Tissue Doppler Imaging and Gradient Echo Cardiac Magnetic Resonance Imaging in Normal Cats and Cats with Hypertrophic Cardiomyopathy

Abstract

Cats with hypertrophic cardiomyopathy (HCM) often develop diastolic dysfunction, which can lead to development of left congestive heart failure. Tissue Doppler imaging (TDI) echocardiography has emerged as a useful, noninvasive method for assessing diastolic function in cats. Cardiac magnetic resonance imaging (cMRI) has been performed in cats and accurately quantifies left ventricular (LV) mass in normal cats. However, assessment of cardiac function in cats by cMRI has not been performed. Six normal Domestic Shorthair cats and 7 Maine Coon cats with moderate to severe HCM were sedated, and TDI of the lateral mitral annulus was performed. Peak early diastolic velocity (Em) was measured from 5 nonconsecutive beats. Cats were anesthetized with propofol and electrocardiogram-gated gradient echo cMRI was performed during apnea after hyperventilation. Short-axis images of the LV extending from the mitral annulus to the apex were obtained throughout the cardiac cycle. LV mass at end systole and LV volumes throughout the cardiac cycle were quantified according to Simpson's rule. To assess the possible influence of propofol on diastolic function, TDI was performed on the 7 cats with HCM while sedated and then while anesthetized with propofol. Em was significantly lower in cats with HCM than normal cats (6.7 +/- 1.3 cm/s versus 11.6 +/- 1.9 cm/s, P < .001, respectively). There was no difference in the cMRI indices of diastolic function in normal and HCM cats. Propofol did not reduce diastolic function (Em) in cats with HCM but mildly reduced systolic myocardial velocity (S) in Maine Coon cats with HCM that were anesthetized with propofol (P = .87 and P = .03, respectively).

Quantitative Planar and Volumetric Cardiac Measurements Using 64 MDCT and 3t Mri vs. Standard 2d and M‐mode Echocardiography: Does Anesthetic Protocol Matter?

“…It has also been applied in experimental animal studies for the left and right ventricle . This variable has rarely been reported generated using MRI or MDCTA in companion animals but left myocardial wall thickness is regularly included in echocardiographic reporting in companion animals and further evaluation of this variable might be helpful in companion animal cardiac MRI or MDCTA …”

“…I n companion animals , the evaluation of cardiac morphology and systolic function has mainly been based on echocardiographic evaluation and cardiac catheterization . The potential role of magnetic resonance imaging (MRI) in the future of veterinary clinical cardiology has been reviewed critically and recent publications have utilized MRI and/or MDCT for functional and morphological cardiac evaluations . Cross‐sectional imaging of the heart utilizing computed tomography (CT) and MRI has been shown to be superior for the evaluation of cardiac morphology and systolic function in humans compared to echocardiography .…”

“…Cross‐sectional imaging of the heart utilizing computed tomography (CT) and MRI has been shown to be superior for the evaluation of cardiac morphology and systolic function in humans compared to echocardiography . Apart from case reports describing congenital or neoplastic morphological abnormalities involving the heart or great vessels in companion animals, these modalities have rarely been compared for their use in evaluation of cardiac function . While these cross‐sectional exams are generally performed in the awake human patient, companion animal patients require anesthesia or heavy sedation at a minimum to undergo these studies.…”

Doppler tecidual do miocárdio de gatos submetidos à anestesia dissociativa

“…Conforme demonstrado na tabela 1, os valores médios observados para Ea septal e Sa septal foram de 7,2±2,5cm s -1 e de 6,3±1,7cm s (MACDONALD et al, 2006). Assim como em humanos, neste trabalho foi verificado que essa técnica possui grande aplicabilidade para melhor avaliar o sistema cardiovascular felino, podendo também contribuir para o diagnóstico e monitoramento de diversas cardiomiopatias.…”

“…Na medicina veterinária, essa técnica é utilizada apenas para fins científicos e, ainda assim, existem poucos estudos com Doppler tecidual em animais (CHETBOUL et al, 2004;CHETBOUL et al, 2005;CHETBOUL et al, 2006a;CHETBOUL et al, 2006b;CHETBOUL et al, 2006c;KOFFAS et al, 2006;MACDONALD et al, 2006;MACDONALD et al, 2007).…”