The CRT yielded improvement in systemic RV function in patients with spontaneous or LV pacing-induced electromechanical dyssynchrony and seems to be a promising adjunct to the treatment and prevention of systemic RV failure.

Objective: To evaluate long term results and independent predictors of outcome of aortic valvoplasty. Design: Retrospective follow up study. Independent predictors of outcome identified by multiple logistic regression. Setting: Tertiary referral centre. Patients: 269 consecutive patients treated at the median age of 8 months (0-23 years): 80 (30%) under 4 weeks, 59 (22%) between 4 weeks and 1 year, and 130 (48%) over 1 year. The follow up period was up to 14.8 years (median 5.3, in survivors 6.4 years). Interventions: Percutaneous balloon valvoplasty with mean (SD) balloon to annulus ratio 0.97 (0.08). Main outcome measures: Restenosis > 70 mm Hg, grade 3 aortic insufficiency, cusps disruption, surgery, death, and valvoplasty failure (significant restenosis or insufficiency or surgery or death). Results: The mortality rate was 10.4% (n = 28), the restenosis rate was 16.7% (n = 45), significant insufficiency developed in 22.3% (n = 60), surgery was needed in 20.1% (n = 54), and ''valvoplasty failure'' occurred in 41.6% (n = 112) patients. Mean (SEM) survival probability 14.4 years after the procedure was 0.89 (0.02) and mean (SEM) probability of surgery-free survival was 0.50 (0.08). The independent predictors were as follows. For restenosis: small aortic annulus; for cusp disruption: large aortic annulus; for insufficiency: bicuspid aortic valve; for need for surgery: bicuspid aortic valve; for death: small aortic annulus, low left ventricular shortening fraction, and low sequential number of the valvoplasty; and for valvoplasty failure: small aortic annulus, bicuspid aortic valve, and high grade of mitral insufficiency. Conclusion: Independent predictors of unfavourable outcome are small aortic annulus, bicuspid aortic valve, poor function of left ventricle or mitral valve, and limited operator experience. P ercutaneous balloon valvoplasty was first described in 1983.1 The effectiveness of the method in gradient reduction and the low incidence of restenosis shortly after the procedure were documented in children with congenital aortic stenosis. 2In 1986, the first balloon valvoplasty was performed in a newborn with critical aortic stenosis.3 Good short term results were obtained in a large cohort of children in a multicentre study. 4 Mid-term results, however, showed a substantial incidence of restenosis, severe aortic insufficiency, and reinterventions.5 6 Long term results have so far been published only for children treated after 1 year of age with a 20% restenosis rate and a 21% incidence of significant aortic insufficiency 2-12 years after the procedure.

The etiology of dilated cardiomyopathy associated with congenital complete AV block has not yet been clarified. Two infants with AV block of autoimmune and surgical etiology, respectively, had received a dual-chamber right ventricular-based pacemaker and developed dilated cardiomyopathy with severe septal to left ventricular free-wall dyssynchrony 3.4 (0.9) years later. After 4 weeks of biventricular pacing and spontaneous junctional narrow QRS rhythm, respectively, both children showed significant improvement in left ventricular function along with reverse remodeling. Thus, electromechanical dyssynchrony associated with conventional right-ventricular-based DDD pacing may play a significant role in the development of dilated cardiomyopathy in the young.

Our experience confirmed better results after the primary repair of interrupted aortic arch, which was associated with lower mortality, prevalence of severe complications and need for re-intervention. Higher prevalence of subaortic stenosis after primary repair could be explained by patient selection early in our experience. We recommend the primary repair of interrupted aortic arch and associated heart lesions in neonates, however, in unfavourable conditions an individualised surgical approach with initial palliative surgery should be considered.

AimsTo identify risk factors for left ventricular (LV) dysfunction in right ventricular (RV) pacing in the young.Methods and resultsLeft ventricular function was evaluated in 82 paediatric patients with either non-surgical (n = 41) or surgical (n= 41) complete atrioventricular block who have been 100% RV paced for a mean period of 7.4 years. Left ventricular shortening fraction (SF) decreased from a median (range) of 39 (24–62)% prior to implantation to 32 (8–49)% at last follow-up (P < 0.05). Prevalence of a combination of LV dilatation (LV end-diastolic diameter >+2z-values) and dysfunction (SF < 0.26) was found to increase from 1.3% prior to pacemaker implantation to 13.4% (11/82 patients) at last follow-up (P = 0.01). Ten of these 11 patients had progressive LV remodelling and 8 of 11 were symptomatic. The only significant risk factor for the development of LV dilatation and dysfunction was the presence of epicardial RV free wall pacing (OR = 14.3, P < 0.001). Other pre-implantation demographic, diagnostic, and haemodynamic factors including block aetiology, pacing variables, and pacing duration did not show independent significance.ConclusionRight ventricular pacing leads to pathologic LV remodelling in a significant proportion of paediatric patients. The major independent risk factor is the presence of epicardial RV free wall pacing, which should be avoided whenever possible.