BACKGROUND In biventricular physiology, abnormal septal motion is a hallmark of mechanical dyssynchrony in the left bundle branch block. However, in single-ventricle (SV) physiology, morphologic variations in systemic ventricles pose a challenge in evaluating the negative impact of mechanical dyssynchrony. The present study aimed to characterize the pathologic dyssynchronous contraction patterns in patients with SV. METHODS In this retrospective study, 70 consecutive postoperative patients with SV anatomy with prolonged QRS duration (25 female patients; median age, 14 years) were enrolled. We divided each SV into two regions and analyzed independent strains using two-dimensional speckle-tracking echocardiography. From an earlier activated ventricular wall, we calculated the strain ratio (Rstrains) of two values (%) during the QRS period and the ejection period: (100 + Strainejection)/(100 + StrainQRS). We reviewed the clinical profiles, B-type natriuretic peptide plasma levels, exercise capacity, and morbidity. Six patients who underwent cardiac resynchronization therapy (CRT) were analyzed regarding changes in strain patterns and ventricular volume. RESULTS Higher Rstrains, indicating a preceding contraction and subsequent dyskinetic dilation of the earlier activated ventricular wall, was associated with increased B-type natriuretic peptide, reduced exercise capacity, and poor outcome. However, delayed contraction of the later activated ventricular wall was not associated with the effects. Decreases in Rstrains and ventricular volume reductions were observed in all patients after CRT. CONCLUSIONS A specific strain pattern in an earlier activated ventricular wall indicates mechanical dyssynchrony in patients with SV. This pattern is very similar to the septal flash in adult patients with left bundle branch block. This strategy might be a promising approach for selecting appropriate candidates for CRT in patients with SV.

中文翻译：

---

早期激活的心室壁的间隔闪光样运动代表了单心室解剖中机械不同步的病理生理学。

背景在双心室生理学中，室间隔异常运动是左束支传导阻滞机械不同步的标志。然而，在单心室 (SV) 生理学中，全身心室的形态变化对评估机械不同步的负面影响构成了挑战。本研究旨在表征 SV 患者的病理性不同步收缩模式。方法 在这项回顾性研究中，连续入组 70 名术后 SV 解剖结构 QRS 持续时间延长的患者（25 名女性患者；中位年龄 14 岁）。我们将每个 SV 分为两个区域，并使用二维斑点跟踪超声心动图分析独立应变。从早期激活的心室壁，我们计算了 QRS 期和射血期两个值 (%) 的应变比 (Rstrains)：(100 + Strainjection)/(100 + StrainQRS)。我们回顾了临床概况、B 型利钠肽血浆水平、运动能力和发病率。分析了六名接受心脏再同步治疗 (CRT) 的患者的应变模式和心室容积的变化。结果 较高的 Rstrains 表明较早激活的心室壁发生了先前的收缩和随后的运动障碍扩张，与 B 型利钠肽增加、运动能力降低和较差的结果相关。然而，后来激活的心室壁的延迟收缩与这些影响无关。在 CRT 后，所有患者均观察到 Rstrains 减少和心室容积减少。结论 早期激活的心室壁中的特定应变模式表明 SV 患者存在机械不同步。这种模式与成人左束支传导阻滞患者的间隔闪光非常相似。该策略可能是为 SV 患者选择合适的 CRT 候选者的一种有前途的方法。