Based on prior knowledge, we can analyze the relationship between the feature "IM_PG_P" and the presence of chronic heart failure in myocardial infarction complications data.

Since the feature "IM_PG_P" represents the presence of a right ventricular myocardial infarction, we can hypothesize that patients with a right ventricular myocardial infarction may be more likely to experience chronic heart failure. Therefore, it is possible that the value "yes" in the "IM_PG_P" feature indicates the presence of chronic heart failure, while the value "no" indicates the absence.

To create the requested dictionary, we can specify the possible values of the "IM_PG_P" feature for each target class:

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

In this case, the feature value "yes" in the "IM_PG_P" feature could represent both the presence or absence of chronic heart failure, as it includes patients who have experienced a right ventricular myocardial infarction. However, since the task specifically asks if the patient shows chronic heart failure, we can assume that the feature value "yes" indicates the presence of chronic heart failure. Therefore, the possible feature values for the target class "yes" include both "no" (indicating the absence of chronic heart failure) and "yes" (indicating the presence of chronic heart failure).