Sequential longitudinal evaluation of cardiac growth and ventricular diastolic filling in fetuses of well controlled diabetic mothers

Summary Hypertrophic cardiomyopathy and abnormal ventricular diastolic filling in the infant of the diabetic mother is related to poor maternal glycemic control. Evaluation of fetuses of well controlled diabetic mothers has not been examined. Eleven fetuses of nondiabetic mothers (normals) and 9 fetuses of well controlled insulin-dependent diabetic mothers (FODMs) under-went serial evaluation of cardiac growth and ventricular diastolic filling using M-mode and Doppler echocardiography at 20–26 weeks' (period 1), 27–33 weeks' (period 2), 34–40 weeks' (period 3), and 48–72 hours after birth (period 4). Indices of right and left ventricular diastolic filling included time velocity integral ratios (E/A and %E/E + A). Cardiac growth and birth weight in the two groups were similar consistent with good glycemic control. This conclusion was supported by similar maternal glycosylated hemoglobin (%A1C) prenatally and newborn %A1C and C-peptide values postnatally. Heart rate before and after birth and placental resistance prenatally were similar. Both normal and FODMs demonstrated an increase in left ventricular E/A and %E/E + A ratios from period 1 to 4 (p<0.0001). This shift occurred earlier (by period 2) in normals (p<0.01). Right ventricular filling ratios increased by period 4 in normals only (p<0.01). No differences were noted between the groups during any period. Good glycemic control in FODMs results in normal cardiac growth and ventricular diastolic filling. Progression of diastolic filling is abnormally delayed, however, and is presumably more exaggerated in poorly controlled diabetics.     

Doppler Echocardiographic Evaluation of Right Ventricular Diastolic Function in Children

Right ventricular diastolic function was evaluated by flow velocity pattern in the right ventricular inflow tract by means of pulsed Doppler echocardiography. Traditionally used to evaluate this function are peak velocities obtained during early diastole (peak E wave) and during atrial contraction (peak A wave), their ratio (peak E/A ratio), and the deceleration half-time. We conducted pulsed Doppler echocardiographic studies of right ventricular inflow and outflow patterns in 171 children (105 normal children and 66 children who were undergoing total surgical repair of congenital heart defects without sequelae). Results showed that summation flow was present in the right ventricular inflow tract in 43 (25%) of the 171 subjects, which made it difficult to separate the peak E wave from the peak A wave. We noted the presence of antegrade late diastolic flow (DW) in the right ventricular outflow tract of all subjects. DW, measured in 121 subjects in whom both E and A waves were detected in the right ventricular inflow tract, showed a highly significant correlation (p < 0.0001) with A waves in the right ventricular inflow tract. The ratio of DW to right ventricular outflow tract velocities during systole (SW) showed a highly significant (p < 0.0001) correlation with E/A ratio. When evaluating right ventricular diastolic function by pulsed Doppler, especially in children, the analysis of right ventricular outflow tract patterns is helpful in addition to that of inflow tract patterns. The DW and DW/SW ratio may present good alternatives to traditional parameters in children.     

Acute loads applied to the right ventricle: Effect on left ventricular filling dynamics in the presence of an open pericardium

To determine whether diastolic ventricular interdependence mechanisms would act in the presence of an open pericardial sac, as during cardiac surgery, moderate acute right ventricle afterload increases were applied to eight dogs with the chest and pericardium open while left ventricular filling dynamics were being assessed by Doppler echocardiography. Dogs were studied under basal conditions and after acute banding of the main pulmonary artery tightened to produce a 100% increase in right ventricular systolic pressure. With banding, the left ventricular filling velocity ratio (E/A), as assessed by Doppler echocardiography of mitral inflow, changed from a baseline value of 1.32 ± 0.05 to 1.16 ± 0.03 (p < 0.02), suggesting a restrictive pattern to early left ventricular filling, which is differed to that during the second half of diastole. Isovolumic relaxation time, measured as the time interval between aortic valve closure and mitral valve opening, assessed by M-mode echocardiography of both valves, was prolonged, though not significantly, from 63.3 ± 2.5 ms to 69.4 ± 2.9 ms, by banding of the pulmonary artery. E wave deceleration time, a filling variable influenced by chamber pressure/volume relations, was shortened by pulmonary artery banding, changing from 75.1 ± 1.7 ms to 68.0 ± 1.8 ms (p < 0.01). It was concluded that pressure loads applied to the right ventricle restricted early left ventricular filling. Prolonged relaxation and altered pressure–volume chamber relations were the diastolic interdependence mechanisms involved that proved to be acting even under open pericardium conditions.     

