Table 4.

Intra-observer variability of three-dimensional echocardiography

Variable	First measurement (ml)	Second measurement (ml)	Relative difference (%)	Group comparison (P-Values)	Correlation coefficient (R)
EDV	25.64	26.05	1.60	0.695	0.81
ESV	13.38	13.84	3.45	0.625	0.95
SV	12.22	12.22	0.00	0.922	0.58
EF	48.47	48.09	0.80	0.846	0.84

Comparison of right ventricular function parameters measured twice at least two weeks apart with three-dimensional echocardiography by the same observer (end-diastolic volume = EDV, end-systolic volume = ESV, ejection fraction = EF, stroke volume = SV).