Sethuraman Swaminathan

Usefulness of tissue Doppler echocardiography for evaluating ventricular function in children without heart disease.

Tissue Doppler echocardiographic imaging (TDI) is a novel method for accurately evaluating ventricular function. Currently, scant data are available on the distribution of tissue Doppler indexes in healthy children in the age range of 1 to 18 years. The aims of this study were to assess the distribution of tissue Doppler indexes of systolic and diastolic ventricular function in healthy children, to assess the influence of age on these indexes, and to compare them with conventional Doppler indexes. A total of 151 consecutive children aged 1 to 18 years were enrolled in the study. Nine different (7 diastolic and 2 systolic) TDI parameters were assessed. Peak velocities of systolic and diastolic excursions of the mitral and tricuspid annuli were obtained from the apical 4-chamber view. Mean velocities of early diastolic recoil of mitral and tricuspid annuli were measured from the apical 4-chamber view. The mean velocity of early diastolic relaxation of the left ventricular posterior wall was measured in the parasternal long-axis view. Results showed a statistically significant difference in some of the TDI indexes among the different pediatric age groups. Most of the TDI indexes showed a very weak correlation with age. There was no significant correlation (p >0.05) between peak velocities of the early diastolic mitral inflow Doppler pattern (E wave) and the corresponding TDI index. In contrast, there was a significant (p <0.001) correlation between the corresponding Doppler indexes in the tricuspid annulus. We conclude that TDI is a valuable tool for assessing ventricular function, particularly diastolic function. Establishment of normative data for TDI in the pediatric age group should broaden the clinical applicability of this useful modality for assessing ventricular function.

Ventricular structure and function in children with sickle cell disease using conventional and tissue Doppler echocardiography.

Conventional 2-dimensional, M-mode, and spectral Doppler echocardiographic techniques have documented abnormal ventricular function in adults with sickle cell disease (SCD), but assessments in children are conflicting. Tissue Doppler echocardiography (TDE) provides additional information about myocardial function. Two-dimensional, M-mode, tricuspid regurgitation jet velocity (TRJV) data, and tissue Doppler echocardiographically derived myocardial velocity measurements of left ventricular (LV) and right ventricular function were taken from children with SCD compared to those of similar healthy historical controls and correlated with clinical characteristics and hemoglobin levels. Compared to 55 controls, 54 children with SCD (mean age 14.2 years, range 6 to 21) had a larger left ventricle, greater LV mass, and higher LV fractional shortening; 30% had increased pulmonary artery pressure (TRJV ≥2.5 m/s). Conventional echocardiographic measurements of LV systolic function and spectral Doppler measurements of LV and right ventricular diastolic function were essentially normal, but TDE indicated that 31% of SCD children had evidence of LV diastolic dysfunction (peak early diastolic velocity of LV inflow Doppler/peak early diastolic velocity at lateral mitral valve annulus >8), a finding that correlated with lower hemoglobin levels. Although decreasing hemoglobin levels in children with SCD correlated with LV hypertrophy, LV dilation, and LV diastolic dysfunction, long-term transfusion or hydroxyurea therapy did not affect these measurements. In conclusion, 1/3 of children with SCD had tissue Doppler echocardiographic evidence of LV diastolic dysfunction, which was correlated with hemoglobin levels. Adding serial assessments of ventricular function with TDE to conventional echocardiography may detect early cardiac changes, especially in children with severe anemia.

Cardiac anomalies in the setting of the Abernethy malformation of the portal vein.

We describe a child with tricuspid atresia associated with a porto-systemic shunt and complete absence of the portal vein, the latter known as the Abernethy malformation. As far as we are aware, this association has not previously been reported. We review the various cardiac defects that have been reported in children with the Abernethy malformation, emphasizing the interesting clinical presentations of this rare malformation of the portal venous system.

Acute effects of inhaled nitric oxide on pulmonary and cardiac function in preterm infants with evolving bronchopulmonary dysplasia.

BACKGROUND: Inhaled nitric oxide (iNO) reduces pulmonary vascular resistance by preferential vasodilation in ventilated lung units. In experimental animals, iNO also reduces airway resistance by smooth muscle relaxation. Hence, there may be a therapeutic role for iNO in evolving bronchopulmonary dysplasia (BPD).OBJECTIVE: To evaluate the acute effects of low-dose iNO on lung mechanics, ventilation distribution, oxygenation, and cardiac function in preterm infants with evolving BPD.METHODS: Measurements of lung compliance (CL), airway resistance (RL), ventilation-distribution (N2 clearance in multiple-breath washout), oxygenation (SpO2), left ventricular ejection fraction (LVEF) and right ventricular shortening fraction were obtained before and during 2 hours of iNO (10 ppm) in a group of ventilated preterm infants with evolving BPD.RESULTS: A total of 13 preterm infants with (mean±SD) BW: 663.8±116 g, GA: 24.9±1.2 weeks, age: 32±14 days, mean airway pressure: 6.7±0.9 cmH2O and fraction of inspired oxygen: 0.35±0.06 were studied. iNO did not affect CL, RL or N2 clearance. There was a small increase in LVEF. Mean SpO2 remained unchanged, but the duration of spontaneous hypoxemic episodes increased during iNO.CONCLUSION: Low-dose iNO had no acute effects on lung function, cardiac function and oxygenation in evolving BPD.

