Abstract 13464: Dominant Frequency Gradient between the Right and Left Atrium is Useful to Identify the Arrhythmogenic Superior Vena Cava after Pulmonary Vein Isolation
The superior vena cava (SVC) plays an important role for the maintenance of atrial fibrillation (AF) after pulmonary vein isolation (PVI) in some patients. Although additional SVC isolation may reduce the recurrence of AF, it may also cause complications such as sinus node dysfunction and phrenic nerve paralysis. We hypothesized that SVC isolation is effective and necessary in the cases whose AF cycle length in right atrium (RA) is shorter than that in left atrium (LA) after PVI. To test this, we compared the dominant frequency (DF) between RA and LA after PVI. This study enrolled consecutive 24 AF patients (mean age, 59±11; paroxysmal AF, 12 patients) in whom AF was sustained after PVI and underwent additional SVC isolation. AF was induced by burst pacing from coronary sinus or pulmonary vein in all paroxysmal AF patients. During AF, 5 RA and 5 coronary sinus bipolar electrograms were continuously recorded and FFT analysis was performed in 5-second segments. In 11 patients (Group A; mean age, 60±7; paroxysmal AF, 9 patients) in whom AF was terminated during SVC isolation, the DF was significantly higher in RA than in LA (5.41±0.29 vs. 5.03±0.23 Hz, P<0.01). On the contrary, in the other 13 (Group B; mean age, 58±13; paroxysmal AF, 3 patients) in whom AF was not terminated by SVC isolation, there was no significant difference in the DF between RA and LA (5.45±0.48 vs. 5.49±0.43 Hz, P=0.7703). DF gradient calculated by subtraction of the DF in LA from RA was significantly greater in Group A than B (0.39±0.10 vs. -0.03±0.09 Hz, P<0.01). The analysis of receiver operating characteristic curve indicated that when DF gradient was increased to >0.2 Hz, AF was terminated by SVC isolation with 91% sensitivity and 69% specificity. Area under the curve was 0.86. Thus, SVC isolation may be effective in patients with higher DF in RA than in LA after PVI. DF gradient between RA and LA may be useful to identify whether SVC is arrhythmogenic after PVI.
- © 2013 by American Heart Association, Inc.