title: Evidence supporting a new rate threshold for multifocal atrial tachycardia.
abstract: BACKGROUND
  Exacerbation of chronic obstructive pulmonary disease (COPD) is overwhelmingly represented among patients presenting with multifocal atrial tachycardia (MAT) and has been used as a paradigm for such patients. The quasidiagnostic tachycardia threshold for MAT is conventionally set at 100 beats/min. Nevertheless, this threshold has not been demonstrated to be optimal.
  
  
  OBJECTIVE
  Using COPD as a paradigm for MAT, clinical experience led to the hypothesis that MAT with a tachycardia threshold < 100 beats/min could be more closely associated with COPD exacerbation.
  
  
  RESULTS
  We reviewed 60 consecutive patients with multifocal atrial arrhythmia (MAA) at any heart rate and found a better association between the incidence of COPD exacerbations and MAT using a tachycardia threshold of 90 beats/min (p = 0.00036) than when using a threshold of 100 beats/min (p = 0.515).
  
  
  CONCLUSIONS
  The rate threshold of MAT should be reduced from 100 to 90 beats/min.
authors.affiliation: Department of Medicine, Worcester Medical Center, and Division of Cardiovascular Medicine, University of Massachusetts Medical Center, Worcester, MA 01655, USA.
authors.forename: Seema A
authors.initials: SA
authors.lastname: Kothari
authors.forename: Sirin
authors.initials: S
authors.lastname: Apiyasawat
authors.forename: Navaid
authors.initials: N
authors.lastname: Asad
authors.forename: David H
authors.initials: DH
authors.lastname: Spodick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005260:Female; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis*; D012189:Retrospective Studies; D012307:Risk Factors; D013612:Tachycardia, Ectopic Atrial / Q000150:complications / Q000175:diagnosis*