CASE PRESENTATION
A 38-year-old woman was referred
to our institution due to skipped beats and general fatigue. Atrial
bigeminy was recorded on a surface electrocardiogram (Fig. 1). Although
the detailed morphology of premature atrial contractions (PACs) was
difficult to discern due to its overlap with T waves, positive P waves
in inferior leads and lead V1 suggested that PACs were originated from
the left atrium close to the right superior pulmonary vein
(PV).1 In a 24-hour Holter electrocardiogram,
premature atrial contractions (PACs) occurred at a frequency of 30,880
beats per day. Although 1.25 mg of bisoprolol reduced the PAC burden, it
had to be discontinued due to sinus bradycardia. Given the severity of
her symptoms, we decided to perform catheter ablation for PACs. The
activation map of PACs was created on a high-density mapping system
(CARTO 3 mapping system, Biosense-Webster, Inc., Diamond Bar, CA). After
transeptal puncture, sequential contact mapping of the left atrium was
performed using a multispline mapping catheter (Pentaray; Biosense
Webster, Inc.). The activation map showed a centrifugal activation with
a widespread breakthrough on the anterior wall (Fig. 2A). Local
potentials recorded in the earliest activation site preceded the distal
coronary sinus potential, which served as a reference, by 110 ms (Fig.
2B). In contrast, the local potentials recorded in the right pulmonary
vein were only 10 ms earlier than the reference (Fig. 2C). Where is the
origin of the PACs? What is the optimal ablation strategy for this case?