M-mode echocardiography in the diagnosis of Ebstein's anomaly of the tricuspid valve.

M-mode echocardiograms of six patients with a diagnosis of Ebstein's anomaly and confirmed by cardiac catheterization were reviewed. All the patients (5 females and 1 male) were Caucasians with their ages ranging from one day to ttoenty-six years. The tricuspid valve was easily located in all the echocardiographic studies. There was a 45 to 100 msec. delay in tricuspid valve closure as compared to the mitral valve closure, in all patients. The aniplitude of the anterior tricuspid valve wasfound to be greater than the amplitude of the anterior mitral valve in all but one case. Paradoxical septal movement type A was observed in four cases. None of the cases -had a right ventricular end diastolic diameter that was larger than the left ventricular end diastolic diameter. The study found that it was extremely difficult to specift'cally diagnose Ebstein's anomaly with Mmode echocardiography alone, as each case has not been able to meet with all the criteria for diagnosis, described by various investigators.