醫(yī)學外文翻譯--心肌梗死初級血管成形術治療術后的超聲心動圖下舒張功能障礙與磁共振心肌梗死面積的關系（英文）

1、C ? 2008, the Authors Journal compilation C ? 2008, Blackwell Publishing, Inc. DOI: 10.1111/j.1540-8175.2008.00679.xEchocardiographic Diastolic Dysfunction and Magnetic Resonance Infarct Size in Healed Myocardial Infarct

2、ion Treated with Primary AngioplastyAndrea Barbieri, M.D.,? Francesca Bursi, M.D., M.Sc.,? Luigi Politi, M.D.,? Luca Rossi, M.D.,?Federica Fiocchi, M.D.,? Guido Ligabue, M.D.,? Alessandro Pingitore, M.D.,? Vincenzo Posit

3、ano, M.D.,? Pietro Torricelli, M.D.,? and Maria Grazia Modena, M.D.??Department of Cardiology, ?Department of Radiology, Modena and Reggio Emilia University, Modena, Italy; and ?CNR Institute of Clinical Physiology, Pisa

4、, ItalyBackground: After acute myocardial infarction (MI) the severity of diastolic dysfunction by echocar- diography represents an independent prognostic marker. However, the mechanisms whereby diastolic dysfunction por

5、tends an increased risk after MI are not fully understood. We investigated the relation- ship between echocardiographic diastolic dysfunction severity and infarct size quantitatively mea- sured by contrast-enhanced magne

6、tic resonance (ce-MR). Methods: Cross-sectional prospective study. We quantified “healed” infarct size by ce-MR measuring the percentage of delayed enhancement with respect to left ventricular mass and diastolic function

7、 by Doppler echocardiography. Both exams were scheduled at least 1 month after a first acute ST segment elevation MI (STEMI) successfully treated with primary angioplasty and stenting. To increase the specificity, indivi

8、dual echocardiographic pa- rameters were integrated to grade global diastolic function in 4 grades: normal diastolic function, impaired relaxation with normal, or near-normal filling pressures; impaired relaxation with m

9、oder- ate elevation of filling pressures, and impaired relaxation with marked elevation of filling pressures, “restrictive filling.” Results: We prospectively enrolled 52 patients (mean age 62 ± 13 years, 77% men).

10、ce-MR and echocardiography were performed 48 ± 15 days after the MI. There was a significant but modest correlation between diastolic function grade and infarct size (r = 0.423, P = 0.002), which was independent of

11、global and regional systolic function and persisted after further adjustment for age, sex, body surface area, left ventricular mass, end-diastolic volumes, and sphericity index (all P10, E/Vp > 1.5, decrease in E/A ≥

12、0.5 during Valsalva maneu- ver, “pseudonormal filling”-grade II/IV); and impaired relaxation with marked elevation of filling pressures, “restrictive filling” (Decel- eration time 1.5-grades III-IV/IV) as previously des

13、cribed.19Left atrial volume was assessed by the modi- fied Simpson method from apical four- and two- chamber views. Measurements were obtained in end-systole from the frame preceding mitral valve opening, and the volume

14、was indexed to BSA.20 Mitral regurgitation was quantified by calculating the area of the regurgitant jet with color Doppler.21 Each value represents the av- erage of three consecutive beats.Determination of Infarct Size

15、by ce-MR ImagingMRI ProtocolMRI was performed on a 1.5 T whole body scanner (Intera CV, Philips Medical Systems) equipped with Quasar gradients. Cardiac MRI was performed with the five-element cardiac synergy coil. Cardi

16、ac synchronization was ob- tained by means of vector electrocardiographicgating. The study protocol consisted of cine MRI at rest to evaluate regional and global left ven- tricular function and volumes, followed by a ce-

17、 MRI to determine the presence and the extent of infarcted tissue. Ten to twelve, depending on the heart size, cine short-axis views were im- aged from apex to base with a sensitivity en- coded balanced fast-field echo (

18、b-FFE) sequence during breathholds of approximately 15 sec- onds. The following parameters were used: echo time, 1.7 msec; repetition time, 4.0 msec; slice thickness, 8 mm with no interslice gap; field of view, 320 mm; d

19、ata matrix size, 256 × 224 mm; phase of field, 0.75; trigger delay, minimum; 85 views per segments,8–14 according to the heart rate; flip angle, 45?. At least 30 cine frames were obtained for each slice. The same ge

20、ometry set- tings of the baseline scans were repeated to ob- tain comparable slices. Postcontrast delayed images were acquired in the short axis of the left ventricle 15 minutes af- ter bolus injection of gadolinium in e

21、nd-diastole for the evaluation of myocardial distribution of hyperenhancement. A 3D gradient echo-based sequence with inversion prepulse was used with the following parameters: echo time, 4.2 msec; flip angle, 20; matrix

22、, 256 × 160; NEX, 2.00; FOV, 36 cm; slice thickness, 8 mm. The inver- sion time ranged from 260 to 340 msec. A real time option allowing the interactive change of inversion time was used to optimize this param- eter

23、 until the nulling of myocardium was ob- tained. A variable number of short-axis slices (10 ± 1.8, maximum = 11, minimum = 8) were traced from the base to the apex to cover the entire left ventricle. Also, one verti

24、cal and one horizontal long-axis views were acquired to as- sess the apex.Definitions and Data AnalysisImages were analyzed on a offline worksta- tion (Viewforum 3.2; Philips Medical Systems). For regional analysis, the

25、left ventricle was di- vided into 17 myocardial segments.14 To as- sess infarct size, the extent of delayed enhanced areas was measured using a semiautomatic, previously validated software.22 The analysis was done in all

26、 short-axis images and in two long-axis images for the analysis of ventricular apex. In each image, the boundaries of contrast- enhanced areas were automatically traced and, eventually, manually corrected. Segmental ex-

27、tent of infarction was scored by the consensus of two investigators (F.F., G.L.), blinded to the clinical data. Regions of interest were acceptedVol. 25, No. 6, 2008 ECHOCARDIOGRAPHY: A Jrnl. of CV Ultrasound & Allie