Based on the description of the feature "n_r_ecg_p_03" and the task of determining if the patient has chronic heart failure, we can analyze the relationship between these variables.

The feature "n_r_ecg_p_03" represents the presence or absence of ventricular contractions on the ECG at the time of admission to the hospital. This is a categorical variable with two possible categories: "no" and "yes". 

To analyze the relationship between this feature and the presence of chronic heart failure, we can consider the following possibilities:

1. If the value of "n_r_ecg_p_03" is "no", it may suggest that there are no ventricular contractions observed on the ECG at the time of admission to the hospital. This could indicate a lower likelihood of chronic heart failure.

2. If the value of "n_r_ecg_p_03" is "yes", it may suggest the presence of ventricular contractions on the ECG at the time of admission to the hospital. This could indicate a higher likelihood of chronic heart failure.

To summarize the relationship between the feature "n_r_ecg_p_03" and the presence of chronic heart failure, we can create a dictionary with the format requested:

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

In this case, the possible values of the feature "n_r_ecg_p_03" for the target class "no" are ["no"], and for the target class "yes" are ["yes"]. This indicates that both "no" and "yes" are possible values for the target classes, and no other distinct values are mentioned in the description of the feature.