ARDMS AE-Adult-Echocardiography Exam With Confidence Using Practice Dumps

Comprehensive and Detailed Explanation From Exact Extract:

Ebstein anomaly is a congenital malformation characterized by apical displacement of the tricuspid valve leaflets, leading to atrialization of the right ventricle and severe tricuspid regurgitation. The most common associated defect is an atrial septal defect (ASD), particularly a secundum type or patent foramen ovale, resulting in right-to-left shunting and cyanosis.

Ventricular septal defect and pulmonary stenosis are less commonly associated. Tricuspid stenosis is not typical; the tricuspid valve is usually regurgitant rather than stenotic.

This association is well described in congenital heart disease and echocardiography textbooks and ASE guidelines【16:Textbook of Clinical Echocardiography, 6e†p.570-575】【12:ASE Adult Congenital Guidelines†p.400-405】.

During dobutamine stress testing, a normal physiological response includes increased myocardial contractility leading to a decrease in left ventricular (LV) cavity size during systole due to more effective ejection. Concurrently, systolic blood pressure increases due to the inotropic and chronotropic effects of dobutamine.

An increase in LV cavity size during stress would suggest impaired contractility or ischemia, which is abnormal.

This normal response is detailed in the "Textbook of Clinical Echocardiography, 6e", Chapter on Stress Echocardiography and Hemodynamic Responses【20:400-405†Textbook of Clinical Echocardiography】.

In significant aortic valve regurgitation (AR), the continuous wave Doppler signal across the valve demonstrates a rapid decline in regurgitant jet velocity, resulting in a pressure half-time (PHT) less than 250 milliseconds. A short PHT indicates severe AR with rapid equalization of aortic and left ventricular pressures during diastole.

Pulsed wave Doppler forward flow in the abdominal aorta evaluates stroke volume but does not directly indicate AR severity. Vena contracta to LVOT diameter ratio less than 25% would indicate mild AR, not significant. Peak velocity ≥4.5 m/s is more characteristic of aortic stenosis rather than regurgitation.

This criterion for AR severity using CW Doppler PHT is described in the "Textbook of Clinical Echocardiography, 6e", Chapter on Aortic Regurgitation Doppler Assessment【20:375-380†Textbook of Clinical Echocardiography】.