Lown-Ganong-Levine Syndrome in a Patient with Hyperthyroidism

Sugako Ishigaki, Satoshi Higa, Akira Maesato, Ichiro Chinen, Hiroaki Masuzaki, Yenn Jiang Lin, Kazuhito Tatsu, Kotaro Obunai, Yoichi Uechi, Moriichi Sugama, Akira Maesato, Shih Ann Chen

Research output: Contribution to journalArticlepeer-review


Introduction: Hyperthyroidism is a serious medical disorder that can be life threatening and is characterized by a sympathovagal imbalance that can be a cause of rapid AF. However, the electrophysiological characteristics of preexcitation syndrome under hyperthyroid condition are unknown. Methods: N/A. Results: We experienced Lown-Ganong-Levine Syndrome (LGLS) in a 49-year-old woman with Graves' hyperthyroidism. She could not continue to take 1-Methyl-2-mercaptoimidazole because of agranulocytosis and liver dysfunction. Therefore, fractioned radioiodine therapy, radiation, and steroid were started to control hyperthyroidism (TSH: <0.1microIU/mL; free T3: >32.6 to 6.3pg/mL; free T4: >7.77 to 3.57ng/dL). ECG showed short PR interval with normal QRS interval without any delta-wave. She received propranolol to reduce highly symptomatic sinus tachycardia. The electrophysiological study demonstrated atrio-His bypass tract (James bundle) with highly enhanced atrioventricular conduction (1:1 conduction:>300bpm; ERP:200ms). We localized the earliest atrial activation site during RVP as James bundle site at left mid septum, and delivered temperature-controlled RF energy (<10W) on James bundle site. Only 1 RF pulse successfully eliminated atrio-His bypass without any complication and recurrence (follow-up 15 months). Conclusion: LGLS combined with hyperthyroidism demonstrated highly enhanced atrio-ventricular conduction. Careful RF application to James bundle was feasible to cure preexcitation and normalize atrio-ventricular conduction.

Original languageEnglish
Journaljournal of arrhythmia
StatePublished - 2011


  • accessory pathway ablation
  • AV conduction


Dive into the research topics of 'Lown-Ganong-Levine Syndrome in a Patient with Hyperthyroidism'. Together they form a unique fingerprint.

Cite this