Ablation of atrial flutter by the femoral approach in the absence of inferior vena cava.

This report describes a case of isthmus-dependent atrial flutter ablation by the femoral approach in a 77-year-old patient with a previously unknown absence of the inferior vena cava (IVC). Multi-row detector CT angiography indicated the absence of the perihepatic IVC, whereas the venous blood is drained into the superior vena cava (SVC) via the vena azygos. An ablation catheter could be advanced through the right femoral vein reaching the right heart via vena azygos and SVC. Despite looping of the catheter, ablation and termination of atrial flutter were performed successfully. This is the first report of an inferior-to-superior approach for ablation of atrial flutter in the absence of the perihepatic IVC.

Randomized comparison between open irrigation technology and intracardiac-echo-guided energy delivery for pulmonary vein antrum isolation: procedural parameters, outcomes, and the effect on esophageal injury.

INTRODUCTION: We performed a prospective study to compare efficacy and safety of both open irrigation tip (OIT) technology with intracardiac echo (ICE)-guided energy delivery in patients presenting for PVAI. METHODS AND RESULTS: Fifty-three patients presenting for PVAI were randomized to ablation using an OIT catheter (Group 1, 26 patients; temperature and power were set at 50 degrees and 50 W, respectively, with a saline pump flow rate of 30 mL/min) or radiofrequency (RF) energy delivery under ICE guidance (Group 2, 27 patients; energy was titrated based on microbubbles formation). The mean procedure time and fluoroscopy exposure were lower in Group 1 (164 +/- 42 min and 7,560 +/- 2,298 microGray m2 vs 204 +/- 47 min and 12,240 +/- 4,356 microGray m2; P = 0.005 and 0.008, respectively). Moreover, the durations of RF lesions applied per PV antrum was lower in Group 1 compared with Group 2 (5.1 +/- 2.2 min vs 9.2 +/- 3.2 min, P = 0.03, respectively). Within 24 hours after PVAI in 35.7% (all erythema) of Group 1 and 57.1% (21.4% erythema and 35.7% necrosis) of Group 2, patients' esophageal wall changes were documented. After 14 +/- 2 months of follow up, recurrences were documented in 19.2% of Group 1 and 22.2% of Group 2 patients. CONCLUSION: Although both OIT and ICE-guided energy delivery possess a similar effect in treating AF, OIT seems to be superior in terms of achieving isolation and shortening fluoroscopy exposure. Moreover, a lower incidence of esophageal wall injury was observed utilizing OIT for PVAI.

Mode of initiation and ablation of ventricular fibrillation storms in patients with ischemic cardiomyopathy.

OBJECTIVES: We report on the initiation of ventricular fibrillation (VF) storm in patients with ischemic cardiomyopathy (ICM) and the results of targeted ablation to treat VF storm. BACKGROUND: Monomorphic premature ventricular contractions (PVCs) have been shown to initiate VF in patients without structural heart disease. METHODS: A total of 29 patients with ICM and documented VF initiation were identified. In 21 patients, VF storm was controlled with antiarrhythmic drugs and/or treatment of heart failure. Eight patients with VF (mean 52 +/- 25 episodes) refractory to medical management required ablation. All patients underwent three-dimensional electroanatomical mapping using CARTO (Biosense-Webster Inc., Diamond Bar, California), and PVCs were mapped when present. Scarred areas were identified using voltage mapping. RESULTS: Monomorphic PVCs initiated VF in all 29 identified patients. Five of eight patients requiring ablation had frequent PVCs that allowed PVC mapping. The earliest activation site was consistently located in the scar border zone. The PVCs were always preceded by a Purkinje-like potential (PLP). Ablation was successfully performed at these sites. In three patients, infrequent PVCs prevented mapping, but PLPs were recorded around the scar border. Ablation targeting these potentials along the scar border was successfully performed. During follow-up (10 +/- 6 months), one patient had a single VF episode and another developed sustained, monomorphic ventricular tachycardia. There was no recurrence of VF storm. CONCLUSIONS: Ventricular fibrillation in ICM is triggered by monomorphic PVCs originating from the scar border zone with preceding PLPs; targeting these PVCs may prevent VF recurrence. In the absence of PVCs, both substrate mapping and ablation appear to be equally effective.