Fouron J C, Douste-Blazy M Y, Ducharme G, van Doesburg N, Davignon A
Br Heart J. 1982 Mar;47(3):277-80. doi: 10.1136/hrt.47.3.277.
Recently it has been shown that in patients with transposition of the great arteries the isometric relaxation time of the left ventricle could be negative in the presence of normal pulmonary artery pressure. In order to find an explanation for this apparently paradoxical situation, it was decided to evaluate the importance of the delay of closure of the pulmonary valve in 15 patients with transposition of the great arteries. This delay is called the hang-out time. The hang-out time was found to correlate inversely with the isometric relaxation time as well as with the pulmonary artery systolic (r = -0 . 70) and mean pressures. A weaker correlation was found between the isometric relaxation time and the time of mitral valve opening. These results show that in transposition of the great arteries with normal pulmonary artery pressure, the pulmonary valve has a prolonged hang-out time, to the extent that it frequently closes after the opening of the mitral valve, explaining the negative isometric relaxation time found in these cases. This finding may help in the non-invasive assessment of the pulmonary vascular resistance of patients with transposition of the great arteries.
最近研究表明，在大动脉转位患者中，当肺动脉压力正常时，左心室等容舒张时间可能为负值。为了找到对这种明显矛盾情况的解释，研究人员决定评估15例大动脉转位患者肺动脉瓣关闭延迟的重要性。这种延迟被称为“悬挂时间”。研究发现，“悬挂时间”与等容舒张时间以及肺动脉收缩压（r = -0.70）和平均压呈负相关。等容舒张时间与二尖瓣开放时间之间的相关性较弱。这些结果表明，在肺动脉压力正常的大动脉转位患者中，肺动脉瓣“悬挂时间”延长，以至于它经常在二尖瓣开放后关闭，这就解释了这些病例中出现的负等容舒张时间。这一发现可能有助于对大动脉转位患者的肺血管阻力进行无创评估。
