Heart attack survivors commonly experience shortness of breath as a direct result of not having sufficient blood flow to their lungs or heart.
This isn't the type of breath catching that occurs when you have just been on the treadmill. This is much more pronounced and scary for the patient to live with.
Many begin to have panic attacks, or severe anxiety episodes as a result of not being able to breathe properly from the early onset of this heart attack symptom. When in doubt, always call 911.