Progressive fetal atrioventricular block in heterotaxy syndrome

We report a fetus with left isomerism, in whom the atrioventricular block progressed from low grade second degree to complete block and fetal hydrops. While it is known that there is a high incidence of heart block in the fetus with left isomerism, as far as we are aware, ours is the first report of Wenckebach type block documented in the fetus by Doppler echocardiography, and demonstration of the progression of heart block during fetus life in the setting of left isomerism.

Tetralogy of Fallot With Absent Pulmonary Valve and Nonconfluent Pulmonary Arteries: A Management Conundrum

Tetralogy of Fallot with absent pulmonary valve syndrome is a rare form of congenital heart disease. Among the different variations with this rare anomaly is nonconfluent pulmonary artery branches with anomalous origin of the left pulmonary artery from the ductus arteriosus. The authors present one such case which was diagnosed prenatally to have tetralogy of Fallot with absent pulmonary valve and identified postnatally to have nonconfluent pulmonary artery branches in addition. We discuss the conundrum of respiratory management in this patient pre- and postoperatively due to a unique ventilation perfusion mismatch problem, which varies between the two lungs.

Impact of Prenatal Diagnosis of Complex Congenital Heart Disease on Neonatal and Infant Morbidity and Mortality

The objective of this study was to analyze the benefits associated with prenatal diagnosis of complex congenital heart disease (CHD) on preoperative morbidity, 30‐day and 1‐year mortality in this population.

Exit Procedure for Fetal Mediastinal Teratoma with Large Pericardial Effusion: A Case Report with Review of Literature

Abstract Background: Large mediastinal teratomas in the fetus are rare and can present with direct compression of intrathoracic structures as well as pericardial and pleural effusions. Mediastinal fetal teratoma may be detected as a mass in the chest during a routine prenatal ultrasound. Because of the pressure on mediastinal structures it may result in non-immune fetal hydrops (NIFH) and polyhydramnios. The development of hydrops may lead to fetal demise. Timely obstetric and/or surgical intervention is important to improve survival in this patient population. Case review: We report a case of a large mediastinal teratoma in a fetus who presented with a large pericardial effusion at 28 weeks gestation. The fetus developed NIFH at 31 weeks gestation. The fetus was successfully managed with an ex utero intrapartum therapy (EXIT) procedure which involved pericardiocentesis and surgical resection of the large teratoma. Histological examination revealed an encapsulated immature teratoma. Discussion: Mediastinal teratomas are usually detected by routine second- and third-trimester ultrasound. Large teratomas have been described to present with airway compromise and NIFH. Some cases have been managed by postnatal surgery and rare cases by EXIT procedure. Conclusions: This is the first reported case of a fetal mediastinal teratoma and severe pericardial effusion who developed NIFH, in whom EXIT procedure was successfully employed to simultaneously drain the effusion and resect the tumor.

Evaluation of Neonates With Suspected Congenital Heart Disease: A New Cost-Effective Algorithm

We assessed the value of existing guidelines for the evaluation of suspected congenital heart disease (CHD) in term neonates and propose a revised algorithm. Retrospective chart review of newborns referred for cardiac evaluation at a tertiary care center was performed. A total of 777 newborns qualified for the study. Among these, 3 critical and 8 major CHD were identified. The sensitivity of the combination of abnormal physical examination and pulse oximetry screening for major and critical CHD was 100%. The cost to detect a case of critical CHD, based on echocardiograms done for all abnormal electrocardiograms, was 3.4 times more than that incurred for performing this test on the basis of abnormal pulse oximetry and physical examination. Adding electrocardiogram to CHD screening increases cost without adding diagnostic yield. Based on our findings, we propose a revised algorithm for a systematic cost-effective approach to cardiac evaluation of term newborns with suspected CHD.

Unilateral lung agenesis, hiatal hernia and atrioventricular septal defect: A rare combination of congenital anomalies

Unilateral lung agenesis is a relatively rare congenital anomaly with a reported incidence of 1 in 15 000 births. It is frequently associated with other congenital malformations. Some of the sequelae of lung agenesis are potentially life-threatening. Here, we report a case of left lung agenesis in association with hiatal hernia and atrioventricular septal defect, a rare combination of anomalies which have not been described previously in the literature.