Based on prior knowledge, the feature "n_r_ecg_p_04" represents the presence or absence of frequent premature ventricular contractions on the electrocardiogram (ECG) at the time of admission to the hospital. 

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

1. If the feature value is "yes" (frequent premature ventricular contractions present), it is more likely that the patient may have chronic heart failure.
2. If the feature value is "no" (frequent premature ventricular contractions absent), it is less likely that the patient has chronic heart failure.

Based on this analysis, we can create the dictionary:

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

In this case, the feature values are categorical (either "yes" or "no"). The "no" class represents the absence of chronic heart failure, and the "yes" class represents the presence of chronic heart failure.

Please note that since there are only two possible values for this feature, there is no ambiguity in including both values in the dictionary.