Statistical method for characterization of hypertrophic cardiomyopathy by use of morphologic and pathologic measurements in pigs (Sus scrofa domestica).
OBJECTIVE
Hypertrophic cardiomyopathy (HCM) is characterized by symmetric or asymmetric hypertrophy of the left and/or right ventricle. Morphologic and pathologic indices (MI and PI) of hearts were established for classification of HCM in pigs.


METHODS
Fifty on-farm-performance-tested pigs (average body weight, 104.3 kg; age, 224.5 days) were randomly selected. Heart weight, length, width, heart-to-body weight ratio, and thickness of the cranial and middle portions of ventricular septum and left ventricular free wall were measured. Myocyte disorganization and necrosis, myocardial and endocardial fibrosis, and intramural coronary arterial occlusion were scored. Principal component analysis and stepwise regression analysis were used to establish MI and PI.


RESULTS
MI was established by using the first principal component as the dependent variable and applying stepwise regression analysis. Hearts were classified as morphologically normal, suspicious, and hypertrophic according to the range of MI. The same statistical method was used to find PI. Hearts were classified as pathologically normal, moderately affected, or seriously affected according to the range of PI. Combining MI and PI, hearts could be classified into five groups: no hypertrophy with minor lesion (normal); hypertrophy but with rare lesion; no hypertrophy but seriously affected; suspicious; and hypertrophy and seriously affected (heart with HCM). Another 119 hearts were collected and classified. The variation of heart measurements was consistent with the original purpose of classification.


CONCLUSIONS
Using fewer measurements for identification of HCM objectively in pigs seems to have practical application.
Huang
S Y
SY
Cardiovascular Research Center, Department of Comparative Medicine, Pig Research Institute, Taiwan, Republic of China.
Tsou
H L
HL
Chiu
Y T
YT
Wu
J J
JJ
Lin
J H
JH
Yang
P C
PC
Liu
S K
SK
D000818:Animals; D001699:Biometry / Q000379:methods*; D001835:Body Weight; D002312:Cardiomyopathy, Hypertrophic / Q000145:classification / Q000175:diagnosis / Q000662:veterinary*; D005260:Female; D006346:Heart Septum / Q000473:pathology; D006352:Heart Ventricles / Q000473:pathology*; D008297:Male; D015999:Multivariate Analysis; D009206:Myocardium / Q000473:pathology; D009929:Organ Size; D012044:Regression Analysis; D013552:Swine; D013553:Swine Diseases / Q000145:classification / Q000175:diagnosis*