May also be called: Arrhythmia Dysrhythmia (dis-RITH-mee-ah) is an abnormality in the heart's beat or rhythm caused by electrical impulses that aren't functioning properly. The heart can beat irregularly, too quickly (tachycardia), or too slowly (bradycardia). More to Know An irregular heart rhythm has been described as a heart that flutters, races, or skips a beat. Other symptoms can include lightheadedness, dizziness, shortness of breath, chest pain, sweating, and fainting. Some people experience no symptoms at all and are surprised when dysrhythmia is detected at a routine doctor's visit. Many factors can lead to dysrhythmia, including heart attack, heart and valve disorders, imbalances in blood chemistry and hormone levels, high blood pressure, smoking, caffeine, substance abuse, and even some medications. Keep in Mind Dysrhythmias are often harmless, but can be an indication of a much larger problem (the heart not adequately pumping blood to vital organs), which can be life threatening. If you suspect dysrhythmia, consult your doctor for testing and treatment. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles Arrhythmia (Abnormal Heartbeat) An arrhythmia is an abnormal heartbeat usually caused by an electrical "short circuit" in the heart. Many are minor and not a health threat, but some can indicate a more serious problem. Read More Arrhythmias Arrhythmias are abnormal heartbeats usually caused by an electrical "short circuit" in the heart. Many are minor and not a significant health threat, but others can indicate a more serious problem. Read More Fainting Fainting is pretty common in teens. The good news is that most of the time it's not a sign of something serious. Read More Heart and Circulatory System The heart and circulatory system (also called the cardiovascular system) make up the network that delivers blood to the body's tissues. Read More Heart and Circulatory System The heart and circulatory system are our body's lifeline, delivering blood to the body's tissues. Brush up on your ticker with this body basics article. Read More Your Heart & Circulatory System Your heart is a hard-working muscle. Find out more in this article for kids. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.