Normal data of left ventricular parameters in non-hypertensive patients using 320-slice cardiac CT: A study on intra-and interobserver variability

Abstract

Objective: Delineate normal data in a Thai population for global left ventricular function, left ventricular mass (LVM), and LV mass index (LVMI) by gated volumetric CT angiography (CTA). Material and Method: Two hundred twenty seven patients with intermediate risk factors for CAD were referred for CT coronary angiography. The non-hypertensive and non-diabetic asymptomatic group was selected with negative coronary CTA. Pre-condition of mild stenosis or less than 50% area stenosis was consistently met for inclusion in the present study. One hundred fifteen patients were included (31 males, 84 females, age range 38-76 years, mean 54.6 ± 7.2 for males and 54.0 ± 6.8 for females respectively). Results: Mean EDV, ESV, SV, CO, and EF in male and females were EDV 122.6 ± 17.3 vs. 94.9 ± 16.6 ml, ESV 48.2 ± 9.9 vs. 34.1 ± 9.1 ml, SV 74.5 ± 14.2 vs. 60.8 ± 10.6 ml, CO 4.2 ± 0.8 vs. 3.6 ± 0.7 L and EF 60.6 ± 6.6 vs. 64.3 ± 5.6% respectively. The mean LVM and LVMI were higher in males than females (LVM 134.6 ± 21.4 vs. 96.9 ± 20.3 g, and LVMI 76.8 ± 12.4 vs. 61.1 ± 11.56 g/m 2 ). Altman and Bland plot for each of them showed that the mean and standard deviation of the differences was constant throughout the range of measurements. Each histogram of differences showed that these differences correspond to approximately normal distribution, indicating that the required assumptions held for the use of 95% limits of agreement are valid. Conclusion: Data from this group represents healthy volunteers and this may serve as an important source of information representing normal reference values to be used for Thai patients.