Who Is At Risk for an Arrhythmia?

Millions of Americans have arrhythmias. They're very common in older adults. About 2.2 million Americans have atrial fibrillation (a common type of arrhythmia that can cause problems).

Most serious arrhythmias affect people older than 60. This is because older adults are more likely to have heart disease and other health problems that can lead to arrhythmias.

Older adults also tend to be more sensitive to the side effects of medicines, some of which can cause arrhythmias. Some medicines used to treat arrhythmias can even cause arrhythmias as a side effect.

Some types of arrhythmia happen more often in children and young adults. Paroxysmal supraventricular tachycardias (PSVTs), including Wolff-Parkinson-White syndrome, are more common in young people. PSVT is a fast heart rate that begins and ends suddenly.

Major Risk Factors

Arrhythmias are more common in people who have diseases or conditions that weaken the heart, such as:

• Heart attack
• Heart failure or cardiomyopathy, which weakens the heart and changes the way electrical signals move around the heart
• Heart tissue that's too thick or stiff or that hasn't formed normally
• Leaking or narrowed heart valves, which make the heart work too hard and can lead to heart failure
• Congenital heart defects (problems that are present at birth) that affect the heart's structure or function

Other conditions also can increase the risk for arrhythmias, such as:

• High blood pressure
• Infections that damage the heart muscle or the sac around the heart
• Diabetes, which increases the risk of high blood pressure and coronary heart disease
• Sleep apnea (when breathing becomes shallow or stops during sleep), which can stress the heart because the heart doesn't get enough oxygen
• An overactive or underactive thyroid gland (too much or too little thyroid hormone in the body)

Also, several other risk factors can increase risk for arrhythmias. Examples include heart surgery, certain drugs (such as cocaine or amphetamines), or an imbalance of chemicals or other substances (such as potassium) in the bloodstream.