Based on prior knowledge, we can analyze the relationship between the "K_SH_POST" feature and the target variable "chronic heart failure" in the myocardial infarction complications data. 

To do this, we need to examine whether having cardiogenic shock at the time of admission to the intensive care unit (ICU) (K_SH_POST = 'yes') is related to the presence or absence of chronic heart failure.

It is expected that there may be a higher likelihood of chronic heart failure in patients who had cardiogenic shock at the time of admission to the ICU. Therefore, we can hypothesize that the "yes" category of the "K_SH_POST" feature might be associated with chronic heart failure.

To generate the dictionary, we need to analyze the "K_SH_POST" feature categories for the two target classes ("yes" and "no") separately.

Here is the dictionary with the possible values of the "K_SH_POST" feature for each target class:

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

Note that since the feature "K_SH_POST" is a categorical variable with only two possible categories ('no' and 'yes'), there is no need to include other possible values in the dictionary as specific values for each target class.