Left ventricular function and cardiopulmonary performance following surgical treatment of morbid obesity

Background: It is well established that morbid obesity affects the respirat ory system and the diastolic function of the heart. During exercise, cardio pulmonary reserve is exhausted because of augmented requirements, leading t o a significant intolerance. A study was undertaken to investigate the infl uence of body weight loss on the characteristics of the left ventricle (LV) and on exercise capacity in obese patients before and 6 months following v ertical banded gastroplasty (VBG). Methods: 16 morbidly obese individuals (BMI >40 kg/m(2)) scheduled for VBG were studied. A symptom-limited cardiopulmonary exercise test and a complet e transthoracic echocardiogram were performed 1 day before operation and 6 months postoperatively (after the patients achieved a body weight loss of g reater than or equal to 20% of their pre-operative values). Results: Exercise duration increased significantly 6 months following surge ry. The mean O-2 consumption at peak exercise (peak VO2) and at the anaerob ic threshold (VO2AT) was significantly higher after weight loss. 6 months a fter VBG the LV thickness decreased significantly. Regarding the diastolic indices, isovolumic relaxation time (IVRT) and early/late (E/A) velocity ra tio, there was a significant improvement after weight loss. Simple linear r egression analysis revealed that peak VO2 and VO2AT were significantly corr elated with IVRT and E/A velocity ratio. Conclusions: Weight loss after VBG improves the cardiac diastolic function and this is associated with an improvement in cardiopulmonary exercise perf ormance. Left ventricular filling variables could be considered among the m ost important determinants of exercise intolerance in obese individuals.