Value of pulmonary venous flow characteristics in the assessment of severity of native mitral valve regurgitation: an angiographic correlated study.

To evaluate the relation between left ventricular angiography and pulmonary venous flow velocity in native mitral valve regurgitation, 28 patients with sinus rhythm and valvular and/or coronary artery disease underwent transesophageal echocardiography within 24 hours after cardiac catheterization. Group I consisted of 17 patients, seven patients without (grade 0) and 10 patients with angiographically mild to moderate mitral regurgitation (grades 1 and 2). Group II consisted of 11 patients with angiographically severe mitral regurgitation (grades 3 and 4). Mitral regurgitation by transesophageal echocardiography was evaluated by measuring the regurgitant jet sizes and color-guided pulsed Doppler pulmonary venous flow velocities. Multivariate analysis revealed that the most powerful predictor (p less than 0.001) of angiographically severe (grades 3 and 4) mitral regurgitation was reversed systolic flow into the left upper pulmonary vein (sensitivity 82%, specificity 100%, positive predictive value 100%). If this variable was excluded from analysis, jet area and jet length (p less than 0.001) were the next best predictors for angiographically severe mitral regurgitation. Mean values of systolic peak pulmonary venous flow velocities were significantly lower in patients from group II, 13.0 +/- 11.1 cm/s versus 43.4 +/- 20.6 cm/s (group I) with p less than 0.005. This finding was also true for systolic time velocity integral, 1.3 +/- 1.3 cm (group II) versus 7.8 +/- 5.3 cm (group I) with p less than 0.005.(ABSTRACT TRUNCATED AT 250 WORDS)

Performance characteristics of a 511-keV collimator for imaging positron emitters with a standard gamma-camera.

Line-source experiments were conducted to assess the performance of a gamma-camera equipped with a specially designed 511-keV collimator for the planar imaging of positron emitters. The results were compared with the camera performance with routinely used collimators and radionuclides (thallium-201, technetium-99m and gallium-67). With positron emitters, scatter contributed less to the widening of the line spread function than with radionuclides emitting lower photon energies. These observations can be explained by the relative deterioration in the discrimination power of the gamma-camera to reject scattered radiation at low energies. Planar 511-keV imaging may provide relevant clinical information, as we showed by fluorodeoxyglucose studies in a patient with a myocardial infarction and in a patient with a malignant lymphoma. It is concluded that positron emitters can be effectively applied for planar imaging with the generally available gamma-cameras. This study implies that radiotracers developed for positron emission tomography may find a place in the practice of conventional nuclear medicine.

Transesophageal color flow Doppler mapping in the assessment of native mitral valvular regurgitation: comparison with left ventricular angiography.

Transesophageal echocardiography (TEE) was performed within 24 hours after cardiac catheterization in 45 patients for assessment of native mitral valvular regurgitation. Color flow mapping was used in evaluating systolic regurgitant jet sizes. A jet demonstrated by TEE was 96% sensitive and 44% specific for angiographic mitral regurgitation. The presence of angiographic mitral regurgitation was best predicted by (single measurement) (1) a holosystolic jet, (2) a jet length greater than 2.5 cm, and (3) a jet area greater than 2 cm2. Severe angiographic mitral regurgitation (grades 3 and 4) was best predicted by (single measurement) (1) a jet area greater than 5 cm2, and (2) a jet length greater than 4 cm. It is concluded that the assessment of angiographic mitral regurgitation by TEE is improved by the measurement of these jet parameters, which have a high sensitivity and higher specificity than the presence of a jet alone. Furthermore, with TEE one is able to differentiate severe (grades 3 and 4) from absent or mild mitral regurgitation (grades 0, 1, and 2).