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Biomedical subjects

Zian H Tseng

Publications and source records attributed to Zian H Tseng.

5 recordsLinked to original sources

Repeat transseptal catheterization after ablation for atrial fibrillation.

INTRODUCTION: A substantial number of patients require a second left atrial procedure after ablation for atrial fibrillation (AF), either for left atrial flutter or recurrent AF. The success and complication rates of repeat transseptal catheterization in these patients are unknown. The aim of this study was to determine the difficulty and/or success rates of repeat transseptal catheterization after left atrial ablation for AF. METHODS AND RESULTS: Consecutive patients undergoing repeat left atrial procedures after ablation for AF over a 1-year period were enrolled. Difficulties with, success rates, and complications of the first and second transseptal catheterizations were recorded. Sixteen patients underwent a repeat transseptal catheterization. Of the 4 in whom the first procedure was performed with an ablation catheter across a patent foramen ovale (PFO), 3 required a transseptal puncture for their repeat procedure. The remaining 12 underwent transseptal puncture without difficulty for their first procedure, and, despite the same operators for each patient, the repeat transseptal was noted to be difficult in 5. Of those 5, the transseptal puncture was unsuccessful due to increased interatrial septal thickness in 2 patients. One repeat transseptal attempt was aborted after posterior right atrial puncture with the transseptal needle occurred, attributed to distorted interatrial septal anatomy not observed prior to the first case. CONCLUSIONS: Compared with the first procedure, repeat transseptal catheterization after ablation for AF, whether initially performed across a PFO or via a transseptal puncture, is more difficult, less often successful, and potentially associated with more complications.

Atrial Fibrillation↗

Famotidine and long QT syndrome.

Numerous drugs have been implicated in causing a prolonged QT interval and Torsades de pointes. However, the association of famotidine and acquired long QT syndrome has rarely been reported. We report 2 cases of famotidine-associated acquired long QT syndrome.

Aged↗

Catecholamine dependent accessory pathway automaticity.

Automaticity from extra nodal accessory pathways appears to be rare. We report the case of a man with the WPW syndrome who presented for repeat electrophysiological study and catheter ablation. After successful ablation of a para-Hisian accessory pathway, an isoproterenol challenge produced an accelerated wide complex rhythm that was dissociated from sinus rhythm and matched the previous pattern of maximal preexcitation. This automatic rhythm was transient and dependent on catecholamine administration. One month after successful ablation, an exercise treadmill test (ETT) did not demonstrate any pre-excitation or ectopy.

Adult↗