AMBULATORY MONITORING OF LEFT-VENTRICULAR FUNCTION - WALK AND BICYCLEEXERCISE IN CONGESTIVE-HEART-FAILURE

The aim of this study was to assess changes in left ventricular (LV) f unction during 6-min walk test and cardiopulmonary exercise by continu ous radionuclide monitoring in patients with congestive heart failure (CHF). Methods: Seventeen patients with CHF and 10 normal subjects und erwent monitoring of LV function (Vest) during 6-min walk test and dur ing bicycle exercise with combined analysis of pulmonary gas exchange. During cardiopulmonary exercise, all parameters of LV function were m easured at rest, at the anaerobic threshold (AT) and al peak oxygen up take (peak VO2). Results: In the normal subjects, during the walk test , heart rate (HR), ejection fraction (EF), end-diastolic volume (EDV), cardiac output (CO) and stroke volume (SV) significantly increased fr om rest to peak (all p < 0.001), while end-systolic volume (ESV) signi ficantly decreased from rest to peak (p < 0.001). In patients with CHF , during the walk test, HR, EDV, ESV and CO significantly increased fr om rest to peak (p < 0.001), EF significantly decreased from rest to p eak (p < 0.001) and SV did not show significant change. During cardiop ulmonary exercise, normal subjects showed a significant increase in HR and CO, from rest to AT and from AT to the peak VO2 (p < 0.001). EF, EDV and SV significantly increased from rest to AT (p < 0.001), with n o significant change from AT to peak VO2. ESV decreased from rest to A T (p < 0.001), showing no significant change from AT to peak VO2, In p atients with CHF, HR, CO, ESV and EDV increased significantly from res t to AT (p < 0.001) and from AT to peak VO2 (p < 0.001), EF and SV did not show significant changes from rest to AT, showing a significant d ecrease from AT to peak VO2 (p < 0.001), Conclusion: Vest can be used to evaluate cardiac responses during 6-min walk test and cardiopulmona ry exercise in patients with CHF. In such patients, significant impair ment of LV function is already present during submaximal physical exer cise becoming more evident during the anaerobic phases of bicycle exer cise.