The treatment of end-stage heart failure in adults has been improved with medical and device therapies, including mechanical circulatory support (MCS). However, there was no effective MCS device until the Berlin Heart EXCOR was introduced in clinical settings. In this article, the currently available MCS devices for the pediatric population and their future prospects are discussed.

Background: Bilateral pulmonary artery banding for patients with Hypoplastic Left Heart Syndrome (HLHS) prevails as the first palliation in Japan, however, concerns remain about the long-term outcomes. Primary Norwood operation, nevertheless, has advantages such as fewer inter-stage palliations. This study’s goal is to review the mid-term results of primary Norwood operations up to the Fontan operations and to analyze risk factors.

Methods: Sixteen consecutive patients with HLHS (male/female: 6/10) were included from October 2004 to May 2014. Of those, fifteen patients underwent the primary Norwood operations. Survival was assessed by the Kaplan–Meier method and compared between groups using the Mantel–Cox log-rank test. A Cox regression model was used for risk factor analysis.

Results: Estimated survival rate was 69％ at one year and 56％ at three years after the Norwood operations. Prior to Fontan operations, palliations were performed in 2.5±0.8 times. Hazard ratio for death of genetic disorder/malformation and heterotaxy was 14.03 (95％CI, 1.17–167.8, p＝0.037) and 18.66 (95％CI, 1.43–244.4, p＝0.026), respectively. Nine patients (9/16＝56％) achieved Fontan operations. All survivors after the Fontan operations except one patient who suffered from protein-losing enteropathy, are in NYHA class 1.

Conclusion: The strategy of primary Norwood operation for patients with HLHS was feasible up to the Fontan operation with fewer inter-stage palliations, except for genetic disorder and heterotaxy. More investigations are required to justify the operational strategy for genetic disorder and heterotaxy patients.

Background: Protein-losing enteropathy (PLE) following the Fontan operation has been an extremely difficult complication to treat successfully. This study aimed to assess the prognosis and to establish appropriate treatment strategies for PLE.

Methods: From 1991 to 2014, 23 patients with PLE following the Fontan operation were identified from clinical database at Okayama University Hospital. Data were collected retrospectively.

Results: A total of 401 patients underwent Fontan operation at our institution during the study period. In this cohort, the 5.7％ incidence of PLE was relative to the total number of Fontan operations. Following PLE diagnosis, patients had a 68％ and 54％ survival rate at 5 and 10 years, respectively. The causes of death included sepsis, multiple organ failure, heart failure, and intracranial bleeding. In the treatment of PLE, 23 (100％) patients were treated with medication, 10 (43％) patients underwent catheter intervention and 15 (65％) patients underwent surgery. Patients who died were older at the time of PLE diagnosis and were associated with a longer interval between the Fontan operation and PLE diagnosis. Decreased survival was observed in patients with the following conditions post-PLE treatment: a cardiac index (CI)＜2.8 L/min/mm, decreased ventricular ejection fraction (vEF)＜50％, and high central venous pressure (meanCVP)≧15 mmHg.

Conclusion: Our current treatment for PLE was only partially successful. Strategies for reducing CVP and improving both CI and vEF may be effective. Further studies are necessary to determine better treatment strategies for the future.

A recipient twin with twin-twin transfusion syndrome (TTTS) exhibited 6～15％ mitral regurgitation (MR), and hence, a poor prognosis. Fetoscopic laser photo (FLP) coagulation was performed on the recipient twin who presented with cardiomegaly and hydrops fetalis, after which severe mitral and tricuspid regurgitation and cardiomegaly failed to resolve. Here, we present the case of a recipient twin with TTTS. The mother, at 19 weeks and 4 days of gestation, was referred for fetal hydrops. Ultrasonography indicated severe MR. FLP was performed at 19 weeks and 5 days, after which the hydrops fetalis resolved gradually. At 27 weeks, we noted cardiomegaly and severe MR in the recipient. The patient was delivered by an emergency caesarian section, which had to be performed because of premature rupture of the membranes at 32 weeks and 4 days. Postnatal cardiac ultrasonography indicated severe mitral regurgitation, with the anterior leaflet of the mitral valve prolapsed and thickened. Despite the presence of pulmonary hemorrhage at the age of 1 day, the patient was treated with indomethacin to close the ductus arteriosus, thereby improving MR and the respiratory state, while resolving pulmonary hypertension. We concluded that the cause of MR was volume overload in the left atrium and mild abnormalities in the mitral valve. MR did not worsen later during infancy.

Endoglin (ENG) and ACVRL1 are causative genes for hereditary hemorrhagic telangiectasia (HHT); ENG causes HHT type 1 and ALK1 causes HHT type 2. In some cases, HHT is complicated by pulmonary arterial hypertension (PAH). Although there are some reports on PAH in patients with HHT type 2, very few exist for PAH in patients with HHT type 1. Here, we report the case of a 7-year-old girl who was diagnosed of a novel mutation in the ENG gene and PAH on the basis of active diagnostic imaging and gene analysis performed because of a family history of HHT. Upon admission, her status was evaluated as WHO functional class 2. A right-heart catheterization test led to the diagnosis of PAH. The mean pulmonary artery pressure, pulmonary vascular resistance, and pulmonary capillary wedge pressure was 50 mmHg, 11.8 WU/m², and 9 mmHg, respectively. Hereditary PAH is generally associated with poor prognosis. Our patient received upfront combination therapy with bosentan, tadalafil, and beraprost, which improved her status to WHO functional class 1 and her mean pulmonary artery pressure to 35 mmHg. Although upfront combination therapy with oral medication was effective in the short to medium term in our case, long-term observation is also necessary.

