Treadmill exercise test in aortic stenosis and mitral stenosis.

Area of Science:

• Cardiology
• Exercise Physiology

Background:

• Submaximal treadmill exercise tests are commonly used to assess cardiac function.
• Ischemic S-T segment depression on electrocardiography (ECG) typically suggests myocardial ischemia.

Purpose of the Study:

• To evaluate the incidence of positive submaximal treadmill exercise tests in patients with significant mitral stenosis (MS) and aortic stenosis (AS).
• To determine if valvular heart disease, in the absence of left ventricular hypertrophy (LVH) or coronary artery disease (CAD), can cause positive exercise test results.

Main Methods:

• Retrospective analysis of patients with MS and AS undergoing submaximal treadmill exercise testing.
• Exclusion criteria included ECG evidence of LVH and normal coronary arteries on angiography.
• Positive test defined as >= 1.0 mm ischemic S-T segment depression.

Main Results:

• 37% (7/19) of patients with AS (gradient 53-80 mm Hg) exhibited positive treadmill tests.
• 20% (3/15) of patients with MS (mean gradient 11-22 mm Hg) showed positive treadmill tests.
• All patients had normal coronary arteries and no ECG evidence of LVH.

Conclusions:

• Significant valvular stenosis, even without LVH or CAD, can lead to positive submaximal treadmill exercise tests.
• Positive tests in this population may result from an imbalance between myocardial oxygen supply and demand.
• These findings highlight the importance of considering valvular heart disease in the interpretation of exercise stress tests.