Sinus node dysfunction after heart transplantation - How much pacing is required?

IntroductionWe investigated the development of sinus node dysfunction (SND) requiring pacemaker implantation after heart transplant (HTx) especially regarding pacing burden in these patients. Patients and methodsPatients requiring a pacemaker for SND were compared to all other patients in an HTx cohort including transplant patients from 1981 to 2016. ResultsSinus node dysfunction requiring pacemaker implantation developed in 118 patients (10%). These patients had received a biatrial anastomosis more frequently than those in the No SND group 95.8% vs 90.0% (P=.042). The ratio of reperfusion time to aortic cross-clamp time was significantly smaller in the SND group compared to the No SND group 71.7% vs 80.3% (P=.033). This also holds for the ratio of reperfusion time to ischemia time, which was 23.2% and 28.6%, respectively (P=.032). Pacing burden decreased from 90.5% to 66.3% after 2years and remained around this value in the remaining 4years of follow-up. ConclusionWe identified the biatrial anastomosis and a low ratio of reperfusion time to aortic cross-clamp time as well as to ischemia time as risk factors for SND requiring pacing. After implantation pacemakers continue to pace for over 60% of the time after 6years.