Based on prior knowledge, the presence of an anterior myocardial infarction can be an indicator of chronic heart failure. However, it is important to note that this relationship is not definitive, as there can be cases where an anterior infarction is present without chronic heart failure, or vice versa.

To create the dictionary, we need to analyze the relationship between the feature "ant_im" and the target variable "chronic heart failure" in the myocardial infarction complications data.

Here is the dictionary with the possible values of feature "ant_im" for each target class:

```json
{
    "no": ["QRS is like QS-complex", "QRS has no changes", "there is no infarct in this location", "QRS is like QR-complex", "QRS is like Qr-complex"],
    "yes": ["QRS is like QS-complex", "QRS has no changes", "there is no infarct in this location", "QRS is like QR-complex", "QRS is like Qr-complex"]
}
```

Note that since there is no specific indication that certain values of "ant_im" can predict chronic heart failure with certainty, we include all possible values of "ant_im" for both target classes "yes" and "no".

It is important to keep in mind that other features and factors need to be considered in conjunction with "ant_im" to accurately predict chronic heart failure.