PMC5399203_01
A 12-lead electrocardiogram at rest (heart rate 90 bpm) (A), on minimal exertion (heart rate 120 bpm) (B), under intravenous administration of a beta-adrenergic agonist (heart rate 150 bpm) (C), and after delivering radiofrequency energy (heart rate 130 bpm) (D). bpm: beats per minute
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His P-wave axis during the tachycardia was similar to that during sinus rhythm, and tall P-waves were noted during the tachycardia, especially in leads II, III, and aVF (Fig. 1A and B) on the 12-lead electrocardiogram. His heart rate (HR) was greater than 100 beats per minute (bpm) with minimal exertion (Fig. 1B), the 24-h Holter monitoring demonstrated a mean HR of greater than 90 bpm with palpitations, and he exhibited an HR of greater than 130 bpm within the first 90 seconds of a standard Bruce protocol on the treadmill test (Table). IST with tall P-waves during the tachycardia in leads II, III, and aVF was steadily induced by a beta-adrenergic agonist (Fig. 1C).
Right anterior oblique view of the EnSiteTM voltage (A, B) and activation (C) maps showing the right atrium (RA). The breakout sites (BOSs) with a heart rate (HR) of less (green circle with 80 and 90) or more (yellow circle with 100, 110, 120, 130, 140, and 150) than 100 bpm could easily and clearly be separated (A, C). The area in the red circle with the dotted line was the target site for the radiofrequency catheter ablation (RFCA) (A, B). After the RFCA, the BOSs observed during an HR of more than 100 bpm (yellow circles with 100, 110, 120, 130, 140, and 150) completely moved to the sites for an HR of less than 100 bpm (green circles with 80 and 90) (B, C). bpm: beats per minute
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The activation maps from the EnSite  images interestingly demonstrated that the breakout sites (BOSs) for HR of less or more than 100 bpm could easily and clearly be separated (Fig. 2A and C). After delivering radiofrequency energy for 30 to 60 seconds with a preset temperature of 50C and power limit of 30 W at the BOSs during an HR of more than 100 bpm, the BOSs observed during an HR of more than 100 bpm completely moved to the sites for an HR of less than 100 bpm (Fig. 2B and C), in accordance with the disappearance of the tall P-waves in leads II, III, and aVF (Fig. 1D).