E. Kanoupakis et al., Left ventricular function and cardiopulmonary performance following surgical treatment of morbid obesity, OBES SURG, 11(5), 2001, pp. 552-558
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.