```json
{
	"no": ["no"],  
	"yes": ["no", "yes"]
}
```
Based on the given feature description, the feature "NITR_S" indicates whether the patient used liquid nitrates in the ICU. In order to determine whether the patient shows chronic heart failure, we need to analyze the relationship between the feature and the target variable.

From the feature alone, we cannot directly determine if the patient has chronic heart failure or not. The feature "NITR_S" only provides information about the use of liquid nitrates in the ICU, which may be related to the treatment plan but not directly indicative of chronic heart failure.

The possible values for the feature "NITR_S" are "no" and "yes". Since we are trying to identify if the patient has chronic heart failure, the target variable will have two classes: "no" indicating no chronic heart failure, and "yes" indicating chronic heart failure.

Based on this analysis, we can see that if the patient has used liquid nitrates in the ICU, the value of the feature "NITR_S" can be either "no" or "yes". However, if the patient has not used liquid nitrates in the ICU, the value of the feature "NITR_S" can only be "no". Therefore, the dictionary for the relationship between the feature "NITR_S" and the target variable is as follows:

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

This indicates that when the target variable shows no chronic heart failure, the value of the feature "NITR_S" can only be "no". When the target variable shows chronic heart failure, the feature "NITR_S" can have the values "no" or "yes".