Objective: To determine whether longitudinal left ventricular systolic function measured by Doppler tissue imaging (DTI) after exercise can identify early left ventricular dysfunction in asymptomatic patients with moderate-severe aortic stenosis.
Design: Case-control study.
Setting: Outpatient cardiology departments.
Patients: 20 patients with aortic stenosis, with or without equivocal symptoms, a peak aortic valve velocity > or =3 m/s, and left ventricular ejection fraction >50% and 15 aged-matched normal controls.
Interventions: Echocardiogram performed at rest and immediately after treadmill exercise.
Main outcome measures: The peak systolic velocity of the lateral mitral annulus (S') by DTI at rest and immediately after exercise, exercise capacity, exercise systolic blood pressure and the plasma level of B-type natriuretic peptide (BNP).
Results: For patients with aortic stenosis, mean (SD) aortic valve area was 0.95 (0.3) cm(2). At rest, S' was similar for patients with aortic stenosis and controls, respectively (8.5 (1.5) vs 9.1 (1.8) cm/s, p = 0.15). However, after exercise, S' (12.2 (3.2) vs 17 (2.8) cm/s, p<0.001) and the increase in S' between rest and exercise (4 (3) vs 7.9 (1.5) cm/s, p<0.001) were lower in patients with aortic stenosis. In patients with aortic stenosis, a smaller increase in S' after exercise was associated with lower exercise capacity (r = 0.5, p = 0.02), a smaller increase in exercise systolic blood pressure (r = 0.6, p = 0.005) and higher plasma level of BNP (r = 0.66, p = 0.002).
Conclusion: In asymptomatic patients with moderate-severe aortic stenosis a lower than normal increase in peak systolic mitral annular velocity after treadmill exercise is a marker of early left ventricular systolic dysfunction.