Achievement of pulmonary vein isolation in patients undergoing circumferential pulmonary vein ablation: a randomized comparison between two different isolation approaches

Introduction: Circumferential pulmonary vein ablation (CPVA) with the endpoint of pulmonary vein (PV) isolation has been developed as an effective therapy for atrial fibrillation (AF). This endpoint can be achieved either by closing gaps along circular lines or by segmental PV isolation inside the circular lines after creation of initial CPVA lesions. We investigated whether the clinical outcome depends on the PV isolation approach used during the first-time CPVA procedure.
Methods and Results: One hundred consecutive patients (69 male; age, 56.7 ± 11.6 years) who underwent first-time CPVA for treatment of symptomatic AF were enrolled. PV isolation was randomly achieved either by CPVA alone (aggressive CPVA [A-CPVA] group, n = 50) or by a combination of CPVA with segmental PV ostia ablation (modified CPVA [M-CPVA] group, n = 50). Recurrence of atrial tachyarrhythmias (ATa) within 3 months after the initial procedure occurred in 30 patients (60%) in the M-CPVA group and in only 15 patients (30%) in the A-CPVA group (P < 0.01). ATa relapse after the first 3 months was detected in 21 patients (42%) in the M-CPVA group, compared with 9 patients (18%) in the A-CPVA group (P = 0.01). At 13 ± 4 months, patients treated by the A-CPVA approach had greater freedom from ATa recurrence than patients who underwent M-CPVA (P = 0.01). The M-CPVA approach was the only independent predictor associated with procedural failure (RR 0.318; 95% CI 0.123–0.821; P = 0.02).
Conclusions: When PV isolation is the endpoint of CPVA, the efficacy of the A-CPVA approach is better than that of M-CPVA.     

The effect of introduction of universal childhood hepatitis B immunization in South Africa on the prevalence of serologically negative hepatitis B virus infection and the selection of immune escape variants.

The effect of universal hepatitis B vaccination on the prevalence of serologically negative hepatitis B virus infection (HBV) and the emergence of HBsAg variants is unknown. We prospectively studied two different cohorts of 12--24 month old children in South Africa. They consisted of the unvaccinated children (n=459) born before the introduction of universal vaccination and the vaccinated children (n=1213) between 1 and 2 years after the introduction of the vaccination program. The frequency of detecting HBV DNA by PCR was reduced from 6.5% in unvaccinated children to 0.3% in vaccinated children (P<0.00001). There were no unique amino acid substitutions within the major hydrophilic region of the S sequence in both pre- and post-vaccination samples. Universal childhood vaccination reduced the frequency of serologically negative HBV infection and did not necessarily lead to selection of escape variants.     

Surgery for cardiac valves and aortic root without cardioplegic arrest ("beating heart"): experience with a new method of myocardial perfusion

Simultaneous antegrade/retrograde warm blood perfusion with a beating heart has not been previously reported as a mean of protecting hypertrophied hearts in cardiac valve and aortic root surgeries. Similarly, beating heart mitral valve surgery via the trans-septal approach with the aorta unclamped, is a novel technique. We, herein, report a series of 346 patients with a variety of cardiac pathologies who were operated upon utilizing a new modality of myocardial perfusion. Among this group of patients, there were 55 patients who were diagnosed with endocarditis of one or more valves. These patients were excluded from this series of patients. Mean age was 59 +/- 12, and there were 196 (67.3%) males and 95 (32.7%) females. There were six aortic root procedures, 90 mitral valve replacements (MVR), 46 mitral valve repairs, 20 MVR+ coronary artery bypass grafting (CABG), 28 tricuspid valve repairs, 106 aortic valve replacements (AVR), 17 AVR+CABG, and 8 AVR/MVR. Crude mortality for the group was 20 of 291 (6.8%). Intra-aortic balloon pump utilization at time of weaning from cardiopulmonary bypass was 6/291 (2.06%), and re-operation for bleeding was needed in 12 of 291 (4.1%) patients. Postoperative stroke occurred in 4 of 291 (1.3%) patients. In these patients, the clinical diagnosis of stroke was made prior to surgery. This initial experience with this new method of myocardial perfusion indicates that results are at least comparable, if not superior, to conventional techniques utilizing intermittent cold blood cardioplegia.     

003 胺碘酮可作为心房纤颤转复为窦性心律的首选药物

在美国,胺碘酮仅被批准用于治疗致命性室性心律失常,而在其他国家,尤其是南欧,也被广泛用于心房纤颤(Af)的治疗。然而有关胺碘酮复律效果报道不一,其成功率在16％～92％。本文前瞻性随机对照研究胺碘酮作为Af复律的首选药物的疗效及安全性。 连续208例症状性Af,男性102例,女性106例,年龄27～78(65±10)岁。将受试者随机分为胺碘酮治疗组与安慰剂组。胺碘酮用法：300mg静脉注射,持续1小时,然后以20mg/kg静脉滴注,持续24小时,继之口服200mg,tid,共1周,400mg/d共3周。如果受试者此前未用地高辛,则给予地高辛0.5mg静脉注射,2小时后再静脉注射0.25mg,继之静脉注射0.25mg,q6h,共24小时,此后调整地高辛剂量以维持治疗剂量的血清浓度,对Af持续48小时以上或持续时间不明、未用抗凝药物者均应用醋硝香豆素(acenocoumaro1),至少21天,复律成功者继续用药21天,未成功者用药时间不定。本研究将Af持续1个月以上者定义为慢性Af,＜24小时者定义为新近发作Af,其余定义为持续性Af。     

(vii) Management of periprosthetic fractures in the lower limb

The incidence of periprosthetic fractures is rising significantly as more replacement arthroplasties are performed. They are a potentially devastating complication associated with high morbidity and mortality. Their management is a sub-specialty in itself. This article outlines the principles of the management of periprosthetic fractures of the lower limb.     

