Abstract 14908: The Success Rate of Automatic Pacing Threshold Determination Functions Differ among the Brands: What Was the Best Brand in a Far-East Single Center?

Abstract

Introduction: Reliable automatic pacing threshold determination functions offer a reduced follow-up examination time and safe remote monitoring. Further, the success rate and accuracy of the automatic pacing threshold determination function have not been sufficiently clarified. Methods: We evaluated 456 patients (male/female: 269/187, age: 70.4±13.3 years, pacemakers/defibrillators: 341/115) with cardiac implantable devices that had an automatic pacing threshold measurement function (the atrium and ventricle/ ventricle only: 298/158). We measured their pacing thresholds with both the automatic and manual methods at periodic device examination visits. Patients who had a high threshold (>4.0V/0.4ms) or out-of-range lead impedance (>2000 or <200Ω) were excluded from the analysis. Results: An automatic pacing threshold was obtained successfully in 206/274 (75.2%) patients in the atrium and in 392/443 (88.5%) in the ventricle. The automatic pacing threshold differed from the manual threshold by more than 1.0mV at the same pulse width in 12 (4.0%) patients in the atrium and in 5 (1.1%) in the ventricle. The success rate of the automatic pacing threshold determination differed depending on which generator manufacturer was used. The success rate for each manufacturer (Medtronic, St. Jude Medical, Biotronik and Sorin) was 167/173 (96.5%), 9/64 (14.1%), 30/37 (81.1%), and 0/0 in the atrium, and 223/224 (99.6%), 79/102 (77.5%), 68/85 (80.0%), and 22/32 (68.8%) in the ventricle, respectively. Regarding the success rate, Medtronic devices were superior to the others in both the atrium and ventricle (P<0.001-P=0.039). St. Jude Medical devices were inferior to the others in the atrium (p<0.001). There were no other significant factors affecting the success rate. The correlation between the pacing threshold measured by the automatic method and that by the manual method was significant in the atrium (r=0.558, P<0.001) and ventricle (r=0.779, P<0.001). Conclusions: The success rate of the automatic pacing threshold determination depended on which generator manufacturer was used. The measurable threshold values using the automatic method were acceptably correlated with those measured by the manual method.