About your heart

Heart attack (myocardial infarction)

A heart attack or myocardial infarction is a medical emergency in which the supply of blood to the heart is suddenly and severely reduced or cut off, causing the muscle to die from lack of oxygen.

400 people in every million experience a heart attack each year, and for many of them, the heart attack is their first symptom of coronary artery disease. A heart attack may be severe enough to cause death or it may be silent. As many as one out of every five people have only mild symptoms or none at all, and the heart attack may only be discovered by routine electrocardiography done some time later.

Symptoms of a heart attack

Not everyone has the same heart attack symptoms when having a myocardial infarction. Common ones include:

During the early hours of a heart attack, heart murmurs and other abnormal heart sounds may be heard through a stethoscope.

Causes of a heart attack

A heart attack is usually caused by a blood clot that blocks an artery of the heart. The artery has often already been narrowed by fatty deposits on its walls. These deposits can tear or break open, reducing the flow of blood and releasing substances that make the platelets of the blood sticky and more likely to form clots. Sometimes a clot forms inside the heart itself, then breaks away and gets stuck in an artery that feeds the heart. A spasm in one of these arteries can cause the blood flow to stop.

Diagnosing a heart attack

A heart attack (myocardial infarction) can be life threatening, men older than 35 or women older than 50 who have chest pain should be examined to see if they are having a heart attack. However, similar pain can be caused by pneumonia, a blood clot in the lung (pulmonary embolism), pericarditis, a rib fracture, spasm of the oesophagus, indigestion or chest muscle tenderness after injury or exertion. A heart attack can be confirmed within a few hours of its occurrence by:

Treating a heart attack

Half the deaths from a heart attack occur in the first 3 or 4 hours after symptoms begin. It is crucial that symptoms of a heart attack be treated as a medical emergency. A person with these symptoms should be taken to the emergency department of a hospital in an ambulance with trained personnel.

The sooner that treatment of a heart attack begins the better. Taking aspirin after an ambulance has been called can help reduce the size of the blood clot. A beta-blocker may be given to slow the heart rate so the heart is not working as hard and to reduce the damage to the heart muscle. Often a person who is having a heart attack is given oxygen, which also helps heart tissue damage to be less.

People who may be having a heart attack are usually admitted to a hospital that has a cardiac care unit. Heart rhythm, blood pressure and the amount of oxygen in the blood are closely monitored so that heart damage can be assessed. Nurses in these units are specially trained to care for people with heart problems and to handle cardiac emergencies.

Drugs may be used to dissolve blood clots in the artery so that heart tissue can be saved. To be effective, these drugs must be given intravenously within six hours of the start of the symptoms of a heart attack. After six hours, most damage is permanent. (People who have bleeding conditions or severe high blood pressure and those who have had recent surgery or a stroke cannot be given these drugs.)

Instead of drug therapy, angioplasty may be performed immediately to clear the arteries. This approach is preferred as primary therapy in heart attacks and has been implemented across the Greater Manchester and Cheshire Cardiac Network.  If the blockages are extensive, then coronary artery bypass surgery may be necessary.

Chances of surviving a heart attack can improve when an individual recognizes the symptoms early and seeks immediate medical attention. One out of every 10 people who have heart attacks, however, die within a year - usually within the first three or four months. Typically, these people continue to have chest pain, abnormal heart rhythms or heart failure. Older people and smaller people tend to not do as well after a heart attack as younger people and larger people. This may be one reason why women tend to fare less well than men after a heart attack - they tend to be both older and smaller. They also tend to wait longer after a heart attack before going to the hospital.

After a heart attack (myocardial infarction), additional tests or treatment may be needed, including:

 

A patient usually receives aspirin, clopidogrel, high dose fish oil, high dose statin, beta blocker and ACE inhibitor.

Get in touch

Dr. Richard Levy MD FACC FESC FRCP

t:
0161 883 0366