PMC6342609_01
A: A 2-dimensional echocardiogram (modified parasternal long-axis view) depicting the extent of the intramyocardial cardiac mass localized inferolaterally. B: Positron emission tomography and computed tomography with F-fluorodeoxyglucose image showing low uptake of F-fluorodeoxyglucose within the tumor (maximum standardized uptake value of 3.24 and mean value of 2.0 are within the range typical for benign tumors). C: The extent of the tumor as seen during cardiac surgery and cryoablation probe at the border zone of the tumor.
gr1.jpg
PMC6342609_01_gr1.jpg
fig1
A transthoracic echocardiogram showed nondilated left ventricle with normal ejection fraction (left ventricular end-diastolic diameter 51 mm) with large intramyocardial mass in the inferolateral wall (29 x 56 mm) (Figure 1A). Positron emission tomography and computed tomography with F-fluorodeoxyglucose revealed the defect in F-fluorodeoxyglucose accumulation corresponding with an intramyocardial mass inferolaterally (60 x 47 x 30 mm) surrounded on the lateral margin by a hypodense envelope without tracer accumulation (Figure 1B). Therefore, encircling cryoablation was performed with the prospect of modification of the border zone around the tumor (Figure 1C).
A: Electrocardiogram recordings of predominant clinical ventricular tachycardia with right bundle branch block morphology and left axis deviation, suggestive of origin close to the lower septum. B: Three-dimensional electroanatomical bipolar voltage map of the left ventricle (modified left lateral view) showing normal voltage (violet color) and 2 regions of catheter ablation close to the posteromedial papillary muscle and the other superiorly in the basal part of ventricle (black arrows).
gr2.jpg
PMC6342609_01_gr2.jpg
fig2
However, 6 months after the procedure, the patient presented with minimally symptomatic, incessant VTs of 2 morphologies, below the detection limit of the ICD (Figure 2A). Owing to the occurrence of 2 morphologies of VT, 2 regions were targeted using activation sequence mapping and pace-mapping (Figure 2B).
Stereotactic radioablation using acquired computed tomography image in transverse (A) and lateral view (B). Orange boundary indicates distribution zone targeted to the tumor.
gr3.jpg
PMC6342609_01_gr3.jpg
fig3
The treatment plan of 25 Gy dose in a single outpatient treatment to the 75% isodose line was designed (Figure 3), encompassing the inferolateral wall from base to apex.