Most people who use cocaine do it because it makes them feel good. It quickly produces a very pleasant, intense feeling that everything is wonderful. The dangerous side effects of cocaine are not as well known and are often overlooked. The effects on the heart and circulation can be life-threatening and may include a sudden increase in heart rate and blood pressure, irregular heartbeats, and heart attack.
How does cocaine cause these effects?

Cocaine is a short-acting, powerful stimulant that acts directly on the heart muscle, brain, blood vessels, and nerve tissue to cause effects that are felt almost immediately. Cocaine's direct effect on nerve tissue to the heart can cause a rapid heart rate or irregular heartbeats that may be fatal. The direct effect on the heart muscle and blood vessels may cause sudden high blood pressure. It may also cause spasm and narrowing of the arteries leading to heart muscle, ending in a heart attack with heart muscle damage and death.
What are the cardiovascular symptoms of cocaine use?

The user may have the sensation of rapid or irregular heartbeats (palpitations). These irregular beats may be very forceful and give the person a feeling of impending doom. These symptoms generally don't last very long.

A big, sudden increase in blood pressure puts a severe strain on the arteries and, if a weakness is present in the wall of an artery, may cause the artery to burst. If the artery is in the brain the rupture may cause a stroke. Either of these events may result in death.

Cocaine users may complain of chest pain. This is often due to the drug's effect on the heart arteries, which is to cause spasm and narrowing that reduces the amount of blood that can flow through them. When the reduced blood flow results in the heart muscle not getting enough oxygen to function properly, a heart attack may result.
How are the symptoms treated?