Investigation of Heart Function in Patients With Heart Valve Defects
Investigation of Heart Function in Patients With Heart Valve Defects
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.
In this investigation, we propose to perform dobutamine stress transesophageal
 echocardiography in patients with aortic regurgitation and in patients with mitral
 regurgitation in order to assess myocardial contractile reserve. The purpose of the study is
 to determine whether the contractile reserve of the myocardium measured during dobutamine
 stress echocardiography is a predictor of the development of subsequent left ventricular
 dysfunction and left ventricular dilatation, as well as recovery of left ventricular function
 after surgery, in these patients.
18 - 65 years of age.

 Patients with severe aortic regurgitation and patients with severe mitral regurgitation.

 Patients will discontinue medications 48 hours prior to the study.

 Women must not be pregnant.

 Patients must not have an associated valvular heart disease (i.e., patients with aortic
 regurgitation will be excluded if there is coexistent mitral valve disease; patients with
 mitral regurgitation will be excluded if there is coexistent aortic valve disease).

 Patients must not have any form of cardiomyopathy.

 Patients must not have coronary artery disease.

 Patients must not have ventricular ectopy during baseline conditions (i.e., couplets,
 frequent PVc's [greater than 6/min], early coupling ["R-on-T" phenomenon], ventricular
 bigeminy) that might potentially predispose the patient for the development of dangerous
 dysrhythmia during dobutamine infusion.

 Patients must not have a history of cardiac arrest or ventricular tachycardia.

 Patients must not have a history of congestive heart failure.

 Patients must not have hypotension (i.e., systolic blood pressure less than 100 mmHg).

 Patients must not have a systolic blood pressure greater than 200 mmHg.

 Patients must not have a left atrial size of greater than 100 mm.

 Patients must not have atrial fibrillation.

 Patients must not have sinus tachycardia greater than or equal to 100 beats/min.

 Patients must not have esophageal disease.

 Patients must not have any other medical condition that , at the discretion of the
 physician in charge, may increase the risk of the procedure.