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- pulmonary vein isolation (2) (remove)
The visualization of heart rhythm disturbance and atrial fibrillation therapy allows the optimization of new cardiac catheter ablations. With the simulation software CST (Computer Simulation Technology, Darmstadt) electromagnetic and thermal simulations can be carried out to analyze and optimize different heart rhythm disturbance and cardiac catheters for pulmonary vein isolation. Another form of visualization is provided by haptic, three-dimensional print models. These models can be produced using an additive manufacturing method, such as a 3d printer. The aim of the study was to produce a 3d print of the Offenburg heart rhythm model with a representation of an atrial fibrillation ablation procedure to improve the visualization of simulation of cardiac catheter ablation. The basis of 3d printing was the Offenburg heart rhythm model and the associated simulation of cryoablation of the pulmonary vein. The thermal simulation shows the pulmonary vein isolation of the left inferior pulmonary vein with the cryoballoon catheter Arctic Front Advance™ from Medtronic. After running through the simulation, the thermal propagation during the procedure was shown in the form of different colors. The three-dimensional print models were constructed on the base of the described simulation in a CAD program. Four different 3d printers are available for this purpose in a rapid prototyping laboratory at the University of Applied Science Offenburg. Two different printing processes were used and a final print model with additional representation of the esophagus and internal esophagus catheter was also prepared for printing. With the help of the thermal simulation results and the subsequent evaluation, it was possible to draw a conclusion about the propagation of the cold emanating from the catheter in the myocardium and the surrounding tissue. It was measured that just 3 mm from the balloon surface into the myocardium the temperature dropped to 25 °C. The simulation model was printed using two 3d printing methods. Both methods, as well as the different printing materials offer different advantages and disadvantages. All relevant parts, especially the balloon catheter and the conduction, are realistically represented. Only the thermal propagation in the form of different colors is not shown on this model. Three-dimensional heart rhythm models as well as virtual simulations allow very clear visualization of complex cardiac rhythm therapy and atrial fibrillation treatment methods. The printed models can be used for optimization and demonstration of cryoballoon catheter ablation in patients with atrial fibrillation.
Pulmonary vein isolation (PVI) is a common
therapy in atrial fibrillation (AF). The cryoballoon was
invented to isolate the pulmonary vein in one step and in a
shorter time than a point-by-point radiofrequency (RF)
ablation. The aim of the study was to model two cryoballoon
catheters, one RF catheter and to integrate them into a heart
rhythm model for the static and dynamic simulation of PVI
by cryoablation and RF ablation in AF. The modeling and
simulation were carried out using the electromagnetic and
thermal simulation software CST (CST, Darmstadt). Two
cryoballons and one RF ablation catheter were modeled
based on the technical manuals of the manufacturers
Medtronic and Osypka. The PVI especially the isolation of
the left inferior pulmonary vein using a cryoballoon catheter
was performed with a -50 °C heatsource and an exponential
signal. The temperature at the balloon surface was -50 °C
after 20 s ablation time, -24 °C from the balloon 0,5 mm in
the myocardium, at a distance of 1 mm -3 °C, at 2 mm 18 °C
and at a distance of 3mm 29 °C. PVI with RF energy was
simulated with an applied power of 5 W at 420 kHz at the
distal 8 mm ablation electrode. The temperature at the tip
electrode was 110 °C after 15 s ablation time, 75 °C from the
balloon at 0,5 mm in the myocardium, at a distance of 1 mm
58 °C, at 2 mm 45 °C and at a distance of 3 mm 38 °C.
Virtual heart rhythm and catheter models as well as the
simulation of the temperature allow the simulation of PVI in
AF by cryo ablation and RF ablation. The 3D simulation of
the temperature profile may be used to optimize RF and cryo
ablation.