Cury Alexandre Ferreira, Bonilha Andre, Saraiva Roberto, Campos Orlando, Carvalho Antonio Carlos C, De Paola Angelo Amato V, Fischer Claudio, Tucci Paulo Ferreira, Moises Valdir Ambrosio
Cardiovascular Laboratory, Department of Cardiology/Medicine of Universidade Federal de São Paulo, Brazil.
J Am Soc Echocardiogr. 2005 May;18(5):454-60. doi: 10.1016/j.echo.2005.01.030.
The aim of the study was to analyze the myocardial performance index (MPI), its relationship with the standard variables of systolic and diastolic functions, and the influence of time intervals in an experimental model of female rats with myocardial infarction (MI).
Forty-one Wistar female rats were submitted to surgery to induce MI. Six weeks later, Doppler echocardiography was performed to assess infarct size (IS,%), fractional area change (FAC,%), ejection fraction biplane Simpson (EF), E/A ratio of mitral inflow, MPI and its time intervals: isovolumetric contraction (IVCT, ms) and relaxation (IVRT, ms) times, and ejection time (ET, ms); MPI = IVCT + IVRT/ET.
EF and FAC were progressively lower in rats with small, medium and large-size MI ( P < .001). E/A ratio was higher only in rats with large-size MI (6.25 +/- 2.69; P < .001). MPI was not different between control rats and small-size MI (0.37 +/- 0.03 vs 0.34 +/- 0.06, P = .87), but different between large and medium-size MI (0.69 +/- 0.08 vs 0.47 +/- 0.07; P < .001) and between these two compared to small-size MI. MPI correlated with IS (r = 0.85; P < .001), EF (r = -0.86; P < .001), FAC (r = -0.77; P < .001) and E/A ratio (r = 0.77; P < .001, non-linear). IVCT was longer in large size MI compared to medium-size MI (31.87 +/- 7.99 vs 15.92 +/- 5.88; P < .001) and correlated with IS (r = 0.85; P < .001) and MPI (r = 0.92; P < .001). ET was shorter only in large-size MI (81.07 +/- 7.23; P < .001), and correlated with IS (r = -0.70; P < .001) and MPI (r = -0.85; P < .001). IVRT was shorter only in large-size compared to medium-size MI (24.40 +/- 5.38 vs 29.69 +/- 5.92; P < .037), had borderline correlation with MPI (r = 0.34; P = .0534) and no correlation with IS (r = 0.26; p = 0.144).
The MPI increased with IS, correlated inversely with systolic function parameters and had a non-linear relationship with diastolic function. These changes were due to the increase of IVCT and a decrease of ET, without significant influence of IVRT.
本研究旨在分析心肌性能指数（MPI），其与收缩和舒张功能标准变量的关系，以及时间间隔在雌性大鼠心肌梗死（MI）实验模型中的影响。
41只Wistar雌性大鼠接受手术诱导MI。六周后，进行多普勒超声心动图检查以评估梗死面积（IS，%）、面积变化分数（FAC，%）、双平面辛普森射血分数（EF）、二尖瓣流入E/A比值、MPI及其时间间隔：等容收缩时间（IVCT，毫秒）和舒张时间（IVRT，毫秒）以及射血时间（ET，毫秒）；MPI =（IVCT + IVRT）/ET。
小、中、大梗死面积的大鼠中，EF和FAC逐渐降低（P <.001）。仅大梗死面积的大鼠E/A比值较高（6.25±2.69；P <.001）。对照大鼠与小梗死面积大鼠的MPI无差异（0.37±0.03对0.34±0.06，P =.87），但大、中梗死面积大鼠之间的MPI不同（0.69±0.08对0.47±0.07；P <.001），且与小梗死面积大鼠相比这两者之间也不同。MPI与IS（r = 0.85；P <.001）、EF（r = -0.86；P <.001）、FAC（r = -0.77；P <.001）和E/A比值（r = 0.77；P <.001，非线性）相关。大梗死面积大鼠的IVCT比中梗死面积大鼠长（31.87±7.99对15.92±5.88；P <.001），且与IS（r = 0.85；P <.001）和MPI（r = 0.92；P <.001）相关。仅大梗死面积大鼠的ET较短（81.07±7.23；P <.001），且与IS（r = -0.70；P <.001）和MPI（r = -0.85；P <.001）相关。与中梗死面积大鼠相比，仅大梗死面积大鼠的IVRT较短（24.40±5.38对29.69±并与MPI有边缘相关性（r = 0.34；P =.0534），与IS无相关性（r = 0.26；p = 0.144）。
MPI随IS增加，与收缩功能参数呈负相关，与舒张功能呈非线性关系。这些变化是由于IVCT增加和ET减少，IVRT无显著影响。
