Exercise-induced Wall Motion Abnormalities and Resting Left Ventricular Dysfunction in the Morbidly Obese as Assessed by Radionuclide Ventriculography.
Rest and exercise first pass radionuclide ventriculograms were obtained in 62 morbidly obese subjects (56 women, six men, mean age 38 years, mean weight 269.2 +/- 46.0 lb, mean height 65.2 +/- 3.1 in., mean Body Mass Index 44.5 +/- 6.2 kg/m(2), mean excess body weight 134.1 +/- 41.1 lb) scheduled for vertical banded gastroplasty. Fifty-six percent demonstrated exercise-induced wall motion abnormalities mimicking coronary disease, compared to 12% of controls (p = 0.03). No subject with exercise-induced abnormalities had coronary disease at cardiac catheterization although only those with an anginal chest pain history underwent angiography. Twenty-six percent demonstrated resting left ventricular systolic dysfunction as manifested by a reduced resting left ventricular ejection fraction ( <0.50). Thirty-one percent of these patients demonstrated exercise-induced abnormalities, versus 65% of morbidly obese subjects with normal resting ejection fractions (p = 0.04). Obesity-induced left ventricular hypertrophy with associated reduced coronary vasodilator reserve could explain the abnormalities. Six month post-gastroplasty follow-up radionuclide ventriculograms show group normalization of the resting left ventricular ejection fraction in those with preoperative dysfunction, possibly due to left ventricular unloading with some regression of hypertrophy.