Background

The aims of the present study were to determine left ventricular (LV) myocardial contractile reserve during exercise stress testing in healthy adults and to evaluate the effects of gender and age on exercise LV global longitudinal strain (GLS).

Methods

The study population consisted of 67 healthy adults (age range, 23–80 years; 49% women). Subjects were analyzed with respect to gender and predefined age groups (age < 35 years, n = 18; age 35–55 years, n = 24; age > 55 years, n = 25). All subjects underwent comprehensive echocardiographic assessment at rest and during symptom-limited semisupine exercise test. LV GLS was determined using two-dimensional speckle-tracking echocardiography.

Results

LV GLS magnitude during peak stress was 25.4 ± 2.0%. The average absolute numeric LV GLS increase was 5.3%, equivalent to a relative 26.7% increase of LV GLS. LV GLS magnitude at peak exercise was without clinically significant differences between age groups (P = .07). No significant difference was found in peak exercise LV GLS between genders (P = .48). Linear regression analysis revealed a significant but weak correlation between peak LV GLS and age (r = −0.30, P = .02), whereas peak LV GLS was independent of maximal heart rate (r = 0.23, P = .07), peak mean arterial blood pressure (r = −0.11, P = .38), body mass index (r = 0.15, P = .22), and peak pulsed Doppler–derived cardiac index (r = −0.06, P = .67).

Conclusions

LV GLS increases significantly during exercise stress in a healthy population. A dose-response relationship was found between LV GLS and exercise level independent of gender, and the influence of age appeared marginal. The technique is feasible, with low intra- and interobserver variability.

中文翻译：

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健康成年人运动压力期间左心室心肌收缩储备：二维斑点跟踪超声心动图研究。

背景

本研究的目的是确定健康成年人运动压力测试期间的左心室（LV）心肌收缩储备，并评估性别和年龄对运动LV总纵向应变（GLS）的影响。

方法

研究人群包括67位健康的成年人（年龄范围23-80岁； 49％的女性）。分析了受试者的性别和预定年龄组（年龄<35岁，n  = 18；年龄35-55岁，n  = 24；年龄> 55岁，n  = 25）。所有受试者在休息时和症状受限的半仰卧运动测试中均接受了全面的超声心动图评估。LV GLS使用二维斑点跟踪超声心动图测定。

结果

峰值应力期间的LV GLS幅度为25.4±2.0％。LV GLS的平均绝对数值增加了5.3％，相当于LV GLS的相对增加了26.7％。高峰运动时的LV GLS幅度在各年龄组之间无临床显着差异（P  = .07）。男女在峰值运动量左室总LS中没有发现显着差异（P  = 0.48）。线性回归分析显示峰值LV GLS与年龄之间存在显着但弱的相关性（r  = -0.30，P  = .02），而峰值LV GLS与最大心率无关（r  = 0.23，P  = .07），峰值均值动脉血压（r  = −0.11，P  = .38），体重指数（r  = 0.15，P  = 0.22）和峰值脉冲多普勒衍生的心脏指数（r  = -0.06，P  = .67）。

结论

在健康人群中，运动负荷期间LV GLS显着增加。LV GLS与运动水平之间存在剂量反应关系，而与性别无关，并且年龄的影响显得微不足道。该技术可行，观察者之间和观察者之间的可变性低。