```json
{
	"no": ["no"],
	"yes": ["yes"]
}
```

Based on the feature description, the feature LID_S_n represents the use of lidocaine in the ICU. Since the task is to determine if the patient shows chronic heart failure, there doesn't seem to be a direct relationship between the use of lidocaine and chronic heart failure. The feature alone does not provide any substantial information to predict the presence or absence of chronic heart failure. Therefore, the only possible values for the feature LID_S_n are "yes" and "no". 

In this case, both "yes" and "no" can be considered as possible values for the target class "no" (indicating absence of chronic heart failure) and "yes" (indicating presence of chronic heart failure) respectively.