In Vivo Invasive Hemodynamic Assessment in Rats

LV hemodynamic function was performed in vivo invasively as described previously [48 (link)]. In brief, rats were anesthetized by intraperitoneal injection of a mixture of Xylazin (4 mg/kg; Bayer, Germany) and Ketamin (100 mg/kg; Dr E. Gräub AG, Switzerland), intubated, and ventilated. The chest was opened and a microtip catheter (SPR-409, 2F, Millar Instruments, Houston, USA) was gently inserted into the LV chamber. Hemodynamic parameters such as LV systolic pressure (LVSP), LV end-diastolic pressure (LVEDP), and heart rate (HR) were continuously recorded on Labchart (v7.3.2, Powerlab System (8/30, both AD Instruments, Spechbach, Germany) connected to a Bridge Amplifier (Bridge Amp, ADInstruments, GmbH, Spechbach, Germany) and a Transducer Control unit (Model TC-510, Millar Instruments Inc., Houston, Texas, USA). In addition, transthoracic echocardiography was performed as described previously [41 (link)]. Briefly, rats were anesthetized (isoflurane 2–3%) and echocardiography was performed prior to sacrifice the rats using Vivid7 system (GE Healthcare, USA) equipped with an 11.5 MHz 10S sector transducer. Left-ventricular ejection fraction (LVEF) was evaluated.