Investigation of Myocardial Contractile Reserve by Dobutamine Stress Transesophageal Echocardiography in Aortic and Mitral Regurgitation

In this study researchers plan to perform a diagnostic test called transesophageal echocardiography in order to see and record the movement and function of the heart.

Transesophageal echocardiography is similar to an upper gastrointestinal endoscopy. Different views of the heart are taken by a small, flexible instrument positioned in the esophagus (the tube that connects the mouth to the stomach). This allows doctors to create a clear picture of the heart through the wall of the esophagus rather than from outside the body through the muscles, fat, and bones of the chest wall.

During transesophageal echocardiography pictures of the heart will be taken while patients rest and as patients receive a medication called dobutamine. Dobutamine is a medication that makes the heart beat stronger and faster, similar to what exercise does to the heart.

Researchers are particularly interested in studying patients with defects in the valves of the heart, especially aortic regurgitation and mitral regurgitation. Patients with these defects in the heart valves tend to develop abnormalities in the size and function of the left ventricle. The left ventricle is one of the four chambers of the heart responsible for ejecting blood out of the heart into the circulation. Researchers believe that by identifying changes in the function of heart muscle, they may be able to predict the occurrence of muscle damage due to the diseased valves.

The purpose of this study is to determine whether the function of heart muscle measured during dobutamine stress transesophageal echocardiography can predict the later development of problems in the function and size of the left ventricle.