Efficacy of oral diltiazem to control ventricular response in chronic atrial fibrillation at rest and during exercise
Journal of the American College of Cardiology
Although digpxin is often the first choice for control of ventricular response in chronic atrial fibrillation, it fails to slow exercise rates. Diltiazem, a calcium channel antagonist that slows atrioventricular conduction, was administered to 16 patients who failed to achieve adequate rate control on low level exercise testing despite digoxin therapy. Therapeutic response to diltiazem was assessed with submaximal and maximal exercise tests and 24 hour ambulatory electrocardiographic monitoring. During the diltiazem treatment phase, ventricular response at rest diminished (96 ± 17 versus 69 ± 10 beats/min, p < 0.001) as did rate during submaximal exercise (155 ± 28 versus 116 ± 26, p < 0.001), maximal exercise (163 ± 14 versus 133 ± 26, p < 0.001) and average ventricular response during 24 hour monitoring (87 ± 13 versus 69 ± 10, p < 0.001). Rate at rest decreased 26 ± 15% and submaximal exercise rate diminished 24 ± 12%. Thirteen (81%) of the 16 patients exhibited at least 15% slowing of rate at rest and during submaximal exercise. Eleven patients (69%) reported alleviation of symptoms. There was no change in serum digoxin levels during diltiazem treatment (1.3 ± 0.5 versus 1.3 ± 0.6 ng/ml, p = NS). On withdrawal of diltiazem, ventricular response returned to baseline values. Diltiazem is an effective agent for control of ventricular response, both at rest and during exercise, in digoxin-treated patients with chronic atrial fibrillation. © 1987, American College of Cardiology Foundation. All rights reserved.
Steinberg, J., Katz, R., Bren, G., Buff, L., & Jacob Varghese, P. (1987). Efficacy of oral diltiazem to control ventricular response in chronic atrial fibrillation at rest and during exercise. Journal of the American College of Cardiology, 9 (2). http://dx.doi.org/10.1016/S0735-1097(87)80396-0