ISSN:
1540-8167
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Atrial Torsades de Pointes?Introduction: In this study, we investigated whether the potassium channel blocker, cesium chloride (CsC1), which is capable of producing early afterdepolarizations (EADs) and polymorphic ventricular tachyarrhythmias resembling torsades de pointes, might exert similar effects in the atria. Methods and Results: In nine anesthetized open chest dogs, 5 mL of CsC1 in incremental doses (0.05, 0.1, 0.15, 0.2, 0.25 mM/mL) was injected into the sinus node artery to induce atrial arrhythmias. A polymorphic atrial tachycardia (P-AT) apparently triggered by an EAD and degenerating into atrial fibrillation resulted after CsC1 administration in six dogs, but not in the remaining three dogs at any dose of CsC1. The P-AT developed during a normal atrial rate (110 ± 13.5 beats/min) on six occasions and during atrial bradycardia (58.6 ± 17.9 heat/min) five times. P-AT that occurred during a normal atrial rate had the last normal P wave temporally closely related to ventricular activation, with a VA interval of almost zero (1.3 ± 3.3 msec), whereas P-AT induced from an atrial hradycardia had no relation to ventricular activation. The%EAD in the atrial hradycardia group (13.9 ± 2.5) exceeded that in the normal atrial rate group (10.9 ± 1.8) (P 〈 0.05). Conclusion: CsC1 induces atrial EADs that provoke P-AT that degenerates into atrial fibrillation. P-AT has some characteristics similar to ventricular torsades de pointes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1540-8167.1998.tb00137.x
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