Effect of carvedilol in comparison with metoprolol on myocardial collagen postinfarction

AbstractOBJECTIVESWe sought to compare the effects of two different beta-blockers, carvedilol and metoprolol, to an angiotensin-converting enzyme (ACE) inhibitor (captopril) on myocardial collagen deposition during healing and ventricular remodeling after myocardial infarction (MI).BACKGROUNDBeta-adrenergic blockade has been shown to be beneficial post-MI and in chronic heart failure. Carvedilol is a new-generation vasodilating beta-blocker with additional alpha1-adrenoceptor antagonism and an antiproliferative action, but it is not known if it is more beneficial than standard selective beta-blockers.METHODSUsing a rat model of MI, induced by left coronary ligation, we studied the effects of 11 weeks of therapy with oral carvedilol, metoprolol or captopril on hemodynamics, tissue weights, collagen volume fraction and hydroxyproline content.RESULTSBoth beta-blockers caused similar decreases in heart rate and LVEDP compared with untreated post-MI rats. At equivalent beta-adrenoceptor blocking doses, however, carvedilol, but not metoprolol, attenuated the increase in collagen content in noninfarcted regions and prevented the increase in right ventricular weight/body weight (all p < 0.05), and its effect was similar to captopril. Metoprolol treatment tended to increase right ventricular weight and heart weight (p < 0.05). There were no differences in infarct size between the groups.CONCLUSIONSLong-term treatment with both beta-blockers, as well as an ACE inhibitor, benefited the healing process in rats post-MI. At equivalent myocardial beta-adrenoceptor blocking doses, however, carvedilol significantly reduced myocardial collagen in the noninfarcted myocardium and cardiac hypertrophy in the right ventricle, whereas metoprolol had no effect on myocardial collagen deposition

Resilience in American Indian and Alaska Native Public Health: An Underexplored Framework

Objective: To conduct a systematic literature review to assess the conceptualization, application, and measurement of resilience in American Indian and Alaska Native (AIAN) health promotion. Data Sources: We searched 9 literature databases to document how resilience is discussed, fostered, and evaluated in studies of AIAN health promotion in the United States. Study Inclusion and Exclusion Criteria: The article had to (1) be in English; (2) peer reviewed, published from January 1, 1980, to July 31, 2015; (3) identify the target population as predominantly AIANs in the United States; (4) describe a nonclinical intervention or original research that identified resilience as an outcome or resource; and (5) discuss resilience as related to cultural, social, and/or collective strengths. Data Extraction: Sixty full texts were retrieved and assessed for inclusion by 3 reviewers. Data were extracted by 2 reviewers and verified for relevance to inclusion criteria by the third reviewer. Data Synthesis: Attributes of resilience that appeared repeatedly in the literature were identified. Findings were categorized across the lifespan (age group of participants), divided by attributes, and further defined by specific domains within each attribute. Results: Nine articles (8 studies) met the criteria. Currently, resilience research in AIAN populations is limited to the identification of attributes and pilot interventions focused on individual resilience. Resilience models are not used to guide health promotion programming; collective resilience is not explored. Conclusion: Attributes of AIAN resilience should be considered in the development of health interventions. Attention to collective resilience is recommended to leverage existing assets in AIAN communities

809-1 Different Respiratory Rates Affect the Measurement of Autonomic Tone by Power Spectral Analysis of Heart Rate Variability in Patients with Heart Failure

Power spectral analysis of heart rate variability is frequently used as an easy non invasive method for assessing autonomic tone. However changes in respiratory rate are frequently ignored and these may have an important effect on the measurements of spectral components, especially in heart failure. We have assessed the effect of different respiratory rates (10, 15, 20 min-1 and spontaneous) on low frequency (LF) and high frequency (HF) components of HR variability in 11 heart failure pts (CCF) (EF=40±4%; 9 males) and 9 normal subjects (5 males).ResultsLF &amp; HF spectral power in normalized units (%); S=spontaneous (mean±SEM)LF10HF10LF15HF15LF20HF20LFSHFSSupineCCF19±863±9*18±554±713±447±8*16±649± 8Normal14±668±818±658±1015±670±522±955±10StandCCF15±766±619±746±830±1051±97±531±10Normal28±955±830±942±958±1027±550±1217±5*p&lt;0.05Supine HF power falls with increasing respiratory rate in most CCF pts and this effect is similar to that seen in normals on standing (i.e. at increased sympathetic levels). An improvement in clinical state of CCF pts will lower respiratory rate and this effect alone will increase HF power rather than any therapy

Projected drought risk in 1.5°C and 2°C warmer climates

The large socioeconomic costs of droughts make them a crucial target for impact assessments of climate change scenarios. Using multiple drought metrics and a set of simulations with the Community Earth System Model targeting 1.5°C and 2°C above preindustrial global mean temperatures, we investigate changes in aridity and the risk of consecutive drought years. If warming is limited to 2°C, these simulations suggest little change in drought risk for the U.S. Southwest and Central Plains compared to present day. In the Mediterranean and central Europe, however, drought risk increases significantly for both 1.5°C and 2°C warming targets, and the additional 0.5°C of the 2°C climate leads to significantly higher drought risk. Our study suggests that limiting anthropogenic warming to 1.5°C rather than 2°C, as aspired to by the Paris Climate Agreement, may have benefits for future drought risk but that such benefits may be regional and in some cases highly uncertain