CAJ | 학술논문

目的观察比格犬急性心肌缺血后左心室不同起搏位点节段整体和节段跨壁心肌峰值径向位移(RD)的变化,量化评价不同起搏位点左室跨壁心肌力学状态特征.方法 10只健康比格犬开胸模型,结扎冠状动脉左前降支诱导产生急性心肌缺血.随机进行缺血后左心室侧壁起搏(LVI/P)、左心室心尖起搏(LVA-P)、左心室缺血与非缺血交界区起搏(LVB-P),分别采集三个心动周期标准二尖辦口、乳头肌及心尖短轴切面动态组织多普勒(TDI)速度二维图像.分析评价左室不同起搏位点节段整体和节段跨壁心肌(RD、达峰时间(RD-Tc)、达峰时间标准差(RD-TSD)等力学参数变化.结果 ①急性心肌缺血后LVL-P、LVA-P和LVB-P状态组内节段跨壁三层心肌间RD差异无统计学意义;LVL-P、LVA-P和LVB-P状态组间节段整体和节段跨壁三层心肌RD差异无统计学意义.②急性心肌缺血后LVL-P和LVB-P状态节段跨壁和相应节段整体的RD相关性高于LVA-P状态.③急性心肌缺血后左室不同起搏位点节段整体和跨壁心肌大部分节段RD-Tc延迟于T波之后,不同起搏位点间大部分节段RD-Tc差异无统计学意义.④急性心肌缺血后LVL-P、LVA-P、LVB-P心内膜下和中层心肌以及LVDP节段整体的RD-TSD.均比缺血非起搏状态相应节段降低,差异有统计学意义(P<O.05).结论急性心肌缺血左室不同起搏位点中,LVA-P状态节段整体和节段跨壁心肌的RD相关性最低;LVL-P、LVA-P和LVB-P状态能部分恢复跨壁心肌运动的同步性.通过左室跨壁心肌超声力学评价,能够深入揭示急性心肌缺血状态下左室不同起搏位点节段整体和节段跨壁心肌的力学状态.
목적 관찰비격견급성심기결혈후좌심실불동기박위점절단정체화절단과벽심기봉치경향위이(RD)적변화,양화평개불동기박위점좌실과벽심기역학상태특정.방법 10지건강비격견개흉모형,결찰관상동맥좌전강지유도산생급성심기결혈.수궤진행결혈후좌심실측벽기박(LVI/P)、좌심실심첨기박(LVA-P)、좌심실결혈여비결혈교계구기박(LVB-P),분별채집삼개심동주기표준이첨판구、유두기급심첨단축절면동태조직다보륵(TDI)속도이유도상.분석평개좌실불동기박위점절단정체화절단과벽심기(RD、체봉시간(RD-Tc)、체봉시간표준차(RD-TSD)등역학삼수변화.결과 ①급성심기결혈후LVL-P、LVA-P화LVB-P상태조내절단과벽삼층심기간RD차이무통계학의의;LVL-P、LVA-P화LVB-P상태조간절단정체화절단과벽삼층심기RD차이무통계학의의.②급성심기결혈후LVL-P화LVB-P상태절단과벽화상응절단정체적RD상관성고우LVA-P상태.③급성심기결혈후좌실불동기박위점절단정체화과벽심기대부분절단RD-Tc연지우T파지후,불동기박위점간대부분절단RD-Tc차이무통계학의의.④급성심기결혈후LVL-P、LVA-P、LVB-P심내막하화중층심기이급LVDP절단정체적RD-TSD.균비결혈비기박상태상응절단강저,차이유통계학의의(P<O.05).결론 급성심기결혈좌실불동기박위점중,LVA-P상태절단정체화절단과벽심기적RD상관성최저;LVL-P、LVA-P화LVB-P상태능부분회복과벽심기운동적동보성.통과좌실과벽심기초성역학평개,능구심입게시급성심기결혈상태하좌실불동기박위점절단정체화절단과벽심기적역학상태.
Objective To evaluate the changes of peak segmental and transmural radial displacement (RD) of left ventricle(LV) during acute myocardial ischemia with different LV pacing patterns. Methods Left anterior descending coronary artery (LAD) was ligated to induce acute myocardial ischemia in open-chest Beagle canine models ( n=10). Two-dimensional gray-scale images with overlaid tissue Doppler velocity imaging in three standard LV short-axis views were acquired with different pacing patterns in a randomized sequence in three complete cardiac cycles. Parameters including peak RD, peak RD time(RD-Tc) ,the standard deviation of TC(RD-TSD) of 12 segments and their myocardial layers(subend,mid,subepi) were measured and analyzed using TDI-Q workstation. Results ① There were no significant differences of peak RD between three myocardial layers of LV wall in each different pacing pattern group;There were no significant difference of peak RD from segments and transmural layers among the different LV pacing patterns. ②With acute myocardial ischemia the RD correlation of LV lateral pacing( LVL-P) and LV border pacing(LVB-P) patterns were higher than that of LV apical pacing(LVA-P) pattern between global segment and its subend, mid, subepi. ③ RD-Tc of 12 LV segments and their subend, mid, subepi appeared after T wave and there were no significant differences of RD-Tc among different LV pacing patterns. ④RD-TSD of the corresponding segments during LVL-P,LVA-P and LVB-P patterns were significant lower than those during acute yocardial ischemia(P<0. 05). Conclusions The existed RD correlation of LVA-P between subend.mid, subepi and the segment were lowest among the different ischemic LV pacing patterns; the synchronization of transmural RD could be recovered partly with LVL-P, LVA-P and LVB-P patterns. The echocardiographic study of LV transmural RD might be useful to reveal the segmental and the transmural myocardial mechanical state with different LV pacing patterns during acute ischemia in detail.