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Biomedical subjects

Yukinori Moriyama

Publications and source records attributed to Yukinori Moriyama.

6 recordsLinked to original sources
PubMed2005

Discrepancy between Doppler and catheter measurements of pressure gradients across small-size prosthetic valve.

OBJECTIVES: The exact role of pressure gradient across the prosthetic valve estimated from Doppler flow velocity remains controversial. This in-vivo study was designed to assess the actual discrepancy between Doppler and catheter measurements of the pressure gradients for small bileaflet prosthetic valves in the aortic position. METHODS: Bileaflet prosthetic valves (19 mm-ATS) were implanted into the aortic position in pigs, and pressure gradients across the valves were examined by volume loading under right heart bypass. The pressure gradient obtained by catheter was defined as the conventional peak-to-peak gradient between the left ventricle and aorta. The peak Doppler gradients were calculated from the maximal instantaneous Doppler velocity with the ultrasound probe positioned on the diaphragm at the level of the cardiac apex. RESULTS: There were strong correlations between pressure gradients and cardiac output. The Doppler gradient was constantly higher than the catheter values, and the resultant discrepancy between Doppler and catheter measurements was directly dependent on cardiac output (y=9.9x+0.6, r2=0.55). For cardiac output > or = 5.0 L/min, the difference between Doppler and catheter gradients reached 40 mmHg, and maximum differences of up to 80 mmHg were observed. CONCLUSIONS: In view of the presence of striking overestimation of catheter gradient by Doppler measurement, Doppler ultrasound should be used cautiously to assess small-size bileaflet prosthetic valve function with consideration of the patient's hemodynamic state.

Animals↗
PubMed2004

Recurrent pericardial tamponade from atrial hemangioma.

We encountered a 72-year-old woman with a left atrial hemangioma arising in the appendage and growing like an extracardiac mass. Life-threatening cardiac tamponade, recurrent over a 5-year clinical course, was the only sign of this rare tumor. The extraatrial growth pattern of the tumor made it difficult to distinguish the cardiac origin from a paracardiac mass. With the aid of cardiopulmonary bypass, the tumor was removed from the left atrium at the base of the appendage. Pathologic diagnosis was a combination of cavernous- and venous-type hemangioma. The postoperative course was uneventful, and the patient was doing well with no pericardial effusion at the 10-month follow-up.

Aged↗
PubMed2004

C-reactive protein and atrial fibrillation. Is inflammation a consequence or a cause of atrial fibrillation?

To clarify whether inflammation is a cause or consequence of atrial fibrillation (AF), we measured high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) before and after pharmacological cardioversion in 15 patients with paroxysmal AF. Levels of hs-CRP, IL-6, and TNF-alpha after cardioversion were significantly higher than those in controls (P < 0.05). Furthermore, the levels of these indices did not differ significantly even at 24 hours and 2 weeks after cardioversion. These results suggest that inflammation is a causative agent of paroxymal AF.

Adult↗
PubMed2002

Pasteurella multocida endocarditis: report of a case.

The present case involves a 48-year-old male patient who presented with Pasteurella multocida endocarditis associated with preexisting mitral valve stenosis. A mitral valve replacement was successfully performed after 3 weeks of intravenous infusion with antibiotics. Pasteurella multocida is a normal inhabitant of the oral cavity of dogs and cats. Therefore, people who have frequent contact with these animals should be examined periodically for signs of infection.

Endocarditis, Bacterial↗