No, high blood pressure is not a sign of heart attack, in fact low blood pressure is more indicative of an impending heart attack.
High blood pressure is a condition that can cause heart disease if it exists for a number of years because it often leads to hardening of the arteries. This means that the veins and arteries lose flexibility and do not enlarge during times of exercise, which would allow more oxygen-rich blood to flow to the muscles.
So instead, the heart must compensate by pumping much faster in order to achieve the level of blood flow necessary. Over time, the heart may become enlarged so that it can handle the increased workload caused by the high blood pressure.
So, high blood pressure can cause heart disease if it is not corrected and exists for a number of years in the patient. But just because the patient has high blood pressure does not mean that he is in danger of having a heart attack.
On the contrary, when the heart becomes weakened is at risk of an attack, the symptom is more commonly low blood pressure because the heart in its weakened state is unable to keep blood pressure within a healthy range.
There is a relationship between high blood pressure and heart disease, but it is not a sign of heart attack.