Robert and Suzanne Tomsich Department of Cardiovascular Medicine, Sydell and Arnold Miller Family, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue/J1-5, Cleveland, OH 44195, USA.
J Nucl Cardiol. 2012 Dec;19(6):1190-7. doi: 10.1007/s12350-012-9627-5. Epub 2012 Sep 29.
Phase analysis of gated myocardial perfusion imaging (MPI) provides automated and reproducible assessment of left ventricular (LV) mechanical dyssynchrony (LVMD) (phase standard deviation [SD]). Many patients undergoing gated MPI have history of prior coronary artery bypass graft surgery (CABG). The latter is often associated with paradoxical septal wall motion (PSM). The effect of prior CABG and PSM on LVMD has not been evaluated.
From the single-photon emission computed tomography (SPECT) and positron emission tomography (PET) MPI clinical database maintained at the Cleveland Clinic, we identified 200 consecutive patients with SPECT (100 control with normal LV ejection fraction [EF], MPI, and QRS < 120 ms; and 100 with LVEF < 35%), and 631 patients with LVEF < 35% with gated PET. Patients with QRS ≥ 120 ms, bundle branch block, ventricular pacing or isolated non-CABG surgery were excluded. There were 162 patients with gated SPECT (46 with prior CABG), and 568 with gated PET (220 with prior CABG) that were left for analysis. Phase SD was derived using Emory Cardiac Toolbox (ECTb) (for gated SPECT) and Corridor 4DM (4DM) (for gated SPECT and PET images). Multivariate linear regression analysis was performed to assess whether prior CABG was an independent predictor of worse LV mechanical dyssynchrony. After adjusting for patients' demographics, co-morbidities, medications, and MPI data, history of prior CABG was not and independent predictor of LV mechanical dyssynchrony (P = .67 with 4DM, P = .97 with ECTb) in patients undergoing gated SPECT or among patients undergoing gated PET imaging (P = .18).
Although paradoxical septal wall motion is commonly seen after cardiac surgery, prior CABG does not affect or impact LV mechanical dyssynchrony indices measured from gated SPECT or PET images. Whether dyssynchrony measurements with echocardiography that has higher temporal resolution might uncover intraventricular delays, remains to be determined.
门控心肌灌注成像（MPI）的时相分析提供了左心室（LV）机械不同步（LVMD）（时相标准差[SD]）的自动和可重复评估。许多接受门控 MPI 的患者都有冠状动脉旁路移植术（CABG）的病史。后者常伴有反常室间隔壁运动（PSM）。先前 CABG 和 PSM 对 LVMD 的影响尚未得到评估。
从克利夫兰诊所维护的单光子发射计算机断层扫描（SPECT）和正电子发射断层扫描（PET）MPI 临床数据库中，我们确定了 200 名连续接受 SPECT（100 名对照组，LV 射血分数[EF]正常，MPI 和 QRS<120ms；100 名 LVEF<35%）和 631 名 LVEF<35%接受门控 PET 的患者。排除 QRS≥120ms、束支传导阻滞、心室起搏或孤立性非 CABG 手术的患者。共有 162 名接受门控 SPECT（46 名有先前 CABG）和 568 名接受门控 PET（220 名有先前 CABG）的患者进行了分析。使用 Emory 心脏工具包（ECTb）（用于门控 SPECT）和 Corridor 4DM（4DM）（用于门控 SPECT 和 PET 图像）得出时相 SD。进行多元线性回归分析，以评估先前 CABG 是否为 LV 机械不同步的独立预测因子。在校正患者的人口统计学、合并症、药物和 MPI 数据后，先前 CABG 不是门控 SPECT 或门控 PET 成像患者 LV 机械不同步的独立预测因子（4DM 时 P=0.67，ECTb 时 P=0.97）（P=0.18）。
尽管心脏手术后常出现反常室间隔壁运动，但先前的 CABG 并不影响或影响从门控 SPECT 或 PET 图像测量的 LV 机械不同步指数。是否具有更高时间分辨率的超声心动图测量可能会发现心室间延迟，仍有待确定。
