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Aortocaval Fistula in Rat: A Unique Model of Volume-Overload Congestive Heart Failure and Cardiac Hypertrophy

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      Abstract

      Despite continuous progress in our understanding of the pathogenesis of congestive heart failure (CHF) and its management, mortality remains high. Therefore, development of reliable experimental models of CHF and cardiac hypertrophy is essential to better understand disease progression and allow new therapy developement. The aortocaval fistula (ACF) model, first described in dogs almost a century ago, has been adopted in rodents by several groups including ours. Although considered to be a model of high-output heart failure, its long-term renal and cardiac manifestations are similar to those seen in patients with low-output CHF. These include Na+-retention, cardiac hypertrophy and increased activity of both vasoconstrictor/antinatriureticneurohormonal systems and compensatory vasodilating/natriuretic systems. Previous data from our group and others suggest that progression of cardiorenal pathophysiology in this model is largely determined by balance between opposing hormonal forces, as reflected in states of CHF decompensation that are characterized by overactivation of vasoconstrictive/Na+-retaining systems. Thus, ACF serves as a simple, cheap, and reproducible platform to investigate the pathogenesis of CHF and to examine efficacy of new therapeutic approaches. Hereby, we will focus on the neurohormonal, renal, and cardiac manifestations of the ACF model in rats, with special emphasis on our own experience.

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        Cardiac remodeling is generally accepted as a determinant of the clinical course of heart failure (HF). Defined as genome expression resulting in molecular, cellular and interstitial changes and manifested clinically as changes in size, shape and function of the heart resulting from cardiac load or injury, cardiac remodeling is influenced by hemodynamic load, neurohormonal activation and other factors still under investigation. Although patients with major remodeling demonstrate progressive worsening of cardiac function, slowing or reversing remodeling has only recently become a goal of HF therapy. Mechanisms other than remodeling can also influence the course of heart disease, and disease progression may occur in other ways in the absence of cardiac remodeling. Left ventricular end-diastolic and end-systolic volume and ejection fraction data provide support for the beneficial effects of therapeutic agents such as angiotensin-converting enzyme (ACE) inhibitors and beta-adrenergic blocking agents on the remodeling process. These agents also provide benefits in terms of morbidity and mortality. Although measurement of ejection fraction can reliably guide initiation of treatment in HF, opinions differ regarding the value of ejection fraction data in guiding ongoing therapy. The role of echocardiography or radionuclide imaging in the management and monitoring of HF is as yet unclear. To fully appreciate the potential benefits of HF therapies, clinicians should understand the relationship between remodeling and HF progression. Their patients may then, in turn, acquire an improved understanding of their disease and the treatments they are given.
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            Author and article information

            Affiliations
            1Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion, IIT, P.O. Box 9649, Haifa 31096, Israel
            2Research Unit, Rambam Medical Center, Haifa 31096, Israel
            3Department of Vascular Surgery, Rambam Medical Center, Haifa 31096, Israel
            Author notes

            Academic Editor: Oreste Gualillo

            Journal
            J Biomed Biotechnol
            JBB
            Journal of Biomedicine and Biotechnology
            Hindawi Publishing Corporation
            1110-7243
            1110-7251
            2011
            11 January 2011
            : 2011
            3025398
            21274403
            10.1155/2011/729497
            Copyright © 2011 Zaid Abassi et al.

            This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

            Categories
            Review Article

            Molecular medicine

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