Recurrent ventricular tachycardia originating from the “left ventricular summit” effectively eliminated by stereotactic irradiation – A case report

Figures

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  Figure 1. A: Epicardial local activation time map of the left ventricular summit premature ventricular contractions (PVC) in a posterior-anterior-like (left anterior oblique 155°) projection with the 8-spline mapping catheter (Octaray, Biosense Webster). The color-coded scale visualizes earlier activated regions (red) in comparison to later activated areas (purple). Overlay with a fluoroscopic image in similar projection: angiography of the left main trunk, transseptal sheath, mapping catheter, and implantable cardioverter=defibrillator lead as marked in the image. On the right side 12-lead electrocardiography (ECG) morphology of a normal beat and PVC (∗). B: Ventricular tachycardia morphology in 12-lead ECG.

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  Figure 2. A: Ventricular tachycardia (VT) episodes and implantable cardioverter-defibrillator (ICD) interventions and VT episodes and B: overview of antiarrhythmic drug (AAD) therapy before and after cardiac stereotactic body radiotherapy (cSBRT). Despite AAD therapy with nonselective beta-blocker, amiodarone, and mexiletine, VT burden remained high until addition of continuous intravenous ajmaline. ICD interventions declined immediately after cSBRT, and AAD could be de-escalated. ATP = antitachycardia pacing.

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  Figure 3. A: Segmented late iodine enhancement (LIE) computed tomography (CT) scan with intramural septal and anterior fibrosis (from left to right in right anterior oblique view, left anterior oblique view, and view to the left ventricular summit). Coronary arteries and aorta (red), coronary sinus (blue) implantable cardioverter-defibrillator (ICD) leads (white), LIE-defined fibrosis (light blue), and phrenic nerve (dark green) are depicted. B: Images from the final cardiac stereotactic body radiation therapy (cSBRT) plan from left to right in axial, sagittal, and frontal reconstruction, showing planning target volume in red and the corresponding dose distribution (24 Gy prescribed to the 80% isodose). C: Three-dimensional datasets visualized with mixed-reality device. Left: Electroanatomic bipolar endocardial map without visible scar. Middle: CT segmentation; intramural fibrosis for better visibility in orange. Right: Reconstructed cSBRT planning with target volume calculation (light green), left anterior descending artery and aorta (red), left circumflex artery (yellow), and ICD (blue/yellow).