Comparison of myocardial contrast enhancement via cardiac magnetic resonance imaging in healthy cats and cats with hypertrophic cardiomyopathy.
OBJECTIVE
To quantify myocardial contrast enhancement (MCE) of the left ventricle (LV) by use of cardiac magnetic resonance imaging (CMRI) in healthy cats and cats with hypertrophic cardiomyopathy (HCM) and to compare MCE between the 2 groups.


METHODS
10 healthy cats and 26 Maine Coon cats with moderate to severe HCM but without clinical evidence of congestive heart failure.


METHODS
Anesthetized cats underwent gradient echo CMRI examination. Short-axis images of the LV were acquired before and 7 minutes after IV administration of gadolinium dimeglumine. Regions of interest were manually traced in the quadrants of 5 mid-LV slices acquired at end systole, and the MCE percentage was calculated from summed weight-averaged data from all slices. Doppler tissue imaging echocardiography was performed to measure the early diastolic myocardial velocity (Em) as an index of diastolic function. Three-way repeated-measures ANOVA was used to determine differences in MCE between cats with HCM and healthy cats. Simple linear regression was used to assess whether MCE was correlated with LV mass, LV mass index (LVMI), or Em. A Student t test was used to compare the SDs of the postcontrast myocardial signal intensity between the 2 groups.


RESULTS
There was no difference in MCE between cats with HCM and healthy cats. There was no correlation of MCE with LV mass, LVMI, or Em. There was no difference in heterogeneity of signal intensities of LV myocardium between the 2 groups.


CONCLUSIONS
Contrast-enhancement CMRI was not useful in detecting diffuse myocardial fibrosis in cats with HCM.
MacDonald
Kristin A
KA
Department of Medicine and Epidemiology, University of California, Davis 95616, USA.
Wisner
Erik R
ER
Larson
Richard F
RF
Klose
Tyler
T
Kass
Philip H
PH
Kittleson
Mark D
MD
D000818:Animals; D024741:Cardiomyopathy, Hypertrophic, Familial / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D002371:Cat Diseases / Q000175:diagnosis*; D002415:Cats; D003287:Contrast Media / Q000737:chemistry; D015150:Echocardiography, Doppler / Q000662:veterinary; D006571:Heterocyclic Compounds / Q000737:chemistry; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008536:Meglumine / Q000031:analogs & derivatives / Q000737:chemistry
D003287:Contrast Media; D006571:Heterocyclic Compounds; C112669:gadolinium DOTA meglumine; D008536:Meglumine