Idiopathic Ventricular Fibrillation
Figure 36–1. Typical example of idiopathic VF. This 54 year old female was referred for neurological consultation because of “recurrent seizures”. Her baseline electrocardiogram shows sinus rhythm with normal PR,…
K+ Channelopathies (IKs, IKr, and Ito)
Figure 14–1. IKr, IKs, and Ito their respective genes and their role in the repolarization of the ventricular action potential Pathologies due to mutation in ion channels were described clinically…
Mechano-Electric Interactions and Their Role in Electrical Function of the Heart
Figure 9–1. Conceptual scheme of cardiac electro-mechanical regulation. Electrical control of cardiac contraction is via Excitation-Contraction Coupling (ECC), while the mechanical environment affects cardiac electrical behaviour via Mechano-Electric Feedback (MEF)…
Basic Physiology of Ion Channel Function
Figure 2–1. Schematic cardiac electrical activity, from molecule to patient channel: single channel current versus time recorded using the patch-clamp technique, upward inflection of the signal indicates outward current through…
Early Repolarization Syndrome: Epidemiology, Genetics, and Risk Stratification
Figure 30–1. Different features of J wave elevation as notching (a) or slurring (b) in inferior or lateral leads in patients with VF Prevalence The prevalence of ER in general…
Caveolae and Arrhythmogenesis
Lipids Cholesterol Ceramide Sphingomyelin Diacylglycerol (DAG) Cis-unsaturated phospholipids Phosphatidylserine Phosphatidylethanolamine Phosphatidylinositol Phosphatidylinositol bi-phosphate (PIP2) Protein Caveolins (-1, -2, and -3) G-proteins G-alpha, -G-beta Adrenergic receptor (AR) Beta-1, beta-2, beta-3? Cytokine…
Cardiac KATP Channels in Health and Diseases
Figure 16–1. The structural basis of KATP channels. (a) KATP channels are formed from Kir6 (left) and SUR (right) subunits. Kir6 subunits each consist of two transmembrane helices (M1, M2),…
Ca2+ Release Channels (Ryanodine Receptors) and Arrhythmogenesis
Figure 17–1. Excitation-contraction coupling in the heart. With the advent of an action potential, L-ype Ca2+ channels are activated resulting in the influx of Ca2+. This influx of Ca2+ activates…
Short QT Syndrome
1999 Discovery of family with SQTS (Bjerregaard P, 1999, personal communication) 2000 Paper describing SQTS (Gussak et al. [1]) 2003 High incidence of SCD in families with SQTS (Gaita et…
Mechanisms of Action of Antiarrhythmic Drugs in Atrial Fibrillation
Figure 8–1. Factors involved in the initiation of atial fibrillation (AF) and pharmocological options to prevent the initiation of this arrhythmia The maintenance of AF is facilitated by the development…
