A rat model of dilated cardiomyopathy to investigate partial left ventriculectomy.
BACKGROUND
This study is the first to assess a small animal model of dilated cardiomyopathy (DCM) for evaluation of partial left ventriculectomy.


METHODS
Eighteen Dahl salt-sensitive (DS) rats were divided into three groups. Six rats were fed an 8% high-salt diet from the age of 7 weeks (Group 1), and similarly six rats from 8 weeks (Group 2) and six from 9 weeks (Group 3). Blood pressure (BP) was measured by the tail-cuff method and left ventricular (LV) dimensions by echocardiography.


RESULTS
In Groups 1 and 2, systolic BP rose and reached 200 mmHg by the 10th to 11th week, when all rats died within a week without signs of heart failure. However, in Group 3, systolic BP gradually rose to 196+/-15 mmHg (mean +/- SD) at the age of 14 weeks, when LV end-diastolic diameter (EDD) was 6.2+/-0.4 mm (control 5.1+/-0.7 mm) and LV fractional shortening (FS) was 77+/-3% (control 68+/-3%). At the age of 25 to 30 weeks, all rats in Group 3 showed signs of congestive heart failure, systolic BP remained high, EDD markedly increased (8.7+/-0.6 mm), and LVFS decreased (38.9+/-8.1%). From this stage, rats survived for 13.7+/-5.9 days. We employed the Group 3 model for our pilot PLV study. Eight rats had PLV with a beating heart by plicating the LV area between the papillary muscle bases. Two rats died perioperatively but the rest survived (60% survival 3 weeks after PLV). Postoperatively, the rats' LVEDD decreased and FS improved significantly.


CONCLUSIONS
Using DS rats, we developed a DCM model for investigating PLV. The model may contribute to scientific investigation of PLV.
Yuasa
S
S
Department of Cardiovascular Surgery, Matsue Red-Cross Hospital, Shimane, Japan.
Nishina
T
T
Nishimura
K
K
Miwa
S
S
Ikeda
T
T
Hanyu
M
M
Fujioka
Y
Y
Kihara
Y
Y
Sasayama
S
S
Komeda
M
M
D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology / Q000601:surgery*; D004195:Disease Models, Animal; D006333:Heart Failure / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000601:surgery*; D051381:Rats; D020303:Rats, Inbred Dahl; D016277:Ventricular Function, Left