Near Doubling of Heart Rate After Intravenous Verapamil for Treatment of Atrial Fibrillation Without Preexcitation |
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Authors: | YELENA S.K. ORLOV MICHAEL A. BRODSKY MICHAEL V. ORLOV BYRON ALLEN |
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Affiliation: | University of California Irvine Medical Center, Department of Medicine, Division of Cardiology, Orange, California |
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Abstract: | Initial treatment of atrial fibrillation often involves pharmacological therapy to control ventricular response. While verapamil is usually safe and effective when used for this purpose, we report a proarrhythmic response. In this report a 30-year-old female presented with paipitations associated with atrial fibrillation and a ventricular response of 145 beats/min. Soon after she was given 5 mg of intravenous verapamil her ECG documented a regular wide QRS tachycardia at 290 beats/min. After 7 seconds the rhythm returned to an irregularly irregular narrow QRS tachycardia at 125–150 beats/min. At a later electropliysiology study there was neither evidence of preexcitation norinducible supraventricular or ventricular tachycardia. These data suggest that verapamil may have been associated with acceleration of the heart rate. The mechanism of proarrhythmia may be reiated to an aiteration in the atrial rhythm from atriaL fibrillation to atrial flutter, with additional factors as well. |
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Keywords: | verapamil atriai fibrillation atrial flutter proarrhythmia |
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