Original Article

Catheter Ablation of Paroxysmal Atrial Fibrillation in Patients with Previous Amiodarone-Induced Hyperthyroidism: A Case–Control Study

  1. EVGENY N. MIKHAYLOV M.D.1,*,
  2. VIKTORYA S. ORSHANSKAYA M.D.1,
  3. ALEXANDER D. LEBEDEV M.D.1,
  4. TAMAS SZILI-TOROK M.D., Ph.D.2,
  5. DMITRY S. LEBEDEV M.D., D.Sc.1

Article first published online: 9 APR 2013

DOI: 10.1111/jce.12140

Additional Information

How to Cite

MIKHAYLOV, E. N., ORSHANSKAYA, V. S., LEBEDEV, A. D., SZILI-TOROK, T. and LEBEDEV, D. S. (2013), Catheter Ablation of Paroxysmal Atrial Fibrillation in Patients with Previous Amiodarone-Induced Hyperthyroidism: A Case–Control Study. Journal of Cardiovascular Electrophysiology. doi: 10.1111/jce.12140

Author Information

  1. 1

    Department of Electrophysiology, Almazov Federal Heart, Blood and Endocrinology Centre, Saint-Petersburg, Russian Federation

  2. 2

    Department of Electrophysiology, Thoraxcenter, Erasmus MC, Rotterdam, the Netherlands

*Address for correspondence: Evgeny Mikhaylov, M.D., 2 Akkuratova St., Saint-Petersburg, 197341, Russian Federation. Fax: +7-812-7023716; E-mail: evgenymikhaylov@gmail.com

  1. E.M. received consultation fee from Biosense Webster. Other authors: No disclosures.

Publication History

  1. Article first published online: 9 APR 2013
  2. Accepted manuscript online: 11 MAR 2013 01:13PM EST
  3. Manuscript Accepted: 4 MAR 2013
  4. Manuscript Revised: 27 FEB 2013
  5. Manuscript Received: 8 JAN 2013

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Keywords:

  • ablation;
  • amiodarone;
  • atrial fibrillation;
  • hyperthyroidism;
  • pulmonary vein isolation

Hyperthyroidism and AF Ablation

Introduction

Many patients with atrial fibrillation (AF) receive amiodarone. Amiodarone-induced hyperthyroidism (AIH) may develop as a complication. We hypothesized that pulmonary vein (PV) isolation in patients with paroxysmal AF and history of AIH may yield a lower success rate.

Methods and Results

Among 704 patients who underwent AF ablation in our center between 2007 and 2010, we identified 20 patients (mean age 58.3 ± 5.0 years; 11 males) with paroxysmal AF and overt AIH in the past. The control group consisted of 40 patients with amiodarone-refractory AF and no thyroid dysfunction. All patients underwent circumferential PV isolation. During redo procedures all tachycardias were targeted for ablation. During a 12-month follow-up, in the AIH group 6 (30%) patients were arrhythmia free after a single procedure, in comparison to 25 (62.5%) controls (P = 0.01). Atrial tachycardia (AT) was registered in 7 (35%) AIH patients and in 1 (2.5%) control patient (P = 0.001). AF recurred in 10 (50%) AIH versus 15 (37.5%) control patients (P = 0.2). Redo ablation was performed in 7 (35%) AIH patients and in 3 (7.5%) non-AIH patients (P = 0.01). During a redo procedure a PV-unrelated tachycardia was diagnosed in 5 (25%) AIH patients (vs 0 in the controls, P = 0.003). After the last performed ablation, 12 (60%) AIH patients and 28 (70%) controls had no recurrence, P = 0.56. AIH was an independent predictor of ATs.

Conclusion

PV isolation alone has a lower efficacy for preventing recurrence in paroxysmal AF in AIH patients. After repeat ablations, overall freedom from tachyarrhythmias is similar to patients with no history of thyroid dysfunction.

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