Aims To compare the use of a minimal (MIN) with a conventional (CON) catheter approach for the mapping and ablation of regular supraventricular tachycardias (SVT) and typical atrial flutter (AFL) in the setting of a randomized-controlled trial. Methods and results Two hundred patients (age 51.2 +/- 15.9 years, 99 male) were randomized to a MIN or CON group. The MIN approach involved using two catheters for AFL, one to three for other SVT (ablation catheter included), whereas the CON approach involved three and five catheters, respectively. Acute procedural success was similar between the two groups. There was no significant difference in overall procedure times, fluoroscopy times, or radiation doses. Procedure times were shorter for AFL ablation in MIN compared with CON [60 (30-150) vs. 85 (40-200) min, median (range), P = 0.03] from subgroup analysis. A median of three (one to six) catheters was used in MIN and five (three to seven) in CON (P < 0.0001). Catheter costs were significantly lower in MIN compared with CON [6.1 (2-61) vs. 8.5 (4.4-21.3) units, P < 0.0001, where one unit is equivalent to the cost of a diagnostic quadripolar catheter]. At 6-week follow-up, two patients in MIN (2.1%) and three patients in CON (3.2%) had documented recurrence of the index arrhythmia. Conclusion The use of a MIN approach in the treatment of SVT and AFL is as effective, quick, and safe as using a CON approach and is therefore more cost-effective.

Aims Catheter ablation (CA) has become the treatment of choice for regular supraventricular tachycardia (SVT). The purpose of this study was to investigate whether the current clinical results in a large single centre are as good as success rates quoted to patients from published trials and national cardiology society websites. Methods and Results We recorded and analysed prospectively the acute and follow-up (FU) results of all CA procedures performed for SVT at our institution over a 2-year period. We compared our results with the success rates of 90-98% for CA quoted in the literature. We performed a total of 547 CA at our institution over 2 years, of which 389 (71%) were for regular SVT. Of these, 71 procedures (18%) were redo procedures. The overall acute procedural success rate was 96.1%(374/389). Follow-up data were available for 367 of 389 (94.3%) procedures. The overall 6-week success rate varied between 74.7 and 91.3% depending on the SVT type (average 83.9%). The FU success rates were lower for redo procedures (47/66, 71.2%) when compared with first ablation (de novo) procedures (261/301, 86.7%), P = 0.003. Conclusion Published success rates are much better than current success rates in a large single centre. It is possible that the information regarding outcome given to patients during the consent process is not accurate.

We report on the case of an 18-year-old girl with asymptomatic incessant ventricular tachycardia. Initial attempts at endocardial ablation failed and she was monitored until her cardiac function deteriorated. A percutaneous epicardial approach with electroanatomical mapping was then used which successfully terminated the tachycardia. Left ventricular size and function subsequently returned to normal. This case demonstrates that percutaneous epicardial ablation of ventricular tachycardia is safe and feasible in young patients and highlights the importance of recognising this at an early stage.

Objective To see if a strategy of ablating the tricuspid annulus-inferior vena cava isthmus (TA-IVC) is superior to electrical cardioversion to prevent recurrences in patients with coarse atrial fibrillation (AF). Design Prospective randomised controlled multi-centre study. Setting 4 tertiary referral hospitals in the United Kingdom. Patients 57 patients with persistent 'coarse AF'(irregular p waves >/=0.15mV in >/=1 ECG lead) Interventions Patients were randomised to receive external cardioversion (Group A, n=30) or TA-IVC ablation +/- DC cardioversion (Group B, n=27). Main outcome measures Cardiac rhythm, scores on quality of life and symptom questionnaires were assessed at 4, 16 and 52 weeks post procedure. Results 20 (67%) patients in Group A and 19 (70%) patients in Group B were in sinus rhythm (SR) immediately following their index procedure. At 4, 16 and 52 weeks, the number of patients in SR were 5 ,3 and 2 in Group A and 3, 3 and 1 in Group B(p=NS). The quality of life and symptom questionnaire scores were similar in the two groups at each period of follow up though they were significantly better in SR as compared to AF at each follow up visit. Conclusions As a first line strategy TA-IVC ablation offers no advantages over DCCV for the management of coarse AF.

