8
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Atenolol is inferior to metoprolol in improving left ventricular function and preventing ventricular remodeling in dogs with heart failure.

      Read this article at

      ScienceOpenPublisherPMC
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          beta-Blockers are standard therapy for patients with heart failure (HF). This study compared the effects of chronic monotherapy with 2 different beta(1)-selective adrenoceptor blockers, namely atenolol and metoprolol succinate, on left ventricular (LV) function and remodeling in dogs with coronary microembolization-induced HF [LV ejection fraction (EF) 30-40%].

          Related collections

          Most cited references27

          • Record: found
          • Abstract: found
          • Article: not found

          The selectivity of beta-adrenoceptor antagonists at the human beta1, beta2 and beta3 adrenoceptors.

          Beta-adrenoceptor antagonists ("beta-blockers") are one of the most widely used classes of drugs in cardiovascular medicine (hypertension, ischaemic heart disease and increasingly in heart failure) as well as in the management of anxiety, migraine and glaucoma. Where known, the mode of action in cardiovascular disease is from antagonism of endogenous catecholamine responses in the heart (mainly at beta1-adrenoceptors), while the worrisome side effects of bronchospasm result from airway beta2-adrenoceptor blockade. The aim of this study was to determine the selectivity of beta-antagonists for the human beta-adrenoceptor subtypes. (3)H-CGP 12177 whole cell-binding studies were undertaken in CHO cell lines stably expressing either the human beta1-, beta2- or the beta3-adrenoceptor in order to determine the affinity of ligands for each receptor subtype in the same cell background. In this study, the selectivity of well-known subtype-selective ligands was clearly demonstrated: thus, the selective beta1 antagonist CGP 20712A was 501-fold selective over beta2 and 4169-fold selective over beta3; the beta2-selective antagonist ICI 118551 was 550- and 661-fold selective over beta1 and beta3, respectively, and the selective beta3 compound CL 316243 was 10-fold selective over beta2 and more than 129-fold selective over beta1. Those beta2-adrenoceptor agonists used clinically for the treatment of asthma and COPD were beta2 selective: 29-, 61- and 2818-fold for salbutamol, terbutaline and salmeterol over beta1, respectively. There was little difference in the affinity of these ligands between beta1 and beta3 adrenoceptors. The clinically used beta-antagonists studied ranged from bisoprolol (14-fold beta1-selective) to timolol (26-fold beta2-selective). However, the majority showed little selectivity for the beta1- over the beta2-adrenoceptor, with many actually being more beta2-selective. This study shows that the beta1/beta2 selectivity of most clinically used beta-blockers is poor in intact cells, and that some compounds that are traditionally classed as "beta1-selective" actually have higher affinity for the beta2-adrenoceptor. There is therefore considerable potential for developing more selective beta-antagonists for clinical use and thereby reducing the side-effect profile of beta-blockers.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Hemodynamic determinants of the time-course of fall in canine left ventricular pressure.

            The hemodynamic determinants of the time-course of fall in isovolumic left ventricular pressure were assessed in isolated canine left ventricular preparations. Pressure fall was studied in isovolumic beats or during prolonged isovolumic diastole after ejection. Pressure fall was studied in isovolumic relaxation for isovolumic and ejecting beats (r less than or equal to 0.98) and was therefore characterized by a time constant, T. Higher heart rates shortened T slightly from 52.6 +/- 4.5 ms at 110/min to 48.2 +/- 6.0 ms at 160/min (P less than 0.01, n = 8). Higher ventricular volumes under isovolumic conditions resulted in higher peak left ventricular pressure but no significant change in T. T did shorten from 67.1 +/- 5.0 ms in isovolumic beats to 45.8 +/- 2.9 ms in the ejecting beats (P less than 0.001, n = 14). In the ejecting beats, peak systolic pressure was lower, and end-systolic volume smaller. To differentiate the effects of systolic shortening during ejection from those of lower systolic pressure and smaller end-systolic volume, beats with large end-diastolic volumes were compared to beats with smaller end-diastolic volumes. The beats with smaller end-diastolic volumes exhibited less shortening but similar end-systolic volumes and peak systolic pressure. T again shortened to a greater extent in the beats with greater systolic shortening. Calcium chloride and acetylstrophanthidin resulted in no significant change in T, but norepinephrine, which accelerates active relaxation, resulted in a significant shortening of T (65.6 +/- 13.4 vs. 46.3 +/- 7.0 ms, P less than 0.02). During recovery from ischemia, T increased significantly from 59.3 +/- 9.6 to 76.8 +/- 13.1 ms when compared with the preischemic control beat (P less than 0.05). Thus, the present studies show that the time-course of isovolumic pressure fall subsequent to maximum negative dP/dt is exponential, independent of systolic stress and end-systolic fiber length, and minimally dependent on heart rate. T may be an index of the activity of the active cardiac relaxing system and appears dependent on systolic fiber shortening.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Prognostic relevance of atrial fibrillation in patients with chronic heart failure on long-term treatment with beta-blockers: results from COMET.

              Atrial fibrillation is common in patients with chronic heart failure (CHF). We analysed the risk associated with atrial fibrillation in a large cohort of patients with chronic heart failure all treated with a beta-blocker. In COMET, 3029 patients with CHF were randomized to carvedilol or metoprolol tartrate and followed for a mean of 58 months. We analysed the prognostic relevance on other outcomes of atrial fibrillation on the baseline electrocardiogram compared with no atrial fibrillation and the impact of new onset atrial fibrillation during follow-up. A multivariate analysis was performed using a Cox regression model where 10 baseline covariates were entered together with study treatment allocation. Six hundred patients (19.8%) had atrial fibrillation at baseline. These patients were older (65 vs. 61 years), included more men (88 vs.78%), had more severe symptoms [higher New York Heart Association (NYHA) class] and a longer duration of heart failure (all P<0.0001). Atrial fibrillation was associated with significantly increased mortality [relative risk (RR) 1.29: 95% CI 1.12-1.48; P<0.0001], higher all-cause death or hospitalization (RR 1.25: CI 1.13-1.38), and cardiovascular death or hospitalization for worsening heart failure (RR 1.34: CI 1.20-1.52), both P<0.0001. By multivariable analysis, atrial fibrillation no longer independently predicted mortality. Beneficial effects on mortality by carvedilol remained significant (RR 0.836: CI 0.74-0.94; P=0.0042). New onset atrial fibrillation during follow-up (n=580) was associated with significant increased risk for subsequent death in a time-dependent analysis (RR 1.90: CI 1.54-2.35; P<0.0001) regardless of treatment allocation and changes in NYHA class. In CHF, atrial fibrillation significantly increases the risk for death and heart failure hospitalization, but is not an independent risk factor for mortality after adjusting for other predictors of prognosis. Treatment with carvedilol compared with metoprolol offers additional benefits among patients with atrial fibrillation. Onset of new atrial fibrillation in patients on long-term beta-blocker therapy is associated with significant increased subsequent risk of mortality and morbidity.
                Bookmark

                Author and article information

                Journal
                Cardiology
                Cardiology
                S. Karger AG
                1421-9751
                0008-6312
                2009
                : 112
                : 4
                Affiliations
                [1 ] Department of Medicine, Division of Cardiovascular Medicine, Henry Ford Heart and Vascular Institute, Detroit, MI 48202, USA.
                Article
                000159123
                10.1159/000159123
                2917737
                18832825
                2d6ea710-79da-4462-903e-bf27837cdb92
                History

                Comments

                Comment on this article