and +3.2% (+15.1 to -0.9%) for storage for 48 h at room temperature or on ice respectively. Pearson correlation coefficients for baseline NT-proBNP concentrations compared with levels at 48 h at room temperature or on ice were r = 0.89 and r = 0.83 respectively (both P < 0.0001). Thus NT-proBNP extracted from plasma samples treated with EDTA and aprotinin is stable under conditions relevant to clinical practice.

scholarly journals Clofibrate Treatment Decreases Inflammation and Reverses Myocardial Infarction-Induced Remodelation in a Rodent Experimental Model

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 270 ◽  
Author(s):  
Luz Ibarra-Lara ◽  
María Sánchez-Aguilar ◽  
Elizabeth Soria-Castro ◽  
Jesús Vargas-Barrón ◽  
Francisco Roldán ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Cardiac Remodeling ◽  
Ventricular Remodeling ◽  
Ex Vivo ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Cardiac Damage ◽  
Artery Ligation ◽  
Apoptotic Proteins

Myocardial infarction (MI) initiates an inflammatory response that promotes both beneficial and deleterious effects. The early response helps the myocardium to remove damaged tissue; however, a prolonged later response brings cardiac remodeling characterized by functional, metabolic, and structural pathological changes. Current pharmacological treatments have failed to reverse ischemic-induced cardiac damage. Therefore, our aim was to study if clofibrate treatment was capable of decreasing inflammation and apoptosis, and reverse ventricular remodeling and MI-induced functional damage. Male Wistar rats were assigned to (1) Sham coronary artery ligation (Sham) or (2) Coronary artery ligation (MI). Seven days post-MI, animals were further divided to receive vehicle (V) or clofibrate (100 mg/kg, C) for 7 days. The expression of IL-6, TNF-α, and inflammatory related molecules ICAM-1, VCAM-1, MMP-2 and -9, nuclear NF-kB, and iNOS, were elevated in MI-V. These inflammatory biomarkers decreased in MI-C. Also, apoptotic proteins (Bax and pBad) were elevated in MI-V, while clofibrate augmented anti-apoptotic proteins (Bcl-2 and 14-3-3ε). Clofibrate also protected MI-induced changes in ultra-structure. The ex vivo evaluation of myocardial functioning showed that left ventricular pressure and mechanical work decreased in infarcted rats; clofibrate treatment raised those parameters to control values. Echocardiogram showed that clofibrate partially reduced LV dilation. In conclusion, clofibrate decreases cardiac remodeling, decreases inflammatory molecules, and partly preserves myocardial diameters.

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