This review highlights aspects of calcific aortic valve disease that encompass the entire range of aortic valve disease progression from initial cellular changes to aortic valve sclerosis and stenosis, which can be initiated by changes in blood flow (hemodynamics) and pressure across the aortic valve. Appropriate hemodynamics is important for normal valve function and maintenance, but pathologi...

BACKGROUND The evaluation of prosthetic valves is very difficult with two-dimensional transthoracic echocardiography alone. Doppler and color flow imaging as well as transesophageal echocardiography are more reliable to detect prosthetic valve dysfunction. However, Doppler study sometimes tends to be misleading due to the load-depending characteristics of peak and mean pressure gradients. The p...

Although the Codman-Hakim programmable valve is one of most popular shunt systems used in the clinical practice for the treatment of hydrocephalus, malfunctions related with this system have been also reported which lead to underdrainage or overdrainage of the cerebrospinal fluid. While obstruction of the ventricular catheter by tissue materials or hematoma and catheter disconnection are relati...

The St. Jude Medical (SJM) Regent valve was developed as a new mechanical valve by improving the conventional SJM valve. The effective orifice area is wider than that of Hemodynamic Plus (HP) series. The efficacy of the new valve has been reported in Europe and the United States. On October 26, 2004, we first performed aortic valve replacement (AVR) with the SJM Regent valve for aortic valve st...

Background Pressure recovery is the variable increase in lateral pressure downstream from a stenotic orifice. The magnitude and clinical significance of pressure recovery in aortic valve stenosis are poorly defined. Methods and Results We obtained high-fidelity pressure and velocity recordings in 11 patients with isolated significant aortic valve stenosis at the time of diagnostic cardiac cathe...

Background Pressure recovery is the variable increase in lateral pressure downstream from a stenotic orifice. The magnitude and clinical significance of pressure recovery in aortic valve stenosis are poorly defined. Methods and Results We obtained high-fidelity pressure and velocity recordings in 11 patients with isolated significant aortic valve stenosis at the time of diagnostic cardiac cathe...

Aims: The purpose of this study was to determine whether there is any association between the optimal increase in mitral valve area and mitral transvalvular gradient decrement and pulmonary arterial pressure decrement after balloon mitral valvuloplasty (BMV) in patients with mitral stenosis. Methods: The study population consisted of 49 patients (47 women, 2 men; mean age = 43.7±13.35 years) wi...

INTRODUCTION Surface relief structures at micro and nanoscales are currently focused in different engineering areas. These structures enable special optical, mechanical or chemical properties of the workpiece surfaces. One example is the riblet surface, on which microgrooves are distributed in flow direction. Compared to smooth surfaces ideal riblet structures have been proven to reduce skin fr...

BACKGROUND The closure sound of the ATS bileaflet mechanical valve is said to be quieter than that of the other mechanical valves. However, the reasons for this are still unknown. In this study, we investigated the reasons for the quietness of the ATS valve closure sound. PATIENTS AND METHODS The valve closure sound was evaluated in 70 patients and in another 70 patients in whom the SJM valve...