Definition of success criteria for ablation of typical right atrial flutter with a single-catheter approach: A pilot study.

BACKGROUND: The success rate of cavotricuspid isthmus ablation to treat right common flutter is high (up to 95%), but needs bidirectional block confirmation, requiring two or three catheters. AIM: To describe a new pacing technique using a single catheter to ablate and confirm cavotricuspid isthmus block with differential PR interval measurements. METHODS: We included 61 patients from five centres, who were referred for cavotricuspid isthmus ablation. All patients had cavotricuspid isthmus ablation, and the cavotricuspid isthmus block was confirmed by differential pacing using two or three catheters. The new method consisted of measuring the PR interval on the surface electrocardiogram using pacing from the tip of the ablation catheter on the lateral side (lateral delay) and the septal side (coronary sinus ostium) of the cavotricuspid isthmus line (difference=delta PR interval), before and after cavotricuspid isthmus ablation. We analysed the value of the delta PR interval in predicting bidirectional cavotricuspid isthmus block as confirmed by standard methods. RESULTS: Among our patient population (mean age 63±12 years), 39 patients were ablated during sinus rhythm, and 22 during common flutter. Cavotricuspid isthmus block was achieved in all patients but one. Lateral delay and delta PR interval increased significantly after validation of cavotricuspid isthmus block (257±42 vs. 318±50ms and 32±23 vs. 96±22ms, respectively; P<0.0001). A delta PR interval cut-off of ≥70ms had 100% sensitivity and specificity to predict bidirectional cavotricuspid isthmus block. CONCLUSIONS: A single-catheter ablation approach to performing cavotricuspid isthmus line based on surface electrocardiogram PR interval measurement is feasible. After ablation, cavotricuspid isthmus block was systematically obtained when the delta PR interval was>70ms.

Femoral vein thrombosis after right-sided electrophysiological procedures.

PURPOSE: Electrophysiological studies and radiofrequency catheter ablations require single or multiple sheath placements through femoral vein cannulation. The objective of this study was to determine the incidence, predictors, and outcomes of deep vein thrombosis (DVT) following such procedures. METHODS AND RESULTS: We prospectively enrolled 220 consecutive patients with a median age of 70 [60-79] years. The median duration of the procedures from insertion to removal of sheaths was 45 [30-75] min. At least two sheaths were inserted in 158 (72%) of the cases. Duplex ultrasonography evaluation of the lower leg veins was performed 6 h after the procedure and revealed common femoral vein thrombosis in 11 (5%) patients. All thrombi were partial and none was complete. Thrombi were mobile in four patients and extended to the external iliac vein in three patients. None of the patients presented with clinical signs of DVT or pulmonary embolism. Anticoagulation was prescribed for 2-4 weeks and a follow-up duplex ultrasonography obtained in the first seven patients revealed complete resolution of thrombi in all cases. On multivariate analysis, two predictors of thrombosis occurrence were identified: a greater sum of sheath diameters (odds ratio, 1.41 [95% confidence interval, 1.25-1.60] per 1-French increase; p < 0.001) and a longer procedural duration (odds ratio, 1.02 [95% confidence interval, 1.00-1.04] per 1-min increase; p = 0.04). CONCLUSIONS: Asymptomatic femoral DVT occur in 5% of electrophysiological studies and right-heart radiofrequency catheter ablations, particularly when large sheaths are inserted for a longer period. The role of anticoagulation in this clinical setting warrants further evaluation.