National Institute of Cardiology, Havana City, Cuba.
Institute of Cardiology, Havana, Cuba.
J Nucl Cardiol. 2020 Aug;27(4):1158-1167. doi: 10.1007/s12350-020-02047-x. Epub 2020 Apr 3.
Left ventricular contraction dyssynchrony (LVCD) has been related to induced ischemia and transmural scar but the interplay of myocardial viability and dyssynchrony is unknown. The aim of the present study was to establish the role of dyssynchrony in the context of a viability study performed with nitrate augmentation gated single photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI).
Fifty-four consecutive patients with ischemic dilated cardiomyopathy (IDC) and depressed left ventricular ejection fraction (LVEF) were included. They underwent a two-day rest/nitroglycerine (NTG) study GSPECT MPI to determine the myocardial viability. Patients with a nitrate-induced uptake increase of > 10% vs baseline, in at least, two consecutive dysfunctional segments were considered viable as well as those who showed no improvement in the uptake but the uptake was > 50% on post NTG study. Patients with no nitrate-induced uptake increase of > 10% and the uptake of < 50% were considered non-viable. Perfusion, function and LVCD were compared in 25 viable patients vs 29 non-viable patients at baseline and after NTG administration.
After NTG administration, in the viable group, the LVEF increased (36.44 ± 6.64% vs 39.84 ± 6.39%) and the end-systolic volume decreased significantly (119.28 ± 31.77 mL vs 109.08 ± 33.17 mL) (P < 0.01). These patients also experienced a significant reduction in the LVCD variables: phase standard deviation was reduced in the post NTG study (57.77° ± 19.47° vs 52.02° ± 17.09°) as well as the phase histogram bandwidth (190.20° ± 78.83° vs 178.0° ± 76.14°) (P < 0.05). Functional and LVCD variables remained similar in the non-viable patients (P > 0.05).
In patients with IDC and depressed LVEF, the myocardial viability detected by rest/ NTG GSPECT MPI, might determine LVCD improvement.
左心室收缩不同步（LVCD）与缺血诱导和透壁疤痕有关，但心肌存活与不同步之间的相互作用尚不清楚。本研究的目的是确定在使用硝酸酯增强门控单光子发射计算机断层扫描（GSPECT）心肌灌注成像（MPI）进行存活研究的情况下，不同步的作用。
连续纳入 54 例缺血性扩张型心肌病（IDC）和左心室射血分数（LVEF）降低的患者。他们进行了为期两天的静息/硝酸甘油（NTG）GSPECT MPI 研究，以确定心肌存活情况。在至少两个连续功能障碍节段中，硝酸盐诱导的摄取增加> 10%的患者被认为是存活的，而那些摄取增加但在 NTG 后研究中摄取增加> 50%的患者也被认为是存活的。那些硝酸盐诱导的摄取增加< 10%和摄取< 50%的患者被认为是不可存活的。在基线和 NTG 给药后，比较 25 例存活患者和 29 例非存活患者的灌注、功能和 LVCD。
在 NTG 给药后，在存活组中，LVEF 增加（36.44 ± 6.64% vs 39.84 ± 6.39%），左心室收缩末期容积显著减少（119.28 ± 31.77 mL vs 109.08 ± 33.17 mL）（P < 0.01）。这些患者的 LVCD 变量也显著降低：在 NTG 后研究中相位标准差降低（57.77°± 19.47° vs 52.02°± 17.09°），相位直方图带宽降低（190.20°± 78.83° vs 178.0°± 76.14°）（P < 0.05）。在非存活患者中，功能和 LVCD 变量保持相似（P > 0.05）。
在 IDC 和 LVEF 降低的患者中，通过静息/NTG GSPECT MPI 检测到的心肌存活可能决定 LVCD 的改善。
