Heart attacks that damage critical or large areas of the heart tend to cause more problems (complications) later. If only a small amount of heart muscle dies, the heart may still function normally after a heart attack.

The chance that these complications will occur depends on the amount of heart tissue affected by a heart attack and whether medicines are given during and after a heart attack to help prevent these complications. Your age, general health, and other things also affect your risk of complications and death.

About half of all people who have a heart attack will have a serious complication. The kinds of complications you may have depend upon the location and extent of the heart muscle damage. The most common complications are:

• Heart rhythm problems, called arrhythmias. These include heart block, atrial fibrillation, and possibly deadly ventricular tachycardia or ventricular fibrillation.
• Heart failure, which can be short-term or can become a lifelong condition. Scar tissue eventually replaces the areas of heart muscle that are damaged by a heart attack. Scar tissue affects your heart's ability to pump as well as it should. Damage to the left ventricle can lead to heart failure.
• Heart valve disease.
• Pericarditis, which is an inflammation around the outside of the heart.

Treatment for heart rhythm problems

If the heart attack caused an arrhythmia, you may take medicines or you may need a cardiac device such as a pacemaker.

If your heart rate is too slow (bradycardia), your doctor may recommend a pacemaker.

Heart Rate Problems: Should I Get a Pacemaker?

If you have abnormal heart rhythms or if you are at risk for abnormal heart rhythms that can be deadly, your doctor may recommend an implantable cardioverter-defibrillator (ICD).

Heart Rhythm Problems: Should I Get an ICD?

For information on different types of arrhythmias, see:

• Atrial Fibrillation.
• Bradycardia (Slow Heart Rate).
• Ventricular Tachycardia.