الفهرس 
Cardiac arrhythmiaOnly 14 pages are availabe for public view
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Abstract
Arrhythmias or heart rhythm problems are experienced by many individuals worldwide. Most people with an abnormal heart rhythm can lead a normal life if it is properly diagnosed. There are four main types of arrhythmia: extra beats, supraventricular tachycardias, ventricular arrhythmias, and bradyarrhythmias.Episodes of SVT are usually paroxysmal and characterized by abrupt onset and termination.This group consists of atrioventricular nodal reentry tachycardia, atrioventricular reciprocating tachycardia,atrial tachycardia, atrial flutter and atrial fibrillation. Most SVTs occur at rest, although exercise can be a trigger in some patients. The average duration is 10 to 15 minutes; however, some episodes last only one to two minutes, while others persist for hours.Both AVRT and AVNRT are reentrant rhythms (two distinct pathways for conduction with unidirectional block in one of the two pathways), which allows an electrical impulse to cycle repetitively resulting in rapid and regular ventricular contractions.The diagnosis of SVT is based on clinical suspicion that includes a history of paroxysmal episodes of palpitations, and a physical examination demonstrating tachycardia during a symptomatic episode. Electrocardiography (ECG) demonstrating tachycardia with a narrow QRS complex is consistent with the diagnosis. However, capturing an episode on standard ECG is sometimes difficult, and the diagnosis may only be confirmed through the use of other studies such as ambulatory monitoring, cardiopulmonary exercise testing, and electrophysiology.