Tailoring the hybrid palliation for hypoplastic left heart syndrome: A simulation study using a lumped parameter model.

The results of Hybrid procedure (HP) for the hypoplastic left heart syndrome (HLHS) depend on several variables: pulmonary artery banding tightness (PAB), atrial septal defect size (ASD) and patent ductus arteriosus stent size (PDA). A HP complication could be the aortic coarctaction (CoAo). The reverse Blalock-Taussig shunt (RevBT) placement was proposed to avoid CoAo effects. This work aims at developing a lumped parameter model (LPM) to investigate the effects of the different variables on HP haemodynamics. A preliminary verification was performed collecting measurements on a newborn HLHS patient to calculate LPM input parameters to reproduce patient's baseline. Results suggest that haemodynamics is affected by ASD (ASD: 0.15-0.55 cm, pulmonary to systemic flow ratio Qp/Qs: 0.73-1, cardiac output (CO): 1-1.5 l/min and ventricular stroke work SW: 336-577 ml mmHg) and by the PAB diameter (PAB: 0.07-0.2 cm, Qp/Qs: 0.46-2.1, CO: 1.3-1.6 l/min and SW: 591-535 ml mmHg). Haemodynamics was neither affected by RevBT diameter nor by PDA diameter higher than 0.2 cm. RevBT implantation does not change the HP haemodynamics, but it can make the CoAo effect negligible. LPM could be useful to support clinical decision in complex physiopathology and to calibrate and personalise the parameters that play a role on flow distribution.

Early left ventricular abnormality/dysfunction in obese children affected by NAFLD.

BACKGROUND AND AIMS: Although it is generally accepted that non alcoholic fatty liver disease (NAFLD) is linked to increased risk of cardiovascular disease, the presence of abnormalities in cardiac function among NAFLD children is limited and controversial. Aim of the study was to detect cardiac abnormalities/dysfunction in a paediatric population of NAFLD. METHODS AND RESULTS: Anthropometric, laboratory, cardiovascular fitness, 24 h blood pressure monitoring and Doppler echocardiography parameters were obtained in 50 untreated children (37 males; mean age 12.2 + 2.5) with biopsy-proven NAFLD. Abnormalities in both cardiac function and geometry could be identified in the whole study population: prevalence of about 35% in left ventricular hypertrophy, 14% of concentric remodelling and 16% of left atrial dilatation. Furthermore children with NAFLD (NAS score <5) showed lower cardiac alterations compared to NASH patients (NAS score >5). After adjusting for age, sex and BMI, a positive correlation was found only between LV mass and NAS score (p < 0.001). CONCLUSION: Our results suggest that cardiac dysfunction can be detectable early in NAFLD children and this is not linked to cardiovascular and metabolic alteration, other than to liver damage. Although as a preliminary stage, we can speculate a possible direct relationship between liver and heart steatosis, already occurring during childhood.

Ventricular assist devices as a bridge to heart transplantation or as destination therapy in pediatric patients.

PURPOSE: Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report on our experience in the pediatric population. METHODS: Retrospective review of 27 consecutive children offered mechanical support with Berlin Heart as a bridge to heart transplant, and Jarvik 2000 as a destination therapy from February 2002 to October 2011. RESULTS: The median patient age was 4.8 years (range = 75 days to 20.5 years). The median patient weight was 18.6 kg (range = 2.9-63 kg). We divided the patients in two groups, including in group I patients assisted for bridging to heart transplantation and in group II patients with Duchenne's dystrophy assisted as destination therapy. In the group I, 11 patients required biventricular mechanical support (BVAD), but in all other cases, a single left VAD proved sufficient (56%). The median duration of VAD support was 48 days (1 to 192 days). The median pre-VAD pulmonary vascular resistance index (Rpi) was 5.7 WU/m(2) (3.5 to 14.4 WU/m(2)). Twelve patients (48%) were successfully bridged to heart transplantation after a median duration of mechanical support of 63 days (range = 2-168 days). Ten deaths occurred (40%), three for neurological complications, two for sepsis, two for multiorgan failure, and three other for device malfunctioning. Since 2007, the survival rate of our patients has increased from 33% to 75%, and the need for BVAD has decreased from 89% to 23%. In the group II, two patients with mean age of 15.3 years were assisted with Jarvik 2000, and both of them are alive in a follow-up of 10.4 months. In two patients with Rpi > 10 WU/m(2), unresponsive to pulmonary vasodilatator therapy, Rpi dropped to 2.2 and 2 WU/m(2) after 40 and 23 days of BVAD support, respectively. Six patients (32%) required at least one pump change. Of 12 patients undergoing heart transplantation, five developed an extremely elevated (>60%) panel-reactive antibody by enzyme-linked immunosorbent assay, confirmed by Luminex. All of them experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow-up of 34.4 months (45 days to 8.7 years). CONCLUSIONS: Mechanical support in children with end-stage heart failure is an effective strategy as a bridge to heart transplantation with a reasonable morbidity and mortality. BVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance. The total implantable system opens a future scenarios for patients not eligible for heart transplantation.