The wearable cardioverter defibrillator (WCD) used by patients at risk of sudden cardiac arrest has been available in Japan since 2014. Here, we report two cases of congenital heart disease (CHD) in patients who wore a WCD.

Case 1: A 35-year-old woman with tetralogy of Fallot (TOF) following the Rastelli procedure had symptomatic non-sustained ventricular tachycardia (VT) during her puerperium with her first child. However, she refused treatment for VT. She eventually became pregnant with her second child. The indications for a WCD were risk management of VT, which developed in the third trimester.

Case 2: A 37-year-old woman with TOF following the Rastelli procedure survived a cardiopulmonary arrest due to ventricular fibrillation revealed by an automated external defibrillator (AED). The indication for a WCD was bridging therapy for an implantable cardioverter defibrillator (ICD).

The WCD was used daily for 8 hours by the first patient and for 18 hours by the second patient. No cardiac events occurred while using the WCD; neither patient received shock therapy as a result of using the device.

Based on our limited experience, WCDs are useful for patients with CHD and do not cause serious complications.

Treprostinil, a prostacyclin analogue, is administered subcutaneously and intravenously as a treatment for pulmonary arterial hypertension in Japanese adults. To the best of our knowledge, this is the first report to describe the successful subcutaneous infusion of treprostinil in a pediatric Japanese patient. The patient was diagnosed with idiopathic pulmonary arterial hypertension (IPAH) at the age of 7 years. Initial treatments included a combination therapy of three oral drugs and home oxygen therapy. When we determined that the treatment was insufficient, we decided to add subcutaneous treprostinil because administering intravenous epoprostenol would have been difficult due to the patient being mentally retarded. World Health Organization functional classification and echocardiographic findings showed improvement 6 months after the initiation of treprostinil. Therefore, we suggested that subcutaneous treprostinil is effective for children with IPAH and suggest that this drug is used for pediatric patients who cannot tolerate intravenous epoprostenol, or who can withdraw from epoprostenol.

We report a case of a 13-year-old girl with multiple pulmonary arteriovenous malformations (PAVM) associated with hereditary hemorrhagic telangiectasia (HHT) type 1. The feeding artery diameter of all PAVMs was less than 3 mm, but the patient presented with hypoxemia. Therefore, we performed coil embolization for the large lesion until oxygenation was improved. A feeding artery of PAVM that exceeds 3 mm in diameter should be treated because it has an increased risk of serious cerebral complications. With progress of tools such as detachable microcoils and vascular plugs, we need to examine adaptation of treatment of PAVM with feeders smaller than 3 mm in every case. HHT is an autosomal-dominant disease caused by mutations in five to six genes. HHT may lead to early diagnosis of PAVM in cases with a family history by conducting a screening test. In particular, HHT type 1 has a high incidence of the complication of multiple PAVMs. Careful follow-up and prevention of complications by appropriate treatment intervention are important.

The Fontan procedure is predominantly performed in children with a functionally univentricular heart. It remains unclear as to whether the Fontan procedure can be applied for adult patients. Furthermore, the optimal conduit route remains unknown for adults with apicocaval juxtaposition. Adult Fontan candidates are likely to have dilated ventricles with poor cardiac function caused by long-term hypoxia and ventricular volume overload. Consequently, an ideal course from the inferior vena cava to the pulmonary artery should be created with caution to avoid the formation of kink or collapse of the conduit. A 48-year-old man with a double outlet right ventricle, single right ventricle, along with valvular and supravalvular pulmonary stenosis, presented with exertional dyspnea and palpitation. The patient showed situs inversus with the cardiac apex and inferior vena cava on the left side. Preoperative catheterization data showed low pulmonary vascular resistance and pulmonary artery pressure because of valvular, supravalvular, and bilateral pulmonary artery stenosis. Primary fenestrated total cavopulmonary connection (TCPC), concomitant with pulmonary artery plasty, was performed. The conduit was constructed via an intra-atrial route to avoid being compressed posteriorly by the dilated ventricle. The postoperative course was uneventful, and the patient was discharged 32 days after surgery. His exercise tolerance improved gradually thereafter. He returned to his previous job 3 months after surgery. Our case demonstrates that adult Fontan candidates whose preoperative conditions satisfy appropriate criteria are capable of undergoing primary TCPC. However, surgical indications for adult TCPC should be carefully determined. In our present case, the intra-atrial conduit route was useful for an adult patient with apicocaval juxtaposition.

Microvascular angina is defined as chest discomfort with normal epicardial coronary arteries, and it is caused by coronary microvascular dysfunction. It is relatively more prevalent in women who are perimenopausal or postmenopausal and is rare in young women. Here we report the case of a 16-year-old girl who presented with a complaint of chest discomfort during exercise and who was diagnosed with microvascular angina. Exercise stress induced chest discomfort, which was not relieved by administering nitroglycerin. Exercise thallium-201 myocardial scintigraphy showed a perfusion defect in the anteroseptal wall. Although no significant stenosis or vasospasm in the epicardial coronary arteries was observed on the angiography, the ergonovine stimulation test induced chest discomfort and delayed distal vessel opacification in the left anterior descending coronary artery. In addition to limiting exercise, concomitant treatment using carvedilol and diltiazem reduced the frequency of chest pain. The perfusion defect showed improvement. Because microvascular angina is very rare in young patients, they might be misdiagnosed. Recent evidence has challenged the assumption that microvascular angina is a benign condition; therefore, early treatment may be very important for young patients. Physicians who examine young patients with angina-like chest discomfort should be aware of the possibility of microvascular angina.