Improved cardiac function and quality of life following upgrade to dual chamber pacing after long-term ventricular stimulation

Aims Many patients with sinus node disease or atrioventricular block have previously received pacemakers with only ventricular stimulation (VVI or VVIR). This study aimed to investigate whether quality of life and cardiac function were affected by an upgrade to dual chamber pacing (DDDR or DDIR) following long-term ventricular stimulation. Methods After implantation of an atrial lead and a DDDR pulse generator, a randomized, double-blind crossover study was performed in 19 patients, previously treated with ventricular pacing for a median time of 6center dot8 years. Patients were randomized to 8 weeks with either VVIR or DDDR/DDIR pacing; after this time, the other mode was programmed for 8 weeks. At the end of each period, the patients' quality of life was evaluated and echocardiography was performed together with Holter monitoring and blood samples for brain natriuretic peptide. Results Sixteen of the patients preferred DDDR and two VVIR pacing (P=0center dot001); one was undecided. Seven patients demanded an early crossover while paced in the VVIR mode, vs none in the DDDR mode (P=0center dot008). Quality of life was higher in the DDDR mode in 11 of 17 modalities, reaching statistical significance for dyspnoea (P<0center dot05) and general activity (P<0center dot05). Echocardiography showed significantly larger left ventricular end-diastolic dimensions in the DDDR mode (P=0center dot01), whereas end-systolic dimensions did not differ. Left ventricular systolic function was significantly superior in the DDDR mode (mean aortic velocity--time integral: P<0center dot001) and left atrial diameter was significantly smaller in the DDDR mode (P=0center dot01). The plasma level of brain natriuretic peptide was significantly lower in DDDR mode (P=0center dot002). Conclusion An upgrade to dual chamber rate adaptive pacing results in significantly improved quality of life and cardiac function as compared to continued VVIR stimulation and should thus be considered in patients with ventricular pacemakers who have not developed permanent atrial fibrillation or flutter. (Less)