Chronic kidney damage in the adult Fontan population.

OBJECTIVES: 1) To determine the accuracy of estimated GFR (eGFR) as compared to directly measured GFR (mGFR) in the adult Fontan population; 2) to determine the true prevalence of chronic kidney damage (CKD) as determined by uACR AND eGFR. METHODS: Prospective study of 81 patients Fontan patients (≥18years) followed at St. Paul's Hospital, University of British Columbia. CKD-EPI and MDRD equations used to calculate eGFR, mGFR determined by 99mTc-DTPA renal dynamic imaging and urine albumin to creatinine ratios were calculated. RESULTS: The mGFR was 93±27ml/min/1.73m2: 28 (53%) had an mGFR<90ml/min/1.73m2 and 1 (2%) had an mGFR <60ml/min/1.73m2. There was a modest correlation between mGFR and eGFR (EPI/MDRD) (r=0.50, p<0.0001 and r=0.54, p<0.0001 respectively). Both eGFR (EPI) (bias 27.0; 95% CI 18.0-27.7ml/min/m2, p<0.0001) and eGFR (MDRD) (bias 15.5; 95% CI 7.6-17.4ml/min/m2, p<0.0001) overestimated GFR as compared to mGFR. Among patients with an eGFR (EPI)/(MDRD) >90ml/min/1.73m2, 50% and 46% respectively had an mGFR <90ml/min/1.73m2. Significant albuminuria (>3mg/mmol) was present in 33% and upwards of 32% of patients with a normal eGFR (MDRD/EPI) had evidence of CKD with uACR >3mg/mmol. Using combined criteria of eGFR <90ml/min/1.73m2 and/or uACR >3mg/mmol, 46% of patients had evidence of CKD. CONCLUSIONS: This study draws attention to the need for stringent CKD screening as an important proportion of CKD is currently not being detected. Mild undetected CKD, an early marker of end organ damage, may also be an early sign of Fontan failure that requires warrants further research.

Longitudinal sequential biventricular assessment in adults with transposition of the great arteries and relationship with adverse outcomes.

BACKGROUND: In a cohort of congenitally corrected transposition of the great arteries (cc-TGA) and transposition of the great arteries after atrial switch procedure (d-TGA) the study objectives were: 1) to assess the change of quantitative systemic right ventricle (sRV) parameters over time and; 2) to examine the relationship of quantitative sRV parameters with adverse clinical outcomes. METHODS AND RESULTS: Single-center cohort study that included 49 (39%) cc-TGA and 76 (61%) d-TGA patients >18years who had at least one MUGA sRV assessment, 18/39 had more than one respectively. The primary clinical endpoint was all-cause mortality, heart transplantation and/or heart failure hospitalization. At a median clinical follow-up of 7years following the first MUGA, the primary endpoint occurred more often in cc-TGA versus d-TGA patients (18 (36.7%) vs. 9 (11.8%), p=0.03). Median time between the MUGA assessments was 5.8 (cc-TGA) and 4.9years (d-TGA). At last MUGA follow-up: 6 (33%) cc-TGA/14 (36%) d-TGA patients showed a significant decline in sRVEF (>5%); 6 (33%) cc-TGA/17 (44%) d-TGA patients had a significant increase in sRVEDVi; and 7 (39%) cc-TGA/19 (49%) PA-TGA patients had a significant increase in sRVESVi. Baseline sRV parameters were not associated with the primary end point or sRV changes over time. CONCLUSIONS: An important proportion of both patient cohorts demonstrated a significant change in sRV parameters over time and these are likely related to multiple factors that vary between individuals given population heterogeneity. The TGA patients have distinct clinical trajectories with increased adverse heart failure outcomes in the cc-TGA population and sRV parameters were not related to adverse heart failure events in either group.

Early and intermediate-term complications of self-expanding stents limit its potential application in children with congenital heart disease.

