Kunio Miyatake

Determination of the Source of Musical Heart Murmur Using Two-Dimensional Doppler Echocardiography

Musical heart murmur is a special form of heart murmur, because of its characteristic acoustical properties (1). So far, the source of musical heart murmurs has been thought to be the vibration of comparatively elastic tissue by the blood flow (2). In some instances, small vibrations are observed by M-mode echocardiography in patients with musical heart murmur (3, 4, 5). However, such conditions are generally difficult to prove in vivo.

Assessment of Tricuspid Regurgitation by Two-Dimensional Doppler Echocardiography

Attempts were made to assess tricuspid regurgitation with two-dimensional Doppler echocardiography. The study consists of two parts. Part 1 is a study on the detection and grading of tricuspid regurgitation by means of two-dimensional Doppler echocardiography, and Part 2 is the comparison of Doppler echocardiography and contrast echocardiography in the assessment of tricuspid regurgiation.

Prediction and Diagnosis of Low Cardiac Output Syndrome After Open-Heart Surgery: An Echocardiographic Study

Although there are various causes of multiple organ failure (MOF), low cardiac output syndrome (LOS) is the major cause after open-heart surgery. The hemodynamic situation is unstable, and LOS frequently occurs soon after cardiac surgery. Therefore, it would be helpful if LOS could be predicted beforehand. Once LOS occurs, early diagnosis of its cause is indispensable to adequate treatment. We examined the above two points using echocardiography.

Analysis of Mitral Regurgitation in Hypertrophic Cardiomyopathy by Two-Dimensional Doppler Echocardiography

Mitral regurgitation is often a complication in hypertrophic cardiomyopathy. However, it has not yet been definitely confirmed whether this mitral regurgitation is a natural complication or partly an artificial phenomenon during angiocardiography. In the present study, this mitral regurgitation was noninvasively examined by means of two-dimensional Doppler echocardiography, in order to determine if it is present under conditions which are as near to normal as possible. Based on the results obtained, the relationship between mitral regurgitation and heart murmur was also studied.

Clinical utilities of single-photon biochemical tracers in estimating pathophysiologic processes in heart failure: 123I-BMIPP and 123I-MIBG

Abstract Information about myocardial perfusion and function has limitations in the assessment of disease severity and prognosis in patients with heart failure. Information about myocardial biochemistry may actually be more important in patient management. In vivo assessment of myocardial biochemistry, which started from the use of positron emission tomography, is now becoming a reality with the use of single-photon emission tomography (SPET). 123 I-BMIPP as a fatty acid tracer and 123 I-MIBG as a norepinephrine (NE) tracer are already used for clinical assessment here in Japan. In this chapter, based on our experiences, we introduce the utilities of these two tracers in assessing disease severity, the effects of medical treatment and prognosis in patients with heart failure. In 123 I-BMIPP imaging, we could not characterize metabolic abnormalities specific for idiopathic dilated cardiomyopathy, but we identified utility in differentiating ischemic from idiopathic dilated cardiomyopathy based on a high prevalence of regional myocardial 123 I-BMIPP defects in ischemic cardiomyopathy. In 123 I-MIBG imaging, we recognized the utility of the washout rate (WR) of 123 I-MIBG from the heart as an index of sympathetic activation. It showed good correlations with the plasma NE concentration and the left ventricular ejection fraction. In addition, we recognized important utilities of WR in evaluating the effectiveness of β-blocker treatment and prognosis in patients with idiopathic dilated cardiomyopathy.

Flow Velocity Measurement and Differentiation Between True and False Lumens in Patients with Abdominal Aortic Dissection by Use of Pulsed Doppler Echocardiography

Feasibility of differential diagnosis between the true and false lumens was studied with pulsed Doppler echocardiography in 8 patients with abdominal aortic dissection. The blood flow signal was obtained in both lumens in 7 of the 8 patients and in only the true lumen in the remaining 1 patient. The blood flow pattern was abruptly changed when the sample volume was moved from the true lumen to the false one. The peak flow velocity was higher in the true lumen (95 ± 19 cm/sec) than in the false one (28± 12 cm/sec) and ejection flow duration was longer in the former (306 ±103 ms) than in the latter (163 ±53 ms). The appearance time of ejection flow was not different between them. The presence of reverse flow during the ejection phase was more frequent in the false lumen (5/7) than in the true one (2/8). Thus, the conventional pulsed Doppler study may provide useful information in making a differential diagnosis between the true and false lumens in patients with abdominal aortic dissection.