Invasive measurements of atrioventricular conduction parameters prior to and following ventricular septal defect closure with the amplatzer device.

BACKGROUND: Because of anatomical proximity, closure of paramembranous ventricular septal defect (pm-VSD) with an Amplatzer occluder has the potential to affect the atrioventricular (AV) conduction system. PATIENTS AND METHODS: Electrophysiology studies (EPS) were performed prior to and following closure of the pm-VSD in 19 children aged 8.9 +/- 4.5 years. Data from electrocardiograms, Holter monitoring and exercise tests before intervention and at follow up (1.9 +/- 0.8 years) were reviewed. RESULTS: There were no EPS catheter-induced complications. Incidence of total conduction anomalies was 31.6% with 21% of patients having permanent conduction anomalies. Complete AV block was not recorded in any subject and transitory 1st-degree AV block occurred in 2 patients. Permanent complete right bundle branch block was observed in 2 patients and incomplete right bundle branch block in 2 others. Prolongation in EPS parameters was significant for His ventricle interval (p = 0.017). Otherwise, EPS parameters with increased measurements > 15% were observed in 18 patients (95%). Prolongation of retrograde Wenckebach cycle length was predictive of new onset conduction abnormalities (p = 0.003). Other parameters changes did not correlate with the observed conduction disturbances however. With respect to device implantation characteristics, a large Amplatzer device was the only predictive risk factor for new conduction abnormalities (p = 0.03). CONCLUSION: Closure of pm-VSD with an Amplatzer device promotes relative changes of the AV conduction system, mainly with large devices. In our limited series, these changes have no apparent clinical impact in the immediate and intermediate terms.

Differential pulmonary perfusion scan after percutaneous occlusion of the patent ductus arteriosus: one-decade consecutive longitudinal study from a single institution.

Reduced left lung perfusion has been described following percutaneous occlusion of the patent ductus arteriosus (PDA). We aimed to identify the incidence of lung perfusion abnormalities and the associated risk factors in our consecutive series. Between November 1994 and December 2003, 150 procedures were performed on 145 patients, age 4.6 +/- 4 years. Gianturco coil was used in 88.2%, Amplatzer duct occluder in 6.7%, and Rashkind Umbrella in 5.5%. Lung perfusion scan was scheduled within 48 h (LPS-1), at 6-12 months (LPS-2) and later (LPS-3) in the case of persistent abnormalities. Left lung perfusion <40% was considered abnormal. LPS-1 was obtained in 95.8% and was abnormal in 31%. LPS-2, available in 48.2%, returned to normal in 65.7% (p < 0.001). LPS-3, required in 6.2%, was normal in 55.6% (p = 0.07). Identifiable risk factors were low age and height (p < 0.01), higher Q(p)/Q(s) ratio (p < 0.05), and larger PDA size indexed for height (p < 0.001) or body surface area (p < 0.01). The number of coils or loops deployed in the pulmonary end of the PDA did not influence lung perfusion. In conclusion, we describe a high incidence of left lung perfusion reduction following percutaneous PDA occlusion, more likely in the young with large PDA. However, spontaneous recovery usually occurs within a few months.