MATERIALS AND METHODS: We tested a hypothesis implicating Na+ current alterations as a mechanism underlying these electrophysiological phenotypes. We applied loose patch-clamp techniques to intact young and aged, WT and Pgc-1β-/-, atrial cardiomyocyte preparations preserving their in vivo extracellular and intracellular conditions.
RESULTS AND DISCUSSION: Depolarising steps activated typical voltage-dependent activating and inactivating inward (Na+) currents whose amplitude increased or decreased with the amplitudes of the activating, or preceding inactivating, steps. Maximum values of peak Na+ current were independently influenced by genotype but not age or interacting effects of genotype and age on two-way ANOVA. Neither genotype, nor age, whether independently or interactively, influenced voltages at half-maximal current, or steepness factors, for current activation and inactivation, or time constants for recovery from inactivation following repolarisation. In contrast, delayed outward (K+) currents showed similar activation and rectification properties through all experimental groups. These findings directly demonstrate and implicate reduced Na+ in contrast to unchanged K+ current, as a mechanism for slowed conduction causing atrial arrhythmogenicity in Pgc-1β-/- hearts.
MAIN METHODS: Male Sprague-Dawley rats were fed with either normal diet or high-fat diet for 8weeks. Firstly, OB rats were divided into (1) OB and (2) OB+R (100mg/kg, p.o, 28days). Then, OB rats were subjected to MI (ISO, 85mg/kg, s.c, 2days) and divided into three groups: (1) OB+MI, (2) OB+MI+R and (3) OB+MI+enalapril for another 4weeks.
KEY FINDINGS: Roselle ameliorated OB and OB+MI's cardiac systolic dysfunction and reduced cardiac hypertrophy and fibrosis. The increased oxidative markers and decreased antioxidant enzymes in OB and OB+MI groups were all attenuated by roselle.
SIGNIFICANCE: These observations indicate the protective effect of roselle on cardiac dysfunction in OB and OB+MI rats, which suggest its potential to be developed as a nutraceutical product for obese and obese patients with MI in the future.
OBJECTIVE: The aim of this study was to determine the rate, factors, and medications associated with ADR-related hospitalisations among HF patients.
SETTING: Two government hospitals in Dubai, United Arab Emirates.
METHODS: This was a prospective, observational study. Consecutive adult HF patients who were admitted between December 2011 and November 2012 to the cardiology units were included in this study. The circumstances of their admission were analysed.
MAIN OUTCOME MEASURES: ADRs-related admissions of HF patients to cardiology units were identified and further assessed for their nature, causality, and preventability.
RESULTS: Of 511 admissions, 34 were due to ADR-related hospitalisation (6.65, 95 % confidence interval 4.8-8.5 %). Number of medications taken by HF patients was the only predictors of ADR-related hospitalisations, where higher number of medications was associated with the odd ratio of 1.11 (95 % CI, 1.03-1.20, P = 0.005). More than one-third of ADR-related hospitalisations (35 %) were preventable The most frequent drugs causing ADR-related hospitalisation were diuretics (32 %), followed by non-steroidal anti-inflammatory drugs (15 %), thiazolidinediones (9 %), anticoagulants (9 %), antiplatelets (6 %), and aldosterone blockers (6 %).
CONCLUSION: ADR-related hospitalisations account for 6.7 % of admissions of HF patients to cardiac units, one-third of which are preventable. Number of medications taken by HF patients is the only predictors of ADR-related hospitalisations. Diuretic induced volume depletion, and sodium and water retention caused by thiazolidinediones and NSAIDs medications are the major causes of ADR-related hospitalisations of HF patients.