Cleveland Clinic, Cleveland, OH
Cardiology, Austin Health, Melbourne, Australia.
J Am Heart Assoc. 2018 Feb 6;7(3):e007489. doi: 10.1161/JAHA.117.007489.
QRS narrowing following cardiac resynchronization therapy with biventricular (BiV) or left ventricular (LV) pacing is likely affected by patient-specific conduction characteristics (PR, qLV, LV-paced propagation interval), making a universal programming strategy likely ineffective. We tested these factors using a novel, device-based algorithm (SyncAV) that automatically adjusts paced atrioventricular delay (default or programmable offset) according to intrinsic atrioventricular conduction.
Seventy-five patients undergoing cardiac resynchronization therapy (age 66±11 years; 65% male; 32% with ischemic cardiomyopathy; LV ejection fraction 28±8%; QRS duration 162±16 ms) with intact atrioventricular conduction (PR interval 194±34, range 128-300 ms), left bundle branch block, and optimized LV lead position were studied at implant. QRS duration (QRSd) reduction was compared for the following pacing configurations: nominal simultaneous BiV (Mode I: paced/sensed atrioventricular delay=140/110 ms), BiV+SyncAV with 50 ms offset (Mode II), BiV+SyncAV with offset that minimized QRSd (Mode III), or LV-only pacing+SyncAV with 50 ms offset (Mode IV). The intrinsic QRSd (162±16 ms) was reduced to 142±17 ms (-11.8%) by Mode I, 136±14 ms (-15.6%) by Mode IV, and 132±13 ms (-17.8%) by Mode II. Mode III yielded the shortest overall QRSd (123±12 ms, -23.9% [<0.001 versus all modes]) and was the only configuration without QRSd prolongation in any patient. QRS narrowing occurred regardless of QRSd, PR, or LV-paced intervals, or underlying ischemic disease.
Post-implant electrical optimization in already well-selected patients with left bundle branch block and optimized LV lead position is facilitated by patient-tailored BiV pacing adjusted to intrinsic atrioventricular timing using an automatic device-based algorithm.
心脏再同步治疗后 QRS 波变窄（双心室[BiV]或左心室[LV]起搏）可能受患者特定的传导特征（PR、qLV、LV 起搏传播间隔）影响，因此通用程控策略可能无效。我们使用一种新的基于设备的算法（SyncAV）来测试这些因素，该算法根据固有房室传导自动调整起搏房室延迟（默认或可编程偏移）。
在植入时，对 75 例接受心脏再同步治疗（年龄 66±11 岁；65%为男性；32%为缺血性心肌病；LV 射血分数 28±8%；QRS 时限 162±16 ms）的患者进行了研究，这些患者具有完整的房室传导（PR 间期 194±34，范围 128-300 ms）、左束支传导阻滞和优化的 LV 导联位置。比较了以下起搏配置的 QRS 时限（QRSd）降低情况：名义上同时的 BiV（模式 I：起搏/感知房室延迟=140/110 ms）、带 50 ms 偏移的 BiV+SyncAV（模式 II）、使 QRSd 最小化的 BiV+SyncAV 偏移（模式 III）或仅 LV 起搏+带 50 ms 偏移的 SyncAV（模式 IV）。固有 QRSd（162±16 ms）在模式 I 下降低至 142±17 ms（-11.8%），在模式 IV 下降低至 136±14 ms（-15.6%），在模式 II 下降低至 132±13 ms（-17.8%）。模式 III 产生的总体 QRSd 最短（123±12 ms，-23.9% [<0.001 与所有模式]），并且是唯一一种在任何患者中都没有 QRSd 延长的配置。QRS 变窄发生与 QRSd、PR 或 LV 起搏间隔或潜在的缺血性疾病无关。
在已经选择良好的左束支传导阻滞患者中，通过自动设备算法调整至固有房室时间的患者定制的 BiV 起搏，可以实现已优化 LV 导联位置的患者的术后电优化。
