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: Eighty - one consecutive patients ( 54 with coronary artery disease , and 20 with dilated cardiomyopathy ) with inducible sustained ventricular tachycardia or ventricular fibrillation received oral d , l - sotalol to prevent induction of the ventricular tachyarrhythmia .
### Output Text:
Eighty - one consecutive patients ( 54 with coronary artery disease , and 20 with dilated cardiomyopathy ) with inducible sustained ventricular tachycardia or ventricular fibrillation received oral <span class="chemical">d , l - sotalol</span> to prevent induction of the ventricular tachyarrhythmia . 