Brush up on your CPR skills.

If your parent has an arrhythmia, cardiac arrest, also known as sudden cardiac death, is a real concern. Cardiac arrest occurs when the heart suddenly stops functioning, most often due to ventricular tachycardia, bradycardia, or fibrillation. When the heart stops pumping, blood stops circulating through the body and brain. Unless the heart starts beating again, cardiac arrest is fatal. The American Heart Association estimates that more than 300,000 Americans die every year from cardiac arrest.

Although most people in cardiac arrest need defibrillation, cardiopulmonary resuscitation (CPR) can keep some blood flowing until emergency care arrives. If you've never taken a CPR class or it's been a while, now is the time to brush up on your skills. The American Heart Association, which sponsors CPR courses all over the country, modified its recommended CPR method in 2005. To find a class near you, visit their website.

Learn about your parent's pacemaker or defibrillator.

If your parent has a pacemaker or implantable defibrillator, it's important to understand how it works and what needs to be done to maintain it. These devices must be checked regularly to make sure they're working properly, so help your parent keep track of scheduled appointments. You'll also need to learn what your parent's heart rate should be and remind him to check his pulse -- or check it yourself -- regularly to make sure it's within the acceptable range. Your parent should always carry an identification card stating that he has one of these devices.

Cut out caffeine, alcohol, and other substances that affect heart rate.

Your parent should avoid substances that might make his arrhythmia worse:

• Caffeine (found in coffee, tea, and many soft drinks)
• Alcohol
• Tobacco
• Some over-the-counter drugs, such as cough and cold medicines or appetite suppressants
• Cocaine and marijuana

Some prescription drugs, including beta-blockers, can also affect heart rhythm. It's a good idea to discuss all medications your parent is taking -- prescription and over-the-counter drugs and supplements -- with the doctor.