AIMS: The efficacy of transvenous Cryoablation (Cryo), for the treatment of atrioventricular nodal re-entry tachycardia (AVNRT), when compared with radiofrequency (RF) ablation, requires further investigation. METHODS AND RESULTS: We sought to compare the acute- and follow-up results of 71 cases each of Cryo and RF for AVNRT using a retrospective matched case-control study design and aimed at identifying patient and procedural factors that may predict success with each strategy. Primary failure of Cryo (thus necessitating RF at the same sitting) was seen in 11 (15.4%) cases, whereas there were two (2.8%) primary failures with RF (P<0.01). Patients in the Cryo group had significantly higher arrhythmia recurrence [14 (19.8%)] when compared with the RF group [4 (5.6%)](P<0.01). The incidence of recurrence following Cryo was significantly higher if an echo beat was still inducible after ablation than if complete slow pathway block was achieved (7/19, vs. 4/46, P<0.001). The median number of Cryo lesions was significantly lower in patients who had recurrence compared with those who did not (1.5 vs. 3.0, P=0.02). CONCLUSION: We have observed a much higher primary failure and recurrence rate with Cryo when compared with RF for AVNRT. It may be possible to decrease this high recurrence rate by aiming to achieve complete slow pathway block and by increasing the number of Cryo lesions.

CT Image Integration for AF Ablation. Background: A detailed appreciation of left atrial/pulmonary vein (LA/PV) anatomy may be important in improving the safety and success of catheter ablation (CA) for atrial fibrillation (AF). Objectives: The aim of this nonrandomized study was to determine the impact of computerized tomography (CT) image integration into a 3-dimensional (3D) mapping system on the clinical outcome of patients undergoing CA for AF. Methods: Ninety-four patients (age: 56 +/- 10 years) with AF (paroxysmal 46, persistent 48) underwent wide encirclement of ipsilateral PV pairs using irrigated radiofrequency ablation with the endpoint of electrical isolation. Ablation was guided by 3D mapping alone (electroanatomic 24, noncontact 23) in 47 (3DM group) patients and by CT image integration (Cartomerge(R)) in 47 (CT group). In persistent AF, a combination of linear ablation and targeted ablation of complex fractionated electrograms was also performed. Results: Successful PV electrical isolation did not differ between the two groups. A significant reduction in fluoroscopy times was demonstrated in the CT group (49 +/- 27 minutes vs 3DM group 62 +/- 26 minutes, P = 0.03). Arrhythmia recurrence was reduced in the CT group (32% vs 51% in the 3DM group, P < 0.01). In 30 symptomatic patients (12 CT and 18 3DM), repeat procedures for AF (13 in 3DM and 5 CT, P </= 0.10) and AT (5 in 3DM and 7 CT, P = NS) were performed. Overall success on 7-day monitor off antiarrhythmic drugs was achieved in 60% in the 3DM group when compared with 83% in the CT group (P < 0.05) at a follow-up of 25 +/- 5 weeks. Conclusion: CA for AF guided by CT integration was associated with reduced fluoroscopy times, arrhythmia recurrence, and increased restoration of sinus rhythm. Improved visualization of complex LA geometries might improve the safety and success of CA for AF.

AIMS: To compare the utility of non-fluoroscopic mapping systems (Carto and Ensite NavX) with that of conventional mapping in patients referred for catheter ablation of a wide variety of arrhythmias. METHODS AND RESULTS: Patients referred for catheter ablation (excluding atrial fibrillation, atypical atrial flutter, ventricular tachycardia in structural heart disease, and complete AV nodal ablation) were randomized equally to a procedure guided by Carto, Ensite NavX, or conventional mapping. A total of 145 patients were recruited (82 men, aged 49 +/- 16, range 18-85). In 19 patients, no ablation was performed, and in the remaining, typical atrial flutter, atrioventricular nodal re-entrant tachycardia, and atrioventricular re-entrant tachycardias [including Wolff-Parkinson-White (WPW)] accounted for 93% of ablations. Overall procedure time, immediate and short-term success, complication rate, and freedom from symptoms at follow-up were identical for all groups. NavX led to the least X-ray exposure: Navx vs. conventional, median (range): 4 (0-50) vs. 13 (2-46) min (P<0.001); NavX vs. Carto, median (range): 4 (0-50) vs. 6 (1-55) min (P=0.008). Both Carto and NavX increased disposable costs by 50% when compared with conventional (P<0.001). For typical atrial flutter, Carto and NavX reduced screening times without increasing procedure cost. If ablation was not performed, NavX was twice as expensive as Carto or conventional. CONCLUSION: Ensite NavX and Carto procedures have similar effectiveness and safety to a conventional approach; however, they both reduce X-ray exposure, with NavX producing a significantly greater effect than Carto. Although this benefit is achieved at a greater financial cost, there may be long-term benefits to catheter laboratory staff.