Based on my prior knowledge, a first-degree AV block on ECG at the time of admission to the hospital may or may not be related to chronic heart failure. Therefore, it is important to analyze the relationship between the feature "n_p_ecg_p_03" and the presence of chronic heart failure in the myocardial infarction complications data.

Here is the dictionary based on the analysis:

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

In this case, the only possible value for feature "n_p_ecg_p_03" is either "no" or "yes". The dictionary shows that, for the target class "no" (indicating no chronic heart failure), the feature value "n_p_ecg_p_03" can only be "no". Similarly, for the target class "yes" (indicating chronic heart failure), the feature value "n_p_ecg_p_03" can only be "yes".

Please note that if there are other possible values for feature "n_p_ecg_p_03" that are hard to predict or not available, they were not included in the dictionary to ensure that each target class has a non-empty list.