2921
There was also a higher incidence of tachyarrhythmias ( P less than 0 . 05 ) and ventricular ectopic beats ( P less than 0 . 05 ) in the morphine infusion group .
 tachyarrhythmias, ventricular ectopic beats, morphine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 tachyarrhythmias, ventricular ectopic beats, morphine