Institute of Public Health and Clinical Medicine, Umea University, Umea, Sweden.
Department of Surgical and Perioperative Sciences, Umea University, Umea, Sweden.
Echocardiography. 2020 Nov;37(11):1908-1918. doi: 10.1111/echo.14698. Epub 2020 May 19.
Diastole is an important component of the cardiac cycle, during which time optimum filling of the ventricle determines physiological stroke volume ejected in the succeeding systole. Many factors contribute to optimum ventricular filling including venous return, left atrial filling from the pulmonary circulation, and emptying into the left ventricle. Left ventricular filling is also impacted by the cavity emptying function and also its synchronous function which may suppress early diastolic filling in severe cases of dyssynchrony. Sub-optimum LA emptying increases cavity pressure, causes enlarged left atrium, unstable myocardial function, and hence atrial arrhythmia, even atrial fibrillation. Patients with clear signs of raised left atrial pressure are usually symptomatic with exertional breathlessness. Doppler echocardiography is an ideal noninvasive investigation for diagnosing raised left atrial pressure as well as following treatment for heart failure. Spectral Doppler based increased E/A, shortened E-wave deceleration time, increased E/e', and prolonged atrial flow reversal in the pulmonary veins are all signs of raised left atrial pressure. Left atrial reduced myocardial strain is another correlate of raised cavity pressure (>15 mm Hg). In patients with inconclusive signs of raised left atrial pressure at rest, exercise/stress echocardiography or simply passive leg lifting should identify those with stiff left ventricular which suffers raised filling pressures with increased venous return.
舒张期是心动周期的重要组成部分，在此期间，心室的最佳充盈决定了随后收缩期的生理射血量。许多因素有助于心室的最佳充盈，包括静脉回流、从肺循环向左心房的填充，以及向左心室的排空。左心室充盈也受到腔室排空功能以及同步功能的影响，在严重不同步的情况下，可能会抑制早期舒张充盈。左心房排空不足会增加腔室压力，导致左心房增大、心肌功能不稳定，从而导致房性心律失常，甚至心房颤动。有明确左心房压力升高迹象的患者通常会出现活动时呼吸困难的症状。多普勒超声心动图是诊断左心房压力升高以及心力衰竭治疗后随访的理想非侵入性检查方法。基于频谱多普勒的 E/A 比值增加、E 波减速时间缩短、E/e'比值增加以及肺静脉内心房血流反向时间延长，均为左心房压力升高的征象。左心房心肌应变减少也是腔室压力升高（>15 毫米汞柱）的另一个相关因素。对于休息时左心房压力升高迹象不明确的患者，运动/应激超声心动图或简单的被动抬腿试验应能识别出那些左心室僵硬的患者，这些患者随着静脉回流的增加而承受升高的充盈压力。
