Mechanisms of optimized biventricular pacing in pulmonary stenosis: effects on left ventricular geometry in swine.
Mechanisms of optimized biventricular pacing in pulmonary stenosis: effects on left ventricular geometry in swine.
复制标题
肺动脉狭窄中优化双心室起搏的机制：对猪左心室几何形状的影响。
DOI：
10.1111/j.1540-8159.2004.00585.x
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Spotnitz,HenryM
中科院分区：
文献类型：
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作者：
Rabkin,DavidG;Cabreriza,SantosE;Curtis,LaurenJ;Quinn,TAlexander;Weinberg,AlanD;Hordof,AlanD;Spotnitz,HenryM
我们验证了优化的双心室起搏（BiVP）通过减弱左心室（LV）几何形状的扭曲来增强危重肺狭窄（PS）期间的心输出量（CO）的假设。6头麻醉猪胸骨正中切口后，采用乙醇消融诱导心脏传导阻滞。在心外膜、DDD BiVP期间，房室延迟（AVD）以30ms为增量，从60ms到180ms不等。在最高CO左右延迟的AVD （RLD）在20 ms的增量中从（+）80 ms （RV优先）到（-）80 ms （LV优先）不等。在每次起搏设置时，在对照状态（CON）和PS期间（通过诱捕肺动脉直至CO降低50%）测量主动脉流量、ECG和左室直径。在（+）和（−）80 ms时获得短轴左室超声心动图。在CON中，RLD对功能或几何没有影响。在PS优化过程中，BiVP显著增加了CO （RLD =+ 40 ms时为1.12 L/min±0.13 SEM, RLD = 0时为0.92±0.12,RLD = - 80时为0.73±0.08）和LV分数缩短（RLD =+ 40 ms时为8.97%±0.51%,RLD = 0时为7.34%±0.58%,RLD = - 80时为6.21%±0.66%）。此外，（-）RLD患者的左室偏心率在舒张末期（0.79±0.07 vs 1.02±0.03,P = 0.011）和收缩期末期（0.83±0.05 vs 1.00±0.02,P = 0.017）与对照组相比均有显著差异。然而，与CON相比，（+）RLD在舒张末期（0.88±0.06 vs 0.99±0.03）或收缩末期（0.92±0.03 vs 1.01±0.03）均无显著差异。在患有PS的猪心脏中，优化的BiVP增加了CO，分数缩短和左室对称性。BiVP作为急性术后心力衰竭的治疗值得进一步研究。
We tested the hypothesis that optimized biventricular pacing (BiVP) enhances cardiac output (CO) during critical pulmonary stenosis (PS) by attenuating distortions in left ventricular (LV) geometry. Following median sternotomy in six anesthetized pigs, heart block was induced by ethanol ablation. During epicardial, DDD BiVP, atrioventricular delay (AVD) was varied from 60 ms to 180 ms in 30 ms increments. At the AVD with the highest CO right‐left delay (RLD) was varied from (+) 80 ms (RV first) to (−) 80 ms (LV first) in 20 ms increments. At each pacing setting, aortic flow, ECG, and LV diameter were measured in the control state (CON) and during PS, created by snaring the pulmonary artery until CO decreased 50%. Short axis LV echocardiograms were obtained at (+) and (−) 80 ms. In CON, RLD had no effect on function or geometry. During PS optimum BiVP resulted in significant increases in CO (1.12 L/min ± 0.13 SEM at RLD =+ 40 ms versus 0.92 ± 0.12 at RLD = 0 and 0.73 ± 0.08 at RLD =−80), and LV fractional shortening (8.97%± 0.51% at RLD =+ 40 ms versus 7.34%± 0.58% at RLD = 0 and 6.21%± 0.66% at RLD =−80). In addition, LV eccentricity with (−) RLD was significantly different versus CON at both end‐diastole (0.79 ± 0.07 vs 1.02 ± 0.03, P = 0.011 Student's t‐test) and end‐systole (0.83 ± 0.05 vs 1.00 ± 0.02, P = 0.017). However, with (+) RLD differences versus CON were not significant at either end‐diastole (0.88 ± 0.06 vs 0.99 ± 0.03) or end‐systole (0.92 ± 0.03 vs 1.01 ± 0.03). In swine hearts with PS, optimized BiVP increases CO, fractional shortening, and LV symmetry. BiVP warrants further study as treatment for acute postoperative heart failure.