3721
In four patients , polymorphous ventricular tachycardia appeared after intravenous administration of 200 to 400 mg of procainamide for the treatment of sustained ventricular tachycardia .
 ventricular tachycardia, procainamide, ventricular tachycardia
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 ventricular tachycardia, procainamide, ventricular tachycardia