Showing papers by "Jae K. Oh published in 1989"

Cardiac Tamponade: Characteristic Doppler Observations

Abstract: Abnormal respiratory variation in diastolic filling has been reported in patients with cardiac tamponade. To determine the characteristic diastolic filling abnormalities in this disorder, we recorded left ventricular isovolumic relaxation time and transvalvular and hepatic venous flow velocities by pulsed-wave Doppler echocardiography in 28 patients with pericardial effusion (16 with and 12 without cardiac tamponade) and 20 normal control subjects. The phase of respiration was recorded simultaneously with all profiles. In 13 of the 16 patients with cardiac tamponade, Doppler examination was repeated after pericardiocentesis. In patients with cardiac tamponade, respiratory variations in transvalvular flow velocities and isovolumic relaxation time were substantially increased in comparison with values in normal subjects, patients without tamponade, and those who had undergone pericardiocentesis. An exaggerated expiratory decrease in diastolic forward flow and increase in reverse flow in the hepatic vein also were characteristic of patients with cardiac tamponade. Thus, Doppler echocardiography is an additional noninvasive means of detecting hemodynamic compromise in patients with pericardial effusion.

Aortic Dissection: Review of Value and Limitations of Two-Dimensional Echocardiography in a Six-Year Experience

Abstract: The utility of transthoracic two-dimensional echocardiography in patients with aortic dissection was assessed by retrospective analysis in 67 patients: 31 patients with DeBakey type I, 21 patients with type 11, 10 patients with type III, and five patients with false-positive diagnoses. Aortic dissection was correctly identified by two-dimensional echocardiography in 49 patients; 13 had false-negative diagnoses. Therefore the sensitivity was 79%, and the positive predictive accuracy was 91%. Transthoracic two-dimensional echocardiography is a reasonable screening technique for diagnosis of aortic dissection.

Color Flow Imaging with Transesophageal Echocardiography

Abstract: Doppler color flow imaging is an angiographic substitute depicting blood flow and is considered an essential component of a comprehensive echocardiographic -examination. Transesophageal echocardiography has received increased application, primarily as a result of its incorporation of higher frequency transducers and color flow imaging.’ The visualization of regurgitant lesions, shunts, vascular anatomy, and unique normal and abnormal blood flow markedly enhances the diagnostic power of transesophageal echocardiography. Although color flow Doppler to date has not been found to be particularly quantitative in the assessment of blood flow, it does have attributes similar to those of conventional qualitative angiography. Gradation of regurgitation (i.e., mild, moderate, and severe) and visualization of normal and abnormal blood flow are in many instances a substitute for conventional angiography. This article describes some of the current applications of color flow imaging when performed in conjunction with a transesophageal echocardiography examination.