Ventricular diastolic filling indices in pulmonary stenosis

Children with valvar pulmonary stenosis have right ventricular diastolic filling abnormalities that may be due to either right ventricular hypertrophy or right ventricular outflow obstruction. In order to investigate the reason for this abnormality, 23 consecutive cases with pulmonary stenosis (mean age 7.94 +/- 3.33 years) undergoing transluminal pulmonary balloon valvuloplasty without significant tricuspid or pulmonary valvar regurgitation were studied prospectively. Right ventricular diastolic filling indices and pulmonary valvar systolic gradients were measured in these children one day before and after pulmonary balloon valvuloplasty and were re-examined six months later. Right ventricular diastolic indices based on rapid early diastolic filling peak velocity (peak E), peak velocity during atrial contraction (peak A), and ratio of E/A were determined by pulsed Doppler echocardiography. In conclusion, right ventricular diastolic filling indices in patients with pulmonary stenosis did not improve after pulmonary balloon valvuloplasty in the first day but when re-examined by the sixth month there was a significant improvement. These data suggest that diastolic filling abnormalities are more likely a result of right ventricular hypertrophy than of right ventricular outflow obstruction.     

NT-proBNP as a Marker for Persistent Cardiac Disease in Children with History of Dilated Cardiomyopathy and Myocarditis

Children with myocarditis and dilated cardiomyopathy may recover clinically and echocardiographically. Plasma levels of the N-terminal segment of B-type natriuretic peptide prohormone (NT-proBNP), a sensitive marker for cardiac dysfunction, may reflect residual cardiac damage in these patients. The purpose of this study was to evaluate NT-proBNP status in pediatric patients with a history of myocarditis and dilated cardiomyopathy. Cardiac evaluation was performed and the levels of NT-proBNP were measured in 23 children who had a history of myocarditis or dilated cardiomyopathy. NT-proBNP levels were also measured in 56 age-matched control children. Nine of the 23 patients had evidence of left ventricular dysfunction (DCM group), whereas 14 had none (recovery). NT-proBNP levels were higher in the DCM group (3154 ± 2858 pg/ml) than in the recovery group (122 ± 75 pg/ml, p < 0.001) and the control group (113 ± 96 pg/ml, p < 0.001). There was no difference between the recovery and the control groups (p = 0.45), and none of the recovered patients had a NT-proBNP level higher than the upper limit of normal. The area under the receiver operating characteristics curve for the diagnosis of persistent left ventricular dysfunction was 0.984. NT-proBNP levels correlated with echocardiographically derived shortening fraction and with clinical score. NT-proBNP is a good marker for persistent left ventricular dysfunction in children who have had myocarditis or cardiomyopathy. In this group of patients, NT-proBNP levels are normal in children who recover echocardiographically, suggesting no residual hemodynamic abnormalities.     

Cardiovascular impairment in children,adolescents, and young adults with type 1 diabetes mellitus (T1DM)

Left ventricular (LV) function was assessed in 42 patients (mean age ± SD, 18.45 ± 3.76 years; 17 males) with type I diabetes mellitus (T1DM; mean duration 9.89 years) and in 43 healthy controls (mean age ± SD, 18.27 ± 3.36 years; 18 males). Systolic, diastolic cardiac function and LV dimensions were assessed using M-mode and Doppler echocardiography. Neural autonomic function was assessed by measuring RR variation during deep breathing, Valsava maneuver, 30/15 ratio, and blood pressure response to standing. Fractional shortening, peak velocity of early ventricular filling (E wave), peak velocity of LV filling (A wave), E/A ratio, deceleration time, isovolumic relaxation time, LV dimensions (interventricular septum, posterior wall thickness, end diastolic diameter [EDD] and systolic diameter [ESD]) were all comparable between patients with T1DM and controls. However, in 11 T1DM patients with microalbuminuria and/or retinopathy, EDD, ESD, E/A ratio, and E wave were all lower (p = 0.0011, p = 0.019, p = 0.0011, and p = 0.030, respectively) while, A wave, heart rate, and diastolic blood pressure were all higher (p = 0.008, p = 0.0024 and p = 0.004, respectively) compared to matched for age and sex controls. Furthermore, in six of the 11 T1DM patients with microangiopathy who had E/A <1.12 (<2 SD of the control mean), significant and marginally significant correlations were found between E/A ratio and the duration of the disease as well as the mean HbA1c of the last year (r = –0.38, p = 0.011 and r =  –0.287, p = 0.064, respectively). In conclusion, it has been found that impairment of diastolic, but not systolic, LV function can be detected early in young patients with T1DM and microangiopathy.     

