To examine the utility of decline in arterial partial pressure of oxygen after exercise as a marker of pulmonary vascular obstructive disease in patients with atrial septal defect and pulmonary hypertension.

Treadmill exercise was performed in 18 patients with atrial septal defect and pulmonary hypertension. Arterial blood gas samples were obtained before and after peak exercise. A decline in the arterial pressure of oxygen of more than 10 millimetres of mercury after exercise was considered significant based on preliminary tests conducted on the controls. Cardiac catheterisation was performed in all patients and haemodynamic data sets were obtained on room air, oxygen, and a mixture of oxygen and nitric oxide (30–40 parts per million).

There were 10 patients who had more than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise and who had a basal pulmonary vascular resistance index of more than 7 Wood units per square metre. Out of eight patients who had less than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise, seven had a basal pulmonary vascular resistance index of less than 7 Wood units per square metre, p equals 0.0001. A decline in arterial partial pressure of oxygen of more than 10 millimetres of mercury predicted a basal pulmonary vascular resistance index of more than 7 Wood units per square metre with a specificity of 100% and a sensitivity of 90%.

A decline in arterial partial pressure of oxygen following exercise appears to predict a high pulmonary vascular resistance index in patients with atrial septal defect and pulmonary hypertension. This test is a useful non-invasive marker of pulmonary vascular obstructive disease in this subset.

Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever.

To optimise accurate diagnosis of rheumatic heart disease, we utilised a two-step model. Portable echocardiography was conducted on 1142 predominantly Māori and Pacific children aged 10–13 years. Children with an abnormal screening echocardiogram underwent clinical assessment by a paediatric cardiologist together with hospital-based echocardiography. Rheumatic heart disease was then classified as definite, probable, or possible. Portable echocardiography identified changes suggestive of rheumatic heart disease in 95 (8.3%) of 1142 children, which reduced to 59 (5.2%) after cardiology assessment. The prevalence of definite and probable rheumatic heart disease was 26.0 of 1000, with 95% confidence intervals ranging from 12.6 to 39.4. Portable echocardiography overdiagnosed rheumatic heart disease with physiological valve regurgitation diagnosed in 28 children. A total of 30 children (2.6%) had non-rheumatic cardiac abnormalities, 11 of whom had minor congenital mitral valve anomalies.

We found high rates of undetected rheumatic heart disease in this high-risk population. Rheumatic heart disease screening has resource implications with cardiology evaluation required for accurate diagnosis. Echocardiographic screening for rheumatic heart disease may overdiagnose rheumatic heart disease unless congenital mitral valve anomalies and physiological regurgitation are excluded.

Dilated cardiomyopathy is an important cause of cardiac failure in both children and adults, but is more progressive in children. In adult dilated cardiomyopathy, left ventricular remodelling is associated with changes in the plasma levels of matrix metalloproteinases and tissue inhibitor of metalloproteinases. Plasma matrix metalloproteinases and tissue inhibitors of metalloproteinase changes in paediatric dilated cardiomyopathy have not been examined. This study developed a low blood volume, high-sensitivity assay to test the hypothesis that unique and differential plasma matrix metalloproteinases and tissue inhibitors of metalloproteinase profile exist in patients with paediatric dilated cardiomyopathy.

A systemic blood sample (1 millilitre) was obtained from seven children aged 8 plus or minus 7 years with dilated cardiomyopathy and 26 age-matched normal volunteers. Using a high-throughput multiplex suspension immunoassay, plasma levels were quantified for collagenases (matrix metalloproteinase-8), gelatinases (matrix metalloproteinase-2 and -9), lysins (matrix metalloproteinase-3 and -7), and tissue inhibitor of metalloproteinases-1, -2, and -4. The matrix metalloproteinase to tissue inhibitors of metalloproteinases ratios were also calculated. The plasma matrix metalloproteinase-2, -7, -8, and -9 levels were increased by greater than twofold in patients with dilated cardiomyopathy than normal patients (with p less than 0.05). Patients with dilated cardiomyopathy also had significantly higher tissue inhibitors of metalloproteinases-1 and -4 (298% and 230%; with p less than 0.05).

These unique findings show that a specific plasma matrix metalloproteinase/tissue inhibitor of metalloproteinase profile occurs in paediatric dilated cardiomyopathy when compared to the cases of normal children. These distinct differences in the determinants of myocardial matrix structure and function may contribute to the natural history of dilated cardiomyopathy in children and may provide a novel biomarker platform in paediatric dilated cardiomyopathy.

To determine the frequency and factors associated with increase in microembolic signals during transcatheter closure of atrial septal defect using the Amplatzer septal occluder.

