It's very common for a heart attack to disrupt the normal way your heart beats. Your heart may beat too fast, too slow or in an uneven way. Having an irregular heartbeat means that instead of beating evenly (thump thump thump) like the ticking of a watch, it might beat like this: thump thump thumpthump thump.
The most dangerous kinds of abnormal rhythms stop your heart from pumping properly. Or they may make your heart work so hard it can't get enough oxygen. Very fast heart rhythms are more common and more dangerous than very slow ones. They can cause your heart to stop, a condition doctors call cardiac arrest.
Abnormal heart rhythms are also called arrhythmias.
Sometimes the rhythm goes back to normal without treatment. If it doesn't, you'll need medication. If your heart's rhythm is dangerously abnormal, particularly if it's very fast, doctors can reset it quickly by passing an electric current through it. This is called cardioversion. If you need to have this operation, you will have an anesthetic first. Then a machine called a defibrillator will be used to find the abnormal rhythm and give an electric shock to your heart.
If your heart attack is severe, your heart muscle may be left too weak to pump correctly. When it's no longer able to move blood around your body, pressure builds up behind the damaged part of your heart. If the damage is mainly on the left side of your heart, pressure builds up in your lungs. Fluid is forced out of your blood vessels, and you may become short of breath. There are many treatments available. To learn more, see our article on Heart failure.
Doctors call this condition hypoxemia. Usually it means that blood isn't flowing through your lungs very well. If this happens, you'll be given extra oxygen to breath through a face mask. Many people are given oxygen after a heart attack whether or not levels of oxygen in their blood are low.
Your blood pressure may be low after a heart attack for several reasons. For example, low blood pressure is a side effect of some of the drugs that are taken for heart failure. But it also can be a sign that your heart attack was serious, and that your heart can no longer pump blood properly. Which treatment you get depends on what is causing the problem. If you have very low blood pressure, you'll be admitted to an intensive care unit and given drugs by injection to increase your blood pressure.
Cardiogenic shock is a dangerous form of low blood pressure that happens when the heart's main pumping chamber is severely damaged. About 7 out of every 100 people admitted to the hospital with heart attacks have cardiogenic shock.1 Between 50 percent and 80 percent of these patients die before they leave the hospital. Patients with cardiogenic shock are treated in an intensive care unit. Treatments include drugs that make the heart beat more strongly and operations to repair your coronary arteries if they are affected by disease. (Your coronary arteries supply blood to your heart muscle.)
Angina is chest pain that occurs when your heart doesn't get enough oxygen. It's often set off by exercise or emotional stress. If your angina gets worse or you develop it after a heart attack, you may be heading for another heart attack. Your doctor will suggest treatment with drugs, heart operations or surgery to keep your angina under control.
Scar tissue in the heart's wall can balloon out, creating a bulge. Doctors call this an aneurysm. An aneurysm can cause abnormal heart rhythms, low blood pressure or blood clots in the heart. If you develop an aneurysm, you'll need to have drugs to keep your blood from clotting. If you still have the problem after drug treatment, your doctor may suggest surgery.
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This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved. |
