Upgrading from VVI to DDD pacing Mode during elective replacement of pulse generator: a comparative clinical-functional analysis.

OBJECTIVE Evaluate the clinical and functional behavior of the ventricular and atrioventricular stimulation modes in the elective replacement of pulse generator in patients with chagasic cardiopathy and atrioventricular block. METHODS Twenty-seven patients under ventricular and atrioventricular stimulation were comparatively evaluated at the beginning of the study, and alternately in ventricular and atrioventricular modes in two 90-day phases, with regard to: the clinical behavior evaluated according to quality of life and functional class, and the functional behavior evaluated by transthoracic echocardiography and the six-minute walk test. The statistical analysis was performed with patients at baseline, and under ventricular and atrioventricular modes, using the chi-square test and the repeated measures analysis of variance, and taking into consideration a 0.05 level of significance. RESULTS The mean quality-of-life scores were: functional capacity (VVI 71.3+/-18.2 , DDD 69.3+/-20.4); overall health status (VVI 68.1+/-21.8, DDD 69.4+/-19.4) and vitality (VVI 64.8+/-24.6 , DDD 67.6+/-25.5); on echocardiography: LVEF (VVI 52.5+/-12.8 , DDD 51.8+/-14.9), LVDD (VVI 53.0+/-7.7 , DDD 42.4+/-7.8), LA (VVI 38.6+/-5.4 DDD 38.5+/-5.1), and in the six-minute walk test: distance walked (VVI 463.4+/-84.7, DDD 462.6+/-63.4). There were four cases of complications, three of them associated with the change in stimulation mode. CONCLUSION This study showed no differences between the two stimulation modes in the clinical behavior assessed by quality of life and functional class, and in the functional behavior, evaluated according to the ecochardiographic findings and the six-minute walk test.