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Interactive real-time mapping and catheter ablation of the cavotricuspid isthmus guided by magnetic resonance imaging in a porcine model.

Hoffmann BA, Koops A, Rostock T, Müllerleile K, Steven D, Karst R, Steinke MU, Drewitz I, Lund G, Koops S, Adam G, Willems S - Eur. Heart J. (2009)

Bottom Line: Catheter position and movement during manipulation were continuously visualized during the entire intervention.Two porcine prematurely died due to VT/VF.In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology/Electrophysiology, University Hospital Eppendorf, University Heart Center, Martinistr 52, D-20246 Hamburg, Germany. b.hoffmann@uke.de

ABSTRACT

Aims: We investigated the feasibility of real-time magnetic resonance imaging (RTMRI) guided ablation of the cavotricuspid isthmus (CTI) by using a MRI-compatible ablation catheter.

Methods and results: Cavotricuspid isthmus ablation was performed in an interventional RTMRI suite by using a novel 7 French, steerable, non-ferromagnetic ablation catheter in a porcine in vivo model (n = 20). The catheter was introduced and navigated by RTMRI visualization only. Catheter position and movement during manipulation were continuously visualized during the entire intervention. Two porcine prematurely died due to VT/VF. Anatomical completion of the CTI ablation line could be achieved after a mean of 6.3+/-3 RF pulses (RF energy: 1807+/-1016.4 Ws/RF pulse, temperature: 55.9+/-5.9 degrees C) in n = 18 animals. In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab.

Conclusion: Completely non-fluoroscopic ablation guided by RTMRI using a steerable and non-ferromagnetic catheter is a promising novel technology in interventional electrophysiology.

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Schematic of the distal catheter. A distally fixed Cu/Ni-thermocouple monitors the ablation temperature. The loop-tuning circuit is embedded between the distal and proximal shaft. The loop is isolated from the electrical conductor wires and tuned with a circuit to magnetic resonance imaging resonance frequency.
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EHP460F1: Schematic of the distal catheter. A distally fixed Cu/Ni-thermocouple monitors the ablation temperature. The loop-tuning circuit is embedded between the distal and proximal shaft. The loop is isolated from the electrical conductor wires and tuned with a circuit to magnetic resonance imaging resonance frequency.

Mentions: We developed a novel ablation catheter with a 7-French diameter and a shaft length of 110 cm. The catheter has a deflectable tip at the distal end and a steering handle at the proximal end. The handle includes an electrical connector that links the electrical wires to both ablation electrodes and to the thermocouple wire. The round-shaped, 4 mm distal electrode is made of a platinum–iridium alloy. The temperature of the ablation electrodes is monitored through distally fixed thermocouple wires, to permit control over the ablation temperatures as well as control over any passive heating of the catheter tip during MRI. For improved visualization, a passive coil is integrated in the distal catheter, isolated from the electrical conductors yielding hyperintensity in RTMRI. The coil is based on a conductor wire loop which is tuned with a circuit to resonance frequency of the MR tomography (63.8 MHz). The loop-tuning circuit is embedded between the distal electrode and shaft (Figure 1). All catheter materials were non-ferromagnetic and bio-compatible to reduce susceptibility artefacts, critical temperature rises, and interaction with blood and tissue.


Interactive real-time mapping and catheter ablation of the cavotricuspid isthmus guided by magnetic resonance imaging in a porcine model.

Hoffmann BA, Koops A, Rostock T, Müllerleile K, Steven D, Karst R, Steinke MU, Drewitz I, Lund G, Koops S, Adam G, Willems S - Eur. Heart J. (2009)

Schematic of the distal catheter. A distally fixed Cu/Ni-thermocouple monitors the ablation temperature. The loop-tuning circuit is embedded between the distal and proximal shaft. The loop is isolated from the electrical conductor wires and tuned with a circuit to magnetic resonance imaging resonance frequency.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2821629&req=5

EHP460F1: Schematic of the distal catheter. A distally fixed Cu/Ni-thermocouple monitors the ablation temperature. The loop-tuning circuit is embedded between the distal and proximal shaft. The loop is isolated from the electrical conductor wires and tuned with a circuit to magnetic resonance imaging resonance frequency.
Mentions: We developed a novel ablation catheter with a 7-French diameter and a shaft length of 110 cm. The catheter has a deflectable tip at the distal end and a steering handle at the proximal end. The handle includes an electrical connector that links the electrical wires to both ablation electrodes and to the thermocouple wire. The round-shaped, 4 mm distal electrode is made of a platinum–iridium alloy. The temperature of the ablation electrodes is monitored through distally fixed thermocouple wires, to permit control over the ablation temperatures as well as control over any passive heating of the catheter tip during MRI. For improved visualization, a passive coil is integrated in the distal catheter, isolated from the electrical conductors yielding hyperintensity in RTMRI. The coil is based on a conductor wire loop which is tuned with a circuit to resonance frequency of the MR tomography (63.8 MHz). The loop-tuning circuit is embedded between the distal electrode and shaft (Figure 1). All catheter materials were non-ferromagnetic and bio-compatible to reduce susceptibility artefacts, critical temperature rises, and interaction with blood and tissue.

Bottom Line: Catheter position and movement during manipulation were continuously visualized during the entire intervention.Two porcine prematurely died due to VT/VF.In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology/Electrophysiology, University Hospital Eppendorf, University Heart Center, Martinistr 52, D-20246 Hamburg, Germany. b.hoffmann@uke.de

ABSTRACT

Aims: We investigated the feasibility of real-time magnetic resonance imaging (RTMRI) guided ablation of the cavotricuspid isthmus (CTI) by using a MRI-compatible ablation catheter.

Methods and results: Cavotricuspid isthmus ablation was performed in an interventional RTMRI suite by using a novel 7 French, steerable, non-ferromagnetic ablation catheter in a porcine in vivo model (n = 20). The catheter was introduced and navigated by RTMRI visualization only. Catheter position and movement during manipulation were continuously visualized during the entire intervention. Two porcine prematurely died due to VT/VF. Anatomical completion of the CTI ablation line could be achieved after a mean of 6.3+/-3 RF pulses (RF energy: 1807+/-1016.4 Ws/RF pulse, temperature: 55.9+/-5.9 degrees C) in n = 18 animals. In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab.

Conclusion: Completely non-fluoroscopic ablation guided by RTMRI using a steerable and non-ferromagnetic catheter is a promising novel technology in interventional electrophysiology.

Show MeSH