During the procedure in 16 patients, we measured microembolic signals using transcranial Doppler. Procedure time was divided into five periods: right cardiac catheterisation; left cardiac catheterisation; left cardiac angiocardiography; sizing and long sheath placement; device placement and release. We compared numbers of microembolic signals among the five periods and identified factors associated with them.

Mean size of septal occluder was 16 millimetres in diameter. Total number of microembolic signals was a median of 31.5, ranging from 3 to 113. Microembolic signals in three periods, left cardiac catheterisation; sizing, and long sheath placement; and device placement and release, were not significantly different from one another, but were significantly higher than those in the remaining two periods, right cardiac catheterisation and left cardiac angiocardiography (median was 9 in left cardiac catheterisation; 6 in sizing and long sheath placement; 6.5 in device placement and release, versus 0 in right cardiac catheterisation and 1 in left cardiac angiocardiography, p less than 0.05, respectively). Importantly, the time for device manipulation positively correlated with total number of microembolic signals (r equals 0.77, p less than 0.001), although fluoroscopic time, age, or size of septal occluder did not.

Transcatheter closure of atrial septal defect using the Amplatzer septal occluder produces microemboli, especially during device placement. To minimise the risk of systemic embolism, we must decrease the time for device manipulation.

Classical Atriopulmonary Fontan connections tend to fail in the long term due to progressive anastomotic site obstruction, right atrial enlargement, and refractory atrial arrhythmias. Conversion to total cavopulmonary connection with concomitant arrhythmia surgery is a promising treatment but optimal timing of the procedure remains controversial.

Between the years 2002 and 2009, 15 patients with a median age of 26.2 (12–43) years underwent Fontan conversion operation with concomitant arrhythmia surgery. All were symptomatic and 14 out of the 15 patients had refractory arrhythmias. The duration of pre-operative arrhythmia and the outcome of surgery were correlated to study the impact of delay in surgical intervention on post-operative survival and arrhythmia control.

There were two patients who died in the early post-operative period (13.3%). At the mid-term follow-up, 53 (20–86) months, late atrial arrhythmias had recurred in two of the 13 surviving patients (15.30%) and one patient developed late sinus node dysfunction. The need for anti-arrhythmic drugs decreased considerably from 93.5% to 15.3% on mid-term follow-up. There was no late death or need for cardiac transplantation. The duration of arrhythmia before surgery was prolonged for more than 10 years in patients who died as well as in those who had complications like late recurrence of arrhythmias, dependence on anti-arrhythmic medications, and worsening of ventricular dysfunction.

Fontan conversion is a well-established treatment option for salvaging the failing atriopulmonary connections. Concomitant arrhythmia surgery effectively resolves the refractory atrial arrhythmias and improves survival, but we need to optimise the timing of Fontan conversion to improve the long-term outcome.

Congenital cardiac diseases are the most frequent congenital malformations. In adult patients, the mineralisation of the aorta due to cardiovascular disease is very common, but vascular mineralisation in paediatric cardiopathies is a topic less studied. This study shows that children with a complex congenital cardiopathy show a high degree of vascular mineralisation in the ascending aorta. This can be part of the cardiac failure pathophysiology due to congenital cardiopathies.

The aim of this study was to determine the presence and degree of vascular mineralisation in samples of the ascending and descending aorta of children with complex congenital cardiopathies.

We conducted a cross-sectional study.

We obtained 34 vascular tissues from the autopsies of 17 children with congenital cardiac disease.

We used a scanning electron microscope with an energy-dispersive X-ray spectroscopy in order to analyse the vascular tissues.

The amount of minerals was two times higher in the ascending aorta than in the descending aorta of children with congenital cardiac disease.

The study provides evidence that vascular mineralisation can start at an early age, and that it is higher in the ascending aorta than in the descending aorta.

To assess the perception of the quality of life of adolescents and young adults with congenital heart disease and to examine the variables that have a negative impact on it and that add a resilience effect.

A total of 22 male and 18 female patients, aged 12–26 years, of whom 27 were admitted to surgery and 13 were not, participated in this study. All patients had complete medical records and were interviewed once; demographic and clinical data were collected, and patients filled a questionnaire on quality of life, the WHOQOL-BREF, and underwent an interview on social support, educational style, self-image, functional limitations, and emotional adjustment.

