Based on prior knowledge, the ECG rhythm at the time of admission (ritm_ecg_p_04) can be an indicator of chronic heart failure. Therefore, it is reasonable to assume that the value of ritm_ecg_p_04 may be related to the occurrence of chronic heart failure.

To analyze the relationship between the feature ritm_ecg_p_04 and the task of determining if the patient has chronic heart failure, we can examine the distribution of ritm_ecg_p_04 values for each target class (yes or no). By comparing the distribution of ritm_ecg_p_04 values for patients with and without chronic heart failure, we can gain insights into the relationship between the feature and the target.

Based on the given information, we need to analyze the possible values of ritm_ecg_p_04 for each target class (yes or no) to determine if there is a relationship between the feature and chronic heart failure. We will create a dictionary with lists of possible ritm_ecg_p_04 values for each target class.

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

Since the feature ritm_ecg_p_04 is a categorical variable with only two possible values ('no' and 'yes'), we include only those values in the dictionary.