Role of the vein of Marshall in atrial fibrillation recurrences after catheter ablation: therapeutic effect of ethanol infusion.

UNLABELLED: Vein of Marshall Ethanol in Recurrent AF. INTRODUCTION: Atrial fibrillation (AF) or flutter can recur after pulmonary vein (PV) antral isolation (PVAI). The vein of Marshall (VOM) has been linked to the genesis of AF. We hypothesized that the VOM may play a role in AF recurrences and that VOM ethanol infusion may have therapeutic value in this setting. METHODS AND RESULTS: Sixty-one patients with recurrent AF or flutter after PVAI were studied. The VOM was successfully cannulated in 54; VOM and PV electrograms were recorded, and differential PV-VOM pacing was performed. VOM signals were present in all patients; however, VOM triggers of AF could not be demonstrated. VOM tachycardia was present in 1 patient. Left inferior (LIPV) and left superior (LSPV) reconnection was present in 32 and 30 patients, respectively. Differential pacing in VOM and LIPV showed VOM-mediated LIPV reconnection in 5/32 patients. In others, VOM and PV connected indirectly via left atrial tissues. Up to four 1 cc infusions of 98% ethanol were delivered in the VOM. Regardless of the reconnection pattern, ethanol infusion eliminated LIPV and LSPV reconnection in 23/32 and 13/30 patients, respectively. Ethanol terminated VOM and LIPV tachycardias in 2 patients. There were no acute procedural complications. CONCLUSIONS: VOM signals are consistently present in recurrent AF. VOM may rarely play a role in PV reconnection. However, VOM ethanol infusion can be useful in patients with recurrent AF after PVAI, assisting in achieving redisconnection of reconnected left PVs.

Predictors of appropriate defibrillator therapy among patients with an implantable defibrillator that delivers cardiac resynchronization therapy.

INTRODUCTION: The purpose of this study was to determine predictors of appropriate implantable defibrillator (ICD) therapy among patients with heart failure who are treated with a cardiac resynchronization therapy-defibrillator (CRT-D). METHODS AND RESULTS: Patients enrolled in the Ventak CHF/Contak CD study were treated with a CRT-D device and were required to have NYHA class II-IV CHF, QRS duration > or = 120 msec, and a class I or II indication for an ICD. The study database was retrospectively analyzed during the 6-month postimplant period to identify predictors of appropriate ICD therapy. Five hundred and one of the 581 patients enrolled in the trial had successful device implantation and were included in this analysis. Patients were mostly male (83%), 66 +/- 11 years old, and had coronary artery disease (69%), a mean left ventricular ejection fraction (EF) = 0.22 +/- 0.07, and NYHA class II (33%), III (58%), or IV (9%) CHF symptoms. During 6 months of follow-up, 73 of 501 (14%) patients received an appropriate ICD therapy. Two independent predictors of appropriate therapy were identified: a history of a spontaneous, sustained ventricular arrhythmia (HR = 2.05; 95% CI = 1.31-3.20; P = 0.002) and NYHA class IV CHF (HR = 1.81; 95% CI = 1.10-2.96; P = 0.019). When patients with NYHA class II were excluded from analysis, a history of a sustained ventricular arrhythmia and the presence of NYHA class IV CHF symptoms remained as independent predictors of appropriate ICD therapy. CONCLUSIONS: In a select population of advanced heart failure patients receiving a CRT-D, NYHA class IV CHF was a powerful independent predictor of appropriate ICD therapy. Approximately one-quarter of the patients with NYHA class IV CHF who received a CRT-D device received an appropriate ICD therapy within 3 months after implant. Additional studies are needed to confirm an association between class IV CHF symptoms and an increased frequency of ICD shocks.

Coronary artery disease in patients with Buerger's disease.

Buerger's disease (thromboangiitis obliterans) is a small- and medium-vessel vasculitis that predominantly involves the distal extremities. Coronary involvement in Buerger's disease is very unusual and rarely reported. We describe the unusual coronary angiogram findings of a 61-year-old Caucasian male with Buerger's disease who underwent cardiac catheterization for preoperative cardiac risk stratification prior to a carotid endarterectomy. Following the case presentation, we review the pathology, pathogenesis, and diagnostic criteria for Buerger's disease, and also include a review of the existing literature on coronary involvement in Buerger's disease.

Direct imaging of transvenous radiofrequency cardiac ablation using a steerable fiberoptic infrared endoscope.

