Changes in the myocardial performance index during dobutamine administration in anesthetized cats.
OBJECTIVE
To investigate the relationship between myocardial performance index (MPI; also known as the Tei index) and cardiac function in anesthetized cats administered dobutamine.


METHODS
6 adult cats.


METHODS
Cats were anesthetized by administration of propofol (6 mg/kg, IV), and anesthesia was maintained by administration of isoflurane. Heart rate and systolic arterial pressure (SAP) were monitored. Stroke volume, cardiac output, and aortic blood flow (ABF) were measured by use of transesophageal ultrasonography. Left ventricular fractional shortening (LVFS), mitral E-wave velocity-to-A-wave velocity (E:A) ratio, and ejection time were measured by use of transthoracic echocardiography. Dobutamine was administrated via a cephalic vein at rates of 2.5, 5.0, and 10 microg/kg/min.


RESULTS
Heart rate, SAP, cardiac output, and ABF increased with dobutamine administration, whereas stroke volume significantly decreased. The LVFS significantly increased, and the E:A ratio significantly decreased. Total isovolumic time and the MPI significantly decreased. The MPI was negatively correlated (r=-0.63) with LVFS. Conversely, the MPI was positively correlated with the E:A ratio (r=0.47), stroke volume (r=0.66), and total isovolumic time (r=0.95). However, the MPI was not significantly correlated with heart rate, SAP, cardiac output, or ABF.


CONCLUSIONS
Analysis suggested that the MPI provides a sensitive clinical assessment of cardiac response to medication in cats, which may be similar to the usefulness of the MPI reported in humans.
Hori
Yasutomo
Y
Veterinary Teaching Hospital, School of Veterinary Medicine & Animal Science, Kitasato University, 23-35-1 Higashi, Towada, Aomori 034-8628, Japan.
Uechi
Masami
M
Indou
Atsuko
A
Yamano
Shigeki
S
Ebisawa
Takashi
T
Teshima
Kenji
K
Asano
Kazushi
K
D000704:Analysis of Variance; D000758:Anesthesia / Q000662:veterinary; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002415:Cats / Q000502:physiology*; D004280:Dobutamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects
D004280:Dobutamine