Effects of low-dose dobutamine on left ventricular diastolic filling in children

To investigate the effects of dobutamine on the Doppler transmitral flow pattern in children with normal left ventricular function, Doppler echocardiography was used to measure the transmitral flow in 14 healthy children before and during infusion of dobutamine (5 μg/kg per minute). Cardiac output was measured by the thermodilution method, and stroke volume was calculated as the cardiac output divided by the heart rate. Dobutamine increased the peak velocity and flow velocity–time integral of early diastolic filling without changing those of atrial contraction and normalized peak velocity of early diastolic filling, suggesting an increase in left ventricular relaxation. Dobutamine increased the stroke volume and rate-corrected mean velocity of fiber shortening with reduced end-systolic wall stress, indicating an increase in left ventricular contractility. The percentage of increase in the flow velocity–time integral of early diastolic filling during dobutamine infusion tended to correlate with the increase in stroke volume (r= 0.67, p < 0.05) and with the decrease in end-systolic wall stress (r=−0.61, p < 0.05). Our results suggest that low-dose dobutamine increases left ventricular relaxation with enhanced systolic function. The observed decreased end-systolic wall stress might have caused enhanced relaxation characteristics with dobutamine.     

Contribution of Doppler Atrioventricular Flow Waves to Ventricular Filling in the Human Fetus

The normal fetal flow velocity profile across the atrioventricular valves is characterized by an early peak (E), which is related to preload and to active ventricular muscle relaxation, and a higher late peak (A), which is caused by the atrial contraction and also influenced by ventricular compliance. The purpose of this study was to determine how these two elements of ventricular filling change during gestation in both ventricles. A total of 485 normal fetuses from 17 weeks to term were examined by Doppler echocardiography. We measured E and A peak velocities and E/A ratio for both mitral and tricuspid valves. Simple regression analysis was applied to assess possible correlation between Doppler variables and gestational age. Moreover, E and A peak velocities were compared using paired Student's t-test. With the advance of gestation a significant linear increase in the E wave and E/A ratio was found for both mitral and tricuspid valves. The A wave shows little change throughout pregnancy. We found significantly higher Doppler velocities for the tricuspid valve than for the mitral valve. The relationship between the E/A ratios for the two valves and gestational age diverge slightly, with higher values for the mitral E/A ratio. This study shows that the A wave velocity remains constant throughout gestation, suggesting little or no change in ventricular compliance. The E wave is mainly responsible for the change in E/A ratio for both atrioventricular valves during gestation. These findings suggest progressive enhancement of relaxation and elastic recoil, an increase in preload, or both, throughout gestation, rather than a change in myocardial compliance as an explanation for the observed increase in the E/A ratio.     

Evaluation of cardiac function by tissue Doppler imaging in children with chronic hepatitis

OBJECTIVES: Pathoanatomic changes in cirrhosis result in impaired ventricular filling and diastolic dysfunction and were named as cirrhotic cardiomyopathy. However, cardiac functions have not been studied in patients with chronic hepatitis. We hypothesized that such patients might have subclinical ventricular dysfunction, detectable by tissue Doppler echocardiography and related to the severity of hepatic inflammation and fibrosis. METHODS: We studied 63 clinically stable patients, 27 patients with mild chronic hepatitis (group 1), 22 patients with moderate chronic hepatitis (group 2) and 14 patients with severe chronic hepatitis (group 3) according to the scoring system of Knodell, and 36 age-matched healthy subjects. RESULTS: Patients with severe chronic hepatitis had impaired right ventricular diastolic function. The early diastolic velocity of the tricuspid valve annulus was lower in patients from group 3 than in healthy subjects (P < 0.001). Patients in group 3 had a greater isovolumic relaxation time (P < 0.001), indicating right ventricular diastolic dysfunction. Comparing group 3 with the healthy subjects, the ratio of peak early myocardial tissue velocity and peak late (or atrial) myocardial tissue velocity was significantly decreased (P < 0.001), at 1.4 (0.7) and 1.9 (0.7), respectively. There was also a slightly lower peak early myocardial tissue velocity and peak late (or atrial) myocardial tissue velocity ratio and a slightly longer isovolumic relaxation time in patients from group 2 than in healthy subjects (P < 0.05). CONCLUSIONS: We detected subclinical dysfunction of the right ventricle in children with chronic hepatitis in whom hepatic inflammation and fibrosis is prominent. Tissue Doppler echocardiography provides a quantifiable indicator useful for detection and monitoring of disease progression.     