A statistical model for quantification and prediction of cardiac remodelling: application to tetralogy of Fallot.

Cardiac remodelling plays a crucial role in heart diseases. Analyzing how the heart grows and remodels over time can provide precious insights into pathological mechanisms, eventually resulting in quantitative metrics for disease evaluation and therapy planning. This study aims to quantify the regional impacts of valve regurgitation and heart growth upon the end-diastolic right ventricle (RV) in patients with tetralogy of Fallot, a severe congenital heart defect. The ultimate goal is to determine, among clinical variables, predictors for the RV shape from which a statistical model that predicts RV remodelling is built. Our approach relies on a forward model based on currents and a diffeomorphic surface registration algorithm to estimate an unbiased template. Local effects of RV regurgitation upon the RV shape were assessed with Principal Component Analysis (PCA) and cross-sectional multivariate design. A generative 3-D model of RV growth was then estimated using partial least squares (PLS) and canonical correlation analysis (CCA). Applied on a retrospective population of 49 patients, cross-effects between growth and pathology could be identified. Qualitatively, the statistical findings were found realistic by cardiologists. 10-fold cross-validation demonstrated a promising generalization and stability of the growth model. Compared to PCA regression, PLS was more compact, more precise and provided better predictions.

Long-term results of catheter-based treatment of pulmonary atresia and intact ventricular septum.

OBJECTIVE: To review the outcome of patients with pulmonary atresia with intact ventricular septum after interventional perforation of the pulmonary valve, to assess the capability of this procedure to avoid neonatal or late intervention and to obtain a long-term biventricular repair. DESIGN: Retrospective interventional study and clinical follow-up study. SETTING: Tertiary referral centre. PATIENT POPULATION: Between November 1994 and December 2007, 40 neonates underwent radiofrequency perforation. Median age at pulmonary valvotomy was 28 hours (range 1-147 hours) and median weight was 2925 g (range 1900-4400 g). MAIN OUTCOME MEASURES: Procedural success and complication rates; early-term and long-term follow-up results. RESULTS: The procedure was successful in 39 patients but 16 of them needed neonatal surgery. The overall mortality was 7.5%. At a median follow-up of 82 months, four patients underwent a bidirectional Glenn procedure, whereas all the other patients achieved a biventricular circulation without any further intervention in 19 of them. Patients who died or needed additional intervention with or without biventricular circulation failure had a higher incidence of bipartite right ventricular (65% vs 15.8% of those not needing additional intervention; p = 0.004) and a lower median tricuspid Z value (-2 (range -3.5 to 1) vs -0.5 (range -2 to 1); p = 0.004)). CONCLUSIONS: The results confirm that percutaneous interventional perforation is an effective first-stage procedure in patients with pulmonary atresia with intact ventricular septum. The right heart appeared to be adequate to maintain a long-term biventricular circulation in the large majority of cases.

Contrast echocardiography for pulmonary arteriovenous malformations screening: does any bubble matter?

AIMS: To evaluate diagnostic accuracy of contrast echocardiography (CE) as compared with CT, for the screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia (HHT); to evaluate the clinical significance of semi-quantitative analysis of a shunt on CE. METHODS AND RESULTS: A blinded prospective study was conducted in 190 consecutive subjects at risk of HHT who underwent screening for PAVMs, including clinical evaluation, pulse oximetry, standard and CE, and chest multirow CT without contrast medium. A semi-quantitative analysis of the shunt size was performed according to the contrast echo opacification of the left-sided chambers: Grade 0, no bubbles; 1, occasional filling with <20 bubbles; 2, moderate filling; 3, complete opacification. The first 100 patients were compared with 100 controls. A total of 119 (63%) patients had positive CE (32.2% Grade 1, 13.1% Grade 2, 11% Grade 3, 6.3% with patent foramen ovale). The overall diagnostic performance of CE was sensitivity 1.00, specificity 0.49, positive predictive value (PPV) 0.32, negative predictive value (NPV) 1.00. The PPV for the different grades was 0.00 for Grade 1, 0.56 for Grade 2, 1.00 for Grade 3; the NPV of Grade 0 was 1.00. A significant correlation was found between the CE grading and the number of PAVM, and complications (P < 0.0001). CONCLUSION: CE is an extremely sensitive procedure for the detection of PAVMs with substantial clinical impact.

