Based on my prior knowledge, a first-degree AV block on an ECG can indicate a conduction delay in the electrical signals between the atria and the ventricles of the heart. This condition might be related to chronic heart failure, but it does not outright determine its presence.

To analyze the relationship between the feature "n_p_ecg_p_03" (First-degree AV block on ECG at the time of admission to hospital) and the presence of chronic heart failure, we will assess the distribution of the feature values for each target class.

Here is the analysis of the relationship:

For the target class "no" (no chronic heart failure):
- 'no': It is expected that a significant portion of patients without chronic heart failure will have no first-degree AV block on the ECG at the time of admission. This would suggest a lack of relationship between the feature and the absence of chronic heart failure.

For the target class "yes" (chronic heart failure):
- 'no': Although a first-degree AV block might not be a direct indicator of chronic heart failure, it is possible that some patients with chronic heart failure will not exhibit this condition.
- 'yes': In some cases, chronic heart failure can occur in conjunction with a first-degree AV block on the ECG at the time of admission. However, it is important to note that not all patients with chronic heart failure will have this specific feature.

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

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

Note: Since the feature "n_p_ecg_p_03" is categorical with only two possible categories ('no' and 'yes'), we include only those categories that are relevant to the target classes. In this case, the 'yes' category does not have any occurrences, but it is still necessary to include it with an empty list to ensure both target classes have the required list.