After conducting a thorough analysis of the relationship between the ST_Slope feature and the presence of heart disease, the following observations can be made:

- The ST_Slope feature represents the slope of the peak exercise ST segment on the electrocardiogram (ECG).
- Typically, an upward slope indicates an ST segment elevation, a flat slope indicates no significant change, and a downward slope indicates a depression.
- It is important to consider that other features and diagnostic criteria need to be taken into account to accurately determine whether the coronary angiography shows heart disease.

Based on this analysis, the dictionary can be created as follows:

```json
{
    "no": ["Flat", "Down"],  
    "yes": ["Up"]
}
```

Please note that the category "Up" for the ST_Slope feature is included in the "yes" class, indicating that an upward sloping ST segment suggests the presence of heart disease. The categories "Flat" and "Down" are included in the "no" class, indicating that a flat or downward sloping ST segment suggests the absence of heart disease.