Echocardiographic evaluations
hyperthyroidism
HYPERTHYROIDISM, SYSTEMIC HYPERTENSION
Baseline echocardiographic evaluations were performed 24 h prior to each treatment dosing. On the morning of the examination, cats were dosed with gabapentin (100 mg PO) approximately one hour prior to the study. The cats were sedated with butorphanol (0.3 mg/kg IM) and acepromazine (0.1–0.5 mg/kg IM) to facilitate echocardiographic evaluation.All echocardiograms were performed by a single board-certified cardiologist (MSO) using a 12–4 mHz sector array transducer with harmonics (Philips EPIC CVx, Philips Healthcare, Andover, MA, USA). Two-dimensional (2D), M-mode, color Doppler, and spectral Doppler echocardiographic images were obtained in standard imaging planes from right and left lateral recumbencyOn the day of echocardiographic evaluation with vehicle or Images were stored and all measurements were performed by a single blinded observer (MSO) using a commercially available offline workstation (Syngo Dynamic Workplace v10.0.01_HF04_Rev5 [Build 2884], Siemens Medical Solutions, Malvern, PA, USA). Two-dimensional right parasternal long axis or short axis imaging planes were measured to obtain the maximum 2D thickness of the interventricular septum (IVSd) and left ventricular posterior wall (LVPWd) in diastole using an inner-edge to inner-edge measuring technique. Segmental or diffuse IVS or LVPW thickness exceeding 6 mm in the absence of systemic hypertension or hyperthyroidism on at least two serial examinations > 1 month apart was considered consistent with HCMM-mode and two-dimensional right parasternal short axis imaging planes were used to measure the left ventricular internal dimensions at end-diastole (LVIDd) and end-systole (LVIDs). Fractional shortening was calculated using the equation (LVIDd-LVIDs)/LVIDd × 100.Left atrial (LA) size was measured in 2D on the right parasternal short axis basilar view to determine the LA/Ao as previously describedSpectral Doppler and pulsed wave tissue Doppler imaging (PW TDI) from the left apical 4-chamber view were used to evaluate diastolic functional parameters including transmitral inflow patterns, lateral E’ and A’, and LV isovolumic relaxation time (IVRT)