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Zoran B Popović,
Giuseppe Saracino,
Dimitri Deserranno,
Hua Yang,
Neil L Greenberg,
Masami Takagaki,
Kiyotaka Fukamachi,
Yoshie Ochiai,
Masahiro Inoue,
Soren Schenk,
Kazuyoshi Doi, Jianxin Qin,
Patrick M McCarthy,
Takahiro Shiota,
James D Thomas
[show abstract]
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ABSTRACT: 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.
Journal of the American Society of Echocardiography 06/2004; 17(5):411-7. · 3.71 Impact Factor
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Circulation 09/2003; 108(8):e54-5. · 14.74 Impact Factor
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Masami Takagaki,
Patrick M McCarthy,
Raymond Dessoffy,
Yoshie Ochiai,
Kazuyoshi Doi,
Michael W Howard, Jianxin Qin,
Hua Yang,
C Takahiro Shiota,
Jason Connor,
Kiyotaka Fukamachi
[show abstract]
[hide abstract]
ABSTRACT: We have reported that device based left ventricular (LV) shape change, accomplished by Myosplint, improved LV systolic function by three-dimensional echocardiography (3-D echo). However, evaluation of this device using the pressure-volume relationship is still important. This study was conducted to validate the use of conductance technology for this evaluation in shape-changed hearts. An ex vivo study using excised ovine hearts (n = 11) and an in vivo study using a canine pacing-induced heart failure model (n = 11) were performed. Three Myosplints were implanted. Before and after the shape changes, volumes measured by a conductance catheter were compared with volumes measured by the amount of saline in the ex vivo study or by 3-D echo in the in vivo study. The conductance volumes were linearly correlated with the saline volumes (r2 = 0.961+/-0.046; p < 0.0001) in the ex vivo study and with 3-D echo volumes (r2 = 0.757+/-0.220; p < 0.0001) in the in vivo study. The conductance volumes were linearly correlated with LV volumes even in the shape-changed hearts. This technology can be used to evaluate pressure-volume loops in the shape-changed hearts as long as the conductance volume is calibrated by a reliable method.
ASAIO Journal 48(3):268-71. · 1.39 Impact Factor
