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

In this case, the feature `ritm_ecg_p_07` has two possible values: "no" and "yes". 

For patients who do not show chronic heart failure (target class "no"), the only possible value for `ritm_ecg_p_07` is "no". 

For patients who show chronic heart failure (target class "yes"), the only possible value for `ritm_ecg_p_07` is "yes". 

Since there are no other possible values for `ritm_ecg_p_07` that correlate with chronic heart failure, those values are not included in the dictionary.