Theophylline Multifocal atrial tachycardia

Multifocal atrial tachycardia associated with theophylline therapy has been identified in 16 patients. All patients had chronic obstructive pulmonary disease and had serum theophylline levels 12.5-60.0 (mean 267) mg/L. Theophylline was withdrawn in 15 patients with serum theophylline > 14 mg/L. As serum theophylline fell atrial and ventricular rates slowed. The mean changes were 152 to 104 beats/min and 148 to 104 beats/min, respectively. Atrial ectopic activity and multifocal atrial tachycardia were also both reduced. Five patients underwent rechallenge with intravenous aminophylline (0.5-2.0 mg/kg/hour) . As serum theophylline levels increased each patient showed a gradual increase in the number of premature contractions, fas ler and more chaotic ectopic activity and finally the development of muUifocal atrial tachycardia . Serum theophylline levels associated with the development of tachycardia were 16-25 mg/L.

The role of theophyll ine in the development of increased atrial activi ty and mullifocal atrial tachycardia was confirmed in this study. Of significance was the lact that these changes occurred at serum theophylline levels within therapeutic levels. Theophylline may preclpilate multi/ocal alrial tachycardia and treatment should be carefu lly considered especiany in patients with respiratory insufficiency and multi focal atrial tachycardia. LevIne. J.H. : Michael. J.R. and Guarnlero T Lancel 1 12·14 (5 Jan 1985)