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Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine
Published on: February 17, 2018
Left atrial enlargement induced by pure mitral regurgitation: time frame in a new swine model
Background:
Atrial enlargement occurs in patients with significant mitral regurgitation. However, the time frame of the development of atrial enlargement induced by mitral regurgitation remains unknown.
Methods:
Fourteen Lanyu miniature pigs (age = 6.6 ± 0.9 months) were studied. Mitral regurgitation was created by placing a predefined hole on the middle scallop of the posterior mitral leaflet under cardiopulmonary bypass. The parasternal long-axis atrial dimension was measured by transthoracic echocardiographic examinations.
Results:
All animals exhibited grade 3 mitral regurgitation immediately after surgery. Seven pigs expired within 2 weeks after the operation [technical complications (n = 1), acute cardiac tamponade (n = 1), and acute and subacute heart failure (n = 5)]. Seven pigs remained alive at a mean follow-up of 7.7 ± 2.1 months. The left atrial diameter indices of the 7 pigs increased significantly at 1 month (33.1 ± 8.6 mm, p = 0.018) and 3 months (41.3 ± 12.6 mm, p = 0.018) after surgery compared with baseline values (22.8 ± 5.2 mm), and the left atrial diameter index increased significantly at 3 months compared to 1 month (p = 0.018).
Conclusions:
Left atrial enlargement develops rapidly and progresses after the creation of significant pure mitral regurgitation.
