Preliminary Characterization of the Vasorelaxant Effect of Thymus atlanticus (Ball) Roussine Using Optical Methods.

Background: Thymus atlanticus (Ball) Roussine is a Moroccan endemic thyme species that is traditionally used as an aromatic and medicinal plant. Several studies have demonstrated its pharmacological significance and therapeutic value.

Objective: The current study aimed to assess the vasorelaxant effect of the aqueous extract of this species.

Antiarrhythmic Action of Flecainide in Polymorphic Ventricular Arrhythmias Caused by a Gain-of-Function Mutation in the Nav 1.5 Sodium Channel.

Background: The cardiac sodium channel Nav 1.5, encoded by the gene SCN5A, is associated with a wide spectrum of hereditary arrhythmias. The gain-of-function mutation p.

Complex Brugada syndrome inheritance in a family harbouring compound SCN5A and CACNA1C mutations.

Brugada syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads and is associated with increased risk of sudden cardiac death. We have recently reported families with BrS and SCN5A mutations where some affected members do not carry the familial mutation. We evaluated the involvement of additional genetic determinants for BrS in an affected family.

Gain-of-function mutation of the SCN5A gene causes exercise-induced polymorphic ventricular arrhythmias.

Background: Over the past 15 years, a myriad of mutations in genes encoding cardiac ion channels and ion channel interacting proteins have been linked to a long list of inherited atrial and ventricular arrhythmias. The purpose of this study was to identify the genetic and functional determinants underlying exercise-induced polymorphic ventricular arrhythmia present in a large multigenerational family.

Methods And Results: A large 4-generation family presenting with exercise-induced polymorphic ventricular arrhythmia, which was followed for 10 years, was clinically characterized.

A long QT mutation substitutes cholesterol for phosphatidylinositol-4,5-bisphosphate in KCNQ1 channel regulation.

Introduction: Phosphatidylinositol-4,5-bisphosphate (PIP2) is a cofactor necessary for the activity of KCNQ1 channels. Some Long QT mutations of KCNQ1, including R243H, R539W and R555C have been shown to decrease KCNQ1 interaction with PIP2. A previous study suggested that R539W is paradoxically less sensitive to intracellular magnesium inhibition than the WT channel, despite a decreased interaction with PIP2.

Multifocal ectopic Purkinje-related premature contractions: a new SCN5A-related cardiac channelopathy.

Objectives: The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease.

Background: Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited cardiac arrhythmias.

Methods: Three unrelated families comprising 21 individuals affected by multifocal ectopic Purkinje-related premature contractions (MEPPC) characterized by narrow junctional and rare sinus beats competing with numerous premature ventricular contractions with right and/or left bundle branch block patterns were identified.

TRPM4 channels in the cardiovascular system: physiology, pathophysiology, and pharmacology.

The transient receptor potential channel (TRP) family comprises at least 28 genes in the human genome. These channels are widely expressed in many different tissues, including those of the cardiovascular system. The transient receptor potential channel melastatin 4 (TRPM4) is a Ca(2+)-activated non-specific cationic channel, which is impermeable to Ca(2+).

Phosphatidylinositol-4,5-bisphosphate (PIP(2)) stabilizes the open pore conformation of the Kv11.1 (hERG) channel.

Phosphatidylinositol-4,5-bisphosphate (PIP(2)) is a phospholipid that has been shown to modulate several ion channels, including some voltage-gated channels like Kv11.1 (hERG). From a biophysical perspective, the mechanisms underlying this regulation are not well characterized.