The Efficacy of Mitral Valve Surgery in Children with Dilated Cardiomyopathy and Severe Mitral Regurgitation

Severe mitral regurgitation predicts poor outcomes in adults with left ventricular dysfunction. Frequently, adult patients now undergo initial mitral valve surgery instead of heart transplant. Pediatric data are limited. This study evaluates the efficacy of mitral valve surgery for severe mitral regurgitation in children with dilated cardiomyopathy. This is a single-institution experience in seven children (range, 0.5–10.9 years) with severe mitral regurgitation and dilated cardiomyopathy who underwent mitral valve surgery between January 1988 and February 2005, with follow-up to January 2006. Children with dilated cardiomyopathy had a depressed fractional shortening preoperatively (24.4% ± 6.1%) that remained depressed (22.9% ± 7.6%) 1.3 ± 1.2 years after surgery (p = 0.50). Left ventricular end-diastolic (6.5 ± 1.5 to 4.8 ± 1.8 z-scores, p < 0.01) and end-systolic (6.8 ± 1.5 to 5.5 ± 2.1 z-scores, p < 0.05) dimensions improved. Hospitalization frequency had a median decrease of 6.0 hospitalizations per year (p < 0.02). Three patients were transplanted 0.2, 2.4, and 3.5 years after surgery. There was no perioperative mortality. Mitral valve surgery in children with dilated cardiomyopathy was performed safely and improved symptoms, stabilizing ventricular dysfunction in most patients. Mitral valve surgery should be considered prior to heart transplant in children with dilated cardiomyopathy and severe mitral regurgitation.     

X-Chromosomal (p21) Muscular Dystrophy and Left Ventricular Diastolic and Systolic Function

In order to screen for cardiac abnormalities, we prospectively studied 15 patients (age 8–25 years, mean 15.5 years) with Duchenne's (DMD) (n= 9) and Becker's (BMD) (n= 6) muscular dystrophy using the echocardiogram. Data were compared to a control group of 92 healthy individuals (age 7.9–25 years, mean 14.3 years). Left ventricular filling in diastole showed a different pattern when comparing echocardiographic Doppler results in patients and controls: Patients had lower peak velocity of early left ventricular diastolic filling (E-vmax)(P < 0.0001) and smaller time velocity integral of the E-wave (E-tvi)(P < 0.0001). In contrast, the atrial component (A-vmax, A-tvi) of diastolic filling in DMD/BMD showed no significant difference to controls. The mean area of the mitral valve orifice was significantly larger in patients (P < 0.0001) without presence of mitral regurgitation. Systolic left ventricular function was significantly impaired in the DMD/BMD group; we found lower heart rate corrected fiber shortening velocity VCFc (P < 0.001) and higher peak systolic wall stress (P < 0.001) in DMD/BMD. In 8 of 15 patients, peak systolic wall stress was above 95th percentile of controls. In 6 of 15 patients, VCFc was lower than the 5th percentile of controls. Systolic and diastolic myocardial impairment was found even in young patients and at low stages of disability—equally among patients with DMD or BMD. Diastolic left ventricular impairment predominantly affected the early diastolic filling, but atrial compensation was poor. Peak systolic wall stress measurements were particularly useful in patients with CMP, reflecting the left ventricular afterload.     

