Identifying early changes in myocardial microstructure in hypertensive heart disease.
The transition from healthy myocardium to hypertensive heart disease is characterized by a series of poorly understood changes in myocardial tissue microstructure. Incremental alterations in the orientation and integrity of myocardial fibers can be assessed using advanced ultrasonic image analysis. We used a modified algorithm to investigate left ventricular myocardial microstructure based on analysis of the reflection intensity at the myocardial-pericardial interface on B-mode echocardiographic images. We evaluated the extent to which the novel algorithm can differentiate between normal myocardium and hypertensive heart disease in humans as well as in a mouse model of afterload resistance. The algorithm significantly differentiated between individuals with uncomplicated essential hypertension (N = 30) and healthy controls (N = 28), even after adjusting for age and sex (P = 0.025). There was a trend in higher relative wall thickness in hypertensive individuals compared to controls (P = 0.08), but no difference between groups in left ventricular mass (P = 0.98) or total wall thickness (P = 0.37). In mice, algorithm measurements (P = 0.026) compared with left ventricular mass (P = 0.053) more clearly differentiated between animal groups that underwent fixed aortic banding, temporary aortic banding, or sham procedure, on echocardiography at 7 weeks after surgery. Based on sonographic signal intensity analysis, a novel imaging algorithm provides an accessible, non-invasive measure that appears to differentiate normal left ventricular microstructure from myocardium exposed to chronic afterload stress. The algorithm may represent a particularly sensitive measure of the myocardial changes that occur early in the course of disease progression.
Harvard Medical School, Boston, Massachusetts, United States of America.
Pranoti
P
Hiremath
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Michael
M
Bauer
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Aaron D
AD
Aguirre
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Hui-Wen
HW
Cheng
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Kazumasa
K
Unno
The Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
Ravi B
RB
Patel
The Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
Bethany W
BW
Harvey
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Wei-Ting
WT
Chang
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
John D
JD
Groarke
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Ronglih
R
Liao
The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Susan
S
Cheng
D000328:Adult; D000368:Aged; D000465:Algorithms; D000818:Animals; D001011:Aorta / Q000473:pathology; D001794:Blood Pressure; D016022:Case-Control Studies; D004195:Disease Models, Animal; D018450:Disease Progression; D004452:Echocardiography / Q000379:methods; D000075222:Essential Hypertension; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology*; D006352:Heart Ventricles; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*