Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, USA.
Division of Pediatric Cardiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
Pediatr Cardiol. 2021 Feb;42(2):278-288. doi: 10.1007/s00246-020-02480-2. Epub 2020 Oct 26.
Left ventricular (LV) morphology may affect right ventricular (RV) function before and after Fontan palliation in patients with hypoplastic left heart syndrome (HLHS). We sought to assess the potential impact of LV morphology on RV function in patients with HLHS using cardiac magnetic resonance (CMR) imaging. A retrospective analysis of available CMR scans from all patients with HLHS was performed. LV morphology was categorized as absent/slit-like or globular/miniaturized. Volumetric analysis was performed using manual disc-summation method on steady-state free precession (SSFP) stack obtained in short-axis orientation of the ventricles. 4-chamber and short-axis SSFP images were used to measure strain on a semi-automated feature-tracking (FT) module. Two sample t-test was used to compare the groups. A total of 48 CMR scans were analyzed. Of those, 12 patients had absent/slit-like and 36 had globular/miniaturized LV morphology. Averaged 4-chamber longitudinal RV strain was significantly higher for absent/slit-like (- 17.6 ± 4.7%) than globular/miniaturized (- 13.4 ± 3.5; P = 0.002). Averaged 4-chamber radial RV strain was also significantly higher for absent/slit-like (33.1 ± 14.9%) than globular/miniaturized (21.6 ± 7.1; P = 0.001). For globular/miniaturized LV morphology, the decreases of 4-chamber longitudinal and radial strains were mainly attributable to the septal basilar and septal mid-ventricular segments. No differences were found in short-axis RV global circumferential strain between the morphologic subtypes (absent/slit-like - 15.0 ± 6.5, globular/miniaturized - 15.7 ± 4.7; P = 0.68). Larger LV remnants, with globular/miniaturized LV morphology, demonstrated diminished strain in the septal base and mid-ventricle segments. Patients with globular/miniaturized LV morphology may benefit with closer monitoring and lower threshold to start heart failure medications. These results exemplify the utility of including both septal and regional deformation in systemic RV strain analysis.
左心室（LV）形态可能会影响左心发育不全综合征（HLHS）患者Fontan 姑息术后的右心室（RV）功能。我们试图使用心脏磁共振（CMR）成像评估 LV 形态对 HLHS 患者 RV 功能的潜在影响。对所有 HLHS 患者的 CMR 扫描进行了回顾性分析。LV 形态分为缺失/裂隙样或球形/小型化。使用心室短轴方向获得的稳态自由进动（SSFP）堆栈的手动圆盘求和方法进行容积分析。使用半自动特征跟踪（FT）模块在 4 腔和短轴 SSFP 图像上测量应变。使用两样本 t 检验比较两组。共分析了 48 次 CMR 扫描。其中 12 例患者 LV 形态缺失/裂隙样，36 例患者 LV 形态球形/小型化。缺失/裂隙样组（-17.6±4.7%）的 4 腔室纵向 RV 应变平均值明显高于球形/小型化组（-13.4±3.5%；P=0.002）。缺失/裂隙样组（33.1±14.9%）的 4 腔室径向 RV 应变平均值也明显高于球形/小型化组（21.6±7.1%；P=0.001）。对于球形/小型化的 LV 形态，4 腔室纵向和径向应变的降低主要归因于室间隔基底和室间隔中室段。形态亚型之间的短轴 RV 整体周向应变无差异（缺失/裂隙样-15.0±6.5，球形/小型化-15.7±4.7；P=0.68）。具有球形/小型化 LV 形态的较大 LV 残端在室间隔基底和中室段显示应变降低。具有球形/小型化 LV 形态的患者可能受益于更密切的监测和更低的心力衰竭药物起始阈值。这些结果证明了在系统性 RV 应变分析中包括间隔和区域性变形的效用。
