Accuracy of left ventricular function from electrocardiographygated myocardial perfusion SPECT by MyoMetrix in Chinese

This work was to determine threshold values foraccurate measurements of left ventricular end-diastolicvolume (EDV), end-systolic volume (ESV), and ejectionfraction (EF) from electrocardiography-gated myocardialperfusion imaging (MPI) in Chinese, and these data werecompared with those of echocardiography. A total of 110patients with definite or suspected coronary artery diseasewere referred for both gated MPI and echocardiographywithin 1 week. The EDV, ESV, and EF automaticallymeasured by MyoMetrix and echocardiography were analyzedusing Bland-Altman plot correlation and pairedt test. The results showed that these parameters quantifiedby MyoMetrix software were correlated, moderately tohighly, with those on echocardiography (q, r C 0.75,P\0.01). However, the EF was not significantly correlated,with post-exercise MPI ESV of\15 mL or restingMPI ESV of\20 mL. At or above this ESV value, EF wasunderestimated by MyoMetrix (t C 4.60, P\0.01). In aword, a small ESV was underestimated by MyoMetrix,which could lead to EF overestimation. On the contrary, anormal or large ESV was overestimated by MyoMetrix,which led to EF underestimation.