Publications (7)22.27 Total impact
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Article: Molecular characterisation of Tyr530Ser and IVS16-1G>T mutations causing severe factor V deficiency.
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ABSTRACT: Our previous study reported a missense mutation (Tyr530Ser) and a splicing site mutation (IVS16-1G>T) in blood coagulation factor V (FV) gene in a two-year-old Chinese boy. However, the linkage between the mutations and severe FV deficiency and the underlying mechanism has not been elucidated. The present study was designed to investigate the effect of the two mutations and the possible pathogenetic mechanism. FV procoagulant activity showed tremendous decrease in the patient with two mutations. The bioinformatics analyses predicted that IVS16-1G>T mutation may cause the entire exon 17 of FV to be skipped in transcription and thereby result in a deletion mutant. To confirm the predicted results, the fragment of exon 16 to exon 18 containing IVS16-1G>T mutation was obtained by PCR and site-directed mutagenesis. IVS16-1G>T mutant and wild-type constructs were transfected into COS-7 cells. Sequence analysis showed that mutant transcript lacked the entire 180-bp length of exon 17. Moreover, compared to wild-type, the expression of the two mutant proteins was decreased and the procoagulant activity was also reduced when the deletion mutant cDNA and Tyr530Ser site mutant cDNA were transfected into COS-7 cells, respectively. Our results indicate that Tyr530Ser and IVS16-1G>T could be separately responsible for severe FV deficiency, while the phenotype in the proband could be caused by the combination effect of the two defects.Thrombosis and Haemostasis 09/2010; 104(3):536-43. · 5.04 Impact Factor -
Article: Left atrial appendage studied by computed tomography to help planning for appendage closure device placement.
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ABSTRACT: To quantitatively study various morphologic parameters of the left atrial appendage (LAA) by computed tomography (CT) to aid the preoperative planning and implantation of left atrial appendage closure devices. In 612 cases of patients with or without atrial fibrillation (AF), a cardiac CT study was performed. The classification of general LAA morphology included ChickenWing type (18.3%), WindSock (46.7%), Cauliflower type (29.1%), and Cactus type (5.9%). Anatomical relationship of the LAA to the left superior pulmonary vein (LSPV) were classified as high type (superior to LSPV, 30.2%), mid type (parallel to LSPV, 58.1%), and low type (inferior to LSPV, 11.7%). LAA ostium could be classified into 5 types including oval (68.9%), foot-like (10%), triangular (7.7%), water drop-like (7.7%), and round (5.7%). Two-dimensional (2D) orthogonal method was obviously not accurate for determining the LAA orifice because the measurement was often unparallel to the LAA orifice. Two-dimensional oblique method was better than 3-dimensional method in reproducibility to determine the size of LAA ostium. The diameter calculated from the perimeter of the LAA ostium was superior to the diameter from direct measurement of the LAA ostium for selecting the occluder. The morphology of the LAA and the LA ostium are extremely complex and heterogeneous. Sixty-four-channel cardiac CT could assist preoperative planning of LAA closure device placement. The diameter of the LAA ostium calculated from the perimeter is the best parameter for sizing the LAA occluder.Journal of Cardiovascular Electrophysiology 09/2010; 21(9):973-82. · 3.06 Impact Factor -
Article: The impact of statins and renin-angiotensin-aldosterone system blockers on pulmonary vein antrum isolation outcomes in post-menopausal females.
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ABSTRACT: To assess whether treatment with statins or renin-angiotensin-aldosterone system (RAAS) inhibitors as potential procedural 'augmenting agents' improved atrial fibrillation (AF) catheter ablation recurrence rates in post-menopausal females (PMFS). Five hundred and eighteen consecutive female patients had undergone AF catheter ablation from January 2005 to May 2008. Post-menopausal females were selected and procedure outcomes were compared between cohorts of PMFS treated with statins or RAAS inhibitors to untreated PMFS. Out of 408 PMFS, 36 (8.8%) were treated with a combination of RAAS inhibitors and statins, thus were excluded leaving a total of 372 (91.2%) patients in the study. Out of 372 patients, 111 (29.8%) were on statins (Group 1), 59 (15.9%) on RAAS inhibitors (Group 2), and 202 (54.3%) without RAAS inhibitors or statins [(Group 3) control population]. Over a mean follow-up time of 24 +/- 8.3 (median 25) months, 78 (70.6%) in Group 1, 38 (65.4%) in Group 2, and 139 (68.8%) in Group 3 had procedural success. Statin or RAAS inhibitor use did not predict lower recurrence rates [hazard ratio (HR): 1.26, P = 0.282 and HR: 1.14, P = 0.728, respectively]. When compared with controls, no difference in the cumulative incidence of recurrence was found with statin or RAAS inhibitors use (P = 0.385 and P = 0.761, respectively). Treatment with statins or RAAS inhibitors did not improve catheter ablation success rates among PMFS. Thereby, from a clinical standpoint, PMFS should not be started on these treatments as a procedural 'augmenting agent' at this time.Europace 03/2010; 12(3):322-30. · 1.98 Impact Factor -
Article: Follow-up imaging of a left atrial appendage closure device.