Measurement of Tricuspid Annular Diastolic Velocities by Doppler Tissue Imaging to Assess Right Ventricular Function in Patients with Congenital Heart Disease

We assessed the clinical utility of using diastolic tricuspid annular velocities obtained by Doppler tissue imaging as a noninvasive index of right ventricular function in patients with congenital heart disease. Doppler tissue imaging at the tricuspid annulus and pulsed Doppler echocardiography of the right ventricular inflow were performed in 71 children with congenital heart disease, with and without elevated right ventricular pressure. Cardiac catheterization was performed in all patients with congenital heart disease, and the hemodynamic determinants of the tricuspid annular and inflow velocities were determined. In patients with congenital heart disease, the ratio of the late-to-early diastolic tricuspid annular velocity (Aa/Ea) showed a highly significant correlation with right ventricle pressure/left ventricle pressure (r = 0.79, p < 0.0001), right ventricular end diastolic pressure (r = 0.46, p < 0.0001), and the first derivatives of the change in right ventricle pressure during diastole (r = 0.72, p < 0.0001). However, the late-to-early diastolic tricuspid inflow velocity (A/E) did not correlate with any invasively measured index of right ventricular function. Aa/Ea, derived from tricuspid annular velocities as measured by Doppler tissue imaging, is a valuable, noninvasive tool for detecting an elevated right ventricular pressure in patients with congenital heart disease.     

M-mode echocardiographic findings in children with idiopathic restrictive cardiomyopathy

Summary The M-mode echocardiographic findings in five pediatric patients, ages 4–15 years, with primary idiopathic restrictive cardiomyopathy, diagnosed by cardiac catheterization, and of 12 normal children (control group) are presented. The M-mode echocardiographic findings in patients with restrictive cardiomyopathy were (1) normal left and right ventricular end-diastolic dimension, (2) normal left ventricular posterior wall and interventricular septal thickness (three patients) or mild concentric hypertrophy (two patients), (3) normal opening and closing velocity of the mitral valve, (4) consistently enlarged left atrium (more than 40 mm) in all, and (5) right ventricular systolic time intervals compatible with pulmonary artery hypertension. The left ventricular ejection phase parameters (systolic time intervals, shortening fraction, and mean velocity of circumferential fiber shortening) were normal. Left ventricular relaxation phase parameters (diastolic function) were abnormal. The isovolumic relaxation time index was prolonged, 68±40 ms (±SD), in the study group as compared with 11±6 ms (±SD) in the control group (P<0.001). Percent relaxation of left ventricular posterior wall endocardium at 50% of diastole was decreased, 58±4% (±SD), in the study group as compared with 85±6% (±SD) in the control group (P<0.005). We conclude that M-mode echocardiography provides arelatively useful and specific noninvasive method for the diagnosis of primary restrictive cardiomyopathy in pediatric patients. This work was supported in part by NHLBI grant HL07436.     

Serial echocardiographic and Doppler evaluation of left ventricular systolic performance and diastolic filling in premature infants

To examine the effects of somatic growth on left ventricular systolic and diastolic functions in premature infants, we performed serial two-dimensional, M-mode and Doppler echocardiograms of 18 premature infants in the early neonatal period (mean of 14 days) and on the day when they were discharged from the hospital (mean of 94 days). The relation between rate-corrected mean velocity of fiber shortening and end-systolic wall stress relation was used as a load-independent estimate of contractility. Diastolic function was assessed by transmitral Doppler filling velocity patterns. The end-systolic wall stress was significantly lower in the first examination than in the second examination (38+/-8 vs. 46+/-10 g/cm2, P < 0.005). However, there was no significant difference in the rate-corrected velocity of fiber shortening between the two examinations. An inverse linear relation between the end-systolic wall stress and the rate-corrected mean velocity of fiber shortening was found in each examination. The slopes of these two regression lines showed no significant difference, suggesting that the left ventricular contractility is on the same level during this study period. The transmitral Doppler flow velocity patterns markedly altered between the two observations. The peak E wave, peak A wave, peak E/A ratio, flow velocity time integral of E/A wave, the first third filling fraction, and the normalized peak filling rate to stroke volume increased significantly during the study period (78+/-14 vs. 31+/-9 cm/s, 61+/-12 vs. 33+/-7 cm/s, 1.29+/-0.18 vs. 0.93+/-0.19, 1.75+/-0.58 vs. 1.17+/-0.24, 0.42+/-0.07 vs. 0.37+/-0.05, and 9.48+/-1.71 vs. 7.30+/-0.96/s, respectively, P < 0.001), suggesting a relative shift of Doppler filling into the early diastole. We demonstrated that the age- and growth-related alterations in the transmitral Doppler filling patterns occurred dramatically without changes in contractility during the first 3 months after birth. This diastolic filling change may be related to the age-related maturation in the left ventricular diastolic properties.     

