EXERCISE CAPACITY, ECHO PARAMETERS AND QUALITY-OF-LIFE IN SYMPTOM-FREE PATIENTS WITH VENTRICULAR PACEMAKERS UPGRADED

The aim of our study was to assess exercise capacity, some echocardiog raphic parameters and quality of life in symptom free patients with ve ntricular pacemakers and after upgrading to dual chamber devices. The study population consisted of 10 patients, aged 43 to 82 years, who we re largely symptom free after chronic VVI pacing for at least 12 month s. The indication for first implantation was I degrees or III degrees atrio-ventricular block in 7 patients and sick sinus syndrome in 3 pat ients. Patients, who showed a significant stroke volume increase in 2D with Echo Doppler examination during synchronized atrio-ventricular d ual chamber temporary pacing with an esophageal atrial lead and an int racardiac ventricular lead, were enrolled in the study. Change in obje ctive (treadmill exercise and echocardiographic indices) and subjectiv e (quality of life) results between pacing modes before and 2 months a fter upgrading were assessed. Exercise capacity was significantly bett er in DDD than in VVI mode (total exercise time: 339 +/- 115 s and 250 +/- 116 s, p<0.001; maximum oxygen uptake: 6.3 +/- 1.6 METS vs. 5.2 /- 2.0 METS, p<0.01). The stroke volumes were significantly higher in DDD than in VVI mode (p<0.01). We observed significant quality of life improvement regarding patients' physical health (p<0.001), mental sta tus (p<0.001), social interaction (p=0.52) and functional capacity (p< 0.01). We conclude that upgrading VVI devices to dual chamber pacing i n apparently symptom free patients, performed even after long-term VVI pacing, gives significant subjective and objective benefits.