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

Based on the feature description and the task, it appears that the feature `n_p_ecg_p_12` represents the presence or absence of complete RBBB (Right Bundle Branch Block) on an electrocardiogram (ECG) at the time of admission to the hospital.

To determine if the patient has chronic heart failure, we need to analyze the relationship between the feature `n_p_ecg_p_12` and the target variable, which is the presence of chronic heart failure.

Since there are only two categories for the `n_p_ecg_p_12` feature, which are "no" and "yes", we can directly map these categories to the target classes "no" and "yes". Hence, the possible values of `n_p_ecg_p_12` for the target class "no" are ["no"] and for the target class "yes" are ["yes"].

Therefore, the dictionary representation of the relationship between the feature `n_p_ecg_p_12` and the target variable is:

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