Discrete subaortic stenosis with pressure recovery: a case report

A 54-year-old woman with subvalvular aortic stenosis was admitted to our hospital. The pressure gradient across the left ventricular outflow tract was estimated as 88 mmHg (peak) and 45 mmHg (mean) by Doppler echocardiography, but only 14 mmHg (peak to peak) and 31 mmHg (mean) by cardiac catheterization. We considered this discrepancy attributable to the presence of moderate aortic regurgitation and the pressure recovery phenomenon. Pressure recovery has clinical relevance particularly in a patient with tunnel-like stenosis, with gradual lumen re-expansion beyond the limiting orifice. Therefore, if Doppler echocardiography shows significant left ventricular outflow tract gradient, precise evaluation of the stenosis geometry is required to investigate the effect of pressure recovery.