Based on prior knowledge, the presence of atrial fibrillation (ritm_ecg_p_02 = 'yes') is known to be strongly related to the development of chronic heart failure. Therefore, we can expect that patients with the feature value 'yes' are more likely to have chronic heart failure compared to those with the feature value 'no'.

Here is the dictionary representing the possible values of the feature 'ritm_ecg_p_02' for each target class:

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

Note that in this case, the possible values for the feature 'ritm_ecg_p_02' are only 'no' and 'yes'. Since the feature value 'yes' is strongly related to chronic heart failure, we include it in the dictionary, even if it might seem obvious.