Arrythymia

ARRYTHMIA

  • Arrythmia is any abnormal pattern of electrical activity in the heart. Normally the waves of depolarization follow a specific sequence, starting in the S-A node and ending with the contraction of the ventricles. Sometimes another area of the myocardium or conducting system begins to depolarize out of sequence or more rapidly than the S-A node, disrupting the normal electric pattern.
  • Arrhythmias are divided into two general groups: those that result in an increased heart rate and those that result in a decreased heart rate.
  • Arrhythmias are further subdivided into groups according to the location of the ectopic foci or lesion causing arrhythmia.
  • A ‘supraventricular arrhythmia’ indicated that the cause of the problem is above the ventricle.
  • A ‘ventricular arrhythmia’ indicates that the problem originates in the ventricles.
  • The abnormal site of depolarization is called an ectopic focus.
  • An ectopic focus in the ventricles may be indicated on the ECG as a single large bizarre wave. Multiple premature ventricular contractions cause flutter. If the conduction disturbance is severe, the heart has no coordinated contractions and the condition is referred to as ventricular fibrillation.

Last modified: Wednesday, 25 April 2012, 11:14 AM