Manifestation and significance of dynamic electrocardiogram after dual chamber pacemaker implantation in patients with sinus node dysfunction or conduction block

AIM To discuss the manifestation and significance of dynamic electrocardiogram (DCG) after dual chamber pacemaker was implanted in patients with sinus node dysfunction or conduction block. METHODS DCG was analyzed in 160 patients who had been implanted with DDD-type dual chamber pacemaker. The patients were divided into sinus node dysfunction group (n=80) and conduction block group (n=80). The manifestation of DCG, the main work pattern, chamber pace-making condition, autologous arrhythmia as well as the arrhythmia caused by pacemaker were compared between the two groups. RESULTS The pace making proportion of ≥ 60% in both sinus node dysfunction group and conduction block group was significantly higher than that of <60% (82% vs. 18%; 85% vs. 15%), with no significant difference between the two groups. The demand pacing mode in sinus node dysfunction group was higher than that in conduction block group (31% vs. 2%, P<0.01), while the chamber demand pacing mode/atrium demand pacing mode in sinus node dysfunction group was significantly lower than that in conduction block group (19% vs. 50%, P<0.01). The comparison of dual chamber demand pacing mode between the two groups showed no statistical significance (50% vs. 48%). The chamber pacing safety detectable rate in sinus node dysfunction group was significantly higher than that in conduction block group (25% vs. 12%, P<0.05), while the pacemaker fusion wave detectable rate in sinus node dysfunction group was significantly lower than that in conduction block group (35% vs. 51%, P<0.05). The detectable rate of chamber pacemaker-mediated tachycardia and perceptional tachycardia in sinus node dysfunction group was significantly higher than that in conduction block group (12% vs. 2%, 24% vs. 11%, P<0.05). The detectable rate of chamber tachycardia and frequent atrial premature beats in sinus node dysfunction group was also significantly higher than that in conduction block group (38% vs. 18%, 22% vs. 4%, both P<0.05). CONCLUSION After dual chamber pacemaker implantation, the corresponding work mode can be recognized by the manifestation of DCG in sinus node dysfunction patients and conduction block patients. Full knowledge of the pacemaker work mode will be good for reasonable control of the implanted pacemaker and autologous arrhythmia.