Our patients showed a better perception of quality of life than did the general population, on the basis of psychological, social relationship and environment scales. Older patients hold a better perception of quality of life on the psychological scale. Cyanosis did not show any significant impact over perception of quality of life decay; however, the number of surgical procedures and the persistence of moderate-to-severe residual injuries had considerable detrimental effect. Social support had an impact on increasing resilience, promoting adjustment to illness. Several factors may play a role in adjustment to congenital heart disease, either improving the perception of quality of life or worsening it. We may conclude that some buffer variables on congenital heart disease may play roles in increasing the perception of quality of life of patients during their lifetime, social support probably explaining why the perception of quality of life is better than in the normal population. The number of surgeries and the moderate-to-severe residual injuries, however, reverted that effect.

We hypothesised that sildenafil would improve hemodynamics in children with pulmonary hypertension and attenuate rebound pulmonary hypertension after inhaled nitric oxide withdrawal.

We undertook an open-label, single-drug study of sildenafil in patients under 5 years of age with either symptomatic or rebound pulmonary hypertension following inhaled nitric oxide withdrawal.

We recruited 25 patients (median age 180 days, 10–1790) to receive sildenafil. The median right ventricular to systemic systolic blood pressure ratio before sildenafil therapy was 1.0 (0.5–1.4) and decreased to 0.5 (with a range from 0.3 to 1.3; p = 0.0002). In five patients the baseline pulmonary vascular resistance index was 10 (7.1–13.6) Wood units metre square and decreased to 5.8 (2.7–15.6) Wood units metre square (p = 0.04) at 6 months. Ten patients were treated with sildenafil for a median of 34 days (9–499) until resolution of pulmonary artery hypertension and continue to do well. Six patients continued sildenafil therapy for a median of 1002 days (384–1574) with improvement but without resolution of pulmonary hypertension. There was no change in serum creatinine, urea, liver function tests, or platelet count. In 15 patients sildenafil abolished rebound pulmonary artery hypertension following withdrawal of inhaled nitric oxide. Median right ventricular pressure to systemic systolic pressure ratio decreased from 1.0 (0.8–1.4) during nitric oxide withdrawal to 0.4 (0.3–0.8) p = 0.006 after pre-treatment with sildenafil.

In children under 5 years of age with severe pulmonary hypertension, sildenafil therapy resulted in prolonged hemodynamic improvements without adverse effects. Sildenafil attenuated rebound pulmonary hypertension after withdrawal of inhaled nitric oxide.

Canadian Cardiovascular Society consensus guidelines recommend that tetralogy of Fallot patients be seen by a congenital cardiologist every 2 years. In Atlantic Canada, tetralogy of Fallot patients are followed up at either tertiary or satellite clinics, which are held in the community and attended by paediatric cardiologists. The effectiveness of satellite clinics in congenital cardiac disease follow-up is unproven. Our objective was to compare patient-reported quality of life measures to determine whether these were impacted by the site of follow-up.

We included patients with tetralogy of Fallot undergoing surgical repair at the Izaak Walton Killam Health Centre from 1 November, 1972 to 31 May, 2002. Quality of life surveys, SF-10 or SF-36v2, were administered to consenting patients. We analysed the subjective health status by patient age and site of follow-up.

Of the 184 eligible patients, 72 were lost to follow-up. Of the locatable patients, 61% completed the questionnaires. In all, 90% (101 out of 112) were followed up at recommended intervals. Of the 112 (68%) patients, 76 were followed up at a tertiary clinic. These patients were older, with a mean age of 18.4 years versus 14.7 years, and scored higher on the SF-36 physical component summary (52.6 versus 45.7, p = 0.02) compared with satellite clinic patients. The SF-36 mental component summary scores were similar for patients regardless of the site of follow-up. SF-10 physical and psychosocial scores were similar regardless of the site of follow-up.

Tetralogy of Fallot patients followed at either satellite or tertiary clinics have similar subjective health status.

We thought of assessing the prevalence and predictors of feeding disorders in patients with congenital heart defects after neonatal cardiac surgery.

Retrospective study of 82 consecutive neonates (48 males, 34 females) who underwent surgery for congenital heart defects from 1999 to 2002. Information was taken from patient charts and nursing notes. The presence of a feeding disorder was assessed by a questionnaire sent to the paediatricians when the child was 2 years of age. A feeding disorder was defined as a need for tube feeding, inadequate food intake for age, or failure to thrive. Data were analysed with descriptive statistics and logistic regression.

Feeding disorders occurred in 22% of the study population. Reoperation and early feeding disorders were identified as independent risk factors for later feeding disorders (odds ratio 5.8, p 0.01; odds ratio 20.7, p 0.02). There was a trend towards more feeding disorders in patients with neurological abnormalities during the first hospital stay.

