Biomedical subjects

J Tanouchi

Publications and source records attributed to J Tanouchi.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Variability of diastolic paradoxical jet flow in a patient with hypertrophic cardiomyopathy with midventricular obstruction: dissociation between systolic and diastolic intracavitary flow dynamics.

Variability of paradoxical jet flow in a case of hypertrophic cardiomyopathy with midventricular obstruction was examined. Propranolol decreased both peak diastolic paradoxical jet flow velocity and peak systolic velocity at the narrowing portion. Nitroglycerin decreased peak diastolic paradoxical jet flow velocity with an increase in peak systolic velocity at the narrowing portion. Thus the diastolic paradoxical jet flow is dynamic as well as the abnormal systolic flow; however, changes in these abnormal flow dynamics may not be necessarily in the same direction. Doppler echocardiography should be useful in assessing effects of interventions on the flow dynamics in patients with hypertrophic cardiomyopathy with midventricular obstruction.

Adult↗

PubMedDate not supplied

Transesophageal echocardiographic diagnosis of thoracic aortic dissection with the completely thrombosed false lumen: differentiation from true aortic aneurysm with mural thrombus.

The conventional criteria of aortic dissection with a completely thrombosed false lumen by transesophageal echocardiography is separation of the intima from the layer of thrombus; however, it is not always easy to distinguish from true aortic aneurysm with mural thrombus. Thus we proposed a new transesophageal echocardiographic diagnostic criteria. Seventeen operative patients with suspected subacute or chronic thoracic aortic dissection in whom it was difficult to exclude true aortic aneurysm with mural thrombus underwent transesophageal echocardiography. In thoracic aortic dissection with in completely thrombosed false lumen, the inner lesion surface composed of intima may be smooth and crescent-shaped thrombus may appear inside the wall surface. Therefore our criteria were on the basis of any two of the following: (1) high-echogenic lesion surface, suggesting intima, over the thrombus, (2) smooth lesion surface, and (3) crescent-shaped thrombus. Imaging data were referenced to intraoperative findings. According to the present criteria only two out of 17 patients were misdiagnosed, whereas according to the conventional criteria six patients were misdiagnosed. The sensitivity was significantly higher than when the conventional criteria were used (90% versus 40%; p < 0.05), whereas the specificity was similar. We conclude that the present transesophageal echocardiographic criteria for detection of thoracic aortic dissection with a completely thrombosed false lumen is clinically useful.

Aortic Dissection↗

PubMedDate not supplied

Reduction of endothelial microfilament bundles in the low-shear region of the canine aorta. Association with intimal plaque formation in hypercholesterolemia.

To interrelate in vivo wall shear stress, endothelial microfilament bundle formation, and atherosclerosis localization, we used a mild abdominal aortic stenosis in 11 beagles to produce a range of wall shear stresses above and below the constriction. Six of the beagles were fed standard animal chow supplemented with 5% cholesterol and 10% coconut oil. Wall shear stresses, endothelial microfilament bundles, and intimal plaque localization were assessed along the stenosed aorta. Shear stress was determined in vivo from the near-wall velocity profiles with a 20-MHz, 80-channel, multigate Doppler velocimeter. Content of the microfilament bundles was quantified by planimetry of transmission electron photomicrographs. After 6 weeks, mean shear stress was higher immediately upstream from the throat of the stenosis than at the proximal site (46.1 +/- 7.3 dynes/cm2 versus 24.0 +/- 6.2 dynes/mc2, p less than 0.001) and was significantly lower immediately distal to the stenosis than at the proximal site (9.4 +/- 0.3 dynes/cm2, p less than 0.01). The microfilament bundle content increased immediately upstream from the throat of the stenosis and decreased immediately distal to the stenosis compared with the proximal site in both normocholesterolemic and hypercholesterolemic fat-fed beagles. Intimal plaques formed exclusively immediately distal to the stenosis in the hypercholesterolemic beagles. These findings suggest that a low shear-stress environment attenuates endothelial microfilament bundle formation, thus leading to a predilection for the initiation of atherosclerosis in atherogenic conditions such as hypercholesterolemia.

Actin Cytoskeleton↗

PubMedDate not supplied

[A diagnosis of venous anomaly with dextrocardia by magnetic resonance imaging and transesophageal echocardiography].

A 56-year-old woman was admitted with the chief complaint of dyspnea. Chest radiograph and echocardiography disclosed mirror image dextrocardia with massive pleural effusion. Magnetic resonance imaging (MRI) and transesophageal echocardiography (TEE) revealed dilated coronary sinus and persistent right-sided superior vena cava which entered the coronary sinus. These findings were compatible with those of digital subtraction angiography. Anomalies of the venous system must be recognized before surgery because adequate venous drainage is essential for extra-corporeal circulation. MRI and TEE are noninvasive and useful methods and should be performed first to detect anomalies of the venous system associated with dextrocardia.

Angiography, Digital Subtraction↗