Hiromichi Nakajima

Quantification of collateral aortopulmonary flow in patients subsequent to construction of bidirectional cavopulmonary shunts

OBJECTIVES We sought to provide a new method for quantifying collateral aortopulmonary flow in patients subsequent to construction of a bidirectional cavopulmonary shunt, and to clarify the clinical advantages of the new method. METHODS We performed lung perfusion scintigraphy and cardiac catheterization in 10 patients subsequent to construction of a bidirectional cavopulmonary shunt. First, the ratio of collateral to systemic flow was determined by whole-body images of lung perfusion scintigraphy, dividing the total lung count by the total body count minus the total lung count. Second, we integrated lung perfusion scintigraphy and cardiac catheterization data using a formula derived from the Fick principle, taking the ratio of pulmonary to systemic flow to be 1 plus the ratio calculated above and multiplied by the systemic saturation minus the inferior caval venous saturation divided by the pulmonary venous saturation minus the inferior caval venous saturation. Finally, the amount of collateral flow was obtained from the ratio of pulmonary to systemic flow. We evaluated the impact of collateral flow on the calculation of pulmonary vascular resistance. RESULTS The median age at bidirectional cavopulmonary shunt was 1.41 years, and the median age at catheterization was 2.33 years. The mean amount of collateral flow was 1.75 +/- 0.46 litres/min/m(2). The pulmonary vascular resistance calculated without considering the collateral flow was overestimated by an average of 57 +/- 23%, compared to the resistance calculated with our new method. CONCLUSIONS The use of scintigraphy combined with catheterization allows accurate determination of aortopulmonary collateral flow, and avoids overestimation of pulmonary vascular resistance in these candidates for the Fontan circulation.

Expression of tumor necrosis factor-α protein in the myocardium in fatal myocarditis

Abstract Background: Tumor necrosis factor (TNF)‐α is the most studied cytokine in the failing human heart and in experimental murine myocarditis. We have investigated the expression of TNF‐α in the myocardium in human myocarditis.

B-type natriuretic peptide at the early stage of univentricular circulation reflects inadequate adaptation to volume overload

BACKGROUND Recent studies showed that children with univentricular heart have elevated plasma B-type natriuretic peptide (BNP) levels prior to bidirectional cavopulmonary anastomosis (BDCPA). However, it remains to be established whether BNP levels reflect the degree of hemodynamic overload and relate to long-term outcome in univentricular circulation. METHODS Fifty one consecutive children with functionally univentricular heart prior to BDCPA were studied. All patients underwent cardiac catheterization and BNP measurement. Ventricular end-systolic wall stress (ESWS) and end-diastolic wall stress (EDWS) were calculated from cardiac catheterization data. RESULTS Median age was 1.1 years and 34% were female. Median BNP concentration was 90.4 pg/ml. Patients with high BNP (≥ 100 pg/ml) had higher pulmonary to systemic flow ratio (p = 0.014), a greater end-diastolic volume (p=0.009), more severe atrioventricular valve regurgitation (p= 0.02) and lower ventricular mass to end-diastolic volume ratio (p=0.006). BNP levels strongly related to EDWS (r = 0.75, p< 0.0001) and ESWS (r = 0.63, p < 0.0001). During median follow-up period of 3.2 years, 15 patients died and one underwent heart transplantation for refractory heart failure. On multivariate Cox regression analysis, high BNP concentration was an independent predictor of death or transplantation (HR 3.05, CI: 1.06-8.83, p = 0.04). CONCLUSIONS High BNP concentration at the first palliative stage towards Fontan circulation reflects high wall stress due to high volume load and insufficient ventricular hypertrophy. Moreover, high BNP levels at this stage were independently related to long-term outcome. BNP may be used as a guide to identify patients with high workload due to inadequate adaptation to hemodynamic load, who are at high risk.

Successful Fontan Completion After Cardiac Resynchronization Therapy

This patient underwent a modified Norwood operation with a right ventricle–pulmonary artery shunt at the age of 7 days following the diagnosis of hypoplastic left heart syndrome with mitral and aortic atresia; this procedure was followed by bidirectional Glenn operation at the age of 5 months. The girl subsequently developed congestive heart failure despite the administration of angiotensin-converting enzyme inhibitors and β-blockers after the initial operation. At the age of 11 months, she required hospitalization and intravenous inotropic support. Coil embolization and surgical ligation of the aortopulmonary collaterals were performed at the age of 1 year but could not control the heart failure. The maximum plasma brain natriuretic peptide level after the second palliative operation was 3823 pg/mL. Cardiac catheterization performed at the age of 1 year and 4 months revealed ventricular dyssynchrony, ventricular ejection fraction of 36.2%, right atrial pressure of 7 mm Hg, superior vena cava pressure of 16 mm Hg, and grade 2 tricuspid regurgitation. QRS duration was 184 ms (Figure 1), and arterial oxygen saturation was 80%. To detect the most delayed and earliest …

Portosystemic Shunt with Polysplenia and Hypoplastic Left Heart Syndrome

We report a unique case of portosystemic shunt with polysplenia and hypoplastic left heart syndrome. The abnormal vessel connected the right renal vein and the splenic vein. The shunt flow was from the systemic vein to the portal vein before the Fontan-type operation, but it reversed and ran from portal vein to systemic vein after the Fontan-type operation.

