Based on my prior knowledge, the feature "n_p_ecg_p_12" represents the presence or absence of Complete Right Bundle Branch Block (RBBB) on the electrocardiogram (ECG) at the time of admission to the hospital. RBBB is a common ECG finding in patients with cardiovascular diseases, including chronic heart failure.

To analyze the relationship between the feature "n_p_ecg_p_12" and the task of determining whether the patient shows chronic heart failure, we can examine the distribution of the feature values for each target class.

Here is the dictionary with the analysis results:

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

Explanation:
- For the target class "no" (indicating no chronic heart failure), the only possible value for the feature "n_p_ecg_p_12" is "no". This suggests that patients without chronic heart failure do not exhibit Complete RBBB on their ECG at the time of admission.
- For the target class "yes" (indicating chronic heart failure), the only possible value for the feature "n_p_ecg_p_12" is "yes". This implies that patients with chronic heart failure have Complete RBBB on their ECG at the time of admission.

Note: Since the feature "n_p_ecg_p_12" is a categorical variable with only two possible values, there are no other values to consider in the analysis.