Abstract：
BACKGROUND: Radiofrequency catheter ablation (RFA) targets the left atrial appendage isthmus (LAA isthmus) and mitral isthmus for treatment of atrial fibrillation. However, proximity of left circumflex artery (LCxA) and great cardiac vein (GCV) in the isthmuses poses fatal risks during ablation.
METHODS: This study investigated relationships of LCxA and GCV across three lines in the LAA and mitral isthmus, using 15 human cadaveric hearts. Distances between the vessels and the endocardium, myocardium, and perivascular fat thickness were measured.
RESULTS: The results showed that LCxA was mostly consistently located in lower atrial segments and GCV was in lower/upper atrial segments, with change of course mainly observed in the middle of the LAA. The LCxA was found as close as 3-5 mm from the lower border of the LAA isthmus in 80% of specimens, at a depth of 2-3 mm within the LAA isthmus, where 1 mm consisted of myocardium and the remainder was fat, which may not provide adequate protection due to the possibility of liquefaction of fat with heat application. The effective myocardial thickness was consistently 1 mm across all cases in both isthmuses. LCxA was 2 mm in second and third sections of LAA isthmus (\"careful segment\"). LCxA distances from left inferior pulmonary vein opening was 5 to 12 mm, occasionally dangerously close as <1 mm in 16% of cases.
CONCLUSIONS: This study measured LCxA and GCV in the LAA and mitral isthmus across three lines for the first time in the Indian population, aiding surgeons in RFA planning.
METHODS: This study investigated relationships of LCxA and GCV across three lines in the LAA and mitral isthmus, using 15 human cadaveric hearts. Distances between the vessels and the endocardium, myocardium, and perivascular fat thickness were measured.
RESULTS: The results showed that LCxA was mostly consistently located in lower atrial segments and GCV was in lower/upper atrial segments, with change of course mainly observed in the middle of the LAA. The LCxA was found as close as 3-5 mm from the lower border of the LAA isthmus in 80% of specimens, at a depth of 2-3 mm within the LAA isthmus, where 1 mm consisted of myocardium and the remainder was fat, which may not provide adequate protection due to the possibility of liquefaction of fat with heat application. The effective myocardial thickness was consistently 1 mm across all cases in both isthmuses. LCxA was 2 mm in second and third sections of LAA isthmus (\"careful segment\"). LCxA distances from left inferior pulmonary vein opening was 5 to 12 mm, occasionally dangerously close as <1 mm in 16% of cases.
CONCLUSIONS: This study measured LCxA and GCV in the LAA and mitral isthmus across three lines for the first time in the Indian population, aiding surgeons in RFA planning.
摘要：
背景：射频导管消融（RFA）靶向左心耳峡部（LAA峡部）和二尖瓣峡部治疗心房颤动。然而,在消融术期间,峡部左旋支动脉(LCxA)和心大静脉(GCV)的接近会带来致命风险.
方法：本研究调查了LCxA和GCV在LAA和二尖瓣峡部三条直线上的关系，用15个人类尸体的心脏.血管和心内膜之间的距离，心肌，测量血管周围脂肪厚度。
结果：结果表明，LCxA大部分始终位于下心房段，而GCV位于下/上心房段，主要在左心耳中部观察到病程变化。在80％的标本中，LCxA与LAA地峡的下边界相距3-5毫米，在LAA地峡内2-3毫米的深度，其中1毫米由心肌组成，其余为脂肪，这可能不能提供足够的保护，由于脂肪液化与热应用的可能性。在两个峡部中，所有病例的有效心肌厚度始终为1mm。LCxA在LAA峡部的第二和第三部分（“小心段”）为2毫米。左下肺静脉开口的LCxA距离为5至12毫米，在16％的病例中，偶尔会危险地接近<1毫米。
结论：这项研究首次在印度人群中测量了LAA和二尖瓣峡部的LCxA和GCV。协助外科医生进行RFA规划。
方法：本研究调查了LCxA和GCV在LAA和二尖瓣峡部三条直线上的关系，用15个人类尸体的心脏.血管和心内膜之间的距离，心肌，测量血管周围脂肪厚度。
结果：结果表明，LCxA大部分始终位于下心房段，而GCV位于下/上心房段，主要在左心耳中部观察到病程变化。在80％的标本中，LCxA与LAA地峡的下边界相距3-5毫米，在LAA地峡内2-3毫米的深度，其中1毫米由心肌组成，其余为脂肪，这可能不能提供足够的保护，由于脂肪液化与热应用的可能性。在两个峡部中，所有病例的有效心肌厚度始终为1mm。LCxA在LAA峡部的第二和第三部分（“小心段”）为2毫米。左下肺静脉开口的LCxA距离为5至12毫米，在16％的病例中，偶尔会危险地接近<1毫米。
结论：这项研究首次在印度人群中测量了LAA和二尖瓣峡部的LCxA和GCV。协助外科医生进行RFA规划。
