Direct visualization of ruptured chordae tendineae by transesophageal two-dimensional echocardiography. To determine the value of transesophageal echocardiography in the detection of ruptured chordae tendineae, 28 patients who had surgical therapy for pure mitral regurgitation were evaluated prospectively by conventional transthoracic and transesophageal two-dimensional echocardiography. Seventeen patients (Group I) had ruptured chordae tendineae and 11 (Group II) had intact chordae tendineae. Transthoracic echocardiography detected ruptured chordae tendineae in 6 patients from Group I (sensitivity 35%) and flail leaflets in 11 patients from Group I (sensitivity 65%). Transesophageal echocardiography disclosed ruptured chordae tendineae in all 17 Group I patients (sensitivity 100%); the sensitivity was significantly higher than that of transthoracic echocardiography. No abnormal chordal echoes were visualized in any patient from Group II by either transthoracic or transesophageal echocardiography (specificity 100%). Transesophageal echocardiography is a highly sensitive method for detecting ruptured chordae tendineae and is superior to transthoracic echocardiography in establishing its diagnosis. 