OBJECTIVES: We report on the early and intermediate-term follow-up results of self-expanding Wallstent (Schneider, Switzerland) implanted in children with congenital heart disease. BACKGROUND: The inherent shortcomings of balloon-expandable stents prompted the trial of an alternative stent. METHODS: Twenty patients underwent 22 implantations of 25 self-expanding Wallstents between December 1993 and June 1997 in two institutions. The mean age and weight were 10.8+/-4.5 years and 30.5+/-14.2 kg, respectively. The patients were divided into two groups: 1) Group I comprised 17 patients with pulmonary arterial stenoses, 2) Group II comprised four patients with venous stenoses (one belonged to both groups). Sixteen patients underwent recatheterization at a median of 5.8 months (range 0.5 to 31, mean 8.1 months) after stenting. Hemodynamic and angiographic changes after the interventional procedures and complications were documented. RESULTS: All the stents were successfully deployed in the intended position. In Group I, the narrowest diameter of the stented vessel increased from 4.1+/-1.5 to 8+/-2 mm (95% increase, p < 0.0001) while the systolic pressure gradient across decreased from 24.6+/-15.8 to 12.1+/-11.4 mm Hg (51% decrease, p = 0.001). In Group II, the dimensional changes of the narrowest segment increased from 4.3+/-0.5 to 7.5+/-0.4 mm (75% increase, p = 0.003), and the pressure gradient reduced from 5.0+/-2.9 to 0.9+/-1.0 mm Hg (82% decrease, p = 0.04) across the stented venous channel. Distal migration of two optimally positioned stents occurred within 24 h of implantation. At recatheterization, significant neointimal ingrowth (>30% of the expanded diameter) was noted in 7 (28%) of the 25 implanted stents. This responded poorly to balloon dilation. Predisposing factors for the neointimal ingrowth included stents of smaller diameter (<9 mm) and longer period after implantation. CONCLUSIONS: Self-expanding Wallstent could be deployed easily and safely to relieve vascular stenoses in children. The complications of distal migration, significant neointimal ingrowth and its unyielding design to overdilation limit its application to this patient group.

Human immunodeficiency virus seroprevalence in an occupational cohort in a South African community.

BACKGROUND: In the early years of the worldwide pandemic, there were no reported cases of acquired immunodeficiency syndrome in Lesotho, a small, mountainous country in South Africa. Since 1986, when the first case of acquired immunodeficiency syndrome was identified, reported diagnoses have risen precipitously. The initiation of the Lesotho Highlands Water Project has resulted in the influx of a migrant workforce of predominantly single males into a relatively isolated, mountainous area where human immunodeficiency virus (HIV) was previously unknown. OBJECTIVE: To ascertain the HIV seroprevalence among a cohort of laborers at the Katse Dam construction site in Bokong, Lesotho. METHODS: During the 5-week study period in late 1992, construction workers (age range, 15 to 59 years) who were first-time clinic users for any chief complaint were randomly selected for serological study. Surveillance complied with the Lesotho National AIDS Control Programme guidelines, which required unlinked, anonymous testing. Serum samples were screened by an enzyme-linked immunosorbent assay; the results were confirmed by the Western blot technique. RESULTS: Unlinked, anonymous HIV testing of 486 persons revealed a seroprevalence of 5.3% (26/486; 95% confidence interval, 3.3% to 7.3%). These data contrasted with a 0.8% seroprevalence in a similar age group in nearby villages that surrounded the construction project. CONCLUSIONS: Lesotho, in the early phase of the HIV/acquired immunodeficiency syndrome epidemic in Africa in the 1980s, was seemingly protected by its relative isolation. Grave concern is now warranted as the country is destined to experience a rapid rise in HIV seroprevalence. Increased surveillance, health education opportunities, and aggressive prevention activities at the Katse Dam construction site are imperative to arrest the spread of HIV from construction workers to nearby villagers.

Technology assessment of nonsurgical closure of patent ductus arteriosus: an evaluation of the clinical effectiveness and costs of a new medical device.

OBJECTIVE: To assess the clinical efficacy and cost impact of a new medical device for the nonsurgical closure of patent ductus arteriosus (PDA). METHODS: This was a before-after study comparing the most recent 20 surgical procedures with the first 20 nonsurgical procedures for PDA using a new medical device. Clinical outcome, hospital stay, device cost, and physician fees were compared. RESULTS: Surgical closure was effective in all 20 patients, with an average cost of $4667. In a similar patient group, nonsurgical closure was achieved in 18 of 20 patients (90%), with an estimated average cost per successful procedure of $4690. A clinically insignificant PDA leak persisted beyond 12 months in four nonsurgically managed patients. CONCLUSION: Nonsurgical closure of PDA can be recommended as an effective new medical technique that is not associated with a measurable increase in direct costs and that provides significant indirect and intangible cost advantages.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot.

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

Echocardiography by telephone--evaluation of pediatric heart disease at a distance.

A 24-hour telephone transmission service was established for pediatric echocardiography between a general hospital and a children's hospital 500 km distant. Studies were transmitted in real time for interpretation and diagnosis by a pediatric cardiologist. In the first 9 months of operation, studies were transmitted for 18 children with a median age of 5 months. Image and sound quality was excellent. Complete segmental diagnosis was made in 16 patients, and further study was needed in 2 others. In 8 of the 18 patients a new diagnosis was provided, and in 10 patients diagnosis was confirmed. Congenital heart disease was found in 12 patients, other heart disease in 2 and a normal heart in 4. The population included 2 fetuses whose echocardiograms showed hypoplastic left heart and intracardiac tumor. In 4 patients transport was avoided. This is the first report of echocardiographic transmission by telephone, which was shown to be clearly feasible, cost-effective and diagnostic. It provides emergency access to specialist expertise, and may avoid hazardous and expensive transport of ill children.

