Get ready to energize your life?
Top Offers Only Today
Support your health and step-up your mental focus
post in: Lifestyle, Health Date:02 Oct 2017, 19:54 views:944
Discussion: Class 1B agents have the lowest affinity for the target sodium channels and decrease the action potential duration (Image B). Because class 1B agents have low affinity for the sodium channel, they are able to bind and release active channels more efficiently and, thus, target ectopic foci. This is particularly relevant in gina the post-myocardial infarction (MI) period because their low affinity for the target sodium channels allows them to specifically target cells with high ectopy.
Class 1 antiarrhythmic agents are all sodium channel blockers. There are three groups within class I: allergy Class 1A includes quinidine, procainide, disopyramide.
These agents have intermediate binding to Na channels and also have some binding to potassium channels. The result is a prolongation of action potential duration (Figure A).
Class 1B agents, described above, include lidocaine, tocainide, and mexiletine. Class 1C includes propafenone, flecainide, and encainide.
Class 1C agents exhibit very tight binding and slow release of Na channels. They do not affect the action potential duration (Figure D). Describe the management of common arrhythmias.
They note that in patients without evidence of structural heart disease, ventricular ectopy (i.e. Premature ventricular complexes PVCs without sustained ventricular tachycardia) does not need to be treated. However, in individuals with established heart disease and PVCs, there stepwise is a greater risk of developing ventricular tachycardia or fibrillation.
These patients should be treated with a beta blocker or class I antiarrhythmic drug. As discussed by Ryan. In the AHA guidelines for treatment of MI, lidocaine (class 1B agent) is used as an alternative to other antiarrhythmic drugs (such as amiodarone) for the acute treatment of hemodynamically compromising ventricular ectopy following myocardial ischemia or infarction.
It is no longer recommended to use lidocaine for prophylaxis against primary ventricular fibrillation following acute. Figures A to D are explained in the incorrect answer explanations below.