An Approach to Catheter Ablation of Cavotricuspid Isthmus Dependent Atrial Flutter

Much of our understanding of the mechanisms of macro re-entrant atrial tachycardia comes from study of cavotricuspid isthmus (CTI) dependent atrial flutter. In the majority of cases, the diagnosis can be made from simple analysis of the surface ECG. Endocardial mapping during tachycardia allows confirmation of the macro re-entrant circuit within the right atrium while, at the same time, permitting curative catheter ablation targeting the critical isthmus of tissue located between the tricuspid annulus and the inferior vena cava. The procedure is short, safe and by demonstration of an electrophysiological endpoint - bidirectional conduction block across the CTI - is associated with an excellent outcome following ablation. It is now fair to say that catheter ablation should be considered as a first line therapy for patients with documented CTI-dependent atrial flutter

Contact force sensing in ablation of ventricular arrhythmias using a 56-hole open-irrigation catheter: a propensity-matched analysis.

PURPOSE: The effect of adding contact force (CF) sensing to 56-hole tip irrigation in ventricular arrhythmia (VA) ablation has not been previously studied. We aimed to compare outcomes with and without CF sensing in VA ablation using a 56-hole radiofrequency (RF) catheter. METHODS: A total of 164 patients who underwent first-time VA ablation using Thermocool SmartTouch Surround Flow (TC-STSF) catheter (Biosense-Webster, Diamond Bar, CA, USA) were propensity-matched in a 1:1 fashion to 164 patients who had first-time ablation using Thermocool Surround Flow (TC-SF) catheter. Patients were matched for age, gender, cardiac aetiology, ejection fraction and approach. Acute success, complications and long-term follow-up were compared. RESULTS: There was no difference between procedures utilising either TC-SF or TC-STSF in acute success (TC-SF: 134/164 (82%), TC-STSF: 141/164 (86%), p = 0.3), complications (TC-SF: 11/164 (6.7%), TC-STSF: 11/164 (6.7%), p = 1.0) or VA-free survival (TC-SF: mean arrhythmia-free survival time = 5.9 years, 95% CI = 5.4-6.4, TC-STSF: mean = 3.2 years, 95% CI = 3-3.5, log-rank p = 0.74). Fluoroscopy time was longer in normal hearts with TC-SF (19 min, IQR: 14-30) than TC-STSF (14 min, IQR: 8-25; p = 0.04). CONCLUSION: Both TC-SF and TC-STSF catheters are safe and effective in treating VAs. The use of CF sensing catheters did not improve safety or acute and long-term outcomes, but reduced fluoroscopy time in normal heart VA

Ablation vs drug use for atrial fibrillation

The relative merits of rate and rhythm control in the treatment of patients with atrial fibrillation (AF) have been compared in several major clinical trials, none of which demonstrated a significant difference in all-cause mortality. Yet, there is clear evidence that restoration and maintenance of sinus rhythm is associated with beneficial reverse atrial and ventricular remodelling. In addition, patients may feel better if AF is resolved, and data from some post hoc analyses suggest a possible mortality benefit. These apparently contradictory findings may reflect the high risk of serious adverse events associated with currently available antiarrhythmic drugs (AAD), counterbalancing their beneficial effect in restoring sinus rhythm. Catheter ablation offers an alternative means of restoring sinus rhythm in patients with AF and several clinical trials have indicated superior outcomes in certain subgroups after ablation with or without AAD vs. antiarrhythmic therapy alone. This study reviews the relative advantages and actual use of catheter ablation and other therapeutic options in the treatment of AF, with or without concomitant heart failure or structural heart disease. Catheter ablation is recognized in the latest ACC/AHA/ESC guidelines as a valid second-line option in patients who have failed or were intolerant of first-line antiarrhythmic therapy. In the absence of new antiarrhythmics with an improved benefit/risk profile, it could become a first-line strategy for certain patient populations. The ongoing CABANA trial should confirm its impact on overall survival relative to that of pharmacological rate or rhythm control

The European Network for Translational Research in Atrial Fibrillation (EUTRAF): objectives and initial results.

Atrial fibrillation (AF) is the most common sustained arrhythmia in the general population. As an age-related arrhythmia AF is becoming a huge socio-economic burden for European healthcare systems. Despite significant progress in our understanding of the pathophysiology of AF, therapeutic strategies for AF have not changed substantially and the major challenges in the management of AF are still unmet. This lack of progress may be related to the multifactorial pathogenesis of atrial remodelling and AF that hampers the identification of causative pathophysiological alterations in individual patients. Also, again new mechanisms have been identified and the relative contribution of these mechanisms still has to be established. In November 2010, the European Union launched the large collaborative project EUTRAF (European Network of Translational Research in Atrial Fibrillation) to address these challenges. The main aims of EUTRAF are to study the main mechanisms of initiation and perpetuation of AF, to identify the molecular alterations underlying atrial remodelling, to develop markers allowing to monitor this processes, and suggest strategies to treat AF based on insights in newly defined disease mechanisms. This article reports on the objectives, the structure, and initial results of this network

Assessment of myocardial injuries in ischemic and non-ischemic cardiomyopathies using magnetic resonance T1-rho mapping.

To identify clinical correlates of myocardial T1ρ and to examine how myocardial T1ρ values change under various clinical scenarios. A total of 66 patients (26% female, median age 57 years [Q1-Q3, 44-65 years]) with known structural heart disease and 44 controls (50% female, median age 47 years [28-57 years]) underwent cardiac magnetic resonance imaging at 1.5-T, including T1ρ mapping, T2 mapping, native T1 mapping, late gadolinium enhancement, and ECV imaging.In controls, T1ρ positively related with T2 (P=0.038) and increased from basal to apical levels (P<0.001). As compared to controls and remote myocardium, T1ρ significantly increased in all patients' sub-groups and all types of myocardial injuries: acute and chronic injuries, focal and diffuse tissue abnormalities, as well as ischemic and non-ischemic aetiologies (P<0.05). T1ρ was independently associated with T2 in patients with acute injuries (P=0.004) and with native T1 and ECV in patients with chronic injuries (P<0.05). Myocardial T1ρ mapping demonstrated good intra- and interobserver reproducibility (ICC=0.86 and 0.83, respectively). Myocardial T1ρ mapping appears to be reproducible and equally sensitive to acute and chronic myocardial injuries, whether of ischemic or non-ischemic origins. It may thus be a contrast-agent-free biomarker for gaining new and quantitative insight into myocardial structural disorders. These findings highlight the need for further studies through prospective and randomized trials