Based on prior knowledge, we can analyze the relationship between the feature "STENOK_AN" and the task of determining if the patient shows chronic heart failure.

Since "STENOK_AN" represents the presence of exertional angina pectoris in the anamnesis, it is a relevant feature to consider in assessing the likelihood of chronic heart failure. Exertional angina pectoris refers to chest pain or discomfort that occurs during physical activity or exertion.

From the given categories of "STENOK_AN" ('never', 'during the last year', 'more than 5 years ago', '4-5 years ago', 'one year ago', 'two years ago', 'three years ago'), it is reasonable to assume that patients who have experienced exertional angina pectoris more recently (e.g., 'during the last year', 'one year ago') may have a higher probability of chronic heart failure.

To create the dictionary, we need to identify the possible values of "STENOK_AN" that correspond to each target class ("yes" or "no"):

```json
{
	"no": ["never", "more than 5 years ago", "4-5 years ago", "two years ago", "three years ago"], 
	"yes": ["during the last year", "one year ago"]
}
```

Please note that we only included the values that have a logical relationship with the task and are expected to be useful in predicting the presence of chronic heart failure.