Abstract 2842: Changes In Right And Left Ventricular Ejection Dynamics After Gastric Bypass Surgery
Background: Right and left ventricular ejection may be desynchronized in patients with severe obesity due to obesity and sleep disordered breathing. Increased pulmonary arterial pressures have been associated with shortening of the time to peak RV outflow tract (RVOT) ejection velocity.
Methods: We prospectively followed 1185 severely obese subjects after assignment to GBS (n=440 ) or non-surgical therapy (n=745). At enrollment, 651 subjects had echocardiograms and a subset (n=164) had echocardiograms at 2 and 5 year follow up. For each echocardiogram, the time from the R-wave to onset and peak of ROVT and LVOT pulsed wave Doppler spectra were measured. Group means were compared with an unpaired t-test.
Results: At 2 and 5-year follow-up, time to peak of RVOT (pRVOT) was longer in GBS group (see figure⇓). At 5 year follow-up, time to onset of RVOT (oRVOT) (80.89(+/−24.35) vs 71.06(+/−19.71) ms p<0.05) and difference between RVOT and LVOT (−28.82(+/−34.27) vs. −8.63(+/−38.51) p<0.05) was longer in GBS group. BMI correlated with pRVOT at 2 and 5 year follow-up with R= −0.43 p<0.04 and −0.30 p<0.005 respectively. Total exercise time during 5 year follow-up had a trend of correlation with R= −0.21 p< 0.06.
Conclusion: Decreased BMI correlated with pRVOT. Increased pRVOT and oRVOT suggests a reduced after load and possible association with reduced pulmonary hypertension but further studies need to be performed to prove such correlation. Increased differences of RVOT and LVOT reflect the increased pRVOT and suggest improved synchronization. The trend of correlation with increased exercise time and pRVOT suggests clinical outcome improvement of patients with substantial weight loss.