A 61-year-old patient was admitted to the intensive care unit for acute onset of palpitations; he had no cardiac medical history. Surface electrocardiogram showed episodes of wide QRS regular tachycardia, right bundle branch block and left axial deviation aspect ( Figs. 1A, 1B ). Echocardiography and coronarography were normal. Thus the diagnosis of fascicular VT was considered. Recurrences of acute VT longer than 30 seconds occurred despite intravenous antiarrhythmic drug therapy, therefore radiofrequency ablation of VT was carried out. After vein puncture, a 4 mm irrigated ablation catheter was inserted into the left ventricle by the atrial transseptal approach under echographic guidance. Several courses of therapy up to 40 W energy were necessary to treat the VT successfully. Two days later, a first cardiac MRI scan was performed (Siemens Symphony TIM, 1.5 T, Erlangen, Germany). Cine sequences after gadolinium injection showed a heterogeneous mid-left ventricular inferior wall. First-pass perfusion imaging demonstrated an important defect in the radiofrequency ablation area ( Fig. 1 C). LGE sequences revealed a larger than expected central no-reflow core in the ablation area, surrounded by a ring of LGE next to the posterior papillary muscle ( Figs. 1D, 1E ). Three months later, a second cardiac MRI was performed. Cine sequences were normal. On first-pass perfusion imaging, the defect had decreased ( Fig. 1 F). Finally, LGE sequences showed a residual scar, significantly decreased but still associated with a central no-reflow area and ring of LGE ( Figs. 1G, 1H ). This report illustrates the usefulness of cardiac MRI for evaluating the natural history of focal scarring after radiofrequency ablation of VT.
