After analyzing the relationship between the feature "n_p_ecg_p_03" and the task of determining whether the patient has chronic heart failure, I can provide you with the following dictionary:

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

In this case, the feature "n_p_ecg_p_03" only has two possible values - "no" and "yes". For the target class "no" (patients without chronic heart failure), the only possible value of the feature is "no". For the target class "yes" (patients with chronic heart failure), the only possible value of the feature is "yes".