Quantitation of the gain in mortality in life-time after pacemaker treatment.

A total of 140 patients given permanent pacemaker 1963--73 were followed during three years with regard to survival. Indication of pacemaker implantation was AV block in 82% and disturbed consciousness in 84%. The first half of the series had a survival equal to that of the second half. The survival was 86, 73 and 64% and the excess mortality, which is above normal, was 9, 16 and 20% after one, two and three years, respectively. Concepts of fractional life-time and death-time were developed. These express the proportion of the total observation time that is life and death, respectively. The fractional life-time was 0.80 and the fractional death-time 0.20. The excess death-time was 0.12 (12%) of the total observation time. Mortality, survival, life-time and death-time were compared in three studies, the present one and two from Denmark. The great similarities were obvious. An estimation of the unpaced survival during three years, based on studies of AV block before the pacemaker era, indicated the great benefit of pacemaker treatment.