Based on prior knowledge, the use of beta-blockers (B_BLOK_S_n) can have an impact on the development of chronic heart failure in patients with myocardial infarction complications.

To analyze the relationship between B_BLOK_S_n and chronic heart failure, we will examine the distribution of B_BLOK_S_n values for each target class:

Target class: no (indicating no chronic heart failure)
- Possible values of B_BLOK_S_n: ['no', 'yes']

Target class: yes (indicating chronic heart failure)
- Possible values of B_BLOK_S_n: ['no', 'yes']

Since the feature 'B_BLOK_S_n' is a categorical variable with values 'no' and 'yes', we can directly map these values to the respective target classes in our dictionary:

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

Note: It is important to include all possible values of the feature for each target class, as leaving out any values can lead to biased analysis or predictions.