title: Noninvasive Doppler-derived myocardial performance index in rats with myocardial infarction: validation and correlation by conductance catheter.
abstract: The rodent model of myocardial infarction (MI) is extensively used in heart failure studies. However, long-term follow-up of echocardiographic left ventricular (LV) function parameters such as the myocardial performance index (MPI) and its ratio with the fractional shortening (LVFS/MPI) has not been validated in conjunction with invasive indexes, such as those derived from the conductance catheter (CC). Sprague-Dawley rats with left anterior descending coronary artery ligation (MI group, n = 9) were compared with a sham-operated control group (n = 10) without MI. Transthoracic echocardiography (TTE) was performed every 2 wk over an 8-wk period, after which classic TTE parameters, especially MPI and LVFS/MPI, were compared with invasive indexes obtained by using a CC. Serial TTE data showed significant alterations in the majority of the noninvasive functional and structural parameters (classic and novel) studied in the presence of MI. Both MPI and LVFS/MPI significantly (P < 0.05 for all reported values) correlated with body weight (r = -0.58 and 0.76 for MPI and LVFS/MPI, respectively), preload recruitable stroke work (r = -0.61 and 0.63), LV end-diastolic pressure (LVEDP) (r = 0.82 and -0.80), end-diastolic volume (r = 0.61 and -0.58), and end-systolic volume (r = 0.46 and -0.48). Forward stepwise linear regression analysis revealed that, of all variables tested, LVEDP was the only independent determinant of MPI (r = 0.84) and LVFS/MPI (r = 0.83). We conclude that MPI and LVFS/MPI correlate strongly and better than the classic noninvasive TTE parameters with established, invasively assessed indexes of contractility, preload, and volumetry. These findings support the use of these two new noninvasive indexes for long-term analysis of the post-MI LV remodeling.
authors.affiliation: Laboratory of Hemodynamics and Cardiovascular Technology, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland. David.Jegger@epfl.ch
authors.forename: David
authors.initials: D
authors.lastname: Jegger
authors.forename: Xavier
authors.initials: X
authors.lastname: Jeanrenaud
authors.forename: Mohammad
authors.initials: M
authors.lastname: Nasratullah
authors.forename: Pierre-Guy
authors.initials: PG
authors.lastname: Chassot
authors.forename: Ajit
authors.initials: A
authors.lastname: Mallik
authors.forename: Hendrik
authors.initials: H
authors.lastname: Tevaearai
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
authors.forename: Patrick
authors.initials: P
authors.lastname: Segers
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Stergiopulos
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization; D004195:Disease Models, Animal; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D006334:Heart Function Tests / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology