Echocardiographic assessment of regional ventricular function after device-based change of left ventricular shape.
We assessed the effects of implantation of Myosplint (Myocor, Maple Grove, Minn), a device that changes left ventricular (LV) cross-sectional shape from circular to bilobar, on regional LV function. A total of 10 open-chest dogs with tachycardia-induced cardiomyopathy were studied before and after Myosplint implantation. LV cross-sectional epicardial echocardiography at the papillary muscle level was performed along with acquisition of hemodynamic data. LV normalized thickening, fractional thickening, end-diastolic thickness, and end-diastolic curvatures were calculated for 10 LV segments. Myosplint implantation did not affect LV hemodynamics, but decreased average end-diastolic curvature (P <.0001) and increased its segmental heterogeneity (P <.0001). There was no change in average fractional thickening, whereas normalized thickening increased (P =.05). In contrast, segmental heterogeneity of both normalized and fractional thickening increased (P =.02 and P =.01, respectively). Structural modeling confirmed that Myosplint implantation increases regional stress heterogeneity and curvature heterogeneity. LV cross-sectional shape markedly affects regional LV performance.
Popović
Zoran B
ZB
Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, OH 44195, USA.
Saracino
Giuseppe
G
Deserranno
Dimitri
D
Yang
Hua
H
Greenberg
Neil L
NL
Takagaki
Masami
M
Fukamachi
Kiyotaka
K
Ochiai
Yoshie
Y
Inoue
Masahiro
M
Schenk
Soren
S
Doi
Kazuyoshi
K
Qin
Jianxin
J
McCarthy
Patrick M
PM
Shiota
Takahiro
T
Thomas
James D
JD
D000818:Animals; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D004285:Dogs; D006353:Heart-Assist Devices; D008955:Models, Cardiovascular; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*