Circulation. 2006;114:e51-e52
doi: 10.1161/CIRCULATIONAHA.105.606681
(Circulation. 2006;114:e51-e52.)
© 2006 American Heart Association, Inc.
Images in Cardiovascular Medicine |
Epicardial Radiofrequency Catheter Ablation of Ventricular Tachycardia in the Vicinity of Coronary Arteries Is Facilitated by Fusion of 3-Dimensional Electroanatomical Mapping With Multislice Computed Tomography
Katja Zeppenfeld, MD;
Laurens F. Tops, MD;
Jeroen J. Bax, MD;
Martin J. Schalij, MD
From the Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands.
Correspondence to K. Zeppenfeld, MD, PhD, Department of Cardiology, Leiden University Medical Center, PO Box 9600, 2300RC Leiden, Netherlands. Email k.zeppenfeld{at}lumc.nl
A 65-year-old male patient was referred for radiofrequency catheter ablation of a ventricular tachycardia (VT). The patient had a history of an anterior non–Q-wave infarction. Angiography revealed no significant lesions and normal left ventricular (LV) function.
Before ablation, a contrast-enhanced 64-slice computed tomography (CT) scan was acquired. CT data were loaded into an electroanatomical (EA) mapping system (Biosense Webster, Inc, Diamond Bar, Calif) to provide 3-dimensional (3D) CT surface reconstruction of the coronary arteries and LV. Endocardial voltage mapping of the LV was performed during sinus rhythm and the 3D EA mapping data were merged with the 3D surface reconstruction data, allowing real-time visualization of the catheter tip in relation to the surface reconstruction (Figure 1). The clinical VT (cycle length 314 ms) was induced (Figure 2A). Endocardial mapping revealed a wide breakthrough area located in the inferolateral wall preceding the QRS complex by 16 ms, which was suggestive of an intramural or epicardial reentrant circuit (Figure 2B). Therefore, a 3D EA epicardial activation map was obtained after a subxiphoid pericardial puncture. This map revealed an early activated inferolateral epicardial site (52 ms before onset of the QRS complex) representing a target site for ablation(Figure 2D). Damage to a coronary artery is a potential and serious complication of epicardial ablation procedures, and usually coronary angiography is performed to visualize the relationship between radiofrequency target sites and the coronary arteries. This approach, however, requires frequent coronary contrast injections in different projections. The fusion of CT and endocardial and epicardial EA mapping data provides real-time visualization of the catheter tip in relation to the epicardial coronary arteries (Figure 3A). A comparison of CT data with coronary angiographic data was performed, and the relationship between the catheter tip and the coronary artery was confirmed (Figure 3B). A single radiofrequency application at this site terminated the VT without complications. This report illustrates that the fusion of pre-acquired CT images with real-time 3D EA mapping data is accurate and may enhance the safety of epicardial catheter ablation procedures by establishing the relationship between the catheter tip and major coronary arteries.
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Figure 1. Three-dimensional CT surface reconstruction of the aorta, the coronary arteries, and the LV fused with the 3D EA voltage map of the LV in a modified right anterior oblique view (A) and modified left anterior oblique view (B).
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Figure 2. A, Twelve-lead ECG of the VT. B, LV endocardial activation map during VT fused with the CT reconstruction (bottom view). Multifocal early endocardial activation occurred in the inferolateral wall (red color). The catheter tip (gray icon, arrow) indicates a site of early endocardial activation. C, ECG leads II, V1, and V5, right ventricular reference signal (R1–R2), and the signal from the mapping catheter (M1–M2) recorded at the site indicated in B. D, Epicardial activation map during the VT (same view). Note the site of earliest epicardial activation (preceding the endocardial activation by 36 ms) indicated by the catheter tip (gray icon, arrow) and its relationship to the right coronary artery. E, Tracings as in (C). The epicardial electrogram is recorded from the site marked by the arrow in (D).
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Figure 3. The position of the catheter tip (arrow) in relation to the right coronary artery (RCA) at the successful ablation site. A, CT surface reconstruction of the aorta, the coronary arteries, and the LV (in a semitransparent view to allow visualization of the RCA) and the fused epicardial electroanatomical activation map of the VT (in a mesh view to allow visualization of the RCA and the catheter position) in a modified right anterior oblique view (top) and a modified left anterior oblique view (bottom). B, Corresponding angiogram of the RCA in a right anterior oblique view (top) and left anterior oblique view (bottom) showing the tip of the mapping catheter in the epicardial space at the same site as indicated in A.
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Acknowledgments
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Disclosures
None.
