Published in:
01-09-2014 | Original Investigation
Kinetics of left ventricular rotation during exercise and its relation to exercise tolerance in atrial fibrillation: assessment by two-dimensional speckle tracking echocardiography
Published in: Journal of Echocardiography | Issue 3/2014
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Background
Left ventricular (LV) rotation plays an important role in cardiac function both at rest and during exercise in sinus rhythm. The kinetics of rotation during exercise and the relation between exercise tolerance and rotation-related parameters in patients with atrial fibrillation (AF) are unknown.
Methods
Twenty-nine patients (age 62 ± 13 years, 6 females) with AF and preserved LV ejection fraction (LVEF) were studied using two-dimensional speckle tracking echocardiography at rest and during exercise with a supine bicycle ergometer (20 W, 10 min). We measured the systolic rotation (Rot) and the peak rotation rate in systole and early diastole (eRotR) at the apical and basal levels of the LV. All patients underwent cardiopulmonary exercise testing to obtain their percent achieved of the predicted peak oxygen consumption (% peak VO2) value.
Results
During exercise, apical Rot-related indices were significantly increased only in the preserved % peak VO2 group. In contrast, E/e′ was significantly elevated only in the reduced % peak VO2 group. Multivariable stepwise regression analysis showed that apical ΔRot was independently associated with % peak VO2 (β = 0.72; p < 0.01). Apical ΔeRotR, which could not be selected as an independent predictor of % peak VO2, had a good linear correlation with apical ΔRot (r = 0.81, p < 0.01).
Conclusions
The augmentation of apical rotation in response to exercise may coincide with an increase of the apical derotation rate, and apical rotation reserve may reflect exercise tolerance in patients with AF and preserved LVEF.