Nobuyuki Fujino

Changes in left ventricular output from fetal to early neonatal life

Using pulsed Doppler and two-dimensionally directed M-mode echocardiographic techniques, we measured left ventricular (LV) output, stroke volume, heart rate, LV end-diastolic dimension (LVEDD), LV end-systolic dimension, and LV percent fractional shortening (%FS) in 34 normal term infants 12 to 24 hours before parturition and thereafter serially 1, 24, and 96 hours after birth. Stroke volume was calculated as the product of the aortic flow velocity integral and aortic valve area. There was a twofold increase in LV output 1 hour after birth (fetal 170 +/- 46 ml/min/kg vs 1 hour 327 +/- 66 ml/min/kg; p less than 0.01) which was associated with significant increases in stroke volume, %FS, and LVEDD (stroke volume 1.21 +/- 0.33 ml/kg vs 2.25 +/- 0.37 ml/kg; %FS 34.3% +/- 5.8% vs 37.7% +/- 5.4%; LVEDD 15.4 +/- 1.1 mm vs 17.7 +/- 1.4 mm). Heart rate did not change 1 hour after birth. During the subsequent hours after birth, LV output decreased significantly to a value of 245 +/- 56 ml/min/kg (p less than 0.01) at 24 hours, which did not change 96 hours after birth. There were significant declines in stroke volume, LVEDD, and heart rate 24 hours after birth (stroke volume 2.02 +/- 0.42 ml/kg; LVEDD 17.0 +/- 1.1 mm; heart rate 121 +/- 11 beats/min). The %FS remained unchanged within the first 96 hours of age. These results indicate that the major regulator of LV output immediately after birth is stroke volume and not heart rate. The increase in stroke volume is related to an increase in LV size and LV myocardial contractility. Our data provide a useful basis for the interpretation of abnormal LV function in the early neonatal period.

Incidence and natural course of trabecular ventricular septal defect: Two-dimensional echocardiography and color Doppler flow imaging study

This study was designed to determine the prevalence of trabecular ventricular septal defect (t-VSD) in neonates and to evaluate the effects of its location, morphologic features, and size on its natural course during infancy. One thousand twenty-eight term newborn infants were examined by color Doppler flow imaging with orthogonal ultrasonographic views. Ten girls and 11 boys (2.0%) were found to have t-VSD. The natural course of the defect was examined in 42 consecutive cases, consisting of this group of 21 neonates and another group of 21 neonates with t-VSD. The morphologic features of the defect within the trabecular septum were classified as one or two defects (36 cases) and as a mesh-like defect (six cases). Reduction in size began from the right ventricular side or from within the trabecular septum. Spontaneous closure occurred most commonly during the first 6 months of life and was observed in 32 cases (76%) by 12 months of age: the frequency of closure was not related to the morphologic features and the initial size of the defect, but apical defects tended to have higher persistent patency than did defects in other locations (p less than 0.05). We conclude that the frequency of t-VSD in neonates and the frequency of spontaneous closure during early infancy are higher than previously believed. This information is important for predicting the natural course of t-VSD and deciding on its proper management.

Regional blood flow distribution and left ventricular output during early neonatal life: A quantitative ultrasonographic assessment

ABSTRACT: To examine the serial changes of left ventricular output and regional blood flow distribution during the early neonatal period, we measured blood flow volume in the ascending aorta, middle cerebral artery, celiac artery, superior mesenteric artery, and renal artery in 23 normal term infants at 1, 4--8, 24, and 96 h after birth. The blood flow volume in each vessel was measured by the pulsed Doppler technique. In the middle cerebral artery, celiac artery, and superior mesenteric artery, the blood flow volume at 1 and 4--8 h of age was significantly lower than after 24 h of age. In contrast, renal artery blood flow volume did not change significantly throughout the study period. The reduced organ blood flow volume soon after birth was related to a low diastolic blood flow in the major vessels, and the percent diastolic integral of blood flow velocity in each vessel showed an inverse linear correlation with the diameter of the ductus arteriosus. The left ventricular output 1 h after birth was 365 ± 69 mL/kg/min, which was significantly higher than after 4-8 h of age. Left ventricular output gradually declined to 301 ± 63 mL/kg/min at 4—8 h of age (p < 0.05 versus 96 h), 272 ± 48 mL/kg/min at 24 h, and 258 ± 54 mL/kg/min at 96 h. There was a significant positive correlation between left ventricular output and the ductus arteriosus diameter. We concluded that 1) there were significant changes in organ blood flow during the period of ductal closure, 2) the high left ventricular output and reduced regional blood flow at 1 and 4—8 h after birth resulted from diastolic left-to-right shunting through the ductus arteriosus, and 3) left ventricular output and regional organ blood flow were not directly related to each other. Our findings on the changes in regional organ blood flow and left ventricular output may provide a useful basis for interpreting abnormal hemodynamics in the early postnatal period.

Hemodynamic Adaptations at Birth and Neonates Delivered Vaginally and by Cesarean Section

In order to assess the possible influence of differences in delivery mode on cardiovascular adaptation at birth, we measured left ventricular output and its regional distribution in the major organs sequentially using an echographic technique during the first 96 h of life. We studied 27 normal newborns, of whom 15 were delivered vaginally and 12 by cesarean section. We also measured umbilical arterial and venous catecholamine concentrations. The umbilical arterial epinephrine and norepinephrine concentrations in the infants delivered vaginally were significantly greater than those in the infants delivered by cesarean section (epinephrine 1,195 +/- 208 vs. 565 +/- 81 pg/ml, p < 0.05; norepinephrine 11,832 +/- 3,819 vs. 5,153 +/- 1,400 pg/ml, p < 0.05). The left ventricular output and its regional distribution showed a similar pattern in the two groups, and there were no significant differences between them. These results indicate that the capacity of infants delivered by cesarean section to tolerate cardiovascular changes during the early neonatal period is comparable to that in infants delivered vaginally, even though there are significant differences in the catecholamine surge between these groups.

