Pacing and clinical electrophysiology : PACE
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Pacing Clin Electrophysiol · Jun 1999
Effect of adenosine and verapamil in catecholamine-induced accelerated atrioventricular junctional rhythm: insights into the underlying mechanism.
Accelerated AV junctional rhythm is postulated to be due to enhanced automaticity of a high AV junctional focus. The adenosine response of this rhythm was tested in 17 patients (7 males, 12-83 years). The indications of electrophysiology study were nonspecific palpitation (n = 5), unexplained syncope (n = 6), postablation of accessory pathways (n = 4), and postmodification of AV nodal reentry tachycardia (n = 2). ⋯ In conclusion, the mechanism of catecholamine-induced accelerated AV junctional rhythm is most likely enhanced automaticity, and catecholamine-induced accelerated AV junctional automaticity is sensitive to adenosine and verapamil. Adenosine appears to have differential effects on catecholamine-enhanced AV junctional automaticity and AV nodal conduction. This suggests that, under catecholamine stimulation, adenosine may have different mechanisms of action on AV nodal conduction and automaticity.
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Pacing Clin Electrophysiol · Jun 1999
Case ReportsEarly proarrhythmia during intravenous amiodarone treatment.
We present a case of early (within the first 24 hours) development of malignant torsades de pointes (TdP) associated with intravenous amiodarone therapy. After correction of predisposing factors (heart failure, hypokalemia, digoxin) amiodarone again resulted in torsades. This observation suggests that in patients who have experienced amiodarone-induced proarrhythmia, amiodarone administration under different, more stable clinical conditions may still be hazardous.