Feeding disorder is a frequent, long-term sequela after neonatal cardiac surgery. Patients with congenital heart defects who undergo multiple cardiac surgeries and those with early feeding disorders are at risk of developing later feeding disorders. Patients with these risk factors need to be selected for preventive strategies.

Transcatheter stent placement carries the risk of cardiovascular aneurysm or rupture. Covered stent implantation reduces these risks. The recently marketed Advanta V12 large-diameter-covered stent is pre-mounted and requires 9 (8)-11 Fr delivery systems. The aim was to report on the early results of the treatment of various cardiovascular obstructions by the implantation of a new polytetrafluoroethylene-covered stent (V12).

Graft stents on balloons with a diameter (12, 14, 16 millimetres) sufficient to anchor the stent in various obstructions (congenital aortic coarctation, n = 5; obstruction after ascending aorta repair, n = 2; pulmonary arteries, n = 5; inferior caval vein, n = 1; atretic superior caval vein, n = 1; pulmonary vein obstruction, n = 1; and right ventricular outflow tract, n = 1) were implanted using the smallest available delivery system. Secondary dilation with larger-diameter balloons was performed when the residual pressure was gradient, the stent-vessel wall relationship or stent re-coiling due to different reasons needed a re-intervention by pure ballooning or second stent placement.

All 16 patients aged 5–46 years underwent V12 implantation. The variability of the treated lesions and the need for additional interventions were responsible for large ranges in fluoroscopy time between 7.3 to 48.2 minutes (median 17.3). Considering the additional procedures, the V12 stent achieved the desired result in all cases. There were no major complications. At short-term median follow-up of 2 months, all patients are alive and well with no evidence of stent failing.

These initial results show that the covered Advanta V12 large-diameter stent is safe and effective in the immediate treatment of various cardiovascular obstructions. Long-term follow-up is required.

To analyse blood pressure characteristics during 24-hour ambulatory blood pressure monitoring in children and to assess factors that influence its success over 24 hours and during patient-recorded awake (DAY) and sleep (NIGHT) periods.

A total of 169 consecutive ambulatory blood pressure monitoring studies were conducted in 154 patients over 30 months. For each ambulatory study, we measured the percentage of successful measurements both at the first attempt (S-initial%) and following any automated repeat attempt if initial attempts had failed (S-final%). These were measured over 24-hour, DAY, and NIGHT periods.

We found that blood pressure measurements at NIGHT were more successful than measurements attempted during the DAY (p<0.05). There was no influence of age, gender, height, weight, body mass index and estimated glomerular filtration rate with the proportion of successful measurements during the 24-hour, DAY, and NIGHT periods. On stepwise multiple regression analysis, the indexed mean systolic blood pressure over 24 hours was the only factor having a significant influence on the proportion of successful measurements over the 24-hour and DAY periods, although it only accounted for three-tenths of the variance; it had no influence on the overall success of measurements at NIGHT.

Ambulatory blood pressure monitoring in children provides reliable data both during the patient's awake and sleep periods with higher success of measurements at NIGHT as opposed to DAY periods.

The left ventricle in patients with hypoplastic left heart syndrome may influence right ventricular function and outcome. We aimed to investigate differences in right ventricular deformation and intraventricular dyssynchrony between hypoplastic left heart syndrome patients with different anatomical subtypes and left ventricle sizes after Fontan surgery using two-dimensional speckle tracking.

We examined 29 hypoplastic left heart syndrome patients aged 5.4 plus or minus 2.8 years after Fontan surgery and compared 15 patients with mitral and aortic atresia with the remaining 14 patients with other anatomic subtypes. We used two-dimensional speckle tracking to measure the global and regional systolic longitudinal strain and strain rate as well as intraventricular dyssynchrony.

Global strain (−19.5, 2.8% versus −17.4, 3.9%) and global strain rate (−1.0, 0.2 per second versus −0.9, 0.3 per second) were not different between groups. The mitral and aortic atresia group had higher strain in the basal septal (−13.0, 5.0% versus −3.9, 9.3%, p = 0.003) and mid-septal (−19.4, 4.7% versus −13.2, 6.5%, p = 0.009) segments, and higher strain rates in the mid-septal segment (−1.14, 0.3 per second versus −0.95, 0.4 per second, p = 0.047), smaller left ventricle area (0.18, 0.41 square centimetre versus 2.83, 2.07 square centimetre, p = 0.0001), and shorter wall-to-wall delay (38, 29 milliseconds versus 81, 57 milliseconds, p = 0.02).

Significant differences in regional deformation and intraventricular dyssynchrony exist between the mitral and aortic atresia subtype with small left ventricles and the other anatomic subtypes with larger left ventricles after Fontan surgery.