Evidence supporting a new rate threshold for multifocal atrial tachycardia

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 quasi-diagnostic tachycardia threshold for MAT is conventionally set at 100 beats/min. Nevertheless, this threshold has not been demonstrated to be optimal. Hypothesis: 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. Methods and 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). Conclusion: The rate threshold of MAT should be reduced from 100 to 90 beats/min.