title: Validation of the myocardial performance index by echocardiography in mice: a noninvasive measure of left ventricular function.
abstract: BACKGROUND
  The myocardial performance index (MPI) is a Doppler-based measure of left ventricular (LV) function. It is noninvasive, independent of LV shape, and does not require dimensional measurements. However, it has never been validated in mice.
  
  
  METHODS
  A total of 29 anesthetized mice with LV pressure catheters underwent echocardiography (2-dimensional, M-mode, and Doppler) at baseline and during manipulations of beta-adrenergic tone, temperature, preload, and afterload. The maximum derivative of LV pressure with respect to time (dP/dt(max)) was compared with MPI, fractional shortening (FS), mean velocity of circumferential fiber shortening, and the FS/MPI ratio.
  
  
  RESULTS
  MPI (baseline 0.44 +/- 0.07) correlated strongly with dP/dt(max) (R = -.779, P <.001), as did FS and mean velocity of circumferential fiber shortening. MPI differed significantly with contractility, preload, and afterload manipulation. FS/MPI showed the best correlation with dP/dt(max).
  
  
  CONCLUSIONS
  MPI strongly correlates with dP/dt(max) over a range of hemodynamic conditions in mice. It can be used as a noninvasive index of LV function in this species.
authors.affiliation: Divisions of Cardiology, Oregon Health and Science University, Portland, Oregon 97221, USA.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Broberg
authors.forename: George A
authors.initials: GA
authors.lastname: Pantely
authors.forename: Brent J
authors.initials: BJ
authors.lastname: Barber
authors.forename: Gordon K
authors.initials: GK
authors.lastname: Mack
authors.forename: Kathryn
authors.initials: K
authors.lastname: Lee
authors.forename: Timothy
authors.initials: T
authors.lastname: Thigpen
authors.forename: Lowell E
authors.initials: LE
authors.lastname: Davis
authors.forename: David
authors.initials: D
authors.lastname: Sahn
authors.forename: A Roger
authors.initials: AR
authors.lastname: Hohimer
mesh_terms: D000318:Adrenergic beta-Agonists / Q000008:administration & dosage; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D004280:Dobutamine / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D015150:Echocardiography, Doppler; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D051379:Mice; D023421:Models, Animal; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D009206:Myocardium / Q000737:chemistry*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011433:Propranolol / Q000008:administration & dosage; D013223:Statistics as Topic; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology
chemical_list: D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D004280:Dobutamine; D011433:Propranolol