Department of Cardiology, First Affiliated Hospital of Kunming Medical College, Kunming, Yunnan 650032, China.
Chin Med J (Engl). 2009 Oct 20;122(20):2455-60.
Cardiac resynchronization therapy (CRT) is a major breakthrough in therapy for advanced heart failure patients; however, a number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to CRT.
Seven patients, six males and one female, aged (56.43 +/- 6.13) years, all diagnosed with dilated cardiomyopathy, were included in this study. They were all non-responders to CRT who underwent routine optimization postoperatively, and received optimal drug therapy. On the basis of biventricular pacing, titrating various atrioventricular (AV) intervals were performed to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction. Then, the effects of AV intrinsic conduction during CRT were evaluated.
On the setting of AV intrinsic conduction during CRT, the true fusional QRS complexes were the narrowest, and all patients showed alleviation of symptoms, improvement of exercise tolerance, life quality and hemodynamic parameters during more than 6 months of follow-up.
Titrating AV intervals to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction will be beneficial for non-responders to CRT. Maintaining AV intrinsic conduction during CRT may decrease the rates of non-responders to CRT.
心脏再同步治疗（CRT）是治疗晚期心力衰竭患者的重大突破；然而，仍有许多关键的临床研究问题悬而未决，也许最重要的问题是为什么显然适合的患者对 CRT 没有反应。
本研究纳入了 7 名患者，6 名男性和 1 名女性，年龄（56.43±6.13）岁，均被诊断为扩张型心肌病。他们都是 CRT 无反应者，术后接受常规优化，并接受最佳药物治疗。在双心室起搏的基础上，对各种房室（AV）间期进行滴定，以获得由双心室起搏和 AV 固有传导组成的真正融合 QRS 复合体。然后，评估 CRT 期间 AV 固有传导的效果。
在 CRT 期间 AV 固有传导的设置下，真正的融合 QRS 复合体最窄，所有患者在随访超过 6 个月期间均表现出症状缓解、运动耐量提高、生活质量和血液动力学参数改善。
滴定 AV 间期以获得由双心室起搏和 AV 固有传导组成的真正融合 QRS 复合体将有利于 CRT 无反应者。在 CRT 期间保持 AV 固有传导可能会降低 CRT 无反应者的比率。
