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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心房切换手术后患者的综合功能分析。

背景技术通过增加右心室（RV）功能不全来确定心房切换手术后的长期病程。我们研究的目的是通过电导技术的侵入性测量和心脏磁共振成像（CMR）的非侵入性检查来研究微妙的功能参数。方法我们使用侵入性（基线条件下的压力-容积环和多巴酚丁胺）和非侵入性技术（具有特征跟踪[FT]方法的CMR）评估RV功能。所有患者均进行了心肺运动测试（CPET）。结果2011年至2013年，该前瞻性研究纳入了16位年龄为28.2±7.3（22-50）岁的心房切换手术患者（87.5％Senning和12.5％Mustard）。所有患者均属于纽约心脏协会（NYHA）的I级至II级，平均峰值耗氧量为30。1±5.7（22.7-45.5）毫升/千克/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，与左肺下心室相比，全身性RV的总收缩期纵，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。电导分析显示明显的机械不同步，在舒张期较高（平均基线为30±4％，24±6％的多巴酚丁胺）（收缩期时平均为17±6％，多巴酚丁胺为19±7％）。结论对不断恶化的系统性RV进行功能评估仍然是一项艰巨的任务。电导指数以及CMR衍生的应变参数显示总体降低值，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性RV不同步。