Heart rhythm: the official journal of the Heart Rhythm Society 12/2009; 6(12):1837-8. · 4.56 Impact Factor -
Article: Outcomes and complications of catheter ablation for atrial fibrillation in females.
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ABSTRACT: Most atrial fibrillation (AF) ablation studies have consisted predominantly of males; accordingly, there is a paucity of information on the safety and efficacy of catheter ablation in a large cohort of female AF patients. The purpose of this study was to evaluate catheter ablation for AF in female patients. From January 2005 to May 2008, 3265 females underwent pulmonary vein antrum isolation. Success rates, patient profiles, and complications were collected. Approximately 16% of our population was female (P <.001). Females were older (59 +/- 13 vs. 56 +/- 19 years; P <.01) and had a lower prevalence of paroxysmal atrial fibrillation (PAF; 46% vs. 55%; P <.001). Females failed more antiarrhythmics (4 +/- 1 vs. 2 +/- 3; P = .04) and were referred later for catheter ablation (6.51 +/- 7 vs. 4.85 +/- 6.5 years; P = .02) than males. More females failed ablation (31.5% vs. 22.5%; P = .001) and had nonantral sites of firing than males (P <.001). Female patients had 11 (2.1%) hematomas versus 27 (0.9%) in males. Five times as many males underwent catheter ablation than females. Females failed more ablations possibly because of a higher prevalence of nonantral firing, non-PAF, and longer history of AF. Females had more bleeding complications than males.Heart rhythm: the official journal of the Heart Rhythm Society 10/2009; 7(2):167-72. · 4.56 Impact Factor -
Article: Catheter ablation for atrial fibrillation: a promising therapy for congestive heart failure.
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ABSTRACT: Atrial fibrillation (AF) and congestive heart failure (CHF) are cardiovascular epidemics. Catheter ablation of AF is increasingly performed in patients with CHF. Atrioventricular junction ablation (AVJA) and pulmonary vein isolation are the two predominant ablation strategies used to treat AF patients who are refractory to drugs. In patients with CHF refractory to drugs, AVJA with a biventricular device is associated with improvement in exercise capacity and quality of life. However, in a head-to-head comparison, pulmonary vein antrum ablation was shown to be superior to AVJA. Cure of AF in patients with CHF resulted in more significant morphological and functional improvements than AVJA.Expert Review of Cardiovascular Therapy 08/2009; 7(7):779-87. -
Article: Ablation of atrial fibrillation utilizing robotic catheter navigation in comparison to manual navigation and ablation: single-center experience.
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ABSTRACT: Robotic catheter navigation and ablation either with magnetic catheter driving or with electromechanical guidance have emerged in the recent years for the treatment of atrial fibrillation. The aim of this study was to compare our center's experience of atrial fibrillation ablation using the Hansen Robotic Medical System with our current manual ablation technique in terms of acute and chronic success, as well as procedure time and radiation exposure to both the patient and the operator. A total of 390 consecutive patients with symptomatic and drug-resistant atrial fibrillation (289 males, 62 +/- 11 years) were prospectively enrolled in the study. All patients underwent the procedure either with conventional manual ablation (group 1, n = 197) or with the robotic navigation system (RNS) (group 2, n = 193). The success rate for RNS was 85% (164 patients), while for manual ablation it was 81% (159 patients) (p = 0.264) at 14.1 +/- 1.3 months with AADs previously ineffective. Fluoroscopy time was significantly lower for RNS (48.9 +/- 24.6 minutes for RNS vs. 58.4 +/- 20.1 minutes for manual ablation, P < 0.001). Mean fluoroscopy time was statistically reduced after 50 procedures (61.8 +/- 23.2 minutes for first 50 cases vs. 44.5 +/- 23.6 minutes for subsequent procedures, P < 0.0001). Robotic navigation and ablation of atrial fibrillation is safe and effective. Fluoroscopy time decreases with experience.Journal of Cardiovascular Electrophysiology 07/2009; 20(12):1328-35. · 3.06 Impact Factor
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2009–2010
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St. David's North Austin Medical Center
Austin, TX, USA
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