Congratulations on your weight loss and recovering left ventricular function. There are many things that can cause right ventricular dilation during exercise, so it's impossible for me to make any specific recommendations. I would recommend losing weight, though. I would also consider an evaluation for obstructive sleep apnea. In my clinical experience, weight loss and/or correction of sleep apnea can improve cardiovascular function and signs of right heart strain during exercise. Good luck!