When areas with CFAE were completely eliminated but the atrial arrhythmias persisted (organized atrial flutter or atrial tachycardia), they were subsequently mapped and ablated (occasionally in conjunction with ibutilide 1–2mg intravenously over 10–20 minutes). The primary end-points during RF ablation were either complete elimination of areas with CFAE or conversion of AF to SR. RF applications were delivered via 8mm Navistar™ (Biosense-Webster, Diamond Bar California) with a maximal temperature of 55–60☌. The CFAE was tagged and associated with the atrial anatomy created by CARTO, thereby identifying target sites for ablation. We used bipolar recordings filtered at 30–500Hz and defined the CFAE as follows: fractionated electrograms composed of two or more deflections, and/or a perturbation of the baseline with continuous deflection of a prolonged activation complex and atrial electrograms with a very short cycle length (<120 milliseconds). We used bipolar maps and tags to recognize the CFAE points. CARTO provided a short cycle length (CFAE) map and enabled the operator to associate areas of CFAE with both atria and coronary sinus the setting of the threshold was 0.05–0.15mV and the duration was 70–120 milliseconds. All electroanatomical maps were created for patients who were in AF, either spontaneously or by induction. After the screening of these patients for catheter ablation (see Figure 1), we found 771 patients with symptomatic refractory AF who all had a high risk for stroke and, similar to those patients studied in the AFFIRM trial, were candidates for ablation.Īll patients underwent non-fluoroscopic electroanatomical mapping with the CARTO™ mapping system (Biosense Webster, Inc., Diamond Bar). We excluded patients with chronic alcoholism, recent myocardial infarction within one month of the study, significant debilitating diseases or terminal disease, and those with documented left atrial thrombus. 15 Patients were at least 65 years old or had at least one or more risk factors for stroke, including hypertension, diabetes, structural heart diseases (coronary artery disease, valvula cardiomyopathy, etc.), a prior history of stroke or transient ischemic attack (TIA), congestive heart failure (CHF), or a left ventricular ejection fraction (EF) of <40%. Our study involved screening 2,356 high-risk AF patients similar to those in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial population. High-risk Patients and Ablation of Atrial Fibrillation Substrates 14 This article will discuss the results of this study with respect to mortality and stroke reduction after maintaining SR following successful catheter ablation. 10 Our recent study also suggests that the catheter-based ablative approach may even have greater benefits for the elderly and high-risk populations with structural heart disease who suffer from AF. The key question is then raised: what is the safety and efficacy of catheter ablation in the older and high-risk populations with AF, and could the benefits of maintaining sinus rhythm (SR) using the ablation approach yield the most sought-after outcomes of improved survival and reduced stroke rates in such patients? We described a new approach to AF ablation by identifying the target ‘substrate’ sites using electroanatomical mapping of complex fractionated atrial electrograms (CFAE). 5,8,9,11–13 However, most of these studies included a younger population of paroxysmal AF patients whose arrhythmias, in general, are not life-threatening or severely disabling. 4–10 Numerous studies from both randomized and non-randomized trials suggest that ablation is probably more effective than antiarrhythmic drugs in treating AF. Over the past decade, catheter ablation has emerged as a promising approach for treating AF, and is now a commonly performed ablation procedure in major hospitals worldwide. 2 AF can occur in the absence of underlying heart disease, but is more frequent in connection with mitral valve disease, heart failure, ischemic heart disease, and hypertension. Atrial fibrillation (AF) is the most common cardiac arrhythmia, becomes more prevalent with age, 1 and is associated with an increased long-term risk for stroke, heart failure, and all-cause mortality.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |