Sequoia c512 system

Echocardiographic measurement of cardiac function was performed by using an Acuson Sequoia C512 system equipped with a 15L8 linear array transducer. Mice were anesthetized with isoflurane (5%) that was mixed with oxygen through a nose cone, and then placed in supine position on a warming pad to maintain boy temperature. The precordial region was applied with ultrasound transmission gel (Aquasonic, Parker Laboratory, Fairfield, NJ) following air removal. Short axis measurements were employed to capture two-dimensional B-mode images and M-mode tracing at the level of the papillary muscles. The measurement was taken at 25 mm signal depth. Three to six consecutive cardiac cycles were collected from the measurement of M-mode tracings on accompanying software. All measurements were conducted by an experienced operator blinded to mouse strains and treatments (Zhang et al., 2014 (link); Du et al., 2016 (link)).

TTE was performed in 22 month-old rats as previously described [27 (link)]. Briefly, the rats were anesthetized with 80 mg/kg Ketamine hydrochloride and 10 mg/kg Diazepam, i.p. An Acuson Sequoia C512 system equipped with a 13-MHz transducer was used (Acuson, Mountain View, CA, USA). The images were acquired with the animals in left lateral decubitus. M-mode imaging of the parasternal short-axis (papillary level) view allowed measurement of end-diastolic internal diameter (LVIDd) and end-systolic internal diameter (LVIDs), posterior wall thickness at diastole (PWd) and interventricular septum thickness at diastole (IVSd); HR was also recorded. Values were determined by averaging the measurements of three consecutive cardiac cycles in accordance with the American Society of Echocardiography guidelines. The above measurements were used to calculate left ventricular mass (LVM), expressed in grams, as previously described [28 (link)], using the following equation:
$LVM=0.8\lfloor 1.04{\left(IVSd+LVIDd+PWd\right)}^3\text{−}LVID{d}^3\rfloor +0.6$

MCE studies were performed as previously described [22] (link). Mice were anesthetized with intraperitoneal injections of sodium pentobarbital (50 mg/kg) and ketamine hydrochloride (50 mg/kg). Heart rate and blood pressure were monitored through a carotid catheter and recorded with a blood pressure analysis module in PowerLab (ADInstruments). A venous line was placed in the left jugular vein for constant infusion of microbubbles. 10% Perflutren lipid microspheres (Definity, Lantheus Imaging) were diluted tenfold in sterile saline and infused intravenously at 20µL/min. A thoracotomy was performed to provide unobstructed visualization of the myocardium. A 7-0 silk suture was passed underneath the LAD and through a custom snare. MCE was performed with a 14 MHz linear transducer using an Acuson Sequoia C512 system, using a mechanical index of 0.24. Perfusion images were obtained in real time following destruction of microbubbles using a sequence of 10 high-energy frames (mechanical index 1.9). Signal intensity was obtained for 10 seconds after the high-energy sequence at a frame rate of 30 Hz. Parasternal long-axis views were recorded at the level of the aortic arch. For temporal monitoring of myocardial blood flow MCE was used to measure blood flow at baseline before ischemia, during ischemia, and at 5, 10, 30 minutes after initiation of reperfusion.

Echocardiographic assessment was performed as previously described assess the relevant heart’s actions^{43 (link)}. Briefly, the LV function in C57BL/6 J mice was conducted just before sacrifice using the Acuson Sequoia C512 system equipped with a 15L8 linear array transducer with 30 MHz. Mice were anesthetized with 1.5% isoflurane mixed with oxygen and placed in a supine position on a heating pad. Short-axis measurements were used to capture M-mode tracing at the level of the papillary muscles with a 25-mm signal depth. Three to six consecutive cardiac cycles were measured using M-mode tracings with the accompanying software.

Left ventricular (LV) function and geometry were evaluated by echocardiography using a Sequoia C512 System (Siemens Medical) with a 15-MHz linear array transducer as previously described.¹⁸ Briefly, the rats were anesthetized by mask with 1.5%–2.0% isoflurane, had their chests shaved, and were situated in the supine position on a warming pad. After placing electrocardiogram limb electrodes, two-dimensional, two-dimensional guided M-mode and Doppler studies of aortic and transmitral flows were performed from parasternal and foreshortened apical windows. All data were analyzed offline with the ultrasound system software. Echocardiographic parameters were measured and calculated as previously described.¹⁸