Based on prior knowledge, paroxysms of ventricular tachycardia (GT_POST) at the time of admission to the intensive care unit can be an indicator of chronic heart failure. Patients with chronic heart failure may experience ventricular tachycardia as a complication of myocardial infarction.

Based on this analysis, the dictionary will be as follows:

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

In this case, there are only two possible values for the GT_POST feature: "no" and "yes". Patients who do not have chronic heart failure will have a GT_POST value of "no", while patients with chronic heart failure will have a GT_POST value of "yes".