Kozàkovà Michaela, Ferrannini Ele, Palombo Carlo
Department of Internal Medicine and CNR Institute of Clinical Physiology, University of Pisa School of Medicine, Pisa, Italy.
Hypertension. 2003 Oct;42(4):528-33. doi: 10.1161/01.HYP.0000090120.22445.B0. Epub 2003 Sep 2.
In systemic hypertension, depressed left ventricular midwall shortening predicts an adverse outcome and is associated with increased left ventricular relative wall thickness, which has been proposed as an independent predictor of cardiovascular risk and reduced coronary reserve. This study was designed to investigate whether depressed midwall shortening is associated with more critical impairment of coronary function and with exercise-induced myocardial ischemia. Sixty untreated hypertensive patients without coronary artery stenosis and 20 normotensive volunteers underwent exercise ECG testing, standard and transesophageal echocardiography to assess the occurrence of exercise-induced myocardial ischemia, left ventricular mass, geometry, and midwall shortening, and coronary vasodilator capacity. Compared with hypertensive patients with normal midwall shortening, those with depressed function (n=15) had higher minimum coronary resistance (1.19+/-0.27 versus 1.39+/-0.20 mm Hg/cm per second, P<0.01) and prevalence of exercise-induced myocardial ischemia (36 versus 67%, P<0.05). Within the hypertensive group, midwall shortening was inversely related to minimum coronary resistance (r=-0.42, P<0.01). Compared with patients with an exercise ECG test negative for myocardial ischemia, those with a positive test result (n=26) had higher minimum coronary resistance (1.13+/-0.21 versus 1.38+/-0.27 mm Hg/cm per second, P<0.01) and lower midwall shortening (104+/-16 versus 93+/-14%, P<0.01). We conclude that hypertensive patients with depressed midwall shortening have more severe impairment of coronary function and a higher prevalence of exercise-induced myocardial ischemia as compared with hypertensive patients with normal midwall shortening. These findings suggest that a decrease in myocardial performance may be related, at least in part, to chronic intermittent myocardial ischemia caused by a critical impairment of coronary vasodilator capacity.
在系统性高血压中，左心室中层壁缩短减弱预示不良预后，且与左心室相对壁厚度增加有关，左心室相对壁厚度增加已被认为是心血管风险和冠状动脉储备降低的独立预测因素。本研究旨在调查中层壁缩短减弱是否与冠状动脉功能更严重受损以及运动诱发的心肌缺血有关。60例无冠状动脉狭窄的未经治疗的高血压患者和20名血压正常的志愿者接受了运动心电图测试、标准和经食管超声心动图检查，以评估运动诱发的心肌缺血的发生情况、左心室质量、几何形状和中层壁缩短情况以及冠状动脉扩张能力。与中层壁缩短正常的高血压患者相比，功能减弱的患者（n = 15）具有更高的最小冠状动脉阻力（1.19±0.27对1.39±0.20 mmHg/cm每秒，P<0.01）和运动诱发的心肌缺血患病率（36%对67%，P<0.05）。在高血压组中，中层壁缩短与最小冠状动脉阻力呈负相关（r = -0.42，P<0.01）。与运动心电图测试心肌缺血阴性的患者相比，测试结果为阳性的患者（n = 26）具有更高的最小冠状动脉阻力（1.13±0.21对1.38±0.27 mmHg/cm每秒，P<0.01）和更低的中层壁缩短（104±16%对93±14%，P<0.01）。我们得出结论，与中层壁缩短正常的高血压患者相比，中层壁缩短减弱的高血压患者冠状动脉功能损害更严重，运动诱发的心肌缺血患病率更高。这些发现表明，心肌功能下降可能至少部分与冠状动脉扩张能力严重受损导致的慢性间歇性心肌缺血有关。