Mitral valve replacement in children.

Mitral valve replacement (MVR) is associated with higher mortality and morbidity rates in children than in adults, and the use of heterograft valves has been encouraged. The results of MVR in 56 consecutive patients, aged 2 to 12 years, presenting between January, 1972, and January 1979, were reviewed to test these beliefs. The etiology of mitral valve disease was rheumatic in 46, congenital in eight, and acute bacterial endocarditis in two. All children were seriously disabled (NYHA Classes III and IV). Cardiac catheterization in 36 patients revealed mixed valve disease in 26, pure mitral regurgitation in seven, and pure mitral stenosis in three. Seventeen Starr-Edwards (SE), five Lillehei (L), Björk-Shiley (BS), eight Hancock (H), and 25 Carpentier-Edwards (CE) mitral prosthesis were inserted. Operative mortality was 2% (1 BS) and late mortality was 10% (three SE, one L, two CE). Serious late complications occurred in 30% of survivors, including 11 instances of calcific valve stenosis (five H, six CE), one case of valve thrombosis (1 L), and two embolic episodes (1 SER, 1 H). Survival curves were similar for patients with heterograft and mechanical valves (92% and 77% at 5 years). Event-free curves showed heterograft valves to have a far higher complication rate than mechanical valves (10% complication free at 4 years compared to 84% free at 5 years). Early operative results in children are excellent, and the overall mortality (10%) compares favorably with figures for MVR in adults. However the long-term durability and choice of prostheses remain problematical, since less than 10% of heterograft valves survive beyond 5 years.

Extracardiac Fontan operation with tube fenestration allowing transcatheter coil occlusion.

A fenestration may improve the immediate postoperative course after a Fontan procedure by preserving the cardiac output. We describe a simple and safe technique of fenestration amenable to coil occlusion, which can be carried out in most cardiac catheterization laboratories.

Immunological abnormalities in children with acute rheumatic carditis and acute post-streptococcal glomerulonephritis.

Immunological functions were investigated in 10 children with acute rheumatic fever and 11 children with acute nephritis to try and elucidate the cause of heart damage in acute rheumatic fever. Children with acute rheumatic fever and carditis showed an increase in serum IgG, IgA and antistreptococcal antibodies during the acute stage. Lymphocyte transformation responses to phytohaemagglutinin and streptococcal antigens were reduced but this was due to a serum suppressor effect. After recovering from acute rheumatic fever a lymphocytosis and an increased lymphocyte blastogenic response to streptococcal antigen were found. T-cells, T-helper cells and T-suppressor cells showed some changes in acute rheumatic fever but these were not statistically significant in our study. None of the changes in immunological responses that were seen in acute rheumatic fever were found in acute nephritis. These results support the hypothesis that an abnormal immune response to streptococcal products is involved in the development of carditis and the other phenomena observed in acute rheumatic fever.

Management of pulmonary atresia or critical pulmonary stenosis and intact ventricular septum with a small or hypoplastic right ventricle.

Twenty-one neonates and infants less than 3 months old undergoing cardiac surgery for an obstructed right ventricular outflow tract, intact ventricular septum and a small or hypoplastic right ventricle were retrospectively analyzed, in order to assess the effects of a change in management protocol. Seven of the 8 patients with critical pulmonary stenosis survived surgery using a transannular outflow patch, whereas only 1 of the 8 patients with pulmonary atresia survived the same operation. Two patients in the latter group died 2 and 3 months after surgery but with complications arising from surgery. Of 5 patients with pulmonary atresia who had a modified Blalock Taussig shunt, 3 patients survived the surgery and were discharged home. These results significantly indicate that there is an unacceptably high mortality for the relief of pulmonary atresia (with intact septum) using a transannular outflow patch, and a Blalock Taussig shunt is the preferred operation. The transannular outflow patch is a safe operation for neonates with critical pulmonary stenosis, irrespective of the size of the right ventricle.

Rupture of tendinous chords during acute rheumatic carditis in young children.

Four children (age range 2 3/4-6 1/2 years) presented with acute mitral regurgitation due to rupture of the tendinous chords. All required urgent replacement of their mitral valve. Subsequent histological examination confirmed acute rheumatic carditis in all. Acute rheumatic carditis is a rare cause of ruptured tendinous chords of the mitral valve especially in young children. The difficulties in diagnosis and management are discussed.

Perinatal supraventricular tachycardia.

