Assessment of Radiofrequency Ablation Lesions by CMR Imaging After Ablation of Idiopathic Ventricular Arrhythmias

作者：Ilg Karl; Baman Timir S; Gupta Sanjaya K; Swanson Scott; Good Eric; Chugh Aman; Jongnarangsin Krit; Pelosi Frank Jr; Crawford Thomas; Oral Hakan; Morady Fred; Bogun Frank^*

来源：JACC: Cardiovascular Imaging , 2010, 3(3): 278-285.

DOI：10.1016/j.jcmg.2009.09.028

• ventricular arrhythmias
• cardiac magnetic resonance imaging
• radiofrequency ablation

OBJECTIVES To identify and characterize ablation lesions after radiofrequency (RF) catheter ablation of ventricular arrhythmias in patients without prior myocardial infarction and to correlate the ablation lesions with the amount of RF energy delivered and the clinical outcome.
BACKGROUND Visualization of RF energy lesions after ablation of ventricular arrhythmias might help to identify reasons for ablation failure.
METHODS In a consecutive series of 35 patients (19 women, age: 48 +/- 15 years, ejection fraction: 0.56 +/- 0.12) without structural heart disease who were referred for ablation of ventricular arrhythmias, cardiac magnetic resonance imaging with delayed enhancement was performed before and after ablation. Ablation lesions were sought in the post-ablation cardiac magnetic resonance images. The endocardial area, depth, and volume of the lesions were measured. Lesion size was correlated with the type of ablation catheter used and the duration of RF energy delivered.
RESULTS In 25 of 35 patients (71%), ablation lesions were identified by delayed enhancement a mean of 22 +/- 12 months after the initial ablation procedure. The mean lesion volume was 1.4 +/- 1.4 cm(3), with a mean endocardial area of 3.5 +/- 3.0 cm(2). The largest lesions (mean volume of 2.9 +/- 2.1 cm(3) with an endocardial area of 6.4 +/- 3.4 cm(2)) were identified in patients in whom the arrhythmias originated in the papillary muscles. Ablation duration correlated with lesion size (r = 0.67, p < 0.001). There was no difference in lesion volume with irrigated versus nonirrigated ablation catheters (1.0 +/- 0.73 vs. 2.0 +/- 2.1 cm(3), p = 0.09). Identification of ablation lesions in patients with a failed procedure identified the sites where ineffective RF energy lesions were created.
CONCLUSIONS RF ablation lesions can be detected long term after an ablation procedure targeting ventricular arrhythmias in patients without previous infarction. Lesion size correlates with the amount of RF energy delivered and is largest when a targeted arrhythmia originates in a papillary muscle.

• 出版日期2010-3