2005 Volume 69 Issue 2 Pages 183-187
Background To quantitate the degree of 3-dimensional asynchronous myocardial contraction, an ECG-gated polar map method was developed with 99mTc-methoxy-isobutyl isonitrile, and used to investigate the relationship between asynchrony and left ventricular (LV) function. Methods and Results Twelve normal subjects and 38 patients with an old myocardial infarction were studied with ECG-gated single-photon emission computed tomography (SPECT). In each frame, a myocardial perfusion polar map was reconstructed and the peak contraction phase in each pixel was displayed (phase map). The degree of asynchronous contraction was assessed from the standard deviations of the peak contraction phase (SDP) on the phase map. Ejection fraction (EF), peak ejection rate (PER), 1/3EF, peak filling rate (PFR) and 1/3 filling fraction (1/3FF) were calculated by the quantitative gated SPECT software, and E/A from Doppler echocardiography. The SDP was compared with these parameters. Correlation coefficients and p values between the SDP and parameters of cardiac function were as follows: EF, r=-0.69 (p<0.001); PER, r=-0.54 (p<0.001); 1/3EF, r=-0.57 (p<0.001); PFR, r=-0.29 (p<0.05); 1/3FF, r=-0.63 (p<0.001); E/A, r=-0.11 (p=0.51). Conclusions There was a negative correlation between the SDP and LV systolic and diastolic function, which confirmed the functional significance of asynchrony on cardiac function. (Circ J 2005; 69: 183 - 187)
