Case 2
A 11-year-old boy with Ebstein anomaly, who underwent tricuspid valve
replacement using a 27 mm St Jude prothesis when he was nine, underwent
ablation due to drug resistant atrial flutter. ECG revealed an atrial
rate of 250 ms and 4:1 AV conduction. Echocardiography revealed no
paravalvular regurgitation from prosthetic valve, thrombosis nor
increase in transvalvular mean doppler gradient of the prosthetic valve,
with a normal ventricular systolic function. He had history of several
CV under medical treatment of amiodarone and propranolol. Since
decapolar reference catheter could not be inserted into the coronary
sinus, a quadripolar catheter (Esolo FIAB, Italy) was inserted into
esophagus as a reference catheter. The EnSite⢠NavX Precision system
(St. Jude Medical St. Paul, MN, USA) is used as three dimensional
mapping system and Tacticath TM Quartz Contact Force
(St. Jude Medical St. Paul, MN, USA) for mapping and ablation procedure.
Widespread scar areas were detected in the posterolateral region of
right atrium. The patient had three distinctive type of tachycardia with
different cycle lengths, two reentries detected involving scar areas in
right atrium posterior and superior region. Ablation lines were applied
on that region in low voltage scar areas forming isthmuses for the
reentries. Since ablation of myocardium under mechanical valve could not
be performed due to loss of contact of catheter. CTI dependent flutter
could not be accomplished even though ablation line extended beyond
mechanical valve. Even though, CTI ablation could not be accomplished,
sinus rhythm achieved under medical treatment of flecainide and
propranolol and remained for two years after ablation procedure.