右心不全の病態生理と機能評価

In pediatric cardiology, many situations require analysis of right ventricular function, but accurate measurement and evaluation of right ventricular function are not easy. The pathophysiology of right heart failure involves three mechanisms: pressure overload, volume overload, and myocardial dysfunction. In practice, however, these mechanisms often overlap to varying degrees. The most frequent and important cause of right ventricular dysfunction is pulmonary hypertension. Assessment of right ventricular dysfunction due to pulmonary hypertension may serve not only as a prognostic factor in this disease, but also as a baseline study that can be applied and inferred in other diseases. Thus, assessment of right ventricular dysfunction in pressure overload can serve as a pivotal study for universal analysis of right ventricular behavior.
In this review, we describe the structure and function of the normal right ventricle, followed by an explanation of the evaluation method of right ventricular dysfunction. We explain that right ventricular dysfunction includes not only changes in the contractile function of the right ventricle as a whole, but also impairments in contractile style, right ventricular-pulmonary coupling, synchrony, interventricular interaction, and diastolic capacity.

小児循環器領域において右室機能解析を要する場面は多いが，正確な右室機能を測定評価することは簡単ではない．右心不全を呈する病態を分類すると，圧負荷，容量負荷，心筋障害の3つの機序が原因として挙げられるが，実際には様々な程度でこれらは混在することが多い．これらのうち右室機能障害の最も重要な原因は肺高血圧症であり，圧負荷に対する右室機能解析は同疾患の予後規定因子として評価が重要であるというだけではなく，右室機能障害を来す他疾患への応用と右室挙動の普遍的な解析のための基軸研究となり得る点で意義深い．
本総説では正常右室の構造・機能を解説したのち，右室機能障害の評価方法について説明する．右室機能障害は，右室全体の収縮機能の変化だけでなく，収縮様式，右室－肺動脈カップリング，同期性，心室間相互作用，拡張能などの障害も含んでいることを解説していく．

© 2021 Japanese Society of Pediatric Cardiology and Cardiac Surgery