Isometric exercise testing and echocardiography at rest in aortic valve incompetence

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Diagnostic Imaging

Background:

• Aortic valve incompetence (AVI) can lead to left ventricular (LV) dysfunction.
• Assessing LV functional reserve during stress is crucial for managing AVI.

Purpose of the Study:

• To evaluate the functional response of the left ventricle to exercise in patients with aortic valve incompetence.
• To determine if resting echocardiography or radionuclide parameters can predict the ejection fraction response during handgrip exercise in AVI patients.

Main Methods:

• M-mode echocardiography and radionuclide ventriculography were performed on 30 AVI patients and 21 controls.
• Measurements were taken at rest and during submaximal handgrip exercise.

Main Results:

• AVI patients exhibited larger LV dimensions and higher end-systolic wall stress at rest compared to controls.
• Controls showed a significant increase in ejection fraction during exercise (+3 +/- 4%), while AVI patients did not (-1 +/- 5%).
• Symptomatic AVI patients had a significantly different ejection fraction response to exercise compared to controls (p < 0.01).
• Resting echocardiographic and radionuclide parameters did not correlate with individual ejection fraction changes during handgrip exercise.

Conclusions:

• The functional response to handgrip exercise in aortic valve incompetence is not predictable by resting left ventricular size, function, or systolic loading conditions.
• Radionuclide angiography is essential for assessing the dynamic functional reserve in AVI patients during stress.