It doesn t work like that. Hypertension will not automatically lead to a heart attack, although hypertension is a major risk factor for heart disease and stroke. Heart attacks occur when there is a prolonged reduction in oxygen supply to a region of myocardium (heart muscle). Tissue death then follows and the area is said to be infarcted. MIs generally occur in people with coronary artery disease where there is significant narrowing of one of more of the three major coronary arteries. As a result of turbulent blood flow at the site of the atheroma, platelets aggregate to form thrombi and blockage of the artery can then occur. The majority of the time, the underlying reason for high blood pressure is not known- this is known as essential hypertension . The pressure in the arteries depends on how hard the heart pumps, and how much resistance there is in the arteries. A narrowing of the arteries increases the resistance to blood flow, which increases the BP- it isn t always known what causes the narrowing. The higher your blood pressure is, the greater the stroke risk. There is no way to put a time scale on it. If your BP is not being well controlled, then you must see your GP and make any appropriate lifestyle changes. With regards to your BP altering when you have a heart attack; it can increase or decrese depending on the extent of the MI. Dyskinetic cardiac impulse occasionally can be palpated. The most common symptoms of a heart attack are chest pains, shortness of breath and pale clamy skin.