Papillary muscle measurements in cats with normal echocardiograms and cats with concentric left ventricular hypertrophy.
BACKGROUND
Papillary muscle hypertrophy can occur in conjunction with, or as the only indication of, hypertrophic cardiomyopathy or other diseases that result in left ventricular concentric hypertrophy (LVCH). Assessment of papillary muscle size is usually subjective because objective measures have not been reported.


OBJECTIVE
The study hypothesis was that papillary muscle dimensions are different between normal cats and cats with LVCH.


METHODS
Echocardiograms from 44 normal cats and 40 cats with LVCH were included in the study.


METHODS
All measurements were taken from the right parasternal short-axis view at the level of the papillary muscles at end-diastole. Three methods were used to assess papillary muscle size: the area subtraction method, the direct area trace method, and the diameter method. Measurements were compared between cat groups and method comparisons were made among methods for area determination.


RESULTS
Cats with LVCH were older and had significantly greater left ventricular septal and free wall thicknesses and larger left atrial measurements than normal cats (P < .0006). Papillary muscle measurements were significantly greater by all measurement methods in cats with LVCH than in cats with normal echocardiograms (P < .0001). The area subtraction method and direct area trace method showed moderate agreement.


CONCLUSIONS
Papillary muscle measurements were larger for LVCH cats than normal cats; however, some overlap was present. The establishment of these objective measures adds to the echocardiographic examination of cats.
Adin
Darcy B
DB
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA. adind8@yahoo.com
Diley-Poston
Lindsey
L
D000818:Animals; D002371:Cat Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002415:Cats; D004452:Echocardiography / Q000662:veterinary*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D010210:Papillary Muscles / Q000000981:diagnostic imaging* / Q000473:pathology