1、Koch三角解剖与临床KochKoch三角的解剖 1.Koch 1909年首先描述,由Todaro腱、冠状静脉窦口及三尖瓣膈环组成。2.房室结位于Koch三角的顶部3.解剖和功能上是心房和希氏束的连接(房室交界区)KochKoch三角的组织学v房室结细胞:小细胞、紧密无序排列,细胞间连接极少v移行细胞:介于结细胞与心房肌细胞之间,有2 2个移行方向v心房肌细胞房室结后延伸(PNEPNE)人房室结后延伸(PNEPNE)v人房室结具有右和左后延伸v左后延伸朝左行向房间隔v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(PNEPNE)N=8N=2N=6N=1右+左
2、右左无InoueN=2113710周聊生N=178612二、KochKoch三角与房室结双径路房室结双径路v1956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v1968年该概念应用于人的心脏。Aschoff 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v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v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v慢径组成:KochKoch三角下后缘心房肌、移行细胞、PNEPNE、真结细胞v快径:房间隔心肌细胞、移行细胞、真结细胞房室结双径路KochKoch三
3、角传导的异向性:双径路的解剖基础vKochKoch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vHocinHocin:犬和猪心脏方向依赖性早搏仅引起KochKoch三角传导延迟4 421ms21ms,而AHAH延长达8080120ms120ms。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(PNEPNE):):慢径的解剖与电生理基础vInoue:人右PNE沿三尖瓣环延伸,可记录到双电位,是慢径消融位置。vMedkour: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vQuintan
4、aQuintana:1 1例AVNRTAVNRT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估计是正常心房肌。v慢径消融时幸免损伤房室结动脉。KozlowskiKozlowski:5050例人心房室结动脉中,2020位于冠状窦口附近心内膜下。v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v起搏标测KochKoch三角能够发现快径缺如或靠近慢径,从而幸免房室传导阻滞慢径消融靶点影像分区 A A区:A1 A2A1 A2 M M区:M1 M2M1 M2 P P区:P1 P2P1 P2腺苷对房室结双径路的作用Effects of ATP(20 mg)on AV c
5、onduction before(A)and after(B)radiofrequency ablation of the slow pathway三、KochKoch三角与迷走神经KochKoch三角内迷走神经分布与作用vKochKoch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v迷走神经主要支配结细胞v刺激房室结区迷走神经能够减慢房颤心室率v消融慢径能够缩短快径有效不应期KochKoch三角迷走神经分布与作用vShahShah:阈下刺激方法证明迷走神经多位于HisHis束下(7/137/13),),也有位于HisHis束和CSCSO O(3/133/13,3/13
6、3/13)临床意义v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。v房颤时慢径和快径均参与了传导,慢径前传多于快径前传。故消融慢径能够减慢房颤时的心室率。v消融慢径能够缩短快径有效不应期v刺激房室结区迷走神经能够减慢房颤心室率Ventricular Rate Control by Selective Vagal Stimulation IsSuperior to Rhythm Regularization by AtrioventricularNodal Ablation and Pacing During Atrial Fibrillationv Selective atrio
7、ventricular 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 puter-controlled algorithm adjusted AVN-VS beat by beat to achieve a mean ventricular RR interval of 75%,100%,125%,or 150%of spontaneous
8、 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 pared with AF、However,AVN
9、-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、v ConclusionsAVN-VS can produce graded slowing of the VR d
10、uring 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;106:185
11、3-1858Selective AV nodal vagal stimulation improveshemodynamics during acute atrial fibrillation in dogsv 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
12、)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 ab
13、ortive ventricular contractions、v 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(PNEPNE)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(PNEPNE)vInoue: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v右+左 13v右 7v左 1上腔静脉下腔静脉卵圆窝房间隔右心耳梳状肌冠状窦口Todaro 腱vKoch 三角解剖与组织学vKoch 三角与房室结双径路vKoch 三角与迷走神经vKoch 三角与腺苷感谢您的聆听！感谢您的聆听！