Intracardiac Fontan procedure for heterotaxy syndrome with complex systemic and pulmonary venous anomalies

OBJECTIVE The extracardiac conduit procedure is widely used for patients with heterotaxy syndrome with complex systemic and pulmonary venous anomalies; however, it lacks conduit-growth potential and requires long-term anticoagulation. We present the intracardiac Fontan procedure, which eliminates the above-mentioned disadvantages. PATIENTS AND METHODS Twenty-four patients (mean age, 4.1 years; weight, 13.0 kg) with heterotaxy syndrome underwent intracardiac Fontan operations between March 1995 and March 2008. In each patient, the anomalous systemic venous return with the isolated hepatic vein was redirected to the pulmonary artery using an intra-atrial baffle without obstructing the pulmonary venous pathway; this was accomplished by anterior (n=5), lateral (n=15) or posterior tunnel methods (n=4), depending on the anatomical relationship of the systemic and pulmonary venous pathways. RESULTS There was one (4%) in-hospital and two (8%) late deaths in total. Five (21%) patients underwent re-operation for either pulmonary venous obstruction or supraventricular tachycardia. The actuarial 12-year survival was 86% (the Kaplan-Meier survival plot). The freedom from re-operation at 10 years was 77%. Anticoagulation was not required except for two patients (8%) who had prosthetic valves and coagulation disorder. Obstruction of the systemic venous pathway was not observed in any patient; however, five (20%) patients had clinically significant postoperative arrhythmias. At the final follow-up, all survivors were categorised as the New York Heart Association class I. CONCLUSIONS Aided by detailed preoperative anatomical and physiological diagnoses, intracardiac Fontan procedures were technically feasible in patients with complex systemic and pulmonary venous anomalies. The specific cardiac anatomy in these patients warranted this procedure; however, taking into consideration the improved outcomes of the modified Fontan procedure, this method should be performed with deliberation.

Sheath placement in femoral artery during cardiac catheterization in children can influence pressure waveform

INTRODUCTION It is reported that pressure wave reflection is enhanced by external compression of the femoral artery. Therefore, it is possible that cardiac catheterization itself can influence the aortic pressure waveform. AIM The purpose of this study is to clarify the influence of sheath placement in a femoral artery on the pressure waveform. METHODS This study enrolled 21 pediatric patients (5.1±4.0years) who underwent cardiac catheterization. A sheath was placed in the femoral arteries of all patients. The change in the pressure waveform induced by the placement of the sheath was investigated using the b/a and d/a ratio of second derivative of a fingertip photoplethysmogram. A high b/a ratio means a stiff aorta and a low d/a ratio represents an enhancement of the aortic pressure wave reflection. RESULTS By the placement of the sheath in their femoral arteries, the b/a ratio was not influenced (sheath (-): -0.556±0.081 vs. sheath (+): -0.558±0.072; p=0.896). However, the d/a ratio was significantly decreased (-0.150±0.074 vs. -0.185±0.084; p=0.0003). CONCLUSIONS The placement of the femoral arterial sheath enhances the pressure wave reflection and would lead to a change in the central aortic pressure waveform.

Severe Cyanosis After Kawashima Operation Resulting From Congenital Portosystemic Shunt

We describe an unusual case of a patient with polysplenia, inferior vena cava (IVC) interruption, and unrecognized congenital portosystemic venous connection (CPVC) in whom severe cyanosis developed in the acute postoperative stage after a Kawashima operation and required urgent surgical division of the CPVC. It has been stressed recently that CPVCs and other abdominal venous abnormalities have been underdiagnosed in patients with polysplenia and IVC interruption, and we think that a routine evaluation of abdominal venous connections should be mandatory before considering the Kawashima operation for these patients.

Multiple fistulas from the coronary arteries to the left ventricle in tricuspid atresia.

It is rare to find multiple fistulas arising from all three coronary arteries and draining into the left ventricle. Coronary angiography revealed this anomaly in a one-year-old girl with tricuspid atresia after conversion to the Fontan circulation. To the best of our knowledge, this is the first report of such multiple fistulas in the setting of tricuspid atresia, and also the first report in childhood.

Interventricular septal hematoma following repair of a ventricular septal defect

An interventricular septal hematoma is a rare complication after patch closure of a ventricular septal defect (VSD). We describe three cases of interventricular septal hematomas following patch VSD and discuss their management.