Failure of Stroke Volume Augmentation During Exercise and Dobutamine Stress Is Unrelated to Load-Independent Indexes of Right Ventricular Performance After the Mustard Operation

Abstract

The stroke volume response to exercise stress is reduced in patients after the Mustard operation. A similar failure to augment stroke volume occurs during dobutamine stress despite appropriate responses in load-independent indexes of contraction and relaxation. This is due to failure to augment right ventricular filling rates during tachycardia, presumably as a result of impaired AV transport, consequent to the abnormal intra-atrial pathways.