HCN channels and heart rate.

Hyperpolarization and Cyclic Nucleotide (HCN) -gated channels represent the molecular correlates of the "funny" pacemaker current (I(f)), a current activated by hyperpolarization and considered able to influence the sinus node function in generating cardiac impulses. HCN channels are a family of six transmembrane domain, single pore-loop, hyperpolarization activated, non-selective cation channels. This channel family comprises four members: HCN1-4, but there is a general agreement to consider HCN4 as the main isoform able to control heart rate. This review aims to summarize advanced insights into the structure, function and cellular regulation of HCN channels in order to better understand the role of such channels in regulating heart rate and heart function in normal and pathological conditions. Therefore, we evaluated the possible therapeutic application of the selective HCN channels blockers in heart rate control.

Could Externalized St. Jude Medical Riata® Lead Be a Culture Medium of a Polymicrobial Endocarditis? A Clinical Case.

We report the case of a man affected by polymicrobial endocarditis developed on a St. Jude Medical Riata lead with a malfunction because of the outsourcing of conductors. The patient was treated with antibiotic targeted therapy and showed different bacteria at the blood cultures and then underwent transvenous leads extraction. Vegetations were highlighted on the caval, atrial, and ventricular tracts of the Riata lead, but the cultures were all negative. The externalization of Riata lead may cause the malfunction but it could also promote bacterial colonies and vegetations. In conclusion, looking for early signs of infection is mandatory during Riata leads follow-up checks.

Serum osteoprotegerin and carotid intima-media thickness in acute/chronic coronary artery diseases.

AIMS: Osteoprotegerin (OPG) plays a key role in atherosclerosis progression and plaque destabilization. We investigated the relationship between intima-media thickness of the common carotid artery (CCA-IMT; an early marker of atherosclerosis) and OPG levels in patients with acute coronary syndrome (ACS) and chronic coronary artery disease (CAD). METHODS: We studied 133 consecutive patients, mean age 65 ± 9 years, referred to our department for coronary angiography. They were evaluated for cardiovascular risk factors, OPG levels and CCA-IMT and accordingly divided in two subgroups: ACS and chronic CAD. RESULTS: Except for age, the two groups were similar according to conventional cardiovascular risk factors. The chronic CAD group showed a CCA-IMT lower than the ACS group (0.86 ± 0.15 vs. 0.94 ± 0.22 mm, P = 0.027); there were no differences regarding the extension of coronary atherosclerosis on angiograms. The OPG levels were higher in chronic CAD patients than in ACS patients (5.36 ± 3.06 vs. 3.85 ± 2.96 pmol/l, P = 0.004). Moreover, the CCA-IMT was significantly correlated with the age of the patients (r = 0.5; P < 0.001). OPG values were not related either to age or to the CCA-IMT. At analysis of covariance, when adjusting the groups for age, the comparison of the two groups lost statistical significance for CCA-IMT (P = 0.41), whereas the OPG values remained significant after the correction (P = 0.001). CONCLUSION: OPG levels are higher in chronic CAD patients. CCA-IMT confirmed its importance in predicting CAD, showing significantly higher values in the patients in the ACS group as compared with those in the chronic CAD group.

Cardiovascular Risk in Women With PCOS.

Polycystic ovary syndrome (PCOS), or Stein-Leventhal syndrome, is a common endocrine disorder defined by two of the three following features: i) oligoovulation or anovulation, ii) clinical and/or biochemical signs of hyperandrogenism, or iii) polycystic ovaries, once the related endocrinological and gynaecological disorders have been excluded. PCOS does not exclusively involve the reproductive apparatus , it has a complex number of systemic relevancy symptoms. It leads to Metabolic Syndrome, with severe consequences on the cardiovascular apparatus. Many clinical studies have underlined the connection between PCOS and the cardiovascular risk profile of such female patients, due to a lipid/glucose altered metabolism, hypertension, systemic inflammatory condition (assessable by markers such as VES, TNF-alfa, citokines and C-reactive protein (hsPCR) levels), and vascular injuries. Considering the early onset of the disease, PCOS could be considered as a real cardiovascular risk factor which affects the quality of life seriously. The current review aimed to point out the main connections between PCOS and cardiovascular risk factors according to the latest findings coming from literature data analysis, and try to depict the great influences that such a common disease can have on the patients' health integrity.

Carotenoids and cardiovascular risk.

Fruits and vegetables (typically associated with the Mediterranean diet) are very rich in carotenoids, i.e. fat-soluble pigments really important in human life. Structurally, carotenoids consists of eleven (beta-carotene, zeaxanthin, lycopene) or ten (alpha-carotene, lutein) conjugated double bonds, responsible for their antioxidant capability in agreement with their substituents. Low-Density Lipoprotein (LDL) particles oxidation process is the one of the most important first steps of atherosclerotic disease and, consequentially, the first pathogenetical step of cerebro- and cardiovascular events like myocardial infarction and stroke, which are the first cause of death in industrialized countries. Reactive oxygen species (ROS) also seem to be the target of Carotenoids main action, by scavenging singlet oxygen (1O2) and free radicals. Literature data showed that ROS increase atherosclerotic individual burden. The carotenoids scavenging action could reduce atherosclerosis progression partly due to such a decrease in ROS concentrations. Many studied demonstrated such a reduction by analyzing the relationship between carotenoids and Intima-Media Thickness of common carotid artery wall (CCA-IMT), [a well established marker of atherosclerosis evolution] reduction. Aim of this review is to evaluate actual knowledge about the importance of carotenoids molecules in slowing down the starting and the progression of atherosclerotic plaque, and to consider their implementation in everyone's diet as a tool to obtain a sharp decrease of LDL oxidation and their possible effect on endothelial function.