Introduction: Heart transplantation is becoming more popular in Russia nowadays. The transplanted heart is characterized by autonomic denervation, chronotropic incompetence and intermittent episodes of allograft rejection. Pacemaker-requiring bradyarrhythmias after cardiac transplantation are common, and rarely can lead to sudden cardiac death.
Materials: In our study we included 14 patients who were undergone cardiac transplantation and permanent pacemaker implantation from 2009 up to 2011 yy. We used dual chamber devices with active fixation leads.
Results: Recipients, aged 54±4 years (donors, 43 ±6 years), were monitored 24±5 months. Acute pacing thresholds were 1.2±0.25 V and 1.1±0.33 V for ventricular and atrial leads, correspondingly. Sensing of R-wave was 12.9±4.6 mV in acute postoperative period. One patient died from pneumonia within 1 month after transplantation. In all patients we programmed DDDR-mode with lower rate limit at 90 bpm , reduced it after 1 week up to 80, and after 6 months of observation - up to 70 bpm. After 1 year we found that the ventricular-pacing threshold slightly increased up to 1.6±0.3 V, and sensing of R-wave decreased to 8.8±3.2 mV. In two cases we observed a twofold decrease in sensing and increase in threshold, which was corresponded with chronic rejection 1A stage (ISHLT). Once we observed double sensing of P-wave (recipient’s sinus node signal) which required optimization of atrial sensing parameters.
Conclusions: Our preliminary data showed that decrease in pacemaker sensitivity and increase in pacing threshold may be considered as the sign of chronic rejection syndrome. Thus, remote monitoring systems should be used for such patients