PHPY 304 Lecture Notes - Lecture 12: Torsades De Pointes, Voltage-Dependent Calcium Channel, Flecainide

• School: U of S
• Department: Physiology and Pharmacology
• Course: PHPY 304
• Professor: Desai Kash

Document Summary

List the 4 (or 5) classes of antiarrhythmic action. Fibrillation, ventricular tachycardia / tachyarrhythmia: treatment of torsades de pointes (tdp or lqts) Drugs classes: class i: na+ channel blockers: Block conduction - affects phase 0 of ap: class ii: - blockers: decease ca2+ influx (metoprolol, sotalol) sa node automaticity conduction velocity in a-v node, class iii: k+ channel blockers amiodarone, sotalol prolongs action pot. & qt interval: class iv: ccbs: (verapamil, diltiazem) Slows conduction velocity in av node: treatment of tdp: mg2+, isoprenaline, hco3_ Phase 0: na channels open, na moves into cell. Inactivation of na channels: k+ moves out of cell, repolarization. Phase 2: voltage gated ca2+ channels open, slow depolarization as ca2+ moves into cell. Phase 3: repolarization, ca2+ channels close, k+ still leaving. Class 1a: na channel, decrease conduction velocity. Increase qt: quinidine -underlined means can act via multiple classes. Class 1b: na channel (in active only, decrease conduction velocity and qt, lidocaine.