cardiovascular disorders
Medications for Arrhythmias
Class III Antiarrhythmic Drugs
Class III drugs are Membrane-stabilizing drugs, primarily potassium channel blockers Class III drugs prolong action potential duration and refractoriness in slow- and fast-channel tissues. Thus, the capacity of all cardiac tissues to transmit impulses at high frequencies is reduced, but conduction velocity is not significantly affected. Because the action potential is prolonged, rate of automaticity is reduced. The predominant effect on the ECG is QT-interval prolongation. These drugs are used to treat Reentrant Supraventricular Tachycardias (SVT) Including Wolff-Parkinson-White Syndrome and ventricular tachyarrhythmias. Class III drugs have a risk of ventricular proarrhythmia, particularly 