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Myocardial mechanics in a rat model with banding and debanding of the ascending aorta.

Cho JS, Cho EJ, Lee J, Choi HD, Park KC, Lee KH, Yang KJ, Park MW, Park GM, Her SH, Kim CJ - J Cardiovasc Ultrasound (2014)

Bottom Line: However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters.The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

ABSTRACT

Background: Aortic banding and debanding models have provided useful information on the development and regression of left ventricular hypertrophy (LVH). In this animal study, we aimed to evaluate left ventricular (LV) deformation related to the development and regression of LVH.

Methods: Minimally invasive ascending aorta banding was performed in rats (10 Sprague Dawley rats, 7 weeks). Ten rats underwent a sham operation. Thirty-five days later, the band was removed. Echocardiographic and histopathologic analysis was assessed at pre-banding, 35 days of banding and 14 days of debanding.

Results: Banding of the ascending aorta created an expected increase in the aortic velocity and gradient, which normalized with the debanding procedure. Pressure overload resulted in a robust hypertrophic response as assessed by gross and microscopic histology, transthoracic echocardiography [heart weight/tibia length (g/m); 21.0 ± 0.8 vs. 33.2 ± 2.0 vs. 26.6 ± 2.8, p < 0.001]. The circumferential (CS) and radial strains were not different between the groups. However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).

Conclusion: In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters. The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.

No MeSH data available.


Related in: MedlinePlus

Correlation of myocardial fibrosis with the peak global CS (A) and RS (B) had a significant negative correlation between myocardial fibrosis and the magnitude of peak global systolic CS (A). However, there was no significant correlation with the peak global systolic RS (B). CS: circumferential strain, RS: radial strain.
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Figure 5: Correlation of myocardial fibrosis with the peak global CS (A) and RS (B) had a significant negative correlation between myocardial fibrosis and the magnitude of peak global systolic CS (A). However, there was no significant correlation with the peak global systolic RS (B). CS: circumferential strain, RS: radial strain.

Mentions: Two-dimensional STE showed no difference in the global peak CS and RS between the sham, banding, and debanding groups (-25.7 ± 6.0 vs. -23.7 ± 5.8 vs. -23.7 ± 5.0, p = 0.661 for CS and 29.8 ± 7.9 vs. 29.0 ± 8.6 vs. 32.6 ± 9.5, p = 281 for RS) (Table 2). In the histological analysis, the size of the myocyte was significantly larger in the banding group than in the sham and debanding groups and was reversed after debanding (Table 2, Fig. 2 and 3). However, myocardial fibrosis was prevalent in the banding and debanding groups compared to the sham group (Table 2, Fig. 3). The 5-weekbanding procedure provoked minimal fibrosis that was lower than approximately 12%. The global peak CS was significantly correlated with the fibrosis severity in the banding group (r = 0.688, p = 0.028) (Fig. 4 and 5). However, there were no correlations between the global peak RS and fibrosis in the banding group (r = -0.618, p = 0.057) (Fig. 4 and 5).


Myocardial mechanics in a rat model with banding and debanding of the ascending aorta.

Cho JS, Cho EJ, Lee J, Choi HD, Park KC, Lee KH, Yang KJ, Park MW, Park GM, Her SH, Kim CJ - J Cardiovasc Ultrasound (2014)

Correlation of myocardial fibrosis with the peak global CS (A) and RS (B) had a significant negative correlation between myocardial fibrosis and the magnitude of peak global systolic CS (A). However, there was no significant correlation with the peak global systolic RS (B). CS: circumferential strain, RS: radial strain.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4286640&req=5

Figure 5: Correlation of myocardial fibrosis with the peak global CS (A) and RS (B) had a significant negative correlation between myocardial fibrosis and the magnitude of peak global systolic CS (A). However, there was no significant correlation with the peak global systolic RS (B). CS: circumferential strain, RS: radial strain.
Mentions: Two-dimensional STE showed no difference in the global peak CS and RS between the sham, banding, and debanding groups (-25.7 ± 6.0 vs. -23.7 ± 5.8 vs. -23.7 ± 5.0, p = 0.661 for CS and 29.8 ± 7.9 vs. 29.0 ± 8.6 vs. 32.6 ± 9.5, p = 281 for RS) (Table 2). In the histological analysis, the size of the myocyte was significantly larger in the banding group than in the sham and debanding groups and was reversed after debanding (Table 2, Fig. 2 and 3). However, myocardial fibrosis was prevalent in the banding and debanding groups compared to the sham group (Table 2, Fig. 3). The 5-weekbanding procedure provoked minimal fibrosis that was lower than approximately 12%. The global peak CS was significantly correlated with the fibrosis severity in the banding group (r = 0.688, p = 0.028) (Fig. 4 and 5). However, there were no correlations between the global peak RS and fibrosis in the banding group (r = -0.618, p = 0.057) (Fig. 4 and 5).

Bottom Line: However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters.The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

ABSTRACT

Background: Aortic banding and debanding models have provided useful information on the development and regression of left ventricular hypertrophy (LVH). In this animal study, we aimed to evaluate left ventricular (LV) deformation related to the development and regression of LVH.

Methods: Minimally invasive ascending aorta banding was performed in rats (10 Sprague Dawley rats, 7 weeks). Ten rats underwent a sham operation. Thirty-five days later, the band was removed. Echocardiographic and histopathologic analysis was assessed at pre-banding, 35 days of banding and 14 days of debanding.

Results: Banding of the ascending aorta created an expected increase in the aortic velocity and gradient, which normalized with the debanding procedure. Pressure overload resulted in a robust hypertrophic response as assessed by gross and microscopic histology, transthoracic echocardiography [heart weight/tibia length (g/m); 21.0 ± 0.8 vs. 33.2 ± 2.0 vs. 26.6 ± 2.8, p < 0.001]. The circumferential (CS) and radial strains were not different between the groups. However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).

Conclusion: In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters. The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.

No MeSH data available.


Related in: MedlinePlus