| 摘要: | 目的：這研究的目的是評估心臟再同步治療中，心房與心室的功能與機械協同。
背景：再同步治療中，右心房電刺激（right atrial pacing）會引起左心房電氣與機械的不協同。右心房感應（right atrial sensing）與右心房電刺激於再同步治療中，對左心室的影響及其差異的原理尚未被完全闡明。
方法：55位心衰竭合併再同步治療的病人（平均再同步治療時間9± 12.5月）與22位患有心律疾病合併雙腔心律調節器被納入研究，傳統與組織都卜勒（tissue Doppler）超音波用來測量心房與心室的機械動力與血行動力。
結果：左心房出口（left ventricular outflow tract）的時間－速度積分（time -velocity integral）(22± 7cm vs. 20± 7cm, p= 0.001)，舒張填充期(468± 124ms vs. 380± 93ms p= 0.001),和全左心形變（global strain）(-32± 24% vs. -27± 22%, p= 0.001)均是右心房感應大於右心房電刺激；心房形變亦是右心房感應大於右心房電刺激，右心房形變（-28.2± 8.6% vs. -22.6± 7.6%, p= 0.0007），心房中膈(-17.1± 6.5% vs. -13.2± 5.4%, p= 0.002），左心房（-16.4± 11.0% vs. -13.6± 8.5%, p= 0.02）。左心室機械協同程度沒有差異，但是心房機械協同是右心房感應優於右心房電刺激（31± 19ms vs. 42± 24ms, p= 0.0002）。
結論：右心房感應方式較可以保留心房收縮功能及機械協同，因而形成較好的左心室舒張灌流、左心室心輸出及左心室機械縮。這種方式使心衰竭合併再同步治療得到最大的左心室輸出及血行動力的好處。
Objects: The purpose of this study was to evaluate atrial and ventricular function and synchrony in patients undergoing cardiac resynchronization therapy.
Background: Right atrial pacing in cardiac resynchronization therapy induces dyssynchrony in electrical and mechanical activation of the left atrium. The impact of atrial sensing versus atrial pacing on left ventricular performance in cardiac resynchronization therapy and the underlying mechanisms leading to differences between these two pacing modes in cardiac resynchronization therapy have not been fully elucidated.
Methods: Fifty-five patients with heart failure undergoing cardiac resynchronization therapy for 9± 12.5 months and 22 control subjects with dual pacemaker for conduction disorders were enrolled. Conventional and tissue Doppler echocardiography was performed to examine atrial and ventricular mechanics and hemodynamic status.
Results: Left ventricular (LV) outflow tract time-velocity integral (22± 7 cm vs. 20± 7 cm, p= 0.001), diastolic filling period (468± 124 ms vs. 380± 93 ms, p= 0.001), and global strain (-32± 24% vs. -27± 22%, p= 0.001) were greater in atrial sensing compared with atrial pacing mode. Atrial strain was higher in atrial sensing compared with atrial pacing mode in the right atrium (-28.2± 8.6% vs. -22.6± 7.6%, p= 0.0007), interatrial septum (-17.1± 6.5% vs. -13.2± 5.4%, p= 0.002), and left atrium (-16.4± 11.0% vs. -13.6± 8.5%, p= 0.02). There was no difference in intra-ventricular dyssynchrony but significantly lower atrial dyssynchrony in atrial sensing compared with atrial pacing mode (31± 19 ms vs. 42 ± 24 ms, p= 0.0002).
Conclusion: Atrial sensing is associated with preserved atrial contractility and synchrony, with the results of optimal LV diastolic filling, stroke volume, and LV systolic mechanics consequently. This pacing mode maximizes LV performance and the hemodynamic benefit of cardiac resynchronization therapy in patients with heart failure. |
