Based on the given feature description and task, we need to analyze the relationship between the feature SVT_POST (Paroxysms of supraventricular tachycardia at the time of admission to intensive care unit) and the occurrence of chronic heart failure.

To conduct this analysis, we can examine the SVT_POST values for both the target classes (yes and no) in the myocardial infarction complications data.

Here's an example of how the dictionary might look like:

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

In this example, the dictionary shows that for the target class "no" (indicating no chronic heart failure), the possible values for the SVT_POST feature are only "no". Similarly, for the target class "yes" (indicating chronic heart failure), the possible value for the SVT_POST feature is "yes".

Please note that this is just an example, and the actual values may vary based on the specific data and analysis performed.