CAJ | 학술논문

目的：应用超声血流向量成像（VFM）技术评价健康比格犬心脏不同位点起搏心动周期内左室流场涡旋分布、强度变化及心肌力学参数，探讨起搏状态下心腔内涡旋变化特征，为临床优化人工心脏起搏位点提供流体力学基础实验数据。方法分别采集8只健康比格犬开胸模型基础窦性心律状态和右室心尖、左室心尖和侧壁起搏状态下二维彩色多普勒血流图，导入血流向量标测软件分析图像，定性观察并比较不同状态下特定时相左室涡旋分布及强度涡量变化，应用速度向量标测软件分析左室心内膜下心肌力学参数，同时测量左室每搏输出量（LVSV）、射血分数（LVEF）、心输出量（LVCO）、dp／dtmax和E／Vp。结果心脏各位点起搏LVSV、LVEF、LVCO和dp／dtmax均较基础状态降低（P＜00．5），E／Vp起搏与基础状态间比较差异无统计学意义（P＞00．5），左室心尖和侧壁起搏LVSV、LVEF、LVCO均低于右室心尖起搏（P＜00．5）；与基础状态相比，不同位点起搏心动周期内左室腔内生理涡旋的方向、有序对称分布及涡旋强度发生改变，其中左室壁各位点起搏均导致了较右室心尖起搏更为明显的变化，左室心尖起搏导致异常最为明显。多变量回归分析中，基础状态收缩早期涡强分别与舒张晚期涡强和整体纵向应变独立相关（R2＝06．3，P＜00．01及P＝00．03）。结论心脏不同位点起搏导致了左室内血流涡旋状态改变，舒张晚期到收缩早期的持续涡旋从血流动力学表明舒张期与收缩期之间良好的耦联。
목적：응용초성혈류향량성상（VFM）기술평개건강비격견심장불동위점기박심동주기내좌실류장와선분포、강도변화급심기역학삼수，탐토기박상태하심강내와선변화특정，위림상우화인공심장기박위점제공류체역학기출실험수거。방법분별채집8지건강비격견개흉모형기출두성심률상태화우실심첨、좌실심첨화측벽기박상태하이유채색다보륵혈류도，도입혈류향량표측연건분석도상，정성관찰병비교불동상태하특정시상좌실와선분포급강도와량변화，응용속도향량표측연건분석좌실심내막하심기역학삼수，동시측량좌실매박수출량（LVSV）、사혈분수（LVEF）、심수출량（LVCO）、dp／dtmax화E／Vp。결과심장각위점기박LVSV、LVEF、LVCO화dp／dtmax균교기출상태강저（P＜00．5），E／Vp기박여기출상태간비교차이무통계학의의（P＞00．5），좌실심첨화측벽기박LVSV、LVEF、LVCO균저우우실심첨기박（P＜00．5）；여기출상태상비，불동위점기박심동주기내좌실강내생리와선적방향、유서대칭분포급와선강도발생개변，기중좌실벽각위점기박균도치료교우실심첨기박경위명현적변화，좌실심첨기박도치이상최위명현。다변량회귀분석중，기출상태수축조기와강분별여서장만기와강화정체종향응변독립상관（R2＝06．3，P＜00．01급P＝00．03）。결론심장불동위점기박도치료좌실내혈류와선상태개변，서장만기도수축조기적지속와선종혈류동역학표명서장기여수축기지간량호적우련。
Objective To investigate the changes of left ventricular(LV) vortex strength(VS) and distribution during selective cardiac pacing in a phases of cardiac cycle using vector flow mapping techniques ,and associate with LV mechanical performance ,so as to provide basic experimental database for optimizing the sites of the artificial cardiac pacing in clinic conditions .Methods Eight heathy open‐chest Beagle dog models were employed for selective right ventricular apical (RVAP ) ,left ventricular apical (LVAP) and lateral wall pacing (LVLP) .The standard two‐dimensional apical three views with color Doppler flow and dynamic two‐dimensional images were acquired consecutively in three cardiac cycles for further off‐line analysis ,conventional parameters were measured at same time .Results Compared with baseline ,LVSV ,LVEF ,LVCO and dp/dtmax were both reduced ,and the parameters obtained leftside cardiac pacing were lower than that of right ventricular pacing ( P < 0 0.5) ,there′s no significant difference in E/Vp .The vortex pattern ,distribution and vorticity at six typical phases induced by selective cardiac pacing were totally different from those at baseline with sinus rhythm ,and leftside pacing were worsen than RVAP ,the LVAP were most obvious .On multivariable regression analysis ,the VS during ES (VSES ) at baseline was independently related to late‐diastolic VS and longitudinal strain (R2 = 0 6.3 ,P < 0 0.01 and P=0 0.03 ,respectively) .Conclusions The selective cardiac pacing could induce intracardiac vortex changes and differ from that at baseline ,and the persistence of vortex from late diastole into ES is a haemodynamic measure of coupling between diastole and systole .