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[Pathophysiology of chronic heart failure]
Joachim Weil1, Heribert Schunkert
1Universität Schleswig-Holstein, Campus Lübeck, Medizinische Klinik II, Lübeck. joachim.weil@innere2.uni-luebeck.de
Summary
Heart failure involves complex signaling pathways that alter heart muscle gene expression. Targeting the adrenergic nervous system may improve heart function and outcomes in patients with heart failure.
Area of Science:
- Cardiology
- Molecular Biology
- Pathophysiology
Context:
- Heart failure is a progressive disease characterized by myocyte dysfunction, cell loss, cardiac remodeling, and arrhythmias.
- These processes are driven by alterations in myocardial gene expression affecting various cellular components and signaling pathways.
- Dysregulation of cardiac adrenergic receptor-signal transduction pathways, particularly beta1-receptor down-regulation, is a prominent feature of the failing heart.
Purpose:
- To explore the complex signaling mechanisms underlying heart failure progression.
- To investigate the role of adrenergic receptor signaling and neurohormonal activation in heart failure.
- To understand the contribution of structural remodeling to the development of congestive heart failure.
Summary:
- Progressive heart failure involves altered myocardial gene expression impacting contractile proteins, ion channels, calcium handling, apoptosis, metabolism, extracellular matrix, and signal transduction.
- Key changes in the failing heart include beta1-adrenergic receptor down-regulation, beta2-adrenergic receptor uncoupling, and increased inhibitory G-protein activity, often linked to elevated norepinephrine levels.
- Antagonists of the adrenergic nervous system show potential in improving left ventricular function and patient outcomes, suggesting a detrimental role of sustained neurohormonal activation.
Impact:
- Findings support the detrimental long-term effects of neurohormonal systems in chronic heart failure.
- Adrenergic desensitization in heart failure may be partially maladaptive, highlighting therapeutic targets.
- Structural remodeling, including changes in myocyte shape, number, and extracellular matrix, significantly contributes to heart failure progression, though the most critical factors may vary by etiology.