Based on prior knowledge, we can analyze the relationship between the feature "n_r_ecg_p_04" and the task of determining if the patient shows chronic heart failure.

The feature "n_r_ecg_p_04" represents frequent premature ventricular contractions on the electrocardiogram (ECG) at the time of admission to the hospital. To determine if this feature is related to chronic heart failure, we can consider the following:

1. Patients with frequent premature ventricular contractions (n_r_ecg_p_04 = 'yes') may have a higher likelihood of developing chronic heart failure. This is because frequent premature ventricular contractions are abnormal heartbeats that can compromise the heart's ability to pump blood effectively, leading to heart failure.

2. Patients without frequent premature ventricular contractions (n_r_ecg_p_04 = 'no') may have a lower likelihood of developing chronic heart failure. Normal heart rate patterns without frequent premature contractions indicate a healthier heart function, reducing the risk of heart failure.

Based on this analysis, we can create a dictionary to show the relationship between the feature "n_r_ecg_p_04" and the presence of chronic heart failure:

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

In this case, the feature "n_r_ecg_p_04" has two possible values ('yes' and 'no'). Patients without frequent premature ventricular contractions (n_r_ecg_p_04 = 'no') are classified as not showing chronic heart failure, while patients with frequent premature ventricular contractions (n_r_ecg_p_04 = 'yes') are classified as showing chronic heart failure.