Vevo 2100 high resolution imaging

In vivo heart function was assessed by transthoracic echocardiography in sedated C57BL/6 mice fixed on a heated platform using a Vevo 2100 high‐resolution imaging system (VisualSonics, Toronto, ON, Canada, 40 MHz transducer) at the end of the experiment. Series of M‐mode images at the level of papillary muscles were obtained; left ventricular internal dimensions, left ventricular ejection fraction and left ventricular fraction shortening were measured using at least three consecutive cardiac cycles.

Echocardiography was performed as reported previously [16 (link)]. In general, the images were obtained with a VEVO2100 high resolution imaging system (Visual Sonics, Toronto, Canada) equipped with transducers MS550D (22–55 MHz) and MS250 (13–24 MHz). Right ventricular wall thickness (RVWT), right ventricular internal diameter (RVID) and tricuspid annular plane systolic excursion (TAPSE), as well as pulmonary artery acceleration time (PAAT) and pulmonary artery ejection time (PAET) were assessed.

In vivo cardiac function was assessed by transthoracic echocardiography in sedated 2- to 4-month-old WT C57BL6 mice (Harlan Italy, San Piero al Natisone, UD, Italy) using a Vevo 2100 high-resolution imaging system (40-MHz transducer, VisualSonics, Toronto, ON, Canada). Mice were anesthetized with Tilotamine (0.09 mg/g), Zolazepam (0.09 mg/g), and 0.01% atropine (0.04 ml/g). Cardiac function was evaluated by non-invasive echocardiography in basal conditions, after 7 days of treatment with trastuzumab, or after 3 days of pre-treatment with ranolazine followed by co-administration of ranolazine and trastuzumab for 7 days. Studies and analysis were performed blinded to heart condition. Data are presented as mean ± standard error of the mean (SEM) unless otherwise noted. Between-group differences were assessed by Student's t-test or one-way analysis if variance (ANOVA) as appropriate. Statistical significance was defined as P < 0.05.
The animal experiments described herein were carried out in accordance with the recommendations of Italian regulations for experimentation on animals. The protocol was approved by the ethical committee and met the standards required by Directive 2010/63/EU of the European Parliament.