Intravenous amiodarone homogeneously prolongs ventricular repolarization in patients with life-threatening ventricular tachyarrhythmia. Issue 2 (August 2015)

• Record Type: Journal Article
• Authors: Kotake, Yasuhito; Kurita, Takashi; Akaiwa, Yuzuru; Yasuoka, Ryobun; Motoki, Koichiro; Kobuke, Kazuhiro; Iwanaga, Yoshitaka; Miyazaki, Shunichi
• Is Part Of: Journal of cardiology. Volume 66:Issue 2(2015:Aug.)
• Page Start: 161
• Page End: 167
• Publication Date: 2015-08
• Subjects: Cardiology -- Periodicals; 616.12
• DOI: 10.1016/j.jjcc.2014.10.004
• Languages: English
• ISSNs: 0914-5087

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <title id="sect0010">Background</title> <p id="spar0005">The most critical adverse effects of class III drugs are marked QT prolongation and torsade de pointes. Even though intravenous amiodarone (iv-Amio) is a representative class III drug, it peculiarly inhibits both clinical ventricular tachycardia/fibrillation (VT/VF) and proarrhythmic effects.</p> <p id="spar0010">To test the hypothesis that iv-Amio homogeneously prolongs repolarization, we evaluated electrocardiographic changes before and during short-term amiodarone therapy, focusing closely on the ventricular dispersion of repolarization.</p> </sec> <sec> <title id="sect0015">Methods</title> <p id="spar0015">Twenty-seven consecutive patients treated with iv-Amio for VT/VF as a first-line antiarrhythmic therapy were enrolled in this study. Twelve-lead electrocardiography was recorded before and during amiodarone therapy to evaluate the following electrocardiographic intervals: R–R, QRS, QT, QRS to T-peak (QTp), and T-peak to T-end (Tp-e; as an index of dispersion of repolarization). Repolarization indices were corrected to the heart rate by Bazett's method (QTc, c-QTp, c-Tp-e).</p> </sec> <sec> <title id="sect0020">Results</title> <p id="spar0020">Amiodarone suppressed VT/VF in 19/27 (70%) patients without conferring any proarrhythmic effect. The QTc, c-QTp, and R–R interval were significantly prolonged during amiodarone (476 ± 45 ms vs 511 ± 45 ms, <italic>p</italic> < 0.05; 338 ± 40 ms vs 364 ± 35 ms, <italic>p</italic> < 0.05; 762 ± 272 ms vs 870 ± 189 ms, <italic>p</italic> < 0.05; respectively), whereas the c-Tp-e and QRS durations did not change significantly (139 ± 33 ms vs 145 ± 41 ms, <italic>p</italic> = 0.25; 96 ± 20 ms vs 97 ± 21 ms, <italic>p</italic> = 0.33; respectively).</p> </sec> <sec> <title id="sect0025">Conclusions</title> <p id="spar0025">Iv-Amio homogeneously prolongs repolarization and properly inhibits original VT/VF recurrence without inducing torsade de pointes.</p> </sec> </abstract>