Satoshi Yasukochi

Has fetal echocardiography improved the prognosis of congenital heart disease? Comparison of patients with hypoplastic left heart syndrome with and without prenatal diagnosis

Abstract Background: As prenatal diagnosis of congenital heart disease has gained in popularity, the questions of whether prenatal diagnosis of congenital heart disease is beneficial for the patient and whether fetal echocardiography has improved the prognosis of congenital heart disease are arising.

Analysis of ventricular septal motion by doppler tissue imaging in atrial septal defect and normal heart.

The aortic root and the upper part of the ventricular septum moves anteriorly in early systole, while the lower part moves posteriorly. The hinge of the counterpart motion of the ventricular septum is called pivot point. Using Doppler tissue imaging (DTI), we attempted to clarify the location of the pivot point of the ventricular septum in children with normal heart and with atrial septal defect (ASD), and to investigate the relation between the degree of the downward shift of the pivot point and that of volume overload of the right ventricle in patients with ASD. Study subjects consisted of 20 healthy children and 36 patients with ASD, aged from 1 to 15 years (mean 5.7+/-3.4) in the normal group and 6 months to 12 years (mean 4.4+/-3.2) in the ASD group, respectively. The pivot point was designated as a border of the color signal of DTI of the ventricular septum in early systole. Measurements were then obtained on cross-sectional echocardiography and DTI: septal length in the parasternal long-axis view, distance from aortic valve to pivot point in early systole, diastolic left ventricular internal dimension, and diastolic right ventricular internal dimension. In the normal group, the ratio of distance from aortic valve to pivot point/septal length was 0.13+/-0.049, whereas it was 0.26+/-0.168 in the group with ASD (p <0.001). In the ASD group, the distance from aortic valve to pivot point normalized by body surface area (mm/m2) correlated with the ratio of diastolic right/left ventricular internal dimension and with the ratio of pulmonary to systemic flow (Qp/Qs) (r = 0.63 and 0.50, respectively). The ratio of the distance from aortic valve to pivot point/septal length correlated with the ratio of diastolic right/left ventricular internal dimension and Qp/Qs (r = 0.56 and 0.44, respectively). By DTI, the pivot point was located at the upper 13+/-5% of the total length of the ventricular septum in normal children, and was located at 26+/-17% in patients with ASD (p < 0.001). The degree of this displacement in ASD correlated with that of volume overload of the right ventricle. The paradoxic motion of the ventricular septum shown in the ASD could be explained by this downward shift of the pivot point.

Sildenafil reduces pulmonary vascular resistance in single ventricular physiology

BACKGROUND High pulmonary vascular resistance (PVR) may be a risk factor for early and late mortality in both Glen shunt and Fontan operation patients. Furthermore, PVR may increase long after the Fontan operation. Whether pulmonary vasodilators such as phosphodiesterase 5 inhibitors can decrease PVR in patients with single ventricular physiology remains undetermined. METHODS AND RESULTS This was a prospective, multicenter study. Patients with single ventricular physiology who have a PVR index higher than 2.5 Wood units·㎡ (WU) were enrolled. Cardiac catheterization was performed before and after administration of sildenafil in all patients. After the Fontan operation, a six minute walk test (6MWT) was also performed. A total of 42 patients were enrolled. PVR was significantly decreased in each stage of single ventricular physiology after sildenafil administration: from 4.3±1.5WU to 2.1±0.6WU (p<0.01) in patients before a Glenn shunt, from 3.2±0.5WU to 1.6±0.6WU (p<0.001) in patients after a Glenn shunt, and from 3.9±1.7WU to 2.3±0.8WU (p<0.001) in patients after Fontan. In patients after Fontan, the 6MWT increased from 416±74m to 485±72m (p<0.01), and NYHA functional class improved significantly (p<0.05) after sildenafil administration. No major side effects were observed in any patients. CONCLUSIONS Sildenafil reduced PVR in patients with single ventricle physiology. Sildenafil increased exercise capacity and improved NYHA functional class in patients after a Fontan operation. This implies that pulmonary vasodilation is a potential therapeutic target in selected patients with elevated PVR with single ventricle physiology. Long-term clinical significance warrants further study.

Quantification of Right and Left Ventricular Volumes in Children with Congenital Heart Disease by Multidetector-Row Computed Tomography

Multidetector-row computed tomography (MDCT) of the heart is a new diagnostic approach for the quantitative evaluation of the coronary artery in adults. However, in children, the quantitative analysis of each cardiac chamber has not been established. We attempt to clarify the feasibility and validation of ECG-gated MDCT as a quantitative diagnostic tool to assess the right and left ventricular volume in children. The study consisted of 16 patients who had definite right and left ventricle. After obtaining multislice images by MDCT, we measured the end diastolic volume of both the right and the left ventricle by direct calculation of the region of interest and calculation from the projected image of three-dimensional reconstruction by traditional formulas. The correlation between the two calculations for both ventricles is excellent (r = 0.99 for LV and 0.94 for RV, respectively). The correlations for ventricular volume between calculation of catheterization and calculation of MDCT is also good (r = 0.99 for LV 0.99 for RV, respectively). Volume measurement by ECG-gated MDCT of the right and left ventricles is well correlated with that by catheterization in children and can reduce the necessity for cardiac catheterization.

