Aortic Stenosis, Regurgitation and Anomalies of the Left Ventricular Outflow Tract

The anatomy of the left ventricular outflow tract and the morphology of the aortic valve can be well displayed by 2D echocardiography allowing the differentiation of subvalvular, valvular and supravalvular stenosis. Colour Doppler displays the jet across the stenotic valve or outflow tract and is essential in the assessment of aortic regurgitation. Pulsed wave and continuous wave Doppler provide the possibility to determine the peak instantaneous and the mean gradient of aortic stenosis. Information of the severity of aortic regurgitation is provided by CW Doppler interrogation of the regurgitant jet with determination of the end-diastolic gradient. Semiquantitative assessment of the severity of aortic regurgitation by determination of diastolic run-off from the aorta is provided by PW and CW Doppler interrogation of flow in the descending aorta and in the systemic arteries.