```json
{
	"no": ["there was no arterial hypertension", "more than 10 years", "6-10 years", "three years", "two years", "one year", "five years", "four years"],
	"yes": ["more than 10 years", "6-10 years", "three years", "two years", "one year", "five years", "four years"]
}
```
In the given dataset, patients with chronic heart failure (target class "yes") have a duration of arterial hypertension ranging from "more than 10 years" to "four years". Patients without chronic heart failure (target class "no") can have any duration of arterial hypertension, including "there was no arterial hypertension".