Department of Cardiology, Liverpool Hospital, Elizabeth Street, Liverpool, Sydney, New South Wales, Australia.
Faculty of Medicine, South Western Sydney Clinical School, The University of New South Wales, Sydney, New South Wales, Australia.
Eur Heart J Cardiovasc Imaging. 2018 Nov 1;19(11):1253-1259. doi: 10.1093/ehjci/jex338.
An impaired contractile reserve (CR) may be an early manifestation of left ventricular (LV) systolic dysfunction in hypertensive patients. Using normotensive patients as controls, we examined LV CR and its correlates in hypertensive patients.
One hundred and twenty-nine (68 men, aged 58.6 ± 9.5 years, 73 had hypertension) patients underwent dobutamine echocardiography. Patients with significant coronary or valvular disease, previous myocardial infarction or revascularization, and diabetes were excluded. LV ejection fraction (LVEF), global longitudinal strain (GLS), circumferential, and radial strain were measured at rest and at low-dose dobutamine. Absolute CR was calculated as the difference in LVEF and multi-directional strain between low-dose dobutamine and their corresponding resting values. Relative CR is the ratio of absolute CR to their corresponding resting values. Hypertensive patients, compared with controls, have significantly impaired GLS at rest (-16.8 ± 2.2% vs. -19.6 ± 1.5%, P < 0.0001) and at low-dose dobutamine (-17.9 ± 2.7% vs. -22.8 ± 2.6%, P < 0.0001). Absolute and relative GLS CR were significantly lower in hypertensive patients (-1.1 ± 2.1% vs. -3.2 ± 2.2% and 7.4 ± 13.9% vs. 16.4 ± 11.7%, respectively, both P < 0.001). Circumferential strain was preserved at rest but impaired at low-dose dobutamine in hypertensive patients (-23.0 ± 4.1% vs. -25.2 ± 3.4%, P = 0.002). There were no differences in LVEF or radial strain between the groups. LV wall thickness and systolic blood pressure correlated significantly with GLS at rest and at low-dose dobutamine. LV wall thickness is the only independent correlates of absolute CR.
Compared with controls, hypertensive patients have impaired LV GLS at rest and impaired CR despite normal LVEF. Impaired CR correlated with LV wall thickness but independent of prevailing blood pressure.
收缩储备（CR）受损可能是高血压患者左心室（LV）收缩功能障碍的早期表现。我们以血压正常的患者作为对照，研究了高血压患者的 LV CR 及其相关因素。
共 129 例患者（68 例男性，年龄 58.6±9.5 岁，73 例患有高血压）接受了多巴酚丁胺超声心动图检查。排除有明显冠状动脉或瓣膜疾病、既往心肌梗死或血运重建以及糖尿病的患者。在静息和低剂量多巴酚丁胺时测量左心室射血分数（LVEF）、整体纵向应变（GLS）、周向和径向应变。绝对 CR 计算为低剂量多巴酚丁胺与相应静息值之间 LVEF 和多方向应变的差异。相对 CR 是绝对 CR 与其相应静息值的比值。与对照组相比，高血压患者静息时（-16.8±2.2% vs. -19.6±1.5%，P<0.0001）和低剂量多巴酚丁胺时（-17.9±2.7% vs. -22.8±2.6%，P<0.0001）的 GLS 明显受损。高血压患者的绝对和相对 GLS CR 明显降低（-1.1±2.1% vs. -3.2±2.2%和 7.4±13.9% vs. 16.4±11.7%，均 P<0.001）。高血压患者静息时圆周应变正常，但低剂量多巴酚丁胺时受损（-23.0±4.1% vs. -25.2±3.4%，P=0.002）。两组之间 LVEF 或径向应变无差异。LV 壁厚度和收缩压与静息和低剂量多巴酚丁胺时的 GLS 显著相关。LV 壁厚度是绝对 CR 的唯一独立相关因素。
与对照组相比，高血压患者静息时和低剂量多巴酚丁胺时的 LV GLS 均受损，尽管 LVEF 正常。CR 受损与 LV 壁厚度相关，但与血压无关。
