Arrhythmias

Basic Facts

Feeling your heart flutter in your chest, even for a moment, can unsettle you—but it’s usually nothing to worry about. An occasional flutter, thumping, or racing feeling is harmless and perfectly normal—in fact, most older adults experience an irregular heartbeat every so often.

What is a Normal Heartbeat?

A normal heart rate for older adults at rest is between 60 and 100 beats per minute. Your heart might beat a little slower if you’re athletic or in good physical shape, or take certain medications.

A normal heart rhythm is regular. Electrical signals in the heart muscle start in the upper chambers (atria) and travel to the lower chambers (ventricles). These signals cause the heart chambers to contract in turn, pumping blood effectively to the rest of the body.

What are Arrhythmias?

Irregular heart rates or rhythms are called arrhythmias. There are many different types of arrhythmias depending on whether the heart is beating too fast or too slow, and whether the irregular rhythm is coming from the atria or the ventricles.

  • Bradycardia is an abnormally slow heart rate
  • Tachycardia is an abnormally fast heart rate
  • Atrial arrhythmias come from the upper heart chambers (atria)
  • Ventricular arrhythmias come from the lower heart chambers (ventricles)
Take irregular heartbeats seriously if you’ve had a heart attack or suffer from coronary artery disease or heart failure.

Types of Arrhythmias

Atrial Fibrillation

Atrial fibrillation happens when the upper (atrial) part of your heart contracts rapidly and irregularly (fibrillates). Atrial fibrillation may be continuous or intermittent. This is the most common irregular heart rhythm in older adults. It occurs in 3 to 5 percent of people over age 65.

Many older adults do not have any symptoms with atrial fibrillation, as long as the heart rate is not too fast. If the atrial fibrillation is too fast, the heart cannot pump blood effectively. This can cause symptoms such as shortness of breath, chest discomfort, dizziness, or lightheadedness.

The irregular rhythm of atrial fibrillation can sometimes cause blood to pool in the heart, leading to the formation of blood clots and a greater risk of stroke. Atrial fibrillation accounts for over 20% of strokes in patients older than 80. 

Bradycardia (slow heart rhythm)

Some people, such as athletes, may have a normally slow heart rate. In older adults, it is common for the heart rate to slow during sleep. Some medications can cause bradycardia, such as beta-blockers, some calcium-channel blockers, and some dementia medications. Bradycardia can also be due to problems with your heart’s electrical signals.

In many older adults, bradycardia does not cause any symptoms. In some people, it may cause symptoms such as fatigue, weakness, lightheadedness or dizziness, shortness of breath, fainting spells, or falls.  

Ventricular tachycardia/Ventricular fibrillation

Ventricular arrhythmias, which come from the lower chambers of the heart (ventricles), are less common but more serious. These arrhythmias most often occur in people with heart disease, such as heart attack, heart failure, or coronary artery disease (blocked arteries in the heart).

Occasional premature or “early” beats from the ventricles are common even in healthy people. If these early ventricular beats become frequent or continuous, they can become life-threatening. Early warning signs may include chest pain, rapid heartbeat, dizziness, or nausea. Because these arrhythmias do not allow the heart to pump effectively, blood stops circulating, and the person becomes unconscious. This is “cardiac arrest.” 

Ventricular fibrillation is a life-threatening emergency. Call 911 and begin CPR.

 

Last Updated November 2016