A.O.U. Policlinico Vittorio Emanuele, PO Ferrarotto, Catania, Italy.
Vito Fazzi Hospital, Lecce, Italy.
JACC Clin Electrophysiol. 2017 May;3(5):482-490. doi: 10.1016/j.jacep.2016.11.011. Epub 2017 Feb 1.
This study sought to compare the Intrinsic Rhythm Support (IRSplus) and Ventricular Pace Suppress (VpS) in terms of right ventricular pacing percentage (VP %), mean atrioventricular interval (MAVI), atrial fibrillation, and cardiac volumes.
Modern pacemakers are provided with algorithms for reducing unnecessary ventricular pacing. These may be classified as: periodic search for intrinsic atrioventricular (AV) conduction prolonging the AV delay accordingly; or DDD-ADI mode switch. The IRSplus and VpS algorithms belong to the former and latter classes, respectively.
Patients with sick sinus dysfunction without evidence of II/III degree AV block were 1:1 randomized to 6-month periods of either IRSplus or VpS, and then crossed over. Subsequent follow-ups were at the 12th month after randomization for device data retrieving, and at the 18th month with the same device programming for echocardiographic assessment.
A total of 230 patients (62% males, median age 75 years [interquartile range: 69 to 79 years]) were enrolled. At a linear mixed-model analysis with order of treatment and investigational sites as nested random effects, differences in VP% and MAVI reached statistical significance: VP% was 1% (0% to 11%) during IRSplus and 3% (0% to 26%) during VpS (p = 0.029); MAVI was 225 ms (198 to 253 ms) during IRSplus and 214 ms (188 to 240 ms) during VpS (p = 0.014). No differences were observed in atrial fibrillation burden and incidence, ejection fraction, and cardiac volumes.
Both IRSplus and VpS algorithms ensured VP% ≤3% in most patients with sinus node dysfunction and preserved AV conduction. The IRSplus was slightly more efficient in reducing VP% at the expense of a small MAVI increase, with statistical but clinically insignificant differences. (Ventricular Pace Suppression Versus Intrinsic Rhythm Support Study; NCT01528657).
本研究旨在比较 Intrinsic Rhythm Support（IRSplus）和 Ventricular Pace Suppress（VpS）在右心室起搏百分比（VP%）、平均房室间期（MAVI）、心房颤动和心腔容积方面的差异。
现代起搏器配备了减少不必要心室起搏的算法。这些算法可分为两类：定期寻找内在的房室（AV）传导，相应延长 AV 延迟；或 DDD-ADI 模式切换。IRSplus 和 VpS 算法分别属于前一类和后一类。
窦房结功能障碍且无 II/III 度 AV 阻滞证据的患者按 1:1 随机分为 IRSplus 或 VpS 组，每组持续 6 个月，然后交叉。随后的随访在随机分组后第 12 个月进行设备数据检索，第 18 个月进行相同设备编程的超声心动图评估。
共纳入 230 例患者（62%为男性，中位年龄 75 岁[四分位间距：69 至 79 岁]）。在线性混合模型分析中，以治疗顺序和研究地点为嵌套随机效应，VP%和 MAVI 的差异具有统计学意义：IRSplus 组的 VP%为 1%（0%至 11%），VpS 组为 3%（0%至 26%）（p=0.029）；IRSplus 组的 MAVI 为 225 ms（198 至 253 ms），VpS 组为 214 ms（188 至 240 ms）（p=0.014）。两组心房颤动负荷和发生率、射血分数和心腔容积无差异。
在窦房结功能障碍且保留 AV 传导的患者中，IRSplus 和 VpS 算法都能确保 VP%≤3%。IRSplus 在降低 VP%方面略有效率更高，但 MAVI 略有增加，差异具有统计学意义，但临床意义不大。（心室起搏抑制与内在节律支持研究；NCT01528657）。
