Yes, your symptoms could be related to a heart attack, but more likely the underlying cause associated with the heart attack may be culprit. For instance, occluded vessels can interrupt a good flow of oxygenated blood and the heart cells functionality is compromised and heart wall movement is impaired, and occluded vessels will cause pain almost anywhere on the upper torso. But deep breathing that causes pain is usually not related to the heart. But there could be concomitant issues with a heart issue.
Pain has so many causes that is difficult to have any decisive answer without tests. Because you recently had a heart attack it may be a good idea to consult with your doctor.
Thanks for your question and if you have any further questions or comments you are welcome to respond. Take,
Ken