Background

Current diagnostic criteria for noncompaction cardiomyopathy (NCC) lack specificity, and the disease lacks prognostic indicators. Reverse apical rotation (RAR) with abnormal rotation of the cardiac apex in the same clockwise direction as the base has been described in adults with NCC. The aim of this study was to test the hypothesis that RAR might differentiate between symptomatic NCC and benign hypertrabeculations and might be associated with ventricular dysfunction.

Methods

Echocardiograms from 28 children with NCC without cardiac malformations were prospectively compared with those from 29 age-matched normal control subjects. A chart review was performed to identify the patients’ histories and clinical characteristics. Speckle-tracking was used to measure longitudinal strain, circumferential strain, and rotation.

Results

RAR occurred in 39% of patients with NCC. History of left ventricular (LV) dysfunction or arrhythmia was universal in, but not exclusive to, patients with RAR. Patients with RAR had lower LV longitudinal strain but similar ejection fractions compared with patients without RAR (median, -15.6% [interquartile range, -12.9% to -19.3%] vs -19% [interquartile range, -14.5% to -21.9%], P < .01; 53% [interquartile range, 43% to 68%] vs 61% [interquartile range, 58% to 67%], P = .08). Only a pattern of contraction with RAR, early arrest of twisting by mid-systole, and premature untwisting was associated with lower ejection fraction (46%; interquartile range, 43% to 52%; P = .006).

Conclusions

RAR is not a sensitive but is a specific indicator of complications in children with NCC. Therefore, RAR may have prognostic rather than diagnostic value. Premature untwisting of the left ventricle during ejection may be an even more worrisome indicator of LV dysfunction.

中文翻译：

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非致密性心肌病患儿左心室旋转力学的初步研究：它们是否影响心室功能？

背景

当前非致密性心肌病（NCC）的诊断标准缺乏特异性，并且该疾病缺乏预后指标。在患有NCC的成人中，已经描述了心尖逆时针旋转（RAR），心尖沿与基部相同的顺时针方向旋转。本研究的目的是检验以下假设：RAR可能在有症状的NCC和良性小梁增高之间进行区分，并且可能与心室功能障碍有关。

方法

前瞻性比较了28例无心脏畸形的NCC儿童的超声心动图与29例年龄相匹配的正常对照组的超声心动图。进行了图表检查，以确定患者的病史和临​​床特征。斑点跟踪用于测量纵向应变，周向应变和旋转。

结果

RAR发生在39％的NCC患者中。左心室功能不全或心律不齐的病史在RAR患者中普遍存在，但并非唯一。与没有RAR的患者相比，RAR的患者左心室纵向张力较低，但射血分数相似（中位数为-15.6％[四分位数范围，-12.9％至-19.3％]与-19％[四分位数范围，-14.5％至-21.9％ ]，P <.01； 53％[四分位间距，从43％到68％]对比61％[四分位间距，从58％到67％]，P = .08）。仅有RAR收缩，收缩中段早期扭转和过早解扭的模式与较低的射血分数有关（46％；四分位间距为43％至52％；P  = .006）。

结论

RAR不是敏感的，而是NCC儿童并发症的具体指标。因此，RAR可能具有预后价值而不是诊断价值。射血过程中左心室过早扭转可能是LV功能障碍的更令人担忧的指标。