Observational study.
Veterans Affairs Medical Center.
After the Institutional Review Board's approval, 8 patients (7 men and 1 woman; age, 62¡À5 y; and ejection fraction, 59 % ¡À5 % ) with AS (peak pressure gradient, 81¡À22 mmHg; aortic valve area, 0.78¡À0.25 cm2) scheduled for aortic valve replacement were compared with 8 patients (all men; age, 63¡À3 y; and ejection fraction, 60 % ¡À7 % ) without AS undergoing coronary artery bypass graft surgery.
None.
Under general anesthesia, peak early LV filling (E) and atrial systole (A) blood flow velocities and their corresponding velocity-time integrals were obtained using pulse-wave Doppler echocardiography to determine E/A and atrial filling fraction (¦Â). Mitral valve diameter (D) was calculated as the average of minor and major axis lengths obtained in the midesophageal bicommissural and long-axis transesophageal echocardiography imaging planes, respectively. Posterior wall thickness (PWT) was measured at end-diastole using M-mode echocardiography. VFT was calculated as 4¡Á(1?¦Â)¡ÁSV/¦ÐD3, where SV = stroke volume measured using thermodilution. Systemic and pulmonary hemodynamics, LV diastolic function, PWT, and VFT were determined during steady-state conditions 30 minutes before cardiopulmonary bypass. Early LV filling was attenuated in patients with AS (eg, E/A, 0.77¡À0.11 compared with 1.23¡À0.13; ¦Â, 0.43¡À0.09 compared with 0.35¡À0.02; p<0.05 for each). LV hypertrophy was observed (PWT, 1.4¡À0.1 cm compared with 1.1¡À0.2 cm; p<0.05) and VFT was lower (3.0¡À0.9 v 4.3¡À0.5; p<0.05) in patients with versus without AS. Linear regression analysis showed a significant correlation between VFT and PWT (VFT = ?2.57 ¡ÁPWT + 6.81; r2 = 0.345; p = 0.017).
The results indicated that pressure-overload hypertrophy produced by AS reduced VFT in patients with normal LV systolic function undergoing aortic valve replacement.