Transthoracic Doppler assessment of coronary flow velocity reserve in children with Kawasaki disease: Comparison with coronary angiography and thallium-201 imaging

OBJECTIVES The purpose of this study was to determine the feasibility of coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) in children with Kawasaki disease (KD). BACKGROUND Doppler-derived CFVR is a reliable marker predicting the presence of myocardial ischemia. METHODS We studied 49 patients (median age 11 years) with KD. The CFVR was calculated as the ratio of hyperemic to basal peak (peak CFVR) and mean (mean CFVR) diastolic flow velocities in the posterior descending coronary artery (PD) and left anterior descending coronary artery (LAD). The CFVR measurements by TTDE were compared with the results of coronary angiography, thallium-201 (Tl-201) single-photon emission computed tomography (SPECT), and intracoronary Doppler study. RESULTS The CFVR measurements by TTDE were obtained in 92 (94%) of 98 vessels of the PD and LAD in 49 study patients. Both peak and mean CFVRs for 21 stenotic vessels were significantly smaller than those for 35 normal vessels and for 20 vessels with aneurysmal lesions (p < 0.0001). Peak and mean CFVR <2.0 predicted significant coronary stenosis, as determined by coronary angiography, with sensitivities and specificities of 89% and 96% and 89% and 97%, respectively. Also, both peak and mean CFVRs were correlated with reversible perfusion defects on Tl-201 SPECT (agreement 80%; kappa 0.4). The correlation between peak and mean CFVRs determined by the TTDE and intracoronary Doppler studies in 36 vessels of 23 patients were 0.76 and 0.80, respectively. CONCLUSIONS The CFVR measured by TTDE predicts the presence of significant coronary stenosis of either the right coronary artery or LAD, as well as myocardial ischemia of these territories in children with KD.

Two-dimensional Doppler echocardiographic assessment of closure of the ductus arteriosus in normal newborn infants

To elucidate the mechanism involved in closure of the ductus arteriosus (DA), 50 normal full-term infants were examined with two-dimensional and pulsed Doppler echocardiography. The examinations were performed initially within 1 hour after delivery and serially for 3 days. The two-dimensionally derived long-axis plane of the DA disclosed a characteristic localized protrusion into its lumen in 30% of the subjects within 1 hour, in 80% by 4 hours, in 96% by 8 hours, and in all by 24 hours after birth. In 10 infants in whom the intraluminal protrusion did not appear within 4 hours after birth, none had any recognizable changes in the inner diameter or length of the DA during this initial period. The development of the intraluminal protrusion resulted in localized narrowing of the ductal lumen. Doppler echocardiography revealed a high-velocity jet within and downstream from the narrowed portion of the DA. Thereafter, ductal narrowing progressed along the entire length. The intraluminal protrusion may be early evidence of ductal changes leading to eventual functional and anatomic closure.

Effect of suture closure of coronary artery fistula on aneurysmal coronary artery and myocardial ischemia

This study indicates the importance of coronary angiography and myocardial scintigraphy on long-term follow-up of patients after surgery for coronary arterial fistula in view of the progression to coronary artery obstruction and myocardial ischemia.

Two-dimensional and Doppler echocardiographic assessment of variably shaped ductus arteriosus by the parasternal approach.

SummaryParasternal two-dimensional and Doppler echocardiography were compared with angiographic, surgical, and postmortem data in 213 patients with various forms of congenital heart disease for its accuracy in determining patency and anatomy of the ductus arteriosus (DA). The age range of the examined patients was from 1 day to 4 years (mean, 7.4 months). Echocardiography was always performed before any invasive procedure. An adequate window for imaging the DA was obtained by parasternal, two-dimensional echocardiography in 209 patients (98%). A persistent ductus arteriosus (PDA) was detected by invasive methods in 79 of 209 patients (38%), and by two-dimensional and Doppler echocardiography in 76 (sensitivity, 96%; specificity, 100%). The echocardiographic and angiographic findings agreed closely as to the ducts morphology. Our technique permits an accurate visualization of the duct in neonates, infants, and small children with various forms of congenital heart disease.

Echocardiographic evaluation of the ductal morphology in patients with refractoriness to lipo‐prostaglandin E1 therapy

Abstract Background : Lipo‐prostaglandin (PG)E1 is effective at lower doses and has fewer side effects than PGE1‐cyclodextrin (CD). Previous studies, however, have suggested that some patients show refractoriness to lipo‐PGE1 in the course of treatment. The present paper examines: (i) whether such cases can be predicted by examining the ductal morphology before and 24 h after the start of lipo‐PGE1 infusion; and (ii) whether PGE1‐CD dilates the ductus arteriosus in patients with refractoriness to lipo‐PGE1.

Obstruction of the proximal pulmonary artery branches after banding of the pulmonary trunk.

Abstract Most of the pulmonary branch obstruction that occurs after banding may be the result of dislocation or placement of the band very near the bifurcation during surgery rather than progressive migration of the band. Two-dimensional and Doppler echocardiography are useful noninvasive techniques for evaluating pulmonary branch size and stenosis after banding.