```json
{
	"no": ["no"],  
	"yes": ["yes"]
}
```
Since the feature "n_r_ecg_p_08" represents the presence or absence of paroxysms of supraventricular tachycardia on ECG at the time of admission to the hospital, the values of this feature can only be "yes" or "no". 

In the given task, we are interested in determining if the patient has chronic heart failure. The presence of paroxysms of supraventricular tachycardia on ECG at the time of admission may or may not be an indicator of chronic heart failure. 

Based on the available information, the possible values for the target class "no" would be "no" and for the target class "yes" would be "yes".