Based on prior knowledge, the functional class of angina pectoris (FK_STENOK) can provide insight into the presence or absence of chronic heart failure in the myocardial infarction complications data. 

To analyze the relationship between FK_STENOK and the presence of chronic heart failure, we can examine the distribution of FK_STENOK values within each target class (yes and no).

Here is a dictionary representing the relationship between FK_STENOK and chronic heart failure:

```json
{
    "no": ["there is no angina pectoris", "II FC"],
    "yes": ["IV FC", "I FC", "III FC."]
}
```

The values "there is no angina pectoris" and "II FC" are associated with the "no" class, indicating that these functional classes are more likely to be present when chronic heart failure is absent. On the other hand, the values "IV FC", "I FC", and "III FC." are associated with the "yes" class, suggesting that these functional classes are more likely when chronic heart failure is present.

Please note that this analysis is based on general knowledge and assumptions, and the actual relationship may vary depending on the specific dataset and context.