Trans-subclavian approach for radiofrequency ablation of premature ventricular contractions originating from subtricuspid annulus: a case report.

BACKGROUND: Catheter ablation has been established as a curative treatment strategy for ventricular arrhythmias. The standard procedure of most ventricular arrhythmias originating from the right ventricle is performed via the femoral vein. However, a femoral vein access may not achieve a successful ablation in some patients. CASE PRESENTATION: We reported a case of a 29-year old patient with symptomatic premature ventricular contractions was referred for catheter ablation. Radiofrequency energy application at the earliest endocardial ventricular activation site via the right femoral vein could not eliminate the premature ventricular contractions. Epicardial mapping could not obtain an earlier ventricular activation when compared to the endocardial mapping, and at the earliest epicardial site could not provide an identical pace mapping. Finally, we redeployed the ablation catheter via the right subclavian vein by a long sheath. During mapping of the subvalvular area of the right ventricle, a site with a good pace mapping and early ventricular activation was found, and premature ventricular contractions were eliminated successfully. CONCLUSION: Ventricular arrhythmias originating from the subtricuspid annulus may be successfully abolished via a trans-subclavian approach and a long sheath. Although access via the right subclavian vein for mapping and ablation is an effective alternative, it is not a routine approach.

Mediastinitis related to probable central vinblastine extravasation in a woman undergoing adjuvant chemotherapy for early breast cancer.

Adjuvant chemotherapy for breast cancer, although generally safe and of proven benefit, can have severe complications. Central venous catheter (CVC) complications are relatively common forms of treatment-related morbidity in this setting. We report a rare type of CVC-related complication, that of chemotherapy-induced mediastinitis from central venous extravasation of the drug vinblastine, in a women undergoing adjuvant chemotherapy. The patient presented with signs and symptoms consistent with mediastinitis, but the diagnosis was delayed because the initial findings were nonspecific and there was little suspicion for a CVC-related problem. A radionuclide venous flow study was misleading, but a computed tomographic study of the chest and contrast venography confirmed the diagnosis. Conservative treatment with CVC removal, systemic anticoagulation, antibiotics, and pain controlled to gradual improvement in the patient's clinical status. More aggressive strategies, such as thrombolytic therapy and surgical intervention, were considered, but these approaches have not been used in this particular setting. The complication reported here is the first described in the literature in an adult patient. Two similar cases have been reported in pediatric patients. It is likely that this clinical problem is underreported. Patients with CVCs actively undergoing chemotherapy with vesicant agents should be watched carefully for early signs of CVC disruption and subsequent extravasation, as it is likely that early intervention will be of benefit.

Incidence and prevention of thrombosis of the subclavian vein during total parenteral nutrition.

In this study, we were able to document by radionuclide venogram the presence of thrombosis of the subclavian vein in seven of 22 patients receiving standard total parenteral infusions. By adding 3,000 U.S.P. units of heparin to each liter of infusate, we were able to reduce the number of instances of thrombosis to two in 24 patients. Although none of the patients in the heparin therapy group experienced laboratory or clinical manifestations of anticoagulation, we suggest that further studies be done to investigate the reduced heparin concentrations to determine the lowest effective level. Based upon these observations, we currently recommend that 3,000 U.S.P. units of heparin be added to each liter of total parenteral nutrition solution infused through a subclavian venous catheter.