Based on prior knowledge, we can analyze the relationship between the feature "nr_11" and the task of determining whether the patient shows chronic heart failure.

Considering the feature "nr_11" - Observing of arrhythmia in the anamnesis, it is possible that the presence of arrhythmia in the patient's medical history could be a predictor of chronic heart failure as a complication of myocardial infarction. Therefore, we can expect that the feature "nr_11" may have a relationship with the target variable.

To create the dictionary, we need to analyze the different values of the feature "nr_11" for each target class (yes and no) in the myocardial infarction complications data.

Here is the generated dictionary based on the given information:

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

This means that for patients who do not show chronic heart failure as a complication of myocardial infarction, the feature "nr_11" has a possible value of "no". However, for patients who do show chronic heart failure, the feature "nr_11" may have values of both "no" and "yes".

Please note that this analysis is based on the assumption and prior knowledge. The actual relationship between the feature and target can only be confirmed by analyzing the specific dataset.