Upon analyzing the relationship between the feature "ritm_ecg_p_08" and the task of determining whether the patient shows chronic heart failure, I would look at the correlation between the ECG rhythm at the time of admission to the hospital (sinus with a heart rate below 60) and the presence of chronic heart failure.

Based on prior knowledge, it is likely that patients with a heart rate below 60 at the time of admission (as indicated by the feature "ritm_ecg_p_08" set to 'yes') would have a higher likelihood of chronic heart failure compared to those with a heart rate within the normal range (as indicated by the feature "ritm_ecg_p_08" set to 'no').

Here is the dictionary that represents the relationship:

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

It seems there is no additional granularity or unique values for the feature "ritm_ecg_p_08" that could provide further insight into the presence of chronic heart failure.