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Assessment of radiofrequency ablation lesions by CMR imaging after ablation of idiopathic ventricular arrhythmias.

Abstract

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.

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  • Authors+Show Affiliations

    ,

    Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA.

    , , , , , , , , , ,

    Source

    JACC. Cardiovascular imaging 3:3 2010 Mar pg 278-85

    MeSH

    Adult
    Catheter Ablation
    Contrast Media
    Electrophysiologic Techniques, Cardiac
    Equipment Design
    Female
    Gadolinium DTPA
    Heart Ventricles
    Humans
    Magnetic Resonance Imaging, Cine
    Male
    Middle Aged
    Predictive Value of Tests
    Tachycardia, Ventricular
    Time Factors
    Treatment Outcome
    Ventricular Premature Complexes

    Pub Type(s)

    Journal Article

    Language

    eng

    PubMed ID

    20223425