Evaluation of contractile function and inotropic reserve with tissue velocity, strain and strain rate imaging in streptozotocin-induced diabetes

AIMS: The aim of the present study was to evaluate left ventricular (LV) function and contractile reserve (CR) with Doppler myocardial imaging (DMI) in a small animal model for type 1 diabetes. METHODS AND RESULTS: Cardiac function was assessed in anaesthetized Wistar rats 6 and 8 weeks after injection of 60 mg/kg of streptozotocin. At 6 weeks of diabetes, colour DMI echocardiography was performed at rest and during incremental dosages of dobutamine (5, 10, 20 microg/kg/min). Left ventricular fractional shortening was decreased after 8 weeks of follow-up [36 +/- 5 (D) vs. 41 +/- 4% (C); P = 0.049]. After 6 weeks of diabetes, DMI measurements were reduced in the diabetic rats in the inferolateral wall at rest [systolic velocity: 2.5 +/- 0.4 (D) vs. 4.4 +/- 0.3 (C) cm/s; P