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: Functional indices assessed by cardiac MRI ( including left ventricular ejection fraction ( LVEF ) , cardiac output , and E / A ratio ) declined progressively , reaching statistical significance after two doses and culminating in " clinical " LV dysfunction by 12 weeks .
### Output Text:
Functional indices assessed by cardiac MRI ( including left ventricular ejection fraction ( LVEF ) , cardiac output , and E / A ratio ) declined progressively , reaching statistical significance after two doses and culminating in " clinical " LV dysfunction by 12 weeks . 