Despite successful surgical repair of aortic coarctation, life expectancy is reduced, and up to one-third of patients remain or become hypertensive. So as to characterize the responses for blood pressure, we have studied 55 patients with surgically repaired coarctation. Their mean age was 11.3 ± 5.97 years. We documented maximal uptake of oxygen, anaerobic threshold, plasma renin activity and blood pressures during a Bruce protocol treadmill test. The velocity across the site of repair as imaged by crosssectional echocardiography was measured before and after exercise. We measured the changes in heart rate and blood pressure subsequent to an infusion of 1 ug per kg of isoprenalin, monitoring blood pressure over 24 hours in all patients.

When compared with 40 healthy age-matched controls, the patients with coarctation had a normal exercise capacity. Resting systolic blood pressures above the 95th percentile were present in 45% of the patients. Exercise-induced hypertension, and an elevation in the average systolic 24 hour blood pressures, were observed, but less frequently than elevated baseline values, suggesting that socalled white-coat” hypertension may be present in this population. Abnormal reactions and elevation of plasma renin activity were related to a history of paradoxical hypertension at the time of surgery. Attenuation of the circadian rhythm for blood pressure was a frequent finding, and may have implications in the development of long-term damage to end-organs. A high correlation was found between mean systolic blood pressure measured by 24 hour monitoring and left ventricular hypertrophy (r=0.65, p<0.05).

Abnormalities in blood pressure occurred independently of significant mechanical obstruction. Despite successful surgical repair, abnormalities in the shape of the aortic arch, reduced sensitivity of baroreceptor reflexes, and neurohumoral factors may all contribute to the development of hypertension.

The long-term haemodynamic effects of a restrictive ventricular septal defect permitting moderate left-to-right shunting are not known.

Echocardiographic measure ments of left heart dimensions and function were compared between a group of 9 older children and adults (median age 21 years, range 12–24.5 years) having restrictive ventricular septal defects (median Qp/Qs 1.7, range 1.4–2.1) and a group of 10 age matched controls.

Left ventricular mass indexed to body surface area was significantly greater in subjects than in controls (102±29 vs. 75±13 g/m2, p=0.02), although there was no significant difference in the ratio of mass to volume. There were no significant differ ences between indexes of left ventricular systolic function. Ratios of peak early to late diastolic ventricular filling were lower in those with septal defects (1.5±0.3 vs. 1.8±0.3, p=0.013), but there were no differences in other indexes of diastolic function.

Resting left ventricular function does not appear to have deteriorated by early adult life in patients with restrictive ventricular septal defects and moderate volume loading. This would support a continued conservative approach to management in these patients.

This prospective study was designed to monitor severe pulmonary hypertension during extra corporeal membrane oxygenation using echo Doppler variables.

All neonates treated with extracorporeal membrane oxygenation also have severe pulmonary hypertension. A study which monitors the reaction of the pre-existing pulmonary hypertension during extracorporeal oxygenation by frequent sampling of those variables related to pulmonary pressure is still lacking. Such a study is necessary to analyze the complex haemodynamic changes in patients undergoing extracorporeal membrane oxygenation.

In 29 neonates, we estimated pulmonary arterial pressure using peakflow velocity of regurgitation across the tricuspid- and pulmonary valve, peakflow velocity of shunting across persistent arterial ductus, and systolic time intervals of the right ventricle. Correlation between the several estimations of pulmonary arterial pressure were analysed with the Spearman correlation coefficient.

Systolic pulmonary arterial pressure measured by the velocity of tricuspid regurgitation illustrated severe pulmonary hypertension prior to extra corporeal membrane oxygenation (mean 63 mmHg, sd 20). Similar levels for the systolic pulmonary arterial pressure could be derived (mean 73 mmHg, sd 17) from ductal shunting. A fair correlation of 0.76 (p< 0.002) could be demonstrated. Pulmonary hypertension responded well and quickly to treatment by extra corporeal membrane oxygenation, with reductions within 24 hours to mean systolic levels of 35 mmHg, sd 23. This very early reaction has not previously been demonstrated and could be of importance in defining parameters for weaning from cardiopulmonary bypass. Diastolic pulmonary arterial pressure was investigated because of its relation to vascular resistance. It proved more difficult to measure because of the low incidence of pulmonary regurgitation. Derived diastolic pressures did not show any good correlations.

Pulmonary hypertension is well documentated prior to extra corporeal membrane oxygenation and respons very quickly to the institution of treatment. Ultra sound techniques are indicated at the bedsite, and prove useful in monitoring pulmonary blood pressure during the procedure.

The purpose of this study was to evaluate the short and intermediate term results of infants who have undergone balloon aortic valvotomy from the carotid arterial approach, and to identify risk factors in those infants who had a poor outcome.

Between 1988 and 1999, balloon aortic valvotomy was attempted at four centres in 95 infants with severe aortic stenosis. Echocardiographic and hemodynamic data, and outcome, were analysed retrospectively.