Normal values for cardiac and great arterial dimensions in premature infants by cross-sectional echocardiography

The number of neonates who undergo intracardiac repair for congenital heart disease has increased in recent years. In considering appropriate surgical options in such circumstances, normal values for various cardiovascular dimensions are needed. We measured 19 parameters for the heart and great arteries (four valves, pulmonary tree, aortic arch, ascending and descending aorta, ventricular septum, left ventricular internal and posterior wall dimensions) using cross-sectional echocardiography in 55 premature and full-term infants (ranging in gestational age from 23 to 41 weeks, in body weight from 543 to 3966 g). The increase in each dimension correlated closely with body weight (r=0.62 to 0.87) and was found to follow a linear regression. The diameter of the isthmus was found to be smaller, and the size of mitral valve annulus larger, than previously published values.

Second-Stage Palliation After Bilateral Pulmonary Artery Bands for HLHS and its Variants—Which is Better, Modified Norwood or Norwood Plus Bidirectional Glenn?

Background. The purpose of this study was to evaluate the surgical outcomes and pulmonary artery (PA) development associated with a new strategy wherein the modified Norwood (N) procedure is performed at 1-2 months after bilateral pulmonary artery banding (PAB). Methods. Between January 2008 and February 2010, 16 patients underwent Norwood-type operation after previous bilateral PAB. For analysis, patients were divided into two groups. Group I (n = 11) underwent modified Norwood procedure with either right modified Blalock Taussig (RMBT) shunt (n = 4) or right ventricle to pulmonary artery (RV-PA) conduit (n = 7). Group II (n = 5) underwent Norwood procedure plus bidirectional Glenn anastomosis. Diagnoses were hypoplastic left heart syndrome in 6 and its variants in 10. Results. There was no surgical death and no late death. Pulmonary artery interventions were performed at the time of the Norwood procedure in 27% in Group I and in 100% in Group II (p < 0.05). Additional PA interventions were performed during the period of follow-up in 4 cases in Group I (36.4%), and in 4 cases in Group II (80.0%). Additional Blalock Taussig shunts were performed in 7 patients, resulting in significant increase in PA index. In all, four patients have reached total cavopulmonary connection, and one has undergone biventricular repair. Eight patients in Group I and one patient in II Group reached bidirectional Glenn anastomosis. In Gp II, two patients showed LPA narrowing or obstruction with PA index of 80 ± 12 mm2/m2. Conclusions. Regarding the second-stage palliation after bilateral PAB, modified Norwood procedure with either RMBT or RV-PA conduit has some advantages compared with Norwood plus BDG with respect to subsequent pulmonary artery development. Additional BT shunt may contribute to PA development, even in the patients with Norwood procedure with RV-PA conduit.

Coupling of central venous pressure and intracranial pressure in a 6-year-old patient with fontan circulation and intracranial hemorrhage.

A sharp rise in intracranial pressure (ICP) was noted in a 6-year-old girl with Fontan circulation after surgical removal of a hematoma associated with intracranial hemorrhage. Inhalation of nitric oxide resulted in reduction of central venous pressure (CVP) and precipitous fall in ICP, which was otherwise resistant to conventional therapy. Specifically, the rate of fall of ICP (9 mm Hg) exceeded that of the CVP (3 mm Hg), indicating disproportionate CVP-ICP coupling. The present case provides not only a novel insight into cardio-cerebral interaction in Fontan physiology but also useful information regarding the treatment of Fontan patients in the setting of increased ICP.

Prenatal Diagnosis of Total Anomalous Pulmonary Venous Connection with Asplenia

The prenatal diagnosis of 2 fetuses with total anomalous pulmonary venous connection was made by color Doppler echocardiography at 31 and 38 weeks of gestation, respectively. Both had asplenic hearts and their diagnoses were confirmed by postnatal echocardiography, magnetic resonance imaging, and angiography. The antenatal diagnosis of total anomalous pulmonary venous connection in right isomerism could provide an optimal postnatal medical and surgical management. Moreover, monitoring of the velocity profile of the pulmonary venous flow is beneficial for decreasing the risk of sudden collapse by pulmonary venous obstruction throughout the perinatal period.

Notable alkaline tolerance of Kocuria marina isolate from blood of a pediatric patient with continuous intravenous epoprostenol therapy

This study was the first to describe the hitherto deficiently evaluated alkaline tolerance of Kocuria marina isolate from a pediatric patient with continuous intravenous epoprostenol dosing therapy. Our isolate from blood of a 7-year-old Japanese boy was finally identified as K. marina by the morphological, cultural, and biochemical properties together with the comparative sequence analyses of the 16S rRNA genes. The K. marina isolate, the causative agent of catheter-related blood-stream infection, was not only revealed to be salt tolerant (NaCl 15%), but also demonstrated to be stably survived with no apparent decrease of cell counts for long periods (120 h) in an alkaline environment (pH 8, 9, 10, and 11) at 35 °C. Its remarkable tolerance to the stresses of high alkalinity compared with a clinical Staphylococcus aureus strain should provide consistent interpretation that the environment of high alkalinity (pH 10.2-10.8) measures should be insufficient to inactivate almost all the causative agents including K. marina strains in the solution of epoprostenol (pH 10.4) (Flolan(®), GlaxoSmithKline, Ltd., Tokyo, Japan.). To the best of our knowledge, the first description of the property of being tolerant to high alkalinity that the K. marina isolate exhibited was noteworthy and a useful piece of information. In conclusion, we believe that the present study should be a notification regarding the potential risk of catheter-related blood-stream infections due to K. marina, suggestive of an alkalophile, especially in patients receiving continuous intravenous epoprostenol dosing therapy.

Successful transluminal angioplasty of renal arterial stenosis using the transcarotid approach

We successfully performed percutaneous transluminal angioplasty to treat severe renovascular hypertension with left ventricular failure in a 5-month-old infant. Using the transcarotid approach, we dilated the stenotic left renal artery without any difficulties, using progressively larger balloons designed for dilation of coronary arteries.