In making your decision to treat with procainamide, which of the following statements would be relevant?: (A) Procainamide may worsen or precipitate hypehyroidism, (B) Procainamide is not effective for atrial arrhythmias, (C) Procainamide prolongs the effective refractory period in atrial and ventricular cells, (D) Procainamide commonly induces thrombocytopenia
Answer is C. Procainamide prolongs the effective refractory period in atrial and ventricular cells. Ref: KDT, tth Edition, Page 511,512 Procainamide prolongs refractory period by blocking sodium channels and by prolonging the AP. All of the other statements are false.