Exercise capacity in apparently healthy survivors of cancer.

AIMS: To evaluate cardiopulmonary exercise tolerance in a large cohort of apparently healthy paediatric cancer survivors in order to determine their participation in sporting activities. METHODS: A total of 84 young (<21 years) asymptomatic childhood cancer survivors, who had been exposed to anthracyclines (mean dose 212 mg/m2) and/or chest irradiation (median dose 2000 cGy), with normal left ventricular systolic function at rest (fractional shortening >29%), and 79 healthy controls were studied. Exercise testing was performed on a treadmill ergometer. Gas exchange analysis and derived variables were measured on a breath-by-breath basis. Pulmonary functional evaluation was performed before exercise. Echocardiographic evaluation at rest was performed within one month before the exercise test. RESULTS: There were no differences in exercise responses between patients and controls. In boys <13 years, mean VO2 max was slightly but significantly lower than in controls. This finding was thought to be a result of decreased physical fitness as all the other exercise parameters were similar to those in the controls. CONCLUSIONS: Results show that apparently healthy survivors of paediatric cancer can take part in dynamic sporting activities if they exhibit a normal response to cardiopulmonary exercise testing, while those that exhibit a reduced VO2 max should be re-evaluated after an aerobic training programme, and should undergo tailored dynamic physical activity if the VO2 max does not normalise.

Doppler ultrasonographic grading of hepatic vascular malformations in hereditary hemorrhagic telangiectasia -- results of extensive screening.

AIMS: In previous studies, the prevalence of hepatic vascular malformations (VMs) in a large Italian family with hereditary hemorrhagic telangiectasia (HHT) was examined by Doppler ultrasonography (US) as screening technique, and the relevant Doppler US findings were described and classified. Thereafter, Doppler US has been routinely used to screen HHT families for liver involvement. Hepatic VMs were evaluated and classified on the basis of Doppler US findings. METHODS: Three hundred and forty-six subjects belonging to 64 pedigrees were checked for the presence of signs of HHT. All of them underwent abdominal Doppler US screening for hepatic VMs. Vascular abnormalities were classified as minimal if the hepatic artery was dilated in extrahepatic tract only and measured > 6 mm; as moderate if the hepatic artery was dilated in both intra and extrahepatic tract; and as severe if complex changes of the arterial hepatic branches were associated with hepatic and/or portal vein dilatation. Furthermore, Doppler parameters, both qualitative (flow direction, turbulence) and quantitative (peak flow velocity and resistivity index in hepatic artery, mean velocity in portal vein, diastolic peak flow velocity in hepatic veins), were entered into our VM classification. RESULTS: HHT was found in 222 subjects, with hepatic VMs detected by Doppler US in 92 (41.4 %) (24 males, 68 females, mean age 52.2). Hepatic VMs were minimal in 11 subjects, moderate in 70, and severe in 11. CONCLUSIONS: On the basis of our proposed grading, hepatic VMs can be easily classified in subjects with HHT by Doppler US. Depending on the degree of hepatic vascular derangement, appropriate programs for follow up and/or therapy can be designed.

Transoesophageal atrial pacing combined with transthoracic two dimensional echocardiography: experience in patients operated on with arterial switch operation for transposition of the great arteries.

OBJECTIVE: To assess the feasibility, safety, and diagnostic accuracy of transoesophageal atrial pacing stress echocardiography (TAPSE) combined with two dimensional transthoracic echocardiography (TTE) for evaluation of coronary perfusion in patients undergoing arterial switch operation for transposition of the great arteries. DESIGN: TAPSE combined with TTE was performed at the end of cardiac catheterisation. An ischaemic response was defined as > 1.5 mm horizontal or downsloping ST segment depression or as a new or worsened wall motion abnormality. The results were compared with results of coronary angiography. SETTING: Tertiary referral centre for paediatric cardiology and cardiac surgery. PATIENTS: 25 patients, mean (SD) age 29.5 (19) months, mean (SD) weight 12.5 (3.4) kg. MAIN OUTCOME MEASURES: Target heart rate (200 beats/min) was attained in 22 of 25 (88%) patients. Electrocardiographic ischaemic changes occurred in 4 of 25 (16%) and wall motion abnormalities in 3 of 25 (12%). Coronary obstructions were found in 2 of 25 (8%) patients. RESULTS: The test was feasible in all patients, without clinical complications requiring treatment. Compared with coronary angiography, the test had a sensitivity and a specificity of 100% and 95%, respectively, for the echocardiographic stress, and of 100% and 91%, respectively, for the electrocardiographic stress. The negative predictive value was 100% for both the echocardiographic and the electrocardiographic stress tests. The positive predictive value was 66% for the echocardiographic stress and 50% for the electrocardiographic stress tests. CONCLUSIONS: In these patients TAPSE combined with TTE was feasible and safe and apparently an accurate diagnostic method for evaluation of coronary perfusion. Patients with a negative test may have a low likelihood of major coronary abnormalities and may not require coronary angiography.

