Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital and Li Ka Shing Institute of Health and Sciences, The Chinese University of Hong Kong, Hong Kong.
Eur Heart J. 2011 Aug;32(15):1891-9. doi: 10.1093/eurheartj/ehr118. Epub 2011 Apr 29.
Right ventricular apex (RVA) pacing may have deleterious effects on left ventricular (LV) systolic function, but its impact on LV diastolic function has not been explored.
Ninety-seven patients with sinus node dysfunction and ejection fraction (EF) ≥ 50% with permanent RVA pacing were randomly programmed to V-sense and V-pace modes and examined by echocardiography. Tissue Doppler imaging was employed to assess myocardial systolic velocity (S') and early diastolic velocity (E') at the mitral annulus. Systolic dyssynchrony was assessed using 12 LV segmental model (Ts-SD). Switching from V-sense to V-pace resulted in the worsening of both diastolic and systolic functions as shown by the decreased EF, reduced mean E' and S' velocities, as well as increase in LV volume and Ts-SD (all P< 0.001). Reduction of mean E' and S' of ≥ 1 cm/s occurred in 35 (36%) and 45 (46%) patients, respectively. In pre-defined subgroup analysis, only patients with pre-existing LV diastolic dysfunction had a significant reduction of mean E' and S' (both P< 0.001) even after age adjustment. Multivariate logistic regression analysis showed that independent factors for the reduction of mean E' ≥ 1 cm/s or mean S' ≥ 1 cm/s at V-pace were pre-existing LV diastolic dysfunction [odds ratio (OR): 4.735, P= 0.007 for E'; OR: 3.307, P= 0.022 for S'] and systolic dyssynchrony at V-pace (OR: 5.459, P= 0.007 for E'; OR: 2.725, P= 0.035 for S').
In patients with preserved EF, RVA pacing is associated with the deterioration of both LV diastolic and systolic functions, which is particularly obvious in those with pre-existing LV diastolic dysfunction and V-pace-induced systolic dyssynchrony.
右心室心尖（RVA）起搏可能对左心室（LV）收缩功能产生有害影响，但尚未探讨其对 LV 舒张功能的影响。
97 例窦房结功能障碍且射血分数（EF）≥50%的患者，其心脏永久 RVA 起搏，采用随机程控为 V-sense 和 V-pace 模式，并接受超声心动图检查。组织多普勒成像用于评估二尖瓣环心肌收缩速度（S'）和早期舒张速度（E'）。采用 12 节段 LV 模型（Ts-SD）评估收缩不同步。从 V-sense 切换到 V-pace 导致舒张和收缩功能均恶化，表现为 EF 降低、平均 E'和 S'速度降低，以及 LV 容积和 Ts-SD 增加（均 P<0.001）。35 例（36%）和 45 例（46%）患者的平均 E'和 S'分别减少≥1cm/s。在预先设定的亚组分析中，仅在存在 LV 舒张功能障碍的患者中，平均 E'和 S'的降低具有显著意义（均 P<0.001），即使在年龄调整后也是如此。多变量逻辑回归分析显示，V-pace 时平均 E'≥1cm/s 或平均 S'≥1cm/s 减少的独立因素是存在 LV 舒张功能障碍[比值比（OR）：4.735，P=0.007，E'；OR：3.307，P=0.022，S']和 V-pace 时的收缩不同步（OR：5.459，P=0.007，E'；OR：2.725，P=0.035，S'）。
在 EF 保留的患者中，RVA 起搏与 LV 舒张和收缩功能的恶化相关，在存在 LV 舒张功能障碍和 V-pace 诱导的收缩不同步的患者中更为明显。
