Edvardsen Thor, Rosen Boaz D, Pan Li, Jerosch-Herold Michael, Lai Shenghan, Hundley W Gregory, Sinha Shantanu, Kronmal Richard A, Bluemke David A, Lima João A C
Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA.
Am Heart J. 2006 Jan;151(1):109-14. doi: 10.1016/j.ahj.2005.02.018.
Impairment of global diastolic function is considered to be the mechanism of congestive heart failure in individuals with preserved systolic left ventricular (LV) function. Left ventricular hypertrophy (LVH) is known to be a risk factor for congestive heart failure with preserved systolic function, and this process may begin as a regional process. We investigated whether regional LV diastolic function measured by magnetic resonance tagging is altered in asymptomatic participants of the MESA with LVH and preserved systolic LV function.
Regional systolic and diastolic strain rates were calculated from strain data in 218 participants of the MESA study. Circumferential strain was calculated from the midwall layer of the septum, anterior, lateral, and inferior walls at mid-LV level. Global LV function measures were studied by magnetic resonance imaging in 4291 MESA participants. Left ventricular hypertrophy for men and women was defined from the MESA population using previously established Framingham criteria.
Global systolic function was slightly less in the LVH (ejection fraction = 0.66 +/- 0.10) versus the non-LVH group (ejection fraction = 0.69 +/- 0.07, P < .001). Stepwise regression analyses showed a direct relationship between regional diastolic dysfunction and increasing LV mass. Regional systolic strain and strain rate measures from participants with LVH were not significantly different from those without LVH. However, regional diastolic strain rate was significantly reduced in participants with LVH (1.5 +/- 1.1 s(-1)) compared with the non-LVH group (2.2 +/- 1.1 s(-1), P < .001) regardless of age or sex.
Left ventricular hypertrophy is associated with regional diastolic dysfunction in individuals without evidence of clinical cardiovascular disease and preserved systolic function. Magnetic resonance imaging tagging provides detailed quantification of regional diastolic function noninvasively.
左心室(LV)收缩功能正常个体发生充血性心力衰竭的机制被认为是整体舒张功能受损。左心室肥厚(LVH)是收缩功能正常的充血性心力衰竭的一个危险因素,且这一过程可能起始于局部。我们研究了在收缩功能正常的左心室肥厚的多民族动脉粥样硬化研究(MESA)无症状参与者中,通过磁共振标记测量的局部左心室舒张功能是否发生改变。
从MESA研究的218名参与者的应变数据中计算局部收缩和舒张应变率。圆周应变从中隔、前壁、侧壁和下壁的LV中部中层计算得出。通过磁共振成像研究了4291名MESA参与者的整体左心室功能指标。使用先前确立的弗明汉标准从MESA人群中定义男性和女性的左心室肥厚。
与非LVH组相比,LVH组的整体收缩功能略低(射血分数 = 0.66 ± 0.10),而非LVH组的射血分数 = 0.69 ± 0.07,P <.001)。逐步回归分析显示局部舒张功能障碍与左心室质量增加之间存在直接关系。LVH参与者的局部收缩应变和应变率测量值与非LVH参与者的无显著差异。然而,无论年龄或性别,LVH参与者的局部舒张应变率(1.5 ± 1.1 s(-1))与非LVH组(2.2 ± 1.1 s(-1))相比显著降低(P <.001)。
在无临床心血管疾病证据且收缩功能正常的个体中,左心室肥厚与局部舒张功能障碍相关。磁共振成像标记可无创地详细量化局部舒张功能。