BACKGROUND Long-term course after atrial switch operation is determined by increasing right ventricular (RV) insufficiency. The aim of our study was to investigate subtle functional parameters by invasive measurements with conductance technique and noninvasive examinations with cardiac magnetic resonance imaging (CMR). METHODS We used invasive (pressure-volume loops under baseline conditions and dobutamine) and noninvasive techniques (CMR with feature tracking [FT] method) to evaluate RV function. All patients had cardiopulmonary exercise testing (CPET). RESULTS From 2011 to 2013, 16 patients aged 28.2 ± 7.3 (22-50) years after atrial switch surgery (87.5% Senning and 12.5% Mustard) were enrolled in this prospective study. All patients were in New York Heart Association (NYHA) class I to II and presented mean peak oxygen consumption of 30.1 ± 5.7 (22.7-45.5) mL/kg/min. CMR-derived end-diastolic volume was 110 ± 22 (78-156) mL/m2 and RV ejection fraction 41 ± 8% (25-52%). CMR-FT revealed lower global systolic longitudinal, radial, and circumferential strain for the systemic RV compared with the subpulmonary left ventricle. End-systolic elastance (Ees) was overall reduced (compared with data from the literature) and showed significant increase under dobutamine (0.80 ± 0.44 to 1.89 ± 0.72 mm Hg/mL, p ≤ 0.001), whereas end-diastolic elastance (Eed) was not significantly influenced (0.11 ± 0.70 to 0.13 ± 0.15 mm Hg/mL, p = 0.454). We found no relevant relationship between load-independent conductance indices and strain or CPET parameters. Conductance analysis revealed significant mechanical dyssynchrony, higher during diastole (mean 30 ± 4% baseline, 24 ± 6% dobutamine) than during systole (mean 17 ± 6% baseline, 19 ± 7% dobutamine). CONCLUSIONS Functional assessment of a deteriorating systemic RV remains demanding. Conductance indices as well as the CMR-derived strain parameters showed overall reduced values, but a significant relationship was not present (including CPET). Our conductance analysis revealed intraventricular and predominantly diastolic RV dyssynchrony.

中文翻译：

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心房开关手术后患者的综合功能分析。

背景心房开关手术后的长期病程由增加的右心室（RV）功能不全决定。我们研究的目的是通过电导技术的有创测量和心脏磁共振成像 (CMR) 的无创检查来研究细微的功能参数。方法 我们使用有创（基线条件下的压力-容积环和多巴酚丁胺）和无创技术（具有特征跟踪 [FT] 方法的 CMR）来评估 RV 功能。所有患者均进行了心肺运动试验（CPET）。结果 从 2011 年到 2013 年，16 名年龄在 28.2 ± 7.3 (22-50) 岁的心房开关手术患者（87.5% Senning 和 12.5% Mustard）参加了这项前瞻性研究。所有患者均属于纽约心脏协会 (NYHA) I 至 II 级，平均峰值耗氧量为 30.1 ± 5。7 (22.7-45.5) 毫升/公斤/分钟。CMR 衍生的舒张末期容积为 110 ± 22 (78-​​156) mL/m2，RV 射血分数为 41 ± 8% (25-52%)。CMR-FT 显示，与肺下左心室相比，全身 RV 的全局收缩纵向、径向和周向应变较低。收缩末期弹性 (Ees) 总体降低（与文献数据相比），并在多巴酚丁胺作用下显着增加（0.80 ± 0.44 至 1.89 ± 0.72 mm Hg/mL，p ≤ 0.001），而舒张末期弹性 (Eed)没有受到显着影响（0.11 ± 0.70 至 0.13 ± 0.15 mm Hg/mL，p = 0.454）。我们发现与负载无关的电导指数与应变或 CPET 参数之间没有相关关系。电导分析显示显着的机械不同步，在舒张期更高（平均 30 ± 4% 基线，24 ± 6% 多巴酚丁胺）比收缩期（平均 17 ± 6% 基线，19 ± 7% 多巴酚丁胺）。结论 对恶化的全身 RV 进行功能评估仍然要求很高。电导指数以及 CMR 衍生的应变参数显示出整体降低的值，但不存在显着关系（包括 CPET）。我们的电导分析显示心室内和主要是舒张期 RV 不同步。