Chronotropic incompetence and exercise capacity after cardiac surgery with left atrium incision

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Chronotropic incompetence (CI) is sometimes observed during exercise training cardiac rehabilitation in patients who underwent surgery, however, little known which factors affect to the incidence CI and capacity those patients. Purpose Because possibility exists that sympathetic nerves might be impaired by surgical procedure, moreover after mitral valve we hypothesized was higher with left atrium incision (LAI) operation as compared without LAI. And if so, factor determines surgery We thus aimed this study elucidate hypothesis cardiopulmonary testing (CPX). Methods performed CPX total 153 had undergone elective (45 LAI, age 60.5±11.0; 108 62.0±11.7). analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), pulse VO2/HR) CPX, echocardiography, blood hemoglobin concentration (Hb). Results The value CRI significantly reduced LAI (with 0.24±0.22 vs. LAI; 0.44±0.18, p<0.001). Exercise such VO2), showed no significant difference between two groups. In VO2 correlations VO2/HR; r=0.36, p<0.05), Hb (r=0.40, p<0.01) dimension (LAD) measured echocardiography (r=-0.54, Conclusions present demonstrated shown Moreover VO2/HR, LAD. These results suggest 1) impairs causes CI, 2) VO2/HR essential element are important for CI. Left enlargement may indicates pre-operative damages atrium, 3) LAD indicate function, also an