Clinical deterioration in patients with idiopathic pulmonary fibrosis: causes and assessment

Patients with idiopathic pulmonary fibrosis (IPF) inevitably experience declines in functional status that are most frequently due to progressive pulmonary fibrosis. However, the cause of the clinical deterioration is often uncertain, and disease progression is difficult to distinguish from disease-associated complications or adverse effects of therapy. In studies of the clinical course of IPF, mortality is most frequently due to respiratory failure (38.7%); other causes of death include heart failure (14.4%), bronchogenic carcinoma (10.4%), ischemic heart disease (9.5%), infection (6.5%), and pulmonary embolism (3.4%). Other, usually nonfatal, disease-associated complications include pneumothorax, corticosteroid-induced metabolic side effects and myopathy, and therapy-related immunosuppression. In evaluating clinical deterioration in patients with IPF, disease-associated complications and adverse effects of therapy should be distinguished from progressive pulmonary fibrosis. The cause of clinical deterioration will alter the therapeutic intervention required and will influence patient prognosis and duration of survival. This article examines the causes of clinical deterioration in patients with IPF and the diagnostic procedures for assessing disease-associated complications and staging IPF progression.     

Influence of technique of coronary artery implantation on long-term results in composite aortic root replacement.

BACKGROUND: Long-term results after composite graft aortic root replacement may depend on the insertion technique. The aim of this study is to assess the influence of the technique of coronary artery implantation on long-term results in composite aortic root replacement. METHODS: One hundred fifty consecutive patients (mean age, 55 years; 119 men) with different disorders of the ascending aorta who underwent aortic root replacement with a composite graft prosthesis between January 1985 and December 1999 were retrospectively studied. Thirteen patients had previously undergone cardiovascular surgery. The open button technique was performed in 65 patients (43.3%, group 1) and the inclusion technique in 85 patients (56.7%, group 2). Mean follow-up was 70.5 months. Surgery was elective in 110 procedures (73%). RESULTS: Global actuarial survival was 76.1% +/- 4.3% for group 1 and 73.7% +/- 3.9% for group 2 at 10 years (p = 0.22). Freedom from reoperation excluding early deaths was 81% +/- 3% for group 1 and 86% +/- 2.2% for group 2 at 10 years (p = 0.62). Group 2 demonstrated a statistically significantly higher occurrence of pseudoaneurysm formation versus group 1 (p = 0.04). CONCLUSIONS: Composite graft aortic root replacement is a safe and effective therapy for proximal aortic aneurysm and dissection, resulting in good early and long-term results irrespective of the anastomotic technique. However, the open button technique seems to avoid late false aneurysm formation at the anastomotic sites.     

Attenuated Salmonella targets prodrug activating enzyme carboxypeptidase G2 to mouse melanoma and human breast and colon carcinomas for effective suicide gene therapy

PURPOSE: We engineered the oncolytic Salmonella typhimurium-derived bacterium VNP20009 as a vector to target delivery to tumors of the prodrug-activating enzyme carboxypeptidase G2 (CPG2) and to show enhanced antitumor efficacy on administration of different prodrugs. EXPERIMENTAL DESIGN: We characterized CPG2 expression in vectors by immunoblotting, immunofluorescence, and enzyme activity. We assessed prodrug activation by high-performance liquid chromatography. Target human tumor cell and bacterial vector cell cytotoxicity was measured by flow cytometry and colony-forming assays. Therapy was shown in two human tumor xenografts and one mouse allograft with postmortem analysis of bacterial and CPG2 concentration in the tumors. RESULTS: CPG2 is expressed within the bacterial periplasm. It activates prodrugs and induces cytotoxicity in human tumor cells but not in host bacteria. Following systemic administration, bacteria multiply within xenografts reaching 2 x 10(7)/g to 2 x 10(8)/g at 40 days postinoculation. The concentration of CPG2 in these tumors increases steadily to therapeutic levels of 1 to 6 units/g. The bacteria alone reduce the growth of the tumors. Subsequent administration of prodrugs further reduces significantly the growth of the xenografts. CONCLUSIONS: The bacteria multiply within tumors, resulting in a selective expression of CPG2. The CPG2-expressing bacteria alone reduce the growth of tumors. However, in the presence of prodrugs activated by CPG2, this oncolytic effect is greatly increased. We conclude that bacterial oncolytic therapy, combined with CPG2-mediated prodrug activation, has great potential in the treatment of a range of cancers.