Koch三角解剖与临床,上海长征医院心内科 廖德宁,一、Koch 三角解剖与组织学,Koch三角的解剖,Koch 1909年首先描述，由Todaro腱、冠状静脉窦口及三尖瓣膈环组成。 房室结位于Koch三角的顶部 解剖和功能上是心房和希氏束的连接（房室交界区）,Koch三角的组织学,房室结细胞：小细胞、紧密无序排列，细胞间连接极少 移行细胞：介于结细胞与心房肌细胞之间，有2个移行方向 心房肌细胞,房室结后延伸（PNE）,人房室结后延伸（PNE）,人房室结具有右和左后延伸 左后延伸朝左行向房间隔 右后延伸与三尖瓣隔瓣近乎平行,可达冠状窦口附近，被认为参与了慢径传导,房室结后延伸（PNE）,N=8,N=2,N=6,N=1,二、 Koch三角与房室结双径路,房室结双径路,1956年Moe在犬的心脏找到房室结双径路的电生理证据，即快径传导快/不应期长；慢径传导慢/不应期短 1968年该概念应用于人的心脏。,Aschoff 标准：组织学差别、踪迹连续、与正常心肌绝缘,房室结双径路,房室结真结细胞和移行细胞虽有组织学差别和踪迹连续，但无绝缘层 移行细胞即为房室结真结细胞与心房肌的传导纽带,房室结双径路,慢径组成：Koch三角下后缘心房肌、移行细胞、PNE、真结细胞 快径：房间隔心肌细胞、移行细胞、真结细胞,房室结双径路,Koch三角传导的异向性： 双径路的解剖基础,Koch三角内心房肌非均一排列传导的异向性传导延缓/单向传导阻滞折返形成 Hocin：犬和猪心脏方向依赖性早搏仅引起Koch三角传导延迟421ms，而AH延长达80120ms。说明传导延迟主要发生在房室结后延伸与真结细胞,房室结后延伸（PNE）： 慢径的解剖与电生理基础,Inoue: 人右PNE沿三尖瓣环延伸，可记录到双电位，是慢径消融位置。 Medkour: 兔心PNE沿三尖瓣环延伸至冠状静脉窦口，与房室结相比，具有更短的周长依赖性不应期，不连续传导，延迟的房室结反应与折返,慢径消融靶点,Quintana：1例AVNRT行慢径消融的患者尸检发现消融线在心房肌慢径消融时消融的可能是正常心房肌。 慢径消融时避免损伤房室结动脉。Kozlowski：50例人心房室结动脉中，20位于冠状窦口附近心内膜下。 冠状窦口附近消融及快径消融可消弱迷走神经的支配，导致心脏迷走神经功能下降 起搏标测Koch三角可以发现快径缺如或靠近慢径，从而避免房室传导阻滞,慢径消融靶点,影像分区 A区 : A1 A2 M区 : M1 M2 P区 : P1 P2,腺苷对房室结双径路的作用,Effects of ATP (20 mg) on AV conduction before （A） and after （B） radiofrequency ablation of the slow pathway,三、 Koch三角与迷走神经,Koch三角内迷走神经分布与作用,Koch三角的迷走神经支配主要来自下腔静脉与左房交界处脂肪垫内的迷走神经节团 迷走神经主要支配结细胞 刺激房室结区迷走神经可以减慢房颤心室率 消融慢径可以缩短快径有效不应期,Koch三角迷走神经分布与作用,Shah：阈下刺激方法证明迷走神经多位于His束下（7/13），也有位于His束和CSO（3/13，3/13）,临床意义,房颤时房室结的递减性与隐匿性传导导致了慢的和不规则的心室率。 房颤时慢径和快径均参与了传导，慢径前传多于快径前传。故消融慢径可以减慢房颤时的心室率。 消融慢径可以缩短快径有效不应期 刺激房室结区迷走神经可以减慢房颤心室率,Ventricular Rate Control by Selective Vagal Stimulation Is Superior to Rhythm Regularization by Atrioventricular Nodal Ablation and Pacing During Atrial Fibrillation,Selective atrioventricular nodal (AVN) vagal stimulation (AVN-VS) was delivered to the epicardial fat pad that projects parasympathetic nerve fibers to the AVN in 12 dogs during AF. A computer-controlled algorithm adjusted AVN-VS beat by beat to achieve a mean ventricular RR interval of 75%, 100%, 125%, or 150% of spontaneous sinus cycle length. The AVN was then ablated, and the right ventricular (RV) apex was paced either irregularly (i-RVP) using the RR intervals collected during AVN-VS or regularly (r-RVP) at the corresponding mean RR. The results indicated that all 3 strategies improved hemodynamics compared with AF. However, AVN-VS resulted in significantly better responses than either r-RVP or i-RVP. i-RVP resulted in worse hemodynamic responses than r-RVP. The differences among these modes became less significant when mean VR was slowed to 150% of sinus cycle length. ConclusionsAVN-VS can produce graded slowing of the VR during AF without destroying the AVN. It was hemodynamically superior to AVN ablation with either r-RVP or i-RVP, indicating that the benefits of preserving the physiological antegrade ventricular activation sequence outweigh the detrimental effect of irregularity.,ShaoweiZhuang Circulation. 2002;106:1853-1858,Selective AV nodal vagal stimulation improves hemodynamics during acute atrial fibrillation in dogs,Electrophysiological-echocardiographic experiments were performed on 11 anesthetized open-chest dogs. Hemodynamic measurements were performed during three distinct periods: 1) sinus rate, 2) AF, and 3) AF with vagal nerve stimulation. AF was associated with significant deterioration of all measured parameters (P ,0.025). The vagal nerve stimulation produced slowing of the ventricular rate, significant reversal of the pressure and contractile indexes (P , 0.025), and a sharp reduction in one-half of the abortive ventricular contractions. Slowing of the ventricular rate during AF by selective ganglionic stimulation of the vagal nerves that innervate the AVN successfully improved the hemodynamic responses.,Wallick, Don W Am J Physiol Heart Circ Physiol 2001；281: H1490H1497,谢 谢！,房室结后延伸（PNE）,兔心PNE沿三尖瓣隔环延伸至冠状静脉窦口。与房室结相比有更短的周长依赖性不应期、不连续传导、延迟的房室结反应及折返。 Medkour,房室结后延伸（PNE）,Inoue：21例人尸体心脏房室结有向右和向左后延伸，右后延伸沿三尖瓣隔环向下，被认为参与了慢径传导 右+左 13 右 7 左 1,Todaro 腱,Koch 三角解剖与组织学 Koch 三角与房室结双径路 Koch 三角与迷走神经 Koch 三角与腺苷,起搏标测Koch三角可以发现快径缺如或靠近慢径，从而避免房室传导阻滞。 the anterogradely conducting fast pathway (AFP) based on the shortest St-H interval obtained by stimulating the anteroseptal, midseptal, and posteroseptal aspects of Kochs triangle. In group 2 (n=422), AFP was anteroseptal in 384 (91%), midseptal in 33 (7.8%), and posteroseptal or absent in 5 (1.2%).,Delise P, Sitta N, Bonso A, J Cardiovasc Electrophysiol. 2005；16:30,