Device treatment of atrial tachycardia—minor additional effect of repeating pacing sequences

Purpose Ramp and burst pacing as treatment for atrial tachycardia (AT), one known trigger mechanism of atrial fibrillation (AF) are available in permanent pacemakers to reduce the burden of AF. An analysis of the success rate of three consecutive antitachycardia pacing sequences is presented. Method The AT 500 (Medtronic) pacemaker was implanted in 36 patients (18 female, mean age 77±11 years) with pacemaker indication due to tachybrady arrhythmias (n=34), and other indications (n=2). A standardized AT treatment of 8 sequences of ramp followed by six and four sequences burst pacing was programmed on after 1 month of tachycardia detection only. 5 consecutive sinus beats or 3 min with atrial rhythm not classified as AF or AT defined treatment success and was registered at 3 months follow-up. Results 2979 episodes (mean 85±316) in 17 patients (7 female) were treated and analyzed. The overall treatment success increased from 42±27% to 44±31% and 45±31% during the consecutive ATP sequences (ns). The average ATP success of the first ramp pacing sequences was 95±10%, the second ramp ATP sequence was successful in 3±6%, and the last ramp ATP sequence in 2±5%. Conclusion 95% of the 45% treatment success of a standard AT treatment was achieved by the first ramp pacing sequence. Further antitachycardia pacing sequences did not increase the success rate significantly.