Limitation
There were several limitations to our study. First, this is a study with a small number of patients. Second, it is possible that the LVA and ACZ varied with heart rate or pacing site. Atrial tachyarrhythmias occur by premature atrial beat during sinus rhythm where electrical activity originating from the sinus node spreads towards the superior vena cava and right atrial appendage. Moreover, a previous study reported that LA activation pattern did not differ regardless of site of earliest LA breakthrough.15 Hence, using LA activation during high right atrial pacing is acceptable. Third, our study completed 3-D mapping after the PV isolation. Fourth, there was no control group in our study. To evaluate our hypothesis, a control group is crucially important. Lastly, the criteria for defining the ACZ was different from previous studies.