Carvedilol in the failing heart

Beta-adrenergic receptors, from their discovery and characterization through their manipulation to beneficial clinical application

β-Adrenergic receptors (β-AR) are central to the overall regulation of cardiac function. From the first proposed receptor/transmitter concept to the latest clinical β-blocker trials β-AR have been shown to play an important role in cardiac disease and heart failure in particular. This study provides a historical perspective, reviews the latest discoveries and beliefs, and discusses the current clinical practices of β-AR and their modulation with their associated guanine-nucleotide regulatory protein/adenylylcyclasesignal transduction pathways.

Reducing the Risk of Sudden Death in Heart Failure With β-Blockers

BACKGROUND

Heart failure (HF) is a serious cardiovascular syndrome that affects nearly 5 million people in the United States. A review of clinical data demonstrates that sudden cardiac death (SCD) accounts for approximately one-third of all HF deaths. This fatal outcome typically involves an unexpected electrical event leading to sustained cardiac arrhythmias resulting in cardiovascular collapse.

METHODS AND RESULTS

A systematic review of the literature was performed to serve as the basis for this review. Factors contributing directly to incidence of SCD in the HF population may include significant remodeling of the left ventricle (hypertrophy, dilation, and fibrosis) in addition to increased sympathetic activation. Using specific therapies to limit these mechanisms are beneficial in the HF patient by preventing SCD. Beta-blockers play a key role in the prevention of SCD for patients with HF by limiting the effects of circulating norepinephrine and by reducing left ventricular remodeling.

CONCLUSIONS

This review outlines the potential mechanisms and contributing factors of SCD in patients with HF and the impact of beta-blocker usage in the prevention of this fatal outcome for this growing patient population.

Brain (B-type) Natriuretic Peptide

Heart failure is the leading cause for hospitalization in the United States, resulting in over $8 billion in costs annually. Over 4.8 million Americans are afflicted with the disease and the number is increasing as the baby boomer generation continues to age. It is imperative that new and innovative modalities of therapy and diagnosis evolve as we continue to redefine the nature of heart failure and discover more about this debilitating disease. This article addresses the implications for endogenous brain (B-type) natriuretic peptide (BNP) testing in patients diagnosed with heart failure as well as the implications for the first available form of exogenous BNP, nesiritide. In addition, the pathophysiology of heart failure and traditional treatment modalities are discussed.