BACKGROUND: Direct imaging through blood has been achieved in vivo using fiberoptics and infrared wavelength technology. OBJECTIVES: The purpose of this study was to determine the feasibility of using a percutaneous, steerable, fiberoptic infrared endoscope to identify and characterize the electrode-tissue interface during transvenous cardiac ablation. METHODS: Infrared endoscopy was performed during 24 catheter ablation attempts in 10 mongrel dogs. Infrared imaging was performed through a transparent dome located at the tip of a 7Fr steerable endoscope using an imaging wavelength of 1,620 nm. Radiofrequency ablation was performed using a 4-mm-tip electrode catheter. Attempts were made to identify the electrode-endocardial interface at each ablation site and to characterize any signal changes during ablation. RESULTS: The electrode-tissue interface could be identified at 19 of the 24 ablation sites. Changes at the electrode-tissue interface were observed during ablation at 14 sites, which included a gradual increase in the tissue signal intensity at 12 sites. Small lucencies near the ablation electrode were observed at six sites. There was no interference during energy delivery. Endocardial features identified by endoscopy correlated with the postmortem appearance. CONCLUSION: Direct imaging of intracardiac structures and the electrode-tissue interface can be achieved through blood during transvenous catheter ablation with infrared endoscopy using a steerable, fiberoptic, infrared endoscopic catheter. Ablation lesion formation can be seen as a gradual increase in signal intensity. Fiberoptic infrared endoscopy appears to be a promising new tool for guiding catheter ablation.

Termination of epicardial left ventricular tachycardia by pacing without global capture.

It is generally accepted that the diagnosis of an epicardial origin of ventricular tachycardia (VT) can be made indirectly by observing VT termination during ablation on the epicardial surface of the heart. There is a caveat, however, which is that termination of VT during radiofrequency current application on the epicardial surface could be due to extension of the lesion beyond the epicardium. Therefore, successful ablation of VT using an epicardial approach does not necessarily prove the reentrant circuit is located superficially. We present a case of a 44-year-old man with VT storm who demonstrated successful termination of VT with radiofrequency current application on the epicardial surface of the heart. This site corresponded to a site where pacing during VT resulted in termination of VT without global capture. Isolated mid-diastolic potentials were only seen at this site as well. We hypothesize that the finding of termination of VT by pacing without global capture supports the argument that the site of pacing is a critical part of the VT circuit.

Transcatheter closure of patent foramen ovale associated with paradoxical embolism using the amplatzer PFO occluder: initial and intermediate-term results of the U.S. multicenter clinical trial.

Closure of patent foramen ovale (PFO) has been proposed as an alternative to anticoagulation in patients with presumed paradoxical emboli. We report the immediate and mid-term results of the phase 1 U.S. Multicenter Clinical Trial of patients who underwent transcatheter PFO closure for paradoxical embolism using the new Amplatzer PFO device. Fifty patients (28 male/22 female) underwent catheter closure of their PFOs at a mean age of 41 +/- 11 years. Thirty-six patients had ischemic stroke, 10 had transient ischemic attack, and 4 had peripheral embolism. Seventeen patients had atrial septal aneurysm. The implantation procedure was successful in 49/49 patients; one patient did not have a PFO. Complete closure was seen immediately after the procedure in 26/49 patients; 17 had minimal residual shunt, 4 had moderate and 2 had large residual shunts. The median fluoroscopy time was 10.5 min (2.8-43 min). There were no complications related to the device. One patient developed an arteriovenous fistula at the catheter site requiring surgical repair. At a mean follow-up interval of 16.5 +/- 7.2 months, there were no deaths or recurrent neurological or peripheral embolic events. Eight patients reported an episode of dizziness or palpitations (four of them within 18 days of the procedure). No episodes of atrial dysrhythmias were noted. Contrast bubble study at last follow-up documented complete closure in 45/48 patients; one patient had minimal, one had moderate residual shunt, and one had a large shunt. One patient was lost to follow-up. We conclude that catheter closure of PFO associated with stroke/transient ischemic attack or peripheral embolism using the new Amplatzer PFO device is a safe and effective method in preventing recurrence of such episodes. Randomized clinical trials comparing device closure versus continued medical therapy are underway.

Transcatheter closure of patent ductus arteriosus in adults using the Amplatzer duct occluder: initial results and follow-up.

BACKGROUND: Surgical closure of patent ductus arteriosus in adult patients may be problematic. Transcatheter closure of patent ductus arteriosus is an established procedure. Recently, transcatheter closure of patent ductus arteriosus using the Amplatzer duct occluder has been shown to be safe and efficacious. We present our experience with this device in adults. METHODS AND RESULTS: Between January 2000 and January 2002,41 adult patients (31 females and 10 males) with a patent ductus arteriosus were referred for closure with the Amplatzer duct occluder. The median age was 35.6 years (range 18-70.7 years) and the median weight was 65.8 kg (range 32.7-164.5 kg). Of these 41 patients, 37 underwent attempted closure of the patent ductus arteriosus using the Amplatzer duct occluder. The device was successfully deployed in all patients except 1. Complete angiographic closure was seen Immediately after device deployment in 29 out of 36 patients (81%). Complete echocardiographic closure was demonstrated within 24 hours post-procedure in 34 out of 36 patients (94%), and at 6-month follow-up in 35 out of 36 patients (97%). No complications related to device implantation occurred in any patient. CONCLUSIONS: Closure of patent ductus arteriosus using the Amplatzer duct occluder is safe and effective in adults.