UNLABELLED The aim of this paper was to investigate the effects of pinacidil and diazoxide, the activators of sarcolemmal and mitochondrial ATP-sensitive K(+) channels (K(ATP)), respectively, on heart rate and force of contraction in female and male guinea pigs. Experiments were performed on the isolated, spontaneously beating, right atria obtained from guinea pigs of both genders. First series...

BACKGROUND The definition of a normal heart rate (HR) response to exercise stress testing in women is poorly understood, given that most studies describing a normative response were predominately based on male data. Measures of an attenuated HR response (chronotropic incompetence) and age-predicted HR have not been validated in asymptomatic women. We investigated the association between HR resp...

Background—The definition of a normal heart rate (HR) response to exercise stress testing in women is poorly understood, given that most studies describing a normative response were predominately based on male data. Measures of an attenuated HR response (chronotropic incompetence) and age-predicted HR have not been validated in asymptomatic women. We investigated the association between HR resp...

INTRODUCTION We aimed to gather knowledge on the cardiac autonomic modulation in patients with fibromyalgia (FM) in response to exercise and to investigate whether this population suffers from chronotropic incompetence (CI). METHODS Fourteen women with FM (age: 46 ± 3 years; body mass index (BMI): 26.6 ± 1.4 kg/m2) and 14 gender-, BMI- (25.4 ± 1.3 kg/m2), and age-matched (age: 41 ± 4 years) h...

To test the ability of the hypertrophied ventricle to increase its contractility in response to sympathetic stimulation, we compared the chronotropic, inotropic, and relaxation responses to graded in fusions of isoproterenol in spontaneously hypertensive rats (SHR) with responses of matched Wistar-Kyoto (WKY) controls. A closed-chested, direct ventricle puncture was used for the study. The SHR ...

This study was aimed at investigating the cardiovascular effects of an Olea europea L. leaf extract (OEE), of a Hibiscus sabdariffa L. flower extract (HSE), and of their 13 : 2 w/w mixture in order to assess their cardiac and vascular activity. Both extracts were fully characterized in their bioactive compounds by HPLC-MS/MS analysis. The study was performed using primary vascular endothelial c...

PURPOSE To assess the presence and the prevalence of arrhythmias and the variability of the heart rate in the medium-term postoperative period following the maze procedure for chronic atrial fibrillation (AF). METHODS Seventeen patients with a mean age of 51.7 +/- 12.9 years, who previously underwent the maze procedure without cryoablation for chronic atrial fibrillation, were evaluated with ...

Some parasympathetic ganglionic cells are located in the epicardial fat pad between the medial superior vena cava and the aortic root (SVC-Ao fat pad) of the dog. We investigated whether the ganglionic cells in the SVC-Ao fat pad control the right atrial contractile force, sinus cycle length (SCL), and atrioventricular (AV) conduction in the autonomically decentralized heart of the anesthetized...

Approximately 60% of adult canine Purkinje fibers respond to alpha 1-adrenergic stimulation with a decrease in automaticity. Recent studies of disaggregated Purkinje myocytes have suggested that this negative chronotropic effect results from alpha 1-adrenergic activation of the Na-K pump. In this study we evaluated 1) whether Na-K pump activation is associated with the negative chronotropic eff...

Objective(s): Cirrhotic cardiomyopathy is a complication of uncured cirrhosis which is associated with hyporesponsiveness of the heart to sympathetic stimulation. The enhancement of portal pressure, nitric oxide (NO) level, pro-inflammatory mediators and down-regulation of Suppressor of Cytokine Signaling 1 (SOCS1) are involved in this situations. The present study see...