Valvotomy was accomplished in 92 of the 95 infants, with a median age of 5 days, a range from 0 to 191 days, and weighing 3.4 kg, with a range from 1.0 to 6.5 kg. Major procedural complications occurred in 10 infants. Post-procedural aortic regurgitation was severe in 5 patients. There were 13 early deaths, and 4 late deaths. The period of mean follow-up has been 2.1 years, with a range from 0 to 9.3 years. The actuarial survival at 3 years was 76 ± 6%. Further interventions were needed in 19 patients, giving a 3-year freedom from reintervention of 67 ± 6%. The 51 infants who were duct-dependent were further analyzed, and found to have a higher mortality (38%) compared to those infants not dependent on the arterial duct (5%). Risk factors for a poor outcome in the duct-dependent infants were mitral stenosis (p<0.005), a left ventricle which did not form the cardiac apex (p<0.005), and an aortic valve with a diameter of less than 6 mm (p<0.05).

This multi-centric registry shows good results in the intermediate term for treating infants with severe aortic valvar stenosis with balloon valvotomy through a carotid arterial cutdown. Infants dependent on prostaglandin had a worse outcome, especially if they had any of the identified risk factors.

To determine factors associated with outcomes after listing for transplantation in children with cardiomyopathies.

Childhood cardiomyopathies form a heterogeneous group of diseases, and in many, the prognosis is poor, irrespective of the etiology. When profound heart failure develops, cardiac transplantation can be the only viable option for survival.

We included all children with cardiomyopathy listed for transplantation between 12/89 and 4/98 in this historical cohort study.

We listed 31 patients, 15 male and 16 female, 27 with dilated and 4 with restrictive cardiomyopathy, for transplantation. The median age at listing was 5.7 years, with a range from fetal life to 17.8 years. Transplantation was achieved in 23 (74%), with a median interval from listing of 54 days, and a range from zero to 11.4 years. Of the patients, 14 were transplanted within 30 days of listing. Five patients (16%) died before transplantation. Within the Canadian algorithm, one of these was in the third state, and four in the fourth state. One patient was removed from the list after 12 days, having recovered from myocarditis, and two remain waiting transplantation after intervals of 121 and 476 days, respectively. Patients who died were more likely to be female (5/5 vs. 11/26; p=0.04) and to have been in the third or fourth states at listing (5/5 vs. 15/26; p=0.04). The use of mechanical ventricular assistance, in 10 patients, was not a predictor of an adverse outcome. While not statistically significant, survival to transplantation was associated with treatment using inhibitors of angiotensin converting enzyme, less mitral regurgitation, a higher mean ejection fraction and cardiac index, and lower right ventricular systolic pressure.

Children with cardiomyopathy awaiting transplantation have a mortality of 16% related to their clinical state at the time of listing.

The advent of 3D echocardiography has provided a technique which, potentially, could afford significant additional information over conventional cross-sectional echocardiography in the assessment of patients with straddling atrioventricular valves prior to surgical correction.

Eight patients, aged from 1 month to 9˙2 years, were examined with 3D echocardiography. All but three had discordant ventriculoarterial connections or double outlet right ventricle. Data suitable for reconstruction was acquired with transthoracic scanning. Right and left ventricular volumes were calculated in the 3D dataset.

3D echocardiography proved capable of defining the exact degree of straddling by imaging theproportion of tension apparatus attached to either side of the ventricular septum. It was able also to display the atrioventricular junction “en face”, thus permitting identification of the precise site of insertion of the muscular ventricular septum relative to the atrioventricular junction. This made it possiblefirst, to calculate the degree of valvar override, and second, to predict the location of the penetrating atrioventricular bundle. End-diastolic volume of the right ventricle in those with straddling tricuspid valves was 73 (61–83)% of normal, and, of the left ventricle in those with mitral valvar straddling 71 (40‐97)% of normal.

3D echocardiography can aid in planning the optimal surgical procedure in patients with straddling or overrriding atrioventricular valves, as it provides diagnostic information superiorto standard crosssectional techniques. It also allows for exact measurement of the volumes of the respective ventricles.

We aimed to investigate whether changes in high-energy phosphate metabolism after treatment of children and young adults with anthracycline can be demonstrated non-invasively by 31P magnetic resonance spectroscopy.

Abnormal myocardial energy metabolism has been suggested as a mechanism for anthracycline-induced cardiotoxicity. Deterioration in such has been shown in animal studies by resonance spectroscopy.

We studied 62 patients, with a mean age of 13.5 ±5 years,3.7±4.3 years after a cumulative anthracycline dose of 270±137 mg/m2. Normal echocardiographic findings had been elicited in 54 patients. The control group consisted of 28 healthy subjects aged 20±7 years. Resonance spectrums of the anterior left ventricular myocardium were obtained at 1.5 Tesla using an image-selected in vivo spectroscopy localization technique.

The ratio of phosphocreatine to adenosine triphosphate after blood correction was 1.09±0.43 for the patients, and 1.36±0.36 (mean±SD)for controls (p = 0.005), with a significantly reducedmean ratio even in the subgroup of patients with normal echocardiographic results ( l.11 ± 0. 44 versus1.36±0.36, p=0.01). The ratio did not correlate with the cumulative dose of anthracycline. The ratio of phosphodiester to adenosine triphosphate was similar in patients and controls (0.90±0.56 versus 0.88±0.62).

In patients treated with anthracyclines in childhood, myocardial high-energy phosphate metabolism may be impaired even in the absence of cardiomyopathy. Our data support the concept that anthracycline-induced cardiotoxicity is not clearly dose dependent.