[Metalloproteinase Tolloid-like 1 gene mutation in Chinese patients with sporadic congenital heart diseases].

OBJECTIVE: To explore whether there are gene mutations of Tolloid-like 1 (TLL-1) gene in Chinese patients with sporadic congenital heart disease (CHD). METHODS: One hundred and fifteen patients with sporadic CHD were selected as CHD group. One hundred and two age and gender-matched healthy people were recruited as control group. After amplifying the exon 10 of the TLL-1 gene by polymerase chain reaction, the polymerase chain reaction products were purified, sequenced and analyzed in order to investigate the TLL-1 gene mutation. RESULTS: An insertion mutation of base A in the exon 10 of TLL-1 gene was identified in 7 out of 115 CHD patients, including 3 patients with atrial septal defect, 2 patients with ventricular septal defect, 1 patients with patent ductus arteriosus and 1 patients with complex CHD, the total mutation rate was 6.1% in CHD group and 0 in control group (P < 0.01). CONCLUSIONS: TLL-1 gene mutation with an insertion mutation of base A in exon 10 is often in Chinese patients with various CHD. The underlying pathogenesis between TLL-1 gene mutation and occurrence of congenital heart disease in Chinese people remains unclear and warrants further investigations.

Real-time three-dimensional echocardiographic determination of right ventricular outflow tract high septal pacing sites.

OBJECTIVE: To investigate the feasibility of determination of right ventricular outflow tract (RVOT) high septal pacing site visualized by real-time three-dimensional echocardiography (RT3DE). METHODS: The forty subjects with RVOT pacing were analysed. RT3DE determination of RVOT high septal pacing sites was compared with chest X-ray (CXR). RESULTS: RVOT septal pacing sites could be obtained in all patients by RT3DE.When pacing sites were categorized as septal or non-septal, there were good agreements between echocardiography and CXR (kappa = 0.745). However, when RVOT pacing sites were categorized as high septal or non-high septal in identifying the exact anatomic location of pacing sites, there was only mild agreement between echocardiography and CXR (kappa = 0.275). Moreover, when RT3DE was used as the gold standard in identifying the exact anatomic location of RVOT, pacing at the RVOT high septal could only be achieved in 37.5% (n= 15) of patients using RT3DE, but in 65% (n= 26) using CXR, because the RVOT septal pacing lead tip found at high septal by CXR is actually found at low septal or free wall by RT3DE. CONCLUSION: It is limited to accurately locate RVOT high septal pacing site only by CXR, RT3DE allows to determinate the RVOT high septal pacing sites helpfully.

Right-sided free wall accessory pathway refractory to conventional catheter ablation: lessons from 3-dimensional electroanatomic mapping.

INTRODUCTION: the aim of this study was to delineate the electroanatomic substrates of right-sided free wall (RFW) accessory pathways (APs) that were refractory to conventional catheter ablation utilizing 3-dimensional (3-D) mapping. METHODS AND RESULTS: eleven patients with RFW APs that failed initial conventional catheter ablation(s) by a mean of 1.9 ± 0.5 attempts were enrolled in the study. Electroanatomic mapping of the right atrium was performed during orthodromic reciprocating tachycardia in 3 patients and right ventricular pacing in 8 patients. The earliest atrial activation site, which represented the atrial insertion of the AP, was separated from the tricuspid annulus by an average of 14.3 ± 3.9 mm, and the local activation time was 27.8 ± 17.0 ms earlier than that of the corresponding annular point. One patient exhibited an AP with wide branching on the atrial side. RF ablation with an irrigated catheter successfully interrupted AP conduction in all patients without complications. CONCLUSIONS: RFW APs resistant to conventional catheter ablation might be due to unique anatomic AP features such as more epicardial course at the annulus level with atrial insertion distant from the tricuspid annulus. Electroanatomic mapping is helpful to accurately localize the atrial insertion sites of these APs and facilitates catheter ablation.