Based on my prior knowledge, paroxysms of atrial fibrillation in the anamnesis (feature nr_03) can be an indicator of chronic heart failure. Atrial fibrillation is a commonly observed arrhythmia in individuals with chronic heart failure, and paroxysms of atrial fibrillation refers to intermittent episodes of abnormal heart rhythm.

To analyze the relationship between feature nr_03 and the presence of chronic heart failure, we can examine the frequency of certain values of nr_03 in the myocardial infarction complications data. 

To accomplish this, we need to access the dataset containing the myocardial infarction complications data for the patient. Once we have the dataset, we can filter it based on the target variable (presence of chronic heart failure) and then analyze the distribution of different values of nr_03 for each target class (yes and no).

Here is an example dictionary outlining the possible values of feature nr_03 for each target class:

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

In this example, we assume that the values of feature nr_03 are limited to "no" and "yes" only. If there are other possible values for nr_03, we would include those in the respective target class list.