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Background: Atrial ejection force (AEF) expresses the force exerted by the left atrium to the mass of blood passing through the mitral valve during atrial systole. It provides a diagnostic and predictive parameter for evaluating left ventricular diastolic abnormalities and a physiologic assessment of atrial systolic function., Methods: We obtained normal values of AEF in a group of 47 newborn infants with normal heart function and structure, using Doppler echocardiographic parameters of transmitral filling flow. AEF is defined as the product of the density of blood, the mitral valve area, and the square of peak A velocity [AEF = 0.5 x rho x mitral valve area x (peak A velocity)(2)]., Results: Mean and SD of AEF was 1.12 +/- 0.42 kilodynes. Atrial filling fraction (r = 0.74, P value = .000), A acceleration rate (r = 0.67, P value = .000), A deceleration rate (r = 0.64, P value = .000), and heart rate (r = 0.70, P value = .000) showed a positive correlation with AEF. Rapid filling fraction (r = -0.71, P value = .000) and E/A ratio (r = -0.6, P value = .000) had a negative correlation with AEF., Conclusion: AEF index in neonatal period is augmented and comparable with the values in adult population that could be explained by the specific pattern of slow ventricular relaxation in newborn infants. Complex aspects of diastolic function in newborn infants could be assessed beyond a simple E to A ratio by providing an estimate of normal values for AEF in this age group.

A comparative morphometric study was performed on the aortomitral valve apparatus of the embryonic and adult chicken hearts. It was found that the thickness of the aortic and mitral valve cusps diminishes dramatically as the embryo matures, however the relative length of the aortic valve, mitral valve and subaortic conus remains constant. A comparison of the aortomitral valve apparatus in chicken and man revealed that the subaortic conus is not completely resorbed in the fowl, whereas this process is well documented in the mammalian hearts. The implications of this observation on "the differential conal growth hypothesis" of transposition of the great arteries are discussed.

A heart specimen is presented which showed a rare combination of atrioventricular valve atresia with single ventricle, truncus arteriosus communis with an anteriorly placed trunk, ie transposition. Because of the problems involved in the classification of this heart, the types of single ventricle are revised with particular attention to the rare cases of atrioventricular valve atresia and single ventricle reported in the literature. Also the rare type of truncus arteriosus communis with truncoatrioventricular valve discontinuity is excluded from the so-called transposition complexes, and properly classified as a form of truncus. The literal meaning of transposition is stressed and it is urged to approach congenital heart defects in a purely anatomic sense with definition of each segment as accurately as possible. Thus the present confusion in terminology and further plethora of new terms are avoided.