Clinical & Experimental Cardiology
Open Access

Evaluation of regional work from ECG-gated SPECT images through solution of equations of continuity for fluids–mechanical cardiac work calculated using thin wall model

5^th International Conference on Clinical & Experimental Cardiology

April 27-29, 2015 Philadelphia, USA

Hisatoshi Maeda

Posters-Accepted Abstracts: J Clin Exp Cardiolog

Abstract :

Regional contraction work (RCW) of left ventricle (LV) was evaluated from cardiac perfusion images of ECG-gated single photon emission computed tomography (ECG-SPECT). The mechanical work was computed as a product of force and displaced distance. Force was determined from Laplace?s lawunder a rectangle pressure. Deformation of wireframe representing LV was calculated from equations of continuity for two-dimensional fluids. Experiments were performed with homemade life-sized cardiac models. Total contraction work (TCW) and stroke work (SW) were 524.0 Å} 166.1 mJ/beat and 709.8 Å} 169.5 mJ/beat, respectively, in normal subjects (n = 23). Moderate correlation was seen between TCW and SW(y=−43.4+0.779 x, r=0.815). The regional contraction amplitude (RCA), synchronous contraction index and RCW were 35.4 Å} 3.5%, 95.4 Å} 3.1% and 5.58 Å} 0.97 mJ cm−2/beat in normal subjects, whereas those in patients with decreased ejection reaction (EF) 30% (n = 6) were 19.6 Å} 7.7%, 64.4 Å} 32.2% and 2.58 Å} 0.82 mJ cm−2/beat (p < 0.0001, Student?s t-test). There was a poor correlation between RCW and RCA (y = 1.648 Å} 0.116 x, r = 0.501) in normal subjects, suggesting that it might not be suitable to use RCA as an alternative to evaluate RCW.