modality, what the indication for each is, and howtheseSuccessfulmodalitiesinteract.maydrugtherapyantiarrhythmicrequiresacombination of understanding the pathophysiologyof the arrhythmia,identification of a drug that cantheinfluencerelevantelectrophysiologicalparameters, and careful titration of the drug's doseto correct the abnormal electrophysiological eventsgiving rise to the arrhythmia. This is accomplishedwhile avoiding the risk of side effects such asproarrhythmia
modality, what the indication for each is, and how these modalities may interact. Successful antiarrhythmic drug therapy requires a combination of understanding the pathophysiology of the arrhythmia, identification of a drug that can influence the relevant electrophysiological parameters, and careful titration of the drug’s dose to correct the abnormal electrophysiological events giving rise to the arrhythmia. This is accomplished while avoiding the risk of side effects such as proarrhythmia
L overviewA.Transmembrane Potential of Cardiac Celltwo membrane potentials:resting potentialaction potentialthe membrane potential of cardiac cell is divided intotwo responsiblepotentials:in the atria, His-Purkinje'sl.fastresponsiblepotentialsystem, ventricles.non-pacemaker cellsinnode,sinoatrial2.slowresponsiblepotentialatrioventricular nodepace maker cells
I. overview A. Transmembrane Potential of Cardiac Cell two membrane potentials: resting potential action potential the membrane potential of cardiac cell is divided into two responsible potentials: 1.fast responsible potential 2.slow responsible potential in the atria, His-Purkinje's system, ventricles. non-pacemaker cells in sinoatrial node, atrioventricular node. pace maker cells
Conducting systemAtriumSinus NodeLeftBundleBranchAV NodeBundleof HiSVentriclesRightBundle Branch
Conducting system
The characteristic action potential is the result ofactivation and inactivation of multiple ion channels.which allows the flow of charged ions across themembrane. The ion channels are transmembraneproteins possessing two important features: an ionselective pore that allows the passage of a specificcation or anion and regulatory components thatrespond to chemical stimulation or changes in thetransmembrane potential by opening or closing.The ions flow through open channels according tothe electrochemical driving forces at any givenmoment
The characteristic action potential is the result of activation and inactivation of multiple ion channels, which allows the flow of charged ions across the membrane. The ion channels are transmembrane proteins possessing two important features: an ion selective pore that allows the passage of a specific cation or anion and regulatory components that respond to chemical stimulation or changes in the transmembrane potential by opening or closing. The ions flow through open channels according to the electrochemical driving forces at any given moment
Like all other electrically active cells, the interior ofthe cardiac muscle cell is electrically negative withrespect to the surrounding medium. This differencebetween the exterior and interior of a myocardialcell results from the action of several energy-requiring pumps, such as the Na-K-ATPase, whichpumps Na out of and K into the cell in a ratio of3Na to 2K,and the presence of large negativelycharged intracellular proteins that do not diffusefreely across the membrane
Like all other electrically active cells, the interior of the cardiac muscle cell is electrically negative with respect to the surrounding medium. This difference between the exterior and interior of a myocardial cell results from the action of several energyrequiring pumps, such as the Na–K–ATPase, which pumps Na out of and K into the cell in a ratio of 3Na to 2K , and the presence of large negatively charged intracellular proteins that do not diffuse freely across the membrane