Section on Cardiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157-1045, USA.
JACC Cardiovasc Imaging. 2012 Sep;5(9):861-70. doi: 10.1016/j.jcmg.2012.05.013.
The aim of this study was to evaluate the hypothesis that the adrenergic response of the intraventricular pressure difference (IVPD) is reduced in patients with preserved ejection fraction (EF) and diastolic dysfunction (DD).
In early diastole, there is a progressive IVPD extending from the left atrium (LA) to the left ventricular (LV) apex. In response to adrenergic stimulation, as occurs during exercise, the IVPD increases allowing rapid filling without an abnormal increase in LA pressure. Patients with heart failure with a reduced EF have impaired adrenergic augmentation of the IVPD.
We studied 166 consecutive patients undergoing dobutamine stress echocardiography who had no inducible ischemia and an EF ≥50%, of which 21 had normal diastolic function, 14 had impaired relaxation (grade 1), 80 had pseudonormal filling (grade 2), and 51 had restrictive filling (grade 3). Color M-mode Doppler (CMMD) images of mitral inflow were obtained at rest and during low (10 μg/kg/min) and peak (20 to 40 μg/kg/min) doses of dobutamine. The total IVPD from the LA to LV apex, LA to mid-LV, and mid-LV to the LV apex were calculated using the CMMD data to integrate the Euler equation.
Total IVPD was not different between groups at rest. With dobutamine, the total IVPD increased by 2.20 ± 1.95 mm Hg in normal subjects and by only 0.73 ± 1.33 mm Hg, 1.84 ± 1.63 mm Hg, and 1.08 ± 1.57 mm Hg in patients with grades 1, 2, and 3 DD, respectively. This difference was due to a failure in augmentation of IVPD from the mid-LV to the LV apex, indicating reduced apical ventricular suction with DD, whereas the IVPD from the LA to the mid-LV responded similarly to dobutamine in normal subjects and those with DD.
In patients with preserved EF, DD is associated with a reduced adrenergic augmentation of the IVPD from the mid-LV to the LV apex, reflecting less apical suction.
本研究旨在验证以下假设，即在射血分数保留（EF）和舒张功能障碍（DD）患者中，心室内压力差（IVPD）的肾上腺素反应降低。
在舒张早期，从左心房（LA）到左心室（LV）心尖处，IVPD 逐渐增大。在肾上腺素刺激下，如运动时，IVPD 增加，允许快速充盈，而不会导致 LA 压力异常升高。EF 降低的心力衰竭患者，IVPD 的肾上腺素增强作用受损。
我们研究了 166 例连续行多巴酚丁胺负荷超声心动图检查的患者，这些患者无诱发性缺血且 EF≥50%，其中 21 例舒张功能正常，14 例为松弛受损（1 级），80 例为假性正常充盈（2 级），51 例为限制性充盈（3 级）。在休息和低剂量（10μg/kg/min）和高剂量（20 至 40μg/kg/min）多巴酚丁胺期间，获取二尖瓣流入彩色 M 型多普勒（CMMD）图像。使用 CMMD 数据计算从 LA 到 LV 心尖、LA 到 LV 中部和 LV 中部到 LV 心尖的总 IVPD，以整合 Euler 方程。
休息时，各组之间的总 IVPD 无差异。在多巴酚丁胺作用下，正常组的总 IVPD 增加了 2.20±1.95mmHg，而 1 级、2 级和 3 级 DD 患者仅分别增加了 0.73±1.33mmHg、1.84±1.63mmHg 和 1.08±1.57mmHg。这种差异是由于 LV 中部至 LV 心尖处 IVPD 增强不足所致，表明 DD 时心尖心室抽吸减少，而 LA 至 LV 中部的 IVPD 对多巴酚丁胺的反应在正常人和 DD 患者中相似。
在 EF 保留的患者中，DD 与 LV 中部至 LV 心尖处 IVPD 的肾上腺素增强减少有关，反映出心尖抽吸减少。
