Terukazu Shiota

Doppler Echocardiographic Evaluation of Left Ventricular Output and Left Ventricular Diastolic Filling Changes in the First Day of Life

ABSTRACT: The aim of this study was to evaluate the changes in Doppler transmitral flow patterns during the 1st d of life. Doppler echocardiography of the ascending aorta and mitral valve was performed serially in 20 normal neonates at 2, 12, and 24 h of age. A computer-interfaced digitizer pad was used to measure the following: ascending aorta flow velocity-time integral, total diastolic filling flow velocity-time integral, flow velocity-time integral of early diastolic filling, and flow velocity-time integral of atrial contraction. The inner diameter of the ductus arteriosus was 4.2 ± 0.6 mm at 2 h of age, 2.3 ± 0.5 mm at 12 h of age, and had closed in 17 of 20 neonates (85%) by 24 h of age. The ascending aorta flow velocity-time integral and total diastolic filling flow velocity-time integral, which were high at 2 h of age, decreased significantly at 12 h of age [12.2 ± 2.1 cm versus 9.6 ± 1.7 cm (p < 0.001) and 8.0 ± 1.1 versus 7.1 ± 1.4 (p < 0.01), respectively] but remained constant thereafter. Although no significant changes in flow velocity-time integral of atrial contraction and peak velocity of atrial contraction were noted during the first 24 h of birth, the flow velocity-time integral of early diastolic filling and peak velocity of early diastolic filling that were high at 2 h of age were reduced significantly at 12 h of age [5.0 ± 0.9 cm versus 4.1 ± 1.1 cm (p < 0.005) and 60.9 ± 9.0 cm/s versus 50.3 ± 9.0 cm/s (p < 0.001), respectively], resulting in significant reductions in the ratio of flow velocity-time integral of early diastolic filling/flow velocity-time integral of atrial contraction and the ratio of peak velocity of early diastolic filling/peak velocity of atrial contraction at 12 h of age. The size of the ductus arteriosus was found to be correlated with the peak velocity of early diastolic filling (r = 0.42, p < 0.05). Our results clearly demonstrate that the pattern of early diastolic filling was dependent on preload, whereas that of late diastolic filling was independent of preload in the early neonatal period.

Effect of Heart Rate on Left Ventricular Diastolic Filling Patterns Assessed by Doppler Echocardiography in Normal Infants

Abstract In conclusion, this study shows that physiologic HR changes cause significant alteration in transmitral Doppler flow velocity patterns, and indicates that such changes should be considered when using Doppler echocardiography to assess diastolic properties.

Changes in the volume and performance of the left ventricle in the early neonatal period

To evaluate the effect of changes in preload on left ventricular (LV) performance, we used echocardiography to measure end-diastolic dimension, end-systolic dimension, and stroke volume in newborns at 2, 12, 24, and 120 h of age. The stroke volume was calculated by the pulsed Doppler technique. The stroke volume showed the highest level at 2 h of age. The size of the ductus arteriosus correlated with the stroke volume. These results indicated that the increase in stroke volume was related to the increase in LV preload due to the shunt flow volume through the patent ductus arteriosus. M-mode echocardiographic indexes such as end-diastolic dimension, LV end-diastolic volume, and LV ejection fraction did not show any significant changes from 2 to 120 h of age. We conclude that M-mode echocardiographic evaluation of LV performance is unreliable in the early neonatal period. Our data also provide a useful basis for the interpretation of abnormal left ventricular systolic function in the early neonatal period.

Congenital atresia of left coronary ostium

Sir: In his letter, Dr. Ozsoylu suggests that since a difference between anti-HCV positive and anti-HCV negative patients does not exist with regard to chronic evolution or histological features of liver damage, iron overload might be considered as the causative factor of liver involvement. Actually, although iron overload as well as oxygen free radicals are undoubtedly involved in the aetiology of liver damage, viral infections play an important role in liver disease and in its evolution to chronicity. The lack of significant differences between anti-HCV positive and anti-HCV negative patients with non-A non-B chronic hepatitis might be explained by the following: