Dib Chadi, Kapa Suraj, Powell Brian D, Packer Douglas L, Asirvatham Samuel J
Department of Medicine, Mayo Clinic, Rochester, MN, USA.
J Interv Card Electrophysiol. 2008 Jun;22(1):23-30. doi: 10.1007/s10840-008-9242-1. Epub 2008 Mar 7.
The SVC may require ablation to treat atrial fibrillation. Phrenic nerve proximity identified with pacing maneuvers may preclude ablation.
We tested a new method using "cryo-mapping" to ablate despite nerve proximity.
Of 833 patients undergoing ablation, 110 (12%) had arrhythmogenic substrate at the SVC/RA junction. Of these 110 patients, 66 (60%) had consistent diaphragmatic stimulation when pacing at 10 mA at the prospective site of ablation. Of these 66 patients, 7 had continued arrhythmogenicity despite attempts to modify this substrate. For these 7 patients, we paced 4 cm into the SVC where consistent phrenic nerve stimulation was obtained, and cryoablation at -30 degrees C was performed at sites requiring ablation. In 6 of 7 patients (86%), with continued diaphragmatic capture, cryoablation at -70/-80 degrees C was then performed. In 1 of 7 patients (14%), diaphragmatic stimulation ceased at -30 degrees C, and energy delivery stopped. In the 6 patients in whom cryoablation was completed, the arrhythmogenic substrate was successfully ablated without phrenic nerve injury.
A novel "cryo-mapping" technique during phrenic nerve pacing can be used to successfully ablate arrhythmogenic substrate at the SVC/RA junction despite phrenic nerve proximity.
上腔静脉（SVC）可能需要进行消融治疗心房颤动。通过起搏操作确定的膈神经靠近情况可能会妨碍消融。
我们测试了一种新方法，即使用“冷冻标测”来进行消融，尽管存在神经靠近情况。
在833例接受消融的患者中，110例（12%）在SVC/右心房（RA）交界处存在致心律失常基质。在这110例患者中，66例（60%）在预期消融部位以10毫安起搏时出现持续的膈肌刺激。在这66例患者中，7例尽管尝试改变这种基质，但仍存在持续的致心律失常性。对于这7例患者，我们将起搏电极置于SVC内4厘米处，在此处获得了持续的膈神经刺激，然后在需要消融的部位进行-30℃的冷冻消融。在7例患者中的6例（86%）中，在持续有膈肌夺获的情况下，接着进行-70/-80℃的冷冻消融。在7例患者中的1例（14%）中，在-30℃时膈肌刺激停止，能量输送也停止。在完成冷冻消融的6例患者中，致心律失常基质被成功消融，且未发生膈神经损伤。
在膈神经起搏期间，一种新的“冷冻标测”技术可用于成功消融SVC/RA交界处的致心律失常基质，尽管存在膈神经靠近情况。
