Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology , Tokyo , Japan.
Department of Animal Science, Faculty of Life and Environmental Science, TEIKYO University of Science , Tokyo , Japan.
Am J Physiol Heart Circ Physiol. 2019 Apr 1;316(4):H882-H888. doi: 10.1152/ajpheart.00686.2018. Epub 2019 Feb 8.
Restrictions on the conventional evaluation of diastolic function have been recognized, especially under various loading conditions. Recently, new noninvasive ventricular vortex indexes have been introduced and are expected to reflect the cardiac function. Physiologically, there is a hypothesis that the intraventricular pressure difference (IVPD) is related to the formation of vortexes. IVPD and vortex indexes were simultaneously measured, and the relationship between the two was investigated. To verify the possibility of diastolic vorticity as an index of diastolic relaxation, a correlation between diastolic vorticity and the load dependency of vorticity [time constant (τ)] was examined. Six healthy dogs were studied using transthoracic echocardiography, pressure, and a conductance catheter. Vorticity was analyzed using vector flow mapping (VFM). IVPD was determined using Euler's equation with color M-mode Doppler images. Data were obtained at baseline, at balloon dilatation in the thoracic aorta to alter afterload, at hydroxyethyl starch infusion to alter preload, and at milrinone administration to alter ventricular relaxation. Peak vorticity at early diastole (E-Vor) and IVPD of the midventricle (MIVPD) decreased under pressure loading, were unchanged under volume loading, and increased during milrinone administration. In multivariate analysis, the independent predictors of τ were global longitudinal strain, strain rate at early diastole, and E-Vor. MIVPD was strongly correlated with E-Vor ( r = 0.84). VFM-derived peak E vorticity was strongly related to IVPD, especially MIVPD, under various loading conditions. Both of these novel indexes are promising as reliable indexes of ventricular relaxation, independent from preload. NEW & NOTEWORTHY We showed the close relationship of vortex and intraventricular pressure difference and showed that both of them can become new markers of the left ventricular relaxation property. Our present study creates a paradigm for future studies in the field of intraventircular flow physiology and clinical diastology.
已经认识到常规舒张功能评估存在局限性，尤其是在各种负荷条件下。最近，引入了新的非侵入性心室涡流指数，预计可反映心功能。从生理学角度来看，有一种假设认为，室内压差（IVPD）与涡流的形成有关。同时测量 IVPD 和涡流指数，并研究两者之间的关系。为了验证舒张期涡流作为舒张期松弛指标的可能性，研究了舒张期涡流与涡流[时间常数（τ）]的负荷依赖性之间的关系。使用经胸超声心动图、压力和传导导管对 6 只健康犬进行研究。使用向量流图（VFM）分析涡流。使用彩色 M 型多普勒图像的欧拉方程确定 IVPD。在基线、胸主动脉球囊扩张改变后负荷、羟乙基淀粉输注改变前负荷和米力农给药改变心室松弛时获得数据。舒张早期峰值涡流（E-Vor）和中部心室的 IVPD（MIVPD）在压力负荷下降低，在容量负荷下不变，在米力农给药时增加。在多变量分析中，τ的独立预测因子为整体纵向应变、舒张早期应变率和 E-Vor。MIVPD 与 E-Vor 呈强相关（r=0.84）。VFM 衍生的舒张早期峰值 E 涡流与 IVPD 密切相关，尤其是 MIVPD，在各种负荷条件下均如此。这两个新指数都是很有前途的左心室松弛特性的可靠指标，与前负荷无关。本研究表明了涡流和室内压差之间的密切关系，并表明两者都可以成为左心室松弛特性的新标志物。本研究为未来的心室流动力学和临床舒张学领域的研究创造了范例。
