<Tr> <Th> Treatment </Th> <Td> Medications, medical procedures (pacemaker), surgery </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> Millions </Td> </Tr> <P> Heart arrhythmia (also known as arrhythmia, dysrhythmia, or irregular heartbeat) is a group of conditions in which the heartbeat is irregular, too fast, or too slow . A heart rate that is too fast--above 100 beats per minute in adults--is called tachycardia and a heart rate that is too slow--below 60 beats per minute--is called bradycardia . Many types of arrhythmia have no symptoms . When symptoms are present these may include palpitations or feeling a pause between heartbeats . In more serious cases there may be lightheadedness, passing out, shortness of breath, or chest pain . While most types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure . Others may result in cardiac arrest . </P> <P> There are four main types of arrhythmia: extra beats, supraventricular tachycardias, ventricular arrhythmias, and bradyarrhythmias . Extra beats include premature atrial contractions, premature ventricular contractions, and premature junctional contractions . Supraventricular tachycardias include atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia . Ventricular arrhythmias include ventricular fibrillation and ventricular tachycardia . Arrhythmias are due to problems with the electrical conduction system of the heart . Arrhythmias may occur in children; however, the normal range for the heart rate is different and depends on age . A number of tests can help with diagnosis including an electrocardiogram (ECG) and Holter monitor . </P>

Is there a difference between arrhythmia and dysrhythmia