Pulse amplitude adjustment provides immediate pacemaker longevity gain

Objective: Adjusting pacemaker pulse amplitude influences the longevityof the pacemaker. Our aim was to establish the initial longevitygain.Methods: Forty randomly selected patients with implanted pacemakerswere analyzed. Mean age was 65.58±13.7 years. All pacemakerswere working on factory settings of pulse amplitude 3.5V and pulse width of 0.4 ms for average of 3 years before the adjustment. Initialmean longevitywas projected to 68.61±18.86 months, mean battery voltage 2.78V, and mean battery current 14.21±2.61 µA.Results: Pulse amplitude threshold test was performed and average value of 0.632±0.22V was obtained. Pulse amplitude was programmedto 2.5V and pulse width was left unchanged. New readings of battery data were obtained. Battery voltage did not show immediate changes,and battery current decreased to 11.53±1.98 µA . New average longevitywas projected to 81.03±19.82 months, which presents a 12.42months of initial longevitygain with statistical significance at 95% confidence interval (p=0.003). Positive correlation was found betweenthe new pulse amplitude and new valuesof battery current (p<0.01).Conclusion: Pulse amplitude decrease of only 1V provides significant initial longevitygain of more than a year. If found correlations would haveany impact on further longevitygains over longer period of time is yet to be established. (Anadolu Kardiyol Derg 2007: 7 Suppl 1; 216-8)Key words:pacemakers, longevity, pulse amplitude, pulse width, pacing threshold