Treadmill exercise in apparently asymptomatic patients with moderate or severe aortic stenosis: relationship between cardiac index and revealed symptoms

Abstract

Revealed symptoms on treadmill exercise in apparently asymptomatic aortic stenosis were associated with lower peak myocardial VO(2) and lower peak stroke index during exercise. The strongest resting predictor of revealed symptoms and of peak cardiac index was the blood BNP level.

Cardiopulmonary Exercise Testing in Patients with Asymptomatic or Equivocal Symptomatic Aortic Stenosis: Feasibility, Reproducibility, Safety and Information Obtained on Exercise Physiology

“…This observation is in contrast with previous reports that used patients with similar degrees of aortic stenoses, but indicated that increases in cardiac output occurred only via increases in heart rate [15]. It agrees, however, with a more recent study that included 37 patients with asymptomatic aortic stenoses [5]. We found a trend toward more frequent abnormal trajectories in those who had values for Vmax greater than 5 m/s, suggesting that with such severe aortic stenosis a significant decrease in stroke volume at peak exercise may be more common.…”

“…These measurements often facilitate a more detailed assessment of the cause of a functional limitation [6]. Determining cardiac output during exercise via inert gas rebreathing (IGR) is promising in patients with heart failure or aortic stenoses [5,7]. Cardiac output and stroke volume, as assessed by either pVO 2 and pO 2 pulse or IGR during exercise, are of great pathophysiological importance in patients with aortic stenoses.…”

“…Furthermore, such predictive values may be inflated by knowledge of the test results [4]. When aortic stenosis is the culprit of a patient's symptoms, the underlying pathophysiology typically includes the inability to increase or maintain stroke volume, which reduces cardiac output and oxygen delivery during exercise [2,5]. During cardiopulmonary exercise testing (CPX), a number of cardio-respiratory parameters are measured, including peak oxygen consumption (pVO 2 ) and peak oxygen pulse (pO 2 pulse), which reflect cardiac output and stroke volume, respectively.…”

Determinants and Functional Significance of Myocardial Perfusion Reserve in Severe Aortic Stenosis

“…There is a paucity of studies in AS, although patients with moderate to severe asymptomatic AS who are limited by symptoms on exercise testing do have lower peak VO 2 and cardiac index than those who are limited by fatigue (10). Resting echocardiographic measures of stenosis severity and ejection fraction do not predict exercise capacity, although LVH and diastolic dysfunction may be important (3,11).…”

Almanac 2011: valvular heart disease. The national society journals present selected research that has driven recent advances in clinical cardiology

“…These results thus suggest that exercise stress echocardiography may provide prognostic information additional to that obtained by standard exercise testing and resting echocardiography 10. Symptoms on treadmill exercise testing in 38 apparently asymptomatic patients with at least moderate AS were associated with a lower peak myocardial VO 2 , a lower peak stroke index during exercise and BNP levels 11. Increased valvuloarterial impedance (Z(va)) (which is calculated by dividing the estimated LV systolic pressure (systolic arterial pressure + mean transvalvular gradient) by the stroke volume indexed for the body surface area) is a marker of excessive LV haemodynamic load, and a value >3.5 successfully identifies patients with AS with a poor outcome 12.…”