Cardiac Center, School of Medicine, Creighton University, Omaha, NE, USA.
Am J Ther. 2009 Nov-Dec;16(6):e44-50. doi: 10.1097/MJT.0b013e3181788cc6.
We studied 95 consecutive patients, mean age 70 years, who received cardiac resynchronization therapy (CRT) for class III or IV heart failure with a left ventricular (LV) ejection fraction < or =35% and a QRS duration > or =120 ms. Sixty-seven patients had intrinsic left bundle branch block (LBBB) (group 1), and 28 patients had right ventricular pacing-induced LBBB (group 2). The time difference (TPW-TDI) between onset of QRS to the end of LV ejection by pulsed wave Doppler and onset of QRS to the end of systolic wave in the basal segment with greatest delay by tissue Doppler imaging was measured before CRT and at the last follow-up after CRT. TPW-TDI >50 ms was defined as left ventricular mechanical dyssynchrony. A positive response to CRT was defined as LV volume at end-systole decreasing > or =15% after CRT. The percentage of CRT responders in group 2 was significantly greater than that in group 1 (68% versus 42%, P = 0.04) during follow-up of 16 months. After adjusting for age, gender, and clinical features, this pattern of CRT response persisted (P = 0.008). Similarly, there was a greater reduction in QRS duration in group 2 (178 ms) after CRT versus 154 ms for group 1, P = 0.01. There was no significant difference in TPW-TDI between the 2 groups at baseline or at follow-up. There was no significant difference in mortality (15% versus 14%) and Kaplan-Meier survival plot during follow-up. Patients with heart failure and right ventricular pacing-induced LBBB have a better response rate to CRT than patients with intrinsic LBBB. The change in left ventricular mechanical dyssynchrony after CRT was similar in these 2 groups of patients.
我们研究了 95 例连续患者，平均年龄 70 岁，这些患者因左心室（LV）射血分数<或=35%和 QRS 持续时间>或=120ms 而接受了 III 或 IV 类心力衰竭的心脏再同步治疗（CRT）。67 例患者存在固有左束支传导阻滞（LBBB）（组 1），28 例患者存在右心室起搏诱导的 LBBB（组 2）。在 CRT 之前和 CRT 后最后一次随访时，通过脉冲波多普勒测量 QRS 起始到 LV 射血结束的时间差（TPW-TDI）和组织多普勒成像中延迟最大的基底段收缩波起始到结束的时间差。将 TPW-TDI>50ms 定义为左心室机械不同步。将 CRT 后的 LV 收缩末期容积减少>或=15%定义为 CRT 阳性反应。在 16 个月的随访中，组 2 的 CRT 反应者百分比明显高于组 1（68%对 42%，P=0.04）。在调整年龄、性别和临床特征后，这种 CRT 反应模式仍然存在（P=0.008）。同样，组 2 的 QRS 持续时间在 CRT 后减少（178ms）明显大于组 1（154ms），P=0.01。两组在基线或随访时的 TPW-TDI 无显著差异。在随访期间，死亡率（15%对 14%）和 Kaplan-Meier 生存图无显著差异。患有心力衰竭和右心室起搏诱导的 LBBB 的患者对 CRT 的反应率高于患有固有 LBBB 的患者。这两组患者 CRT 后左心室机械不同步的变化相似。
