In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The patient had no apparent associated conditions which might have predisposed him to the development of bradyarrhythmias ; and , thus , this probably represented a true idiosyncrasy to lidocaine .
### Output Text:
The patient had no apparent associated conditions which might have predisposed him to the development of bradyarrhythmias ; and , thus , this probably represented a true idiosyncrasy to <span class="chemical">lidocaine</span> . 