Details

Autor(en) / Beteiligte

• Asanuma, Toshihiko
• Nakayama, Tomohito
• Masuda, Kasumi
• Takeda, Serina
• Nakatani, Satoshi

Titel

Regional heterogeneity of afterload sensitivity in myocardial strain

Ist Teil von

• Journal of medical ultrasonics (2001), 2020-10, Vol.47 (4), p.501-506

Ort / Verlag

Singapore: Springer Singapore

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• Purpose The peak systolic strain decreases due to afterload augmentation. However, its deterioration (i.e., afterload sensitivity) may be different within the left ventricular (LV) segments. We investigated how afterload influences regional strain and whether there is regional heterogeneity of afterload sensitivity. Methods Afterload was increased by aortic banding in 20 open-chest dogs. Short-axis images were acquired at baseline and during banding. Circumferential strain was analyzed in six segments, and the absolute decrease in the peak systolic strain during banding (Δ ε ) was calculated for each segment. To assess the effect of the compensatory preload recruitment during banding, the endocardial lengths of the septum and free wall were measured at end-diastole, and the rate of increase due to banding was calculated. Results LV systolic pressure was significantly increased during banding (100 ± 14 vs. 143 ± 18 mmHg, P  < 0.001). The peak systolic strain in all segments was significantly decreased during banding. Δ ɛ in the anterior segment, which is a part of the free wall, was significantly lower than that in the inferoseptal segment (2.6 ± 4.7 vs. 6.5 ± 3.5%, P  = 0.035). The rate of increase in endocardial length in the free wall was significantly larger than that in the septum (15.6 ± 10.4 vs. 8.1 ± 7.4%, P  = 0.014). Conclusion The decrease in septal strain during afterload augmentation was larger than that in free wall strain, indicating that there was regional heterogeneity of afterload sensitivity in circumferential strain. The larger compensatory preload recruitment in the free wall than in the septum is implicated as a cause of the heterogeneity.