title: Overview of electrocardiographic findings and clinical presentation of common cardiac arrhythmias.
abstract: OBJECTIVE
  To review the components and interpretation of the 12-lead electrocardiogram (ECG) and compare and contrast the ECG waveforms and clinical presentation associated with major cardiac arrhythmias.
  
  
  CONCLUSIONS
  A 12-lead ECG reflects the electrical activity of the heart from many different perspectives, and individual leads may reveal conduction disturbances and disorders in a particular area of the heart. Components of the ECG complex include the P wave, QRS complex, and T wave. The timing and amplitude of ECG waveforms provide valuable information about heart rate and rhythm. This information can be used in conjunction with clinical signs and symptoms to differentiate between major arrhythmias, including atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation.
  
  
  CONCLUSIONS
  The monitoring of drug therapies used to treat arrhythmias is facilitated by an understanding of ECG interpretation and the typical clinical characteristics of major cardiac arrhythmias.
authors.affiliation: Department of Pharmacy Practice, Jefferson School of Pharmacy, Thomas Jefferson University, Philadelphia, PA 19107-5233, USA. cynthia.sanoski@jefferson.edu
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Sanoski
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular