Lee Joseph C, Steven Daniel, Roberts-Thomson Kurt C, Raymond Jean-Marc, Stevenson William G, Tedrow Usha B
Cardiac Arrhythmia Service, Cardiovascular Division, Brigham & Women's Hospital, Boston, Massachusetts 02115, USA.
Heart Rhythm. 2009 Aug;6(8):1186-91. doi: 10.1016/j.hrthm.2009.03.056. Epub 2009 Apr 2.
Ablation of atrial tachycardias (AT) arising from the crista terminalis region (CT) can be complicated by phrenic nerve (PN) injury.
This study sought to describe epicardial protection techniques to prevent PN injury from endocardial ablation of AT.
Ablation was attempted in 4 patients with focal AT arising from the CT in whom conventional endocardial ablation was limited by PN proximity identified by capture during pacing.
Four women ages 20, 28, 30, and 31 years with structurally normal hearts presented with symptomatic ATs failing medical therapy. In the first patient, endocardial cryoablation was performed during superior vena cava (SVC) PN pacing. After acute success, AT recurred. Open surgical ablation was then performed, but AT was noninducible under anesthesia, and an anatomic ablation was performed. AT was abolished, but sinus node dysfunction required pacemaker implantation. In the subsequent 3 patients with AT adjacent to the right PN, protection of the PN was attempted by inserting a peripheral angioplasty balloon (2 patients) or steerable ablation catheter and sheath into the epicardial space between the PN and atrium. Endocardial radiofrequency ablation was successful in all 3 patients without PN injury.
Epicardial protection of the PN allowing for safe endocardial ablation of CT ATs is a feasible method of managing these challenging cases and seems to be preferable to surgery.
起源于界嵴区域（CT）的房性心动过速（AT）消融可能并发膈神经（PN）损伤。
本研究旨在描述心外膜保护技术，以防止因AT心内膜消融导致的PN损伤。
对4例起源于CT的局灶性AT患者进行消融尝试，在起搏过程中通过夺获确定常规心内膜消融因PN靠近而受限。
4例年龄分别为20、28、30和31岁、心脏结构正常的女性患者，出现症状性AT且药物治疗无效。第1例患者，在上腔静脉（SVC）PN起搏期间进行心内膜冷冻消融。急性成功后，AT复发。随后进行了开放性手术消融，但在麻醉下AT不能诱发，遂进行了解剖性消融。AT消失，但窦房结功能障碍需要植入起搏器。在随后3例AT靠近右PN的患者中，尝试通过将外周血管成形术球囊（2例患者）或可操纵的消融导管及鞘管插入PN与心房之间的心外膜间隙来保护PN。所有3例患者的心内膜射频消融均成功，且无PN损伤。
对PN进行心外膜保护从而安全地对CT AT进行心内膜消融，是处理这些具有挑战性病例的一种可行方法，似乎优于手术治疗。
