Based on prior knowledge, we can analyze the relationship between the feature "n_p_ecg_p_03" (First-degree AV block on ECG at the time of admission to hospital) and the presence of chronic heart failure. 

Since the feature is categorical with two possible values - "no" and "yes" - we can analyze how the values of this feature relate to the target variable, chronic heart failure.

To generate the dictionary, we need to identify the possible values of the feature "n_p_ecg_p_03" for each target class (no and yes).

Based on the available information, we cannot make assumptions about the possible values of "n_p_ecg_p_03" that indicate chronic heart failure or the lack of it. Hence, we will generate a dictionary that includes all the possible values for each target class.

Here is the dictionary in the required JSON format:

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

Please note that the dictionary includes each unique value of the feature "n_p_ecg_p_03" for the respective target class.