Effects of Two Different Catheter Ablation Techniques on Spectral Characteristics of Atrial Fibrillation
Kristina Lemola, MD ,1,
Michael Ting, MS*,
Priya Gupta, MS*,
Jeffrey N. Anker, PhD ,
Aman Chugh, MD,
Eric Good, DO,
Scott Reich, MD,
David Tschopp, MD,
Petar Igic, MD,
Darryl Elmouchi, MD,
Krit Jongnarangsin, MD,
Frank Bogun, MD,
Frank Pelosi, Jr, MD,
Fred Morady, MD,2 and
Hakan Oral, MD,2,*
* Department of Electrical Engineering & Computer Science, University of Michigan, Ann Arbor, Michigan
LSA Chemistry and Applied Physics, University of Michigan, Ann Arbor, Michigan
Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan.
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Figure 1 Circumferential pulmonary vein ablation. Shown is a posteroanterior projection of a 3-dimensional construction of the left atrium and the pulmonary veins (PV). Red tags indicate ablation sites. The PVs were encircled 1 to 2 cm from their ostia, with additional ablation lines in the mitral isthmus and roof. LI = left inferior; LS = left superior; RI = right inferior; RS = right superior.
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Figure 2 Electrogram-guided ablation. Shown is a right anterior-oblique projection of a 3-dimensional construction of the left atrium with caudal angulation. Focal applications of radiofrequency energy were delivered at sites that displayed complex electrograms. No linear lesions were created. Red tags indicate ablation sites. Abbreviations as in Figure 1.
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Figure 3 QRST subtraction. On digitized signals, QRST subtraction was performed as described in the Methods section. The green line represents an averaged QRST complex, and the blue line illustrates the averaged QRST effect (A). Incoming electrocardiogram signal is depicted in panel B. (C) Superimposed incoming electrocardiogram signal (green line) and the electrocardiogram signal after subtraction (red line) are shown. (D) The electrocardiogram signal after QRST subtraction is shown.
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Figure 4 Effect of ablation on dominant frequency. The dominant frequencies recorded in the left atrium in all patients and in patients with paroxysmal and persistent atrial fibrillation (AF) are shown before (open bars) and after (solid bars) circumferential pulmonary vein ablation (CPVA) (A) and electrogram-guided ablation (EGA) (B), respectively. Similar significant reductions in dominant frequency were also observed in the coronary sinus and electrocardiogram lead V1. *p < 0.05 (paired t test).
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Figure 5 Effect of electrogram-guided ablation on dominant frequency (DF). A representative example of fast Fourier transformation analysis of left atrial electrograms before (A) and after (B) electrogram-guided ablation is shown. A 10-s fragment of the 60-s sample was magnified to better illustrate the electrograms in both panels. As described in the text, fast Fourier transformation analysis was performed using samples 60-s long. There was a marked decrease in the DF after electrogram-guided ablation.
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Figure 6 An example of fast Fourier transformation (FFT) analysis of lead V1 before (A) and after (B) electrogram-guided ablation. A 10-s fragment of the 60-s sample was magnified to better illustrate the electrograms in both panels. Electrograms before QRST subtraction are shown in green. After the QRST subtraction, the electrograms are shown in red.
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