"Torsade de pointes" in patients with structural heart disease and atrial fibrillation treated with amiodarone, beta-blockers, and digitalis.
Amiodarone is one of the most efficient and safe antiarrhythmic drugs in the treatment of atrial fibrillation (AF). Yet, though rare, proarrhythmic effects remain a clinical problem. We present three cases of amiodarone-associated "Torsade de pointes" tachycardia (Tdp) in patients treated concomitantly with heart rate controlling medication for AF. Amiodarone loading therapy was started for the treatment of tachyarrhythmic AF in all the three patients. All presented with a history of coronary heart disease, resulting in a severely reduced left ventricular ejection fraction in two patients. One received oral amiodarone loading, in the others, amiodarone was administered intravenously because of hemodynamically relevant AF episodes. Amiodarone therapy was combined with a heart rate controlling medication including a beta-blocking agent and digitalis in all the cases. All the subjects suffered from clinically relevant Tdp in the early run after initiation of amiodarone loading (max. 48 hours). The mean QTc in all patients before induction of Tdp was prolonged. The present case reports imply that amiodarone in combination with beta-blocker/digitalis therapy may be associated with an elevated proarrhythmic risk in selected patients with structural heart disease and AF.
Schrickel
Jan W
JW
Department of Medicine/Cardiology, University of Bonn, Bonn, Germany. jan.schrickel@ukb.uni-bonn.de
Schwab
Joerg O
JO
Yang
Alexander
A
Bitzen
Alexander
A
Lüderitz
Berndt
B
Lewalter
Thorsten
T
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D000638:Amiodarone / Q000009:adverse effects* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D003324:Coronary Artery Disease / Q000150:complications / Q000188:drug therapy*; D004071:Digitalis Glycosides / Q000009:adverse effects* / Q000627:therapeutic use; D004338:Drug Combinations; D006801:Humans; D008297:Male; D008875:Middle Aged; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000175:diagnosis*
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D004071:Digitalis Glycosides; D004338:Drug Combinations; D000638:Amiodarone; C034791:digitalin