title: Usefulness of echo-guided cardiac resynchronization pacing in patients undergoing "ablate and pace" therapy for permanent atrial fibrillation and effects of heart rate regularization and left ventricular resynchronization.
abstract: An acute comparative study of right ventricular (RV) pacing and echocardiographically guided cardiac resynchronization pacing (CRP) was performed in patients who underwent "ablate and pace" therapy for permanent atrial fibrillation. It was hypothesized that optimized CRP guided by tissue Doppler echocardiography would exert an additive beneficial hemodynamic effect to that of rate regularization achieved through atrioventricular junction ablation. An acute intrapatient comparison of echocardiographic parameters was performed between baseline preablation values and RV pacing and CRP (performed <24 hours after ablation) in 50 patients. Optimized CRP configuration was defined as the modality of pacing corresponding to that of the shortest intra-left ventricular (LV) delay among simultaneous biventricular pacing, sequential biventricular pacing, and single-chamber pacing. The intra-LV delay was defined as the difference between the longest and the shortest activation time in the six basal segments of the left ventricle. Compared with preablation measures, the ejection fraction increased by 10.8% during RV pacing (19% in patients with intra-LV delays <47.5 ms and 3% in those with intra-LV delays >47.5 ms). Compared with RV pacing, CRP caused a 9.2% increase in the ejection fraction, a 6.8% decrease in LV systolic diameter, and a 17.3% decrease in mitral regurgitation area; LV dyssynchrony was reduced from 52 +/- 27 to 21 +/- 12 ms. Similar results were observed in patients with and without depressed systolic function and in patients with and without left bundle branch block. In conclusion, rate regularization achieved through atrioventricular junction ablation and RV pacing provides a favorable hemodynamic effect that is inversely related to the level of LV dyssynchrony. Minimizing LV dyssynchrony by means of optimized CRP yields an additional important benefit.
authors.affiliation: Department of Cardiology, Ospedali del Tigullio, Lavagna, Italy. mbrignole@asl4.liguria.it
authors.forename: Michele
authors.initials: M
authors.lastname: Brignole
authors.forename: Carlo
authors.initials: C
authors.lastname: Menozzi
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Botto
authors.forename: Lluís
authors.initials: L
authors.lastname: Mont
authors.forename: Joaquín
authors.initials: J
authors.lastname: Osca Asensi
authors.forename: Dolores
authors.initials: D
authors.lastname: García Medina
authors.forename: Daniele
authors.initials: D
authors.lastname: Oddone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Navazio
authors.forename: Mario
authors.initials: M
authors.lastname: Luzi
authors.forename: Saverio
authors.initials: S
authors.lastname: Iacopino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Fabrizio
authors.forename: Alessandro
authors.initials: A
authors.lastname: Proclemer
authors.forename: Panos
authors.initials: P
authors.lastname: Vardas
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D001283:Atrioventricular Node / Q000601:surgery; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017115:Catheter Ablation; D003131:Combined Modality Therapy; D015150:Echocardiography, Doppler; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012372:ROC Curve; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*