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

Based on the given feature description, the feature zab_leg_01 represents chronic bronchitis in the patient's medical history. Since the task is to determine if the patient has chronic heart failure, it is not clear how chronic bronchitis relates to chronic heart failure. From the information provided, it is not possible to analyze how the feature zab_leg_01 is related to the target variable. Therefore, we include the possible values of feature zab_leg_01 for both target classes, 'no' and 'yes', but since we have no information about the relationship, the lists contain only the possible values mentioned.