Recurrent unilateral bacterial pneumonias and interstitial fibrosis associated with pulmonary vein atresia: successful treatment with endovascular stent implantation.

A variety of pulmonary vascular disorders, such as hemangiomatosis, telangectasia, and veno-occlusive disease, may be involved in the pathogenesis of interstitial lung diseases. We describe the case of a girl with recurrent bacterial pneumonia and progressive interstitial fibrosis affecting the right lung. Morphologic evaluation of the lung biopsy showed structural changes of the vessel walls suggesting pulmonary hypertension. The echocardiogram showed the presence of centripetal blood flow in the right pulmonary artery from the periphery of the lung to the heart. A selective right angiography demonstrated the presence of pulmonary venous obstruction at the veno-atrial junction, successfully treated by endovascular stent implantation during cardiac catheterization.

Paraplegia following percutaneous balloon angioplasty of aortic coarctation: a case report.

Balloon angioplasty of recurrent coarctation of the aorta is considered a low-risk procedure with high success rate. In the literature, the major complications are death, rupture of the aorta, recoarctation, aneurysm formation, cerebrovascular accident, and femoral artery thrombosis. Spinal cord ischemia as an unusual complication of balloon angioplasty is reported.

Percutaneous transluminal angioplasty of the left internal thoracic artery graft: a case report of a child operated on for anomalous origin of the left coronary artery from the pulmonary artery.

We report a case of an 8-year-old girl operated on with left internal thoracic artery-coronary artery anastomosis for anomalous left coronary artery from the pulmonary artery, in whom an early stenosis of the graft was successfully treated by percutaneous transluminal angioplasty.

Giant aneurysm following coil occlusion of patent ductus arteriosus.

A case is described in which a giant aneurysm developed following successful PDA coil occlusion in an infant with Marfan syndrome. This rare and severe complication brings into question the need for careful evaluation of these children before and after transcatheter occlusion.

Myocardial ischaemia un-masked by transesophageal atrial pacing combined with two-dimensional transthoracic echocardiography in a pediatric patient: a case report.

We describe a case of a child operated on for an anomalous origin of the left coronary artery from the pulmonary artery and proximal hypoplasia of the anomalous coronary, in whom residual inducible myocardial ischaemia was detected by means of transesophageal atrial pacing combined with transthoracic echocardiography.

Interruption of the aortic arch, ventricular septal defect, aortic atresia and aortopulmonary fistulous communication.

Interruption of the aortic arch in association with aortic atresia is a rare condition. We report the second case in literature in which survival was provided by an aortopulmonary fistulous communication.

Surgical management of complete atrioventricular canal associated with tetralogy of Fallot.

Between 1984 and 1993, 12 children with an atrioventricular canal and tetralogy of Fallot underwent surgical repair. The mean(s.d.) age at operation was 58(18) months, and the mean(s.d.) body weight 15(4) kg. Nine patients underwent 11 palliative procedures. The ventricular septal defect was closed through a combined (right atrial and right ventricular) approach in nine cases, and through a right atrial approach in three, using a prosthetic patch with a wide anterior extension, secured with a running suture. The 'ostium primum' defect was closed with a separate prosthetic patch in 11 cases (double-patch technique). Right ventricular outflow obstruction was relieved by a composite infundibular patch (seven cases) or a transanular patch (five). There were four hospital deaths (33%). These were caused by low cardiac output in three cases and infection in one (three deaths occurred in patients with a transanular patch). One patient has so far died during follow-up. Assessment at 50(36) months by echo-Doppler showed moderate-to-severe 'mitral' regurgitation in three cases, and moderate 'tricuspid' regurgitation with right ventricular dysfunction in one case. Two patients have required further surgery.

Randomized comparison of atenolol and fludrocortisone acetate in the treatment of pediatric neurally mediated syncope.

Overall, these results indicate that oral treatment of neurally mediated syncope is safe and efficacious. Further randomized trials in children will be required to determine the significance of a placebo effect, as well as potential differences in results related to the mechanism of syncope.