OBJECTIVE: To determine the incidence, therapy required and prognosis of perinatal supraventricular tachycardia (SVT). DESIGN: Retrospective chart review of eight years. SETTING: Tertiary level perinatal and pediatric centres in Halifax, Nova Scotia. PATIENTS: All newborn infants who developed SVT either in utero or in the first 30 days of life. RESULTS: SVT was present in 33 neonates, with a male:female ratio of 2.7:1 and an incidence of 1:4347. Fetal SVT was recorded in nine (group I) but these patients did not differ from those with postnatal SVT (group II) in birthweight, noncardiac illnesses and associated heart disease. Thirty-one of the babies (94%) received digoxin and eight (24%) also required propranolol. All were asymptomatic after 48 h. One late death occurred due to renal failure unrelated to the dysrhythmia. No major congenital heart disease was found in either group. Follow-up over 44 months revealed four late relapses requiring prolonged therapy. CONCLUSIONS: Perinatal SVT is a common disorder in a tertiary centre and may represent a transient adaptation phenomenon. It is usually benign, easily treated and rarely associated with major congenital heart disease.

Congenitally corrected transposition of the great arteries and exercise-induced ventricular tachycardia.

Congenitally corrected transposition of the great arteries (CCTGA) is an uncommon condition. Few patients survive past 50 years of age, because of associated congenital defects, systemic (morphological right) ventricular dysfunction, atrioventricular valvular insufficiency or complete heart block. A unique case is presented of exercise-induced ventricular tachycardia, which led to the diagnosis of CCTGA, without atrioventricular block or other cardiac anomalies.

Trends in the prevalence of congenital heart disease: comprehensive observations over a 24-year period in a defined region of Canada.

OBJECTIVE: To determine the prevalence of congenital heart disease (CHD) in the three Maritime provinces, and to study prevalence differences among provinces and defined regions within these provinces. DESIGN: Each province was divided by counties into regions. All cases of CHD who were born alive in the study area between 1966 and 1989 were entered in a registry. Prevalences were analyzed for each province and for selected regions per year, per 1000 live births, and by diagnosis made by one year of age and by the 16th birthday. Comparison was then made with prevalences of a group who had severe lesions. INTERVENTIONS: Excepting a small number of CHD cases who were diagnosed by autopsy only, diagnosis was made by pediatric cardiologists using appropriate procedures, including cardiac ultrasound and cardiac catheterization. SETTING: The only tertiary care centre for children's heart disease in the provinces of Nova Scotia, New Brunswick and Prince Edward Island, areas of relative geographic isolation (combined population of 1.75 million people). MAIN RESULTS: A statistically significant positive linear trend occurred in these provinces during the study. The recorded prevalence of CHD in New Brunswick was significantly lower. Pooled prevalences by the first and 16th birthdays (8.0 and 12.5 per 1000 live births, respectively) of two regions of highest prevalence for 1980-86 were significantly higher (P < 0.05) than the pooled prevalence rate of all the remaining regions. Prevalence rates of a group with severe lesions were stable for 1976-86 in all regions. CONCLUSIONS: Differences in prevalence of CHD among provinces and regions were related to ascertainment levels. Prevalence of CHD with diagnosis by the first and 16th birthdays were approximately 8.0 and 12.5 per 1000 live births, respectively. The prevalence rate of a severe lesion group was a stable measure.

The evolution of ductus arteriosus treatment.

The treatment of patent ductus arteriosus (PDA) has evolved over the years. We reviewed 231 non-premature children (group 1) undergoing surgical closure of a PDA between January 1985 and December 1997, and 30 children (group 2) undergoing transcatheter closure from May 1995 to December 1998. The median age and weight at operation in group 1 were 13 months (range, 0.5-174 months) and 9.5 kg (range, 1.9-49.7 kg), respectively. There was one intra-operative death (0.4%) secondary to hemorrhage. Immediate extubation was performed in 208 patients (90%). Intra-operative chest tube use decreased from 73.3% to 10% between the 1985-88 and 1996-97 periods (P < 0.001). Postoperative pneumothoraces occurred in 33/131 (25%) patients with only one patient (0.7%) requiring drainage. Eleven patients had complications including wound infection in four, vocal cord paralysis in three, and left pulmonary artery stenosis in one. The median length of stay (LOS) was 5 days (range, 2-43 days). Follow-up echocardiogram was performed in 146/230 patients (63%) and revealed a residual PDA in six (4%); two being re-ligated, two remaining clinically insignificant, and two spontaneously resolved at 7 and 28 months follow-up. The remaining 84 patients had no clinical signs of a residual PDA. In group 2, where a transcatheter coil occlusion technique was used, the median age and weight at procedure were 31 months (range, 9-320 months) and 14.9 kg (range, 9-69.7 kg), respectively. Vascular complications occurred in four patients (13.3%). One patient developed hemolysis and hemoglobinuria requiring hospital admission. Four patients required a second intervention. At the most recent echocardiographic assessment, four patients (13.3%) had a residual PDA.

Reye's syndrome.

The occurrence of Reye's syndrome in 3 children in Bulawayo is reported, and a short review of the diagnostic features and pathogenesis is offered.