Prognostic value role of radiofrequency lesion size by cardiac magnetic resonance imaging on outcomes of ablation in patients with ischemic scar-related ventricular tachycardia

Abstract

Inadequate ablation lesion formation may be responsible for post-ablation ventricular tachycardia (VT) recurrences.We aimed to evaluate whether visualisation of radiofrequency (RF) lesion size by cardiac magnetic resonance imaging (CMR) has any role in predicting adequacy of lesion and in estimating outcome.Retrospective pilot studyNine consecutive patients (8 male, age 60 ± 13 years) underwent ablation for sustained VT because of ischemic scar were evaluated for pre- and post-procedure scar tissue by CMR to characterize ablation lesions. Microvascular obstruction (MVO) surrounded by late gadolinium enhancement was defined as irreversible RF lesion. All patients were followed for at least 6 months for recurrences.Five of the patients had previous inferior myocardial infarction (MI), whereas remaining 4 had anterior MI. Acute procedural success, as defined by termination of the arrhythmia without recurrence in 30 minutes, was attained in all patients. Contrast enhancement and wall motion abnormality in presumed infarction area were confirmed by pre-ablation CMR images. MVO was detected at the reported ablation site in 6/9 patients, all arrhythmia- and symptom-free at median 24 months (range 8–38 months) follow-up. In remaining 3 patients who had VT recurrence (clinical VT in 2, sustain VT with a new morphology in 1), MVO was not detected despite achievement of acute procedural success. There was no correlation with pre-ablation scar size and clinical arrhythmia recurrence.CMR is a useful imaging modality to guide ablation procedures by detecting scar tissue. Additionally MVO seen by post-procedural imaging may be related to adequacy of RF ablation lesions and may correlate with clinical outcome.

Late gadolinium enhancement cardiac magnetic resonance imaging of ablation lesions after postinfarction ventricular tachycardia ablation: Implications for ventricular tachycardia recurrence

“…Similar acute changes on nonweighted images can be seen in animal models of both healthy and postinfarction cardiac tissue 9,12 . In human studies, LGE‐CMR imaging performed 24 h postablation can identify imaging characteristics resembling microvascular obstruction (a region of dark core surrounded by LGE enhancement in native scar tissue) in targeted areas 13 . Our group has recently demonstrated that these acute changes consistent with microvascular obstruction (DCL) persist in the chronic postablation phase and correlate well to areas of myocardial inexcitability at the time of repeat procedures 7 .…”

“…LGE-CMR imaging performed 24 h postablation can identify imaging characteristics resembling microvascular obstruction (a region of dark core surrounded by LGE enhancement in native scar tissue) in targeted areas. 13 Our group has recently demonstrated that these acute changes consistent with microvascular obstruction (DCL) persist in the chronic postablation phase and correlate well to areas of myocardial inexcitability at the time of repeat procedures. 7 The current study highlights the role of these prior ablation lesions as fixed, inexcitable barriers on a modified arrhythmogenic substrate.…”

Persistent microvascular obstruction-like lesion after ventricular tachycardia ablation detected by novel dark-blood late gadolinium enhancement

“…Moreover, there has been evidence that the presence of MVO post-ablation is associated with a lower incidence of VT recurrence. 11 Although different wash-in kinetics of very dense scar might be a possible explanation for the persistence of MVO-like lesions, further studies and histological validation are required to unravel the underlying pathophysiology and evaluate clinical implications. 6…”

Impact of Wideband Late Gadolinium Enhancement Cardiac Magnetic Resonance Imaging on Device‐Related Artifacts in Different Implantable Cardioverter‐Defibrillator Types

“…The practical need for MRI in patients with implantable non-MR conditional devices spans many common clinical scenarios, including assessment of the etiology of nonischemic cardiomyopathy by LGE pattern, substrate detection for ventricular arrhythmia ablation procedures, and prognostic stratification for mortality and morbidity across a spectrum of cardiomyopathies. [12][13][14][15][16][17][18][19][20] Previous studies have also illustrated that there is clinical value in the performance of MRI in patients with a range of cardiac implantable electronic devices, resulting in an altered diagnosis in up to 16% of patients and a change in management in 83% of patients. 21 The advancements made in demonstrating both general safety and clinical utility of MRI in patients with ICDs over the last several years have helped to secure its role as an important diagnostic tool, as well as garner recognition for reimbursement by payer groups.…”