The effect of treatment with angiotensin-converting enzyme inhibitors on survival of pediatric patients with dilated cardiomyopathy

Summary Outcome in 81 pediatric patients with dilated cardiomyopathy was reviewed to assess whether treatment with angiotensin-converting enzyme (ACE) inhibitors affected survival. Age at onset was 3.6±0.6 years. Twenty-seven children (group 1) were treated with ACE inhibitors. Conventional therapy was used in the remaining 54 patients (group 2). There were no significant differences between the two groups in age at onset, left ventricular shortening fraction, left ventricular end-diastolic pressure, or mean pulmonary artery pressure. Patients treated with ACE inhibitors had a significantly better survival during the first year (p<0.05) with continuation of this trend throughout the second year (p=0.06). Beyond 2 years there was a tendency toward better survival in ACE inhibitor-treated patients, but the differences were no longer significant (p=0.14). These data, along with observations in adult patients with chronic cardiac failure, indicate that converting enzyme inhibitors have a beneficial effect on prolonging survival of infants and children with severe left ventricular dysfunction from dilated cardiomyopathy.     

Diastolic Function and Patient-Reported Quality of Life for Adolescents and Adults With Repaired Tetralogy of Fallot: A Tissue Doppler Study

Left ventricular systolic function is an important indicator of clinical well-being and outcomes for patients with repaired tetralogy of Fallot (TOF). This study tested the hypothesis that left ventricular diastolic function by pulsed-wave tissue Doppler is associated with quality of life in this population. In this study, 38 subjects (age, 31.0 ± 14.1 years) with repaired TOF underwent echocardiogram and completed the Short-Form 36, version 2, a validated quality-of-life assessment, within a median of 0 days (range, 0–90 days). Available cardiovascular magnetic resonance data within 1 year after the echocardiogram were analyzed. The ratio of peak early inflow to peak early annular velocity (E/E′) at the lateral mitral annulus correlated inversely with the ability to participate in usual activities without physical limitations (r = −0.37; p = 0.02), whereas the right ventricular diastolic indices were not predictive. The relation of left ventricular diastolic function to quality of life was independent of left ventricular systolic function. This may be related to adverse ventricular–ventricular interactions because lateral mitral E/E′ correlated with tricuspid E/E′ (r = 0.46; p = 0.008) and the right ventricular myocardial performance index (r = 0.42; p = 0.01). Pulsed-wave tissue Doppler of the mitral annulus is a useful tool in this population and may potentially identify patients in need of intervention before the development of left or right ventricular systolic dysfunction.     

Abnormal left ventricular diastolic filling patterns in small-for-gestational-age infants

Doppler transmitral flow velocity patterns in assessing left ventricular diastolic function in small-for-gestational-age infants have been poorly understood. The purpose of this study is to examine Doppler filling patterns in small-for-gestational-age infants (n=13) and to compare them with those in age-matched appropriate-for-gestational-age infants (n=29). We measured peak flow velocities of early diastole (peak E wave) and atrial contraction (peak A wave), ratio of peak E wave to peak A wave (peak E/A wave), velocity time integrals of E wave (VTIE wave) and A wave (VTIA wave), ratio of VTIE wave to VTIA wave (VTIE/A wave), first third filling fraction, peak filling rate normalized to stroke volume, and deceleration time. Mean gestational age and heart rate did not show a significant difference between the appropriate- and the small-for-gestational-age infants. The mean birth weight in the small-for-gestational-age infants was significantly lower than that in the appropriate-for-gestational-age infants (802±220 vs. 1184±260 g, P<0.01). In the small-for-gestational-age infants, the peak E wave, peak A wave, peak E/A wave, VTIE wave, first third filling fraction, and peak filling rate normalized to stroke volume were significantly lower than those in the age-matched appropriate-for- gestational-age infants (21.9±6.7 vs. 32.2±6.9 cm/s, 26.5±6.2 vs. 34.5±6.2 cm/s, 0.82±0.15 vs. 0.93±0.14, 1.88±0.45 vs. 2.39±0.51 cm, 0.36±0.04 vs. 0.41±0.04, 5.86±0.75 vs. 7.11±0.63/s, P<0.05, respectively). In the small and appropriate for gestational age infants, peak E wave, VTIE wave, and peak E/A increased significantly with increasing body weight. In the small-for-gestational-age infants, the slopes of regression lines between body weights and peak E wave and VTIE wave were significantly lower than those in the appropriate for gestational age infants, suggesting a significant reduction in E wave even when considering a difference in their body weight. This study suggests that the significant decreases in the early diastolic filling in the small-for-gestational-age infants may be related to the reduced left ventricular diastolic function.     

Effect of patent ductus arteriosus on doppler-derived right ventricular systolic time intervals

Summary Right ventricular systolic time intervals (RVSTI) and noninvasive Dopplerderived pulmonary blood flow were measured before and after surgical ductus ligation in 18 otherwise healthy infants and children who were older than 3 months of age. Right ventricular preejection period (PEP) and the ratio of preejection period and right ventricular ejection time (PEP/REVET), both corrected or uncorrected for heart rate, decreased significantly following surgery (PEP 71±14 vs. 50±13,p<0.001 and PEP/RVET 0.29±0.06 vs. 0.21±0.05,p<0.001). The volume of pulmonary blood flow correlated with PEP/RVET (r=0.48,p=0.003). The magnitude of the change in pulmonary blood flow correlated with the change in PEP/RVET (r÷0.56,p=0.016). The velocity of circumferential fiber shortening (VCFc) increased after surgery, but not significantly. We speculate that patent ductus arteriosus has a similar effect on right ventricular performance when other congenital heart defects are present.     

Mitochondrial myopathy,encephalopathy, lactic acidosis,and stroke-like episodes (MELAS) decrease in diastolic left ventricular function assessed by echocardiography

Summary Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are known to be associated with cardiomyopathy. Systolic and diastolic left ventricular functions were assessed by M-mode and Doppler echocardiography in four patients with MELAS and in 14 normal controls. The interventricular septal thickness and left ventricular posterior wall thickness were greater (11.0±1.6 mm vs. 5.8±0.7 mm and 11.0±2.2 mm vs. 5.9±0.8 mm) in patients with MELAS than in a control group. Parameters of systolic left ventricular functions (ejection fraction, shortening fraction, systolic time intervals, and mean Vcf) and left ventricular dimensions were not significantly different between the two groups. To assess the diastolic function, blood flow velocity across the mitral valve was measured by Doppler echocardiography and various indexes were obtained. In patients with MELAS, the impairment of diastolic left ventricular filling was demonstrated by decrease in the following indexes: peak flow velocity in the early passive filling period (E) (0.76±0.10 m/s vs. 0.94±0.09 m/s), integrated velocity for total E (10.2±1.3 vs. 13.0±0.9), the ratio of E and late atrial filling integrated velocities (1.72±0.06 vs. 2.49±0.29).     

Body Mass Index Can Predict Left Ventricular Diastolic Filling in Asymptomatic Obese Children

To examine the effects of body mass index on left ventricular diastolic function, flow velocity patterns of the pulmonary vein and mitral valve were measured by pulse Doppler echocardiography in 21 asymptomatic obese children and were compared with those of an age-matched control population. The degree of obesity was calculated as (actual body mass index/ideal body mass index -1) x 100. The pulmonary venous flow indexes were peak systolic (S) and diastolic (D) velocities and peak D/S. The mitral inflow indexes were peak velocities of early diastole (E) and atrial contraction (A) and peak E/A. The pulmonary venous flow velocity pattern in obese patients was characterized by unchanged peak S, decreases in peak D (43 +/- 7 vs 51 +/- 8, p < 0.01) and peak D/S (0.98 +/- 0.19 vs 1.29 +/- 0.20, p < 0.01), suggesting the reduction in the early diastolic filling. The peak D/S decreased significantly with an increase in the percentage body mass index (r = -0.84, p < 0.01). In contrast to the pulmonary venous flow pattern (peak D > peak S) as seen in normal controls, all of the obese patients with > 70% over body mass index had abnormal pulmonary venous flow velocity patterns (peak D < peak S). The mitral flow velocity pattern in obese patients was also characterized by a decrease in early diastolic filling. However, these indices did not correlate with an increase in the percentage over body mass index. This study suggests that body mass index predicts the abnormality of left ventricular diastolic filling assessed by pulmonary venous flow patterns.