Arrhythmias An arrhythmia is an abnormal rhythm of the heart that can cause the heart to pump less effectively. Atrial Fibrillation Atrial fibrillation is a type of arrhythmia in which the electrical signals in the atria, or the two small chambers of the heart, are fired in a very fast and uncontrolled manner. Atrial Flutter Atrial flutter is a common type of arrhythmia, where your atria beat more quickly than they should. Although usually not life-threatening, the condition makes it difficult for your heart to pump blood efficiently. Frequently Asked Questions About Pacemakers and Implantable Cardioverter Defibrillators (ICDs) Do cell phones interfere with pacemakers? Do ICDs need to be adjusted? Here are answers to these and other questions. Heart Block When you have heart block, there is interference with the electrical signals that usually move from the top chambers of your heart (the atria) to the bottom chambers of your heart (the ventricles), telling it when to beat. This is known as a conduction disorder. Living with a Pacemaker or Implantable Cardioverter Defibrillator (ICD) With advances in technology, pacemakers and ICDs generally last several years and, in most cases, allow a person to lead a normal life. Long QT Syndrome Your heartbeat is a complex bodily function — many systems must work in unison. Disruptions in the electrical activity of your heart can lead to problems. Long QT syndrome (LQTS) is one of them. Overview of Pacemakers and Implantable Cardioverter Defibrillators (ICDs) A pacemaker is a small device implanted under the skin that sends electrical signals to start or regulate a slow heartbeat. Sick Sinus Syndrome Sick sinus syndrome is a type of abnormal heartbeat, or arrhythmia. If you have this condition, you may have episodes when your heart beats very slowly, stops beating for a short while, or beats very rapidly. Ventricular Fibrillation Ventricular fibrillation (V-fib) is a type of arrhythmia, or irregular heartbeat, that affects your heart’s ventricles. Ventricular Tachycardia Ventricular tachycardia is a rapid heart rate that begins in your heart’s lower chambers, or ventricles. Experts describe it as three or more heartbeats in a row, at a rate of more than 120 beats a minute. Wolff-Parkinson-White Syndrome Wolff-Parkinson-White syndrome (WPW) is a type of abnormal heartbeat. If you have WPW, you may have episodes of tachycardia, when your heart beats very rapidly. Automated External Defibrillator An AED is a small, portable, battery-powered machine with a computer in it. The machine detects heart